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2.2.2.2 Pressure leaching of copper sulfides
The most common copper sulfides ore is chalcopyrite. The development of pressure leaching
of copper sulfide concentrates was motivated by favorable thermodynamics at elevated pressure
and technical improvements [8]. After pressure leaching, the pregnant leach solution (PLS) is
suitable for traditional copper recovery techniques: solvent extraction and electrowinning.
Depending on the conditions, two main HPOX processes were implemented:
- Partial oxidation process taking place at 150˚C, with formation of elemental sulfur
(chalcopyrite acid leaching developed by Sherritt Gordon)
- Total oxidation process taking place at 220˚C, with formation of sulfate
Figure 2.4 illustrates the conditions of formation of sulfur vs. sulfate. Sulfate ion is stable
over a wide range of pH, but mostly in oxidizing conditions (blue area). In acid medium, the
stability domain of sulfate ions is adjacent to elemental sulfur (red area), which explains why S0
can form at low to medium temperature. If the process temperature exceeds 150°C, elemental
sulfur becomes unstable [1].
Figure 2.4: Eh-pH diagram for sulfides at 100°C [1]
Total oxidation suggests harsher conditions (higher temperature and oxygen partial
pressure) and is more energy consuming. Sulfate formation is favored over elemental sulfur in
many cases such as gold bearing copper deposits which are also treated by cyanidation.
Elemental sulfur is hindered to avoid downstream cyanide consumption and thiocyanate
formation [5]. Higher temperatures are also favored to produce hematite if there is a significant
amount of iron in solution.
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The world‘s first commercial application of high temperature pressure leaching of
chalcopyrite was implemented by Phelps Dodge (now Freeport-McMoRan) in 2003 at Bagdad,
AZ (Figure 2.5). The success of this process was due to:
- Possible recycling of sulfuric acid produced during the process for leaching of oxide ores
and low grade materials. Generating and neutralizing acid is expensive and can represent
a prohibitive cost.
- Possibility of also treating ores containing gold and silver along with copper. The
principle connects to refractory ore processing techniques presented in section 2.2.1.
- Possible precipitation of iron as by-product hematite.
The Phelps Dodge process achieves excellent copper extraction (>97%) and operates at
475psi and 225˚C. Equation 2.4 presents the acid leaching of chalcopyrite reaction in oxidative
conditions (oxygen overpressure).
4CuFeS + 17 O + 2 H SO = 4CuSO + 10 H SO + 2 Fe (SO ) + 2 H O Equation (2.4)
2 2 2 4 4 2 4 2 4 3 2
Figure 2.5: Process flowsheet for Phelps‘s Dodge's leaching facility at Bagdad, AZ [9]
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2.2.3 Pressure leaching of bauxites
In terms of annual tonnage of ore processed, pressure leaching of bauxite or Bayer
Process is the largest pressure leaching process (90 million tonnes/year) [1]. The patent for the
Bayer Process was deposited in 1888; it is the oldest pressure leaching process in
hydrometallurgy. A very few changes have been made to the Bayer Process over the years. For
this specific leaching procedure, sodium hydroxide is used rather than sulfuric acid due to the
presence of iron and titanium oxides in the ore. It would lead to acid consumption and
contamination issues during the precipitation stage, especially since iron hydroxide is very
difficult to filter. Moreover, aluminum hydroxide precipitated from acid solutions forms a
gelatinous product that is difficult to treat.
The Bayer Process will not be further detailed in this thesis. But it is interesting to note that
iron is also an important contamination issue during bauxite leaching. In this case, it does not
report to the pregnant leach solution but to the residue as it is insoluble in alkaline media. The
product of the process is called red mud, and causes pronounced disposal issues as BIS and
jarosites.
2.3 Pressure leaching characteristics and control
This section describes pressure leaching fundamentals and operating parameters. Leaching
takes place in high pressure vessels, also called autoclaves.
2.3.1 General design and operation facts
Autoclaves can measure up to 40m long and 7m diameter. They are cylinders, horizontal
or vertical depending on the application. More rarely, spherical autoclaves or tubes are also used.
Most autoclaves are static, but agitation is sometimes achieved by rotating the entire unit. In
vertical autoclaves, agitation comes from steam injection, while horizontal vessels are partitioned
and agitated with propellers [1]. If required, the injection of oxygen or air is usually performed
from the bottom of the vessels for ideal dispersion (Figure 2.6).
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Table 2.1: Typical operating values for high pressure vessels [1], [9], [12], [13] and [14]
Parameters Refractory gold ores Hematite Process Copper sulfides
Total pressure 400-500 psi 225-275 psi 470 psi
Oxygen overpressure 20 psi 15-60 psi 100 psi
Temperature 190-230°C 200°C 225˚C
Average residence time 1 to 2 hrs 2 hrs 1 hr
The main parameters conditioning process efficiency and oxidation rate are:
- temperature
- oxygen partial pressure
- acid concentration
- contamination (other metals, carbon, carbonates…)
- pulp density
- residence time
In the case of sulfide ores, the extend of oxidation can be monitored through redox potential.
It is paramount to determine the maximum rate of oxidation as fast as possible in the process
development. Indeed, the optimum residence time is directly related to the size of the vessel.
Knowing this parameter helps with the estimation of capital cost and later condition the
feasibility of the project [4].
2.3.2 Autoclave integration in the metallurgical circuit
Leaching circuits are usually also equipped with conditioning tanks (heating and
homogenization) and flash tanks to release the pressure at the exit (Figure 2.8). Most commonly,
several compartments are mounted in series in continuous systems [1].
The slurry pumped in the autoclave is usually preconditioned. Carbonates, which are
common contaminants in refractory ores, are neutralized with sulfuric acid treatment. This
prevents acid consumption as well as formation of carbon dioxide in the autoclave, and therefore
helps keeping a high oxidation rate. When the ore carbonate content is too high, the process is
changed and the autoclave is operated under alkaline conditions, like at Barrick‘s former Mercur
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Gold Mine in Utah [15]. Alkaline conditions imply longer residence time and higher
temperatures, but the operating costs are balanced by higher recovery.
Figure 2.8: Typical HPOX leaching plant [1]
Preconditioning is also achieved by controlling the feed density. The solid:liquid ratio of
the slurry is modified to its optimum where solids density and sulfide concentration will help
decreasing heat and acid supply [4]. Because sulfide oxidation is exothermic, the heat balance
can be controlled by adjusting the amount of sulfides to maintain the desired temperature in the
autoclave. Even if it is more reasonable to plan the need for supplemental heating, sulfide
content is a reliable parameter to use for plant design. Conway and Gale [16] formulated the
optimum pulp density for a pyrite-containing feed (Equation 2.5):
P.D. = (Equation 2.5)
Although sulfide oxidation is exothermic, the slurry is often pre-heated to optimize the
leaching stage for the treatment of low sulfide ores. Heat is recovered at the vessel discharge, and
then transferred back ahead by counter current heat exchangers. When the sulfide ore is high
grade, oxidation provides enough heat to maintain temperature in the autoclave, and excessing
heat is usually discharged by releasing scrubbed steam in the atmosphere or adding cooling
water. For the same reason, the vessels are usually equipped with cooling devices in order to
control any runaway reaction. Cooling of the discharge is performed via a series of flash tanks
heat exchangers.
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Acid is recycled or neutralized depending on the leaching conditions. In the case of gold
recovery, neutralization precedes cyanidation and CIP unit operations. If acid is recycled, the
PLS is filtered or goes through Counter-Current Decantation (CCD) [4].
2.4 Iron removal using pressure leaching
Iron is often found in complex ores such as sulfides bearing formations. It represents an issue
during leaching which is widely used for the treatment of this type of ore:
- Iron has the particularity of forming hydroxides when leached under certain conditions.
Iron hydroxides form a viscous gel difficult to filter and trap some valuable elements
such as silver.
- Iron is solubilized along with other metals and interferes with the following extraction
steps.
As a result, purification of the pregnant leach solutions is required to achieve economical
extraction. In the 1960s, metallurgists developed purification by precipitation [7]. Nowadays,
precipitation of iron bearing species (goethite, hematite, jarosite) has become one of the most
common methods used in the industry to purify leach liquors. To be suitable, the precipitate has
to be readily filterable and have a minimum particle size. Precipitation takes place in autoclaves
at medium to high temperatures, under oxygen or air overpressure [17]. It can also be cited that
several achievements have been made using solvent extraction but no operating facility has
successfully used this technology yet [18].
In the following paragraphs, three precipitation processes are detailed. Because most
developments were achieved for the zinc industry, zinc hydrometallurgy is used to describe these
processes named after the precipitate chemistry.
2.4.1 Goethite process
Goethite (FeO.OH) is a common iron hydroxide found in weathered iron-rich rocks. It is
the most commonly mined iron ore because of its high iron content. Goethite can also be
precipitated from leach solution, during a process occurring at 70-90°C and pH 2-3.5 (Equation
2.6).
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Fe (SO ) + 4H O ↔ 2FeO.OH + 3H SO (Equation 2.6)
2 4 3 2 2 4
The reaction produces sulfuric acid which has to be neutralized during the process
(Figure 2.9). To precipitate iron as goethite from a sulfate solution, the concentration of ferric ion
must be less than 1g/L. Two different processes have been developed: the Vieille Montagne and
the Electrolytic Zinc processes [17].
Figure 2.9: General flowsheet of the Goethite Process [17]
2.4.1.1 The Vieille Montagne process
The Vieille Montagne process (VM) was developed by at the Balen Plant in Belgium by,
Vieille Montagne S.A. and described in 1973 by Andre and Masson [14]. After hot acid
leaching, all ferric ions are reduced to homogenize the solution (Figure 2.10). Then, a slow
oxidation by pressurized air is performed at controlled rate. Equation 2.7 presents the global
reaction:
Fe (SO ) + ZnS + ½O + 3H O → 2FeO.OH + ZnSO + S + 2H SO (Equation 2.7)
2 4 3 2 2 4 2 4
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used for the treatment, and the amount of solid produced is lesser than for jarosite process [14].
Some other benefits are high iron removal and no requirement for alkali components. The VM
process has been shown to achieve better iron extraction, but the EZ process is easier to
implement [17]. Contamination by zinc ferrite can occur with both methods, which means
thorough washing is required. The main drawback of the goethite process is the presence of
cations and anions in the precipitate, decreasing its purity and thus its quality as a by-product.
Sulfate anions especially represent a problem. They are sorbed on the goethite particles and
become difficult to extract down to an acceptable content.
2.4.2 The Jarosite Process
The Jarosite process is widely used in the zinc industry. It was developed by Asturiana de
Zinc S.A. of Spain, Det Norske Zinc kompani A/S of Norway and the Electrolytic Zinc Co. of
Australasia Ltd. in the mid-60s [13]. Jarosite describes a family of compounds of formula
MFe (SO ) (OH) , where M can be Na+, NH +, H O+, Li+, K+, metals such as Pb, Ag, Zn, Hg, Rb
3 4 2 6 4 3
[17]... The reaction equation is the following (Equation 2.8):
3Fe (SO ) + M SO + 12H O → 2MFe (SO ) (OH) + 6H SO (Equation 2.8)
2 4 3 2 4 2 3 4 2 6 2 4
Zinc and iron are readily dissolved by sulfuric acid if the temperature has reached the boiling
point. Iron sulfate is then precipitated as jarosite while zinc stays in solution. Influencing factors
are:
- Temperature: jarosite precipitates over a wide range of temperatures (20 to 200°C).
However, 90-100°C are the optimum values used in industry. Even if the rate of reaction
increases with temperature, jarosite stability starts decreasing at 180°C.
- pH: precipitation occurs in acidic conditions, depending on the temperature (0<pH<2).
Practical operation takes place at pH 1.5. Acid concentration also has an important effect
on jarosite formation: the higher the initial H SO concentration, the lower the
2 4
precipitation.
- Alkali concentration: increasing the ratio of alkali ions to iron in solution enhance jarosite
precipitation. Lower concentration limit for precipitation is 10-3M [19]. Potassium-
jarosite is the two most stable compound of the family.
- Contaminants: high iron concentrations inhibit co-precipitation.
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- Seeding seems to enhance sharply the jarosite precipitation (both amount and rate). It also
helps improving settling, filtering and washing.
The weakness of the process is the co-precipitation of other elements, which increases with
pH of solution and concentration of contaminants (Cu, Zn, Co, Ni, Mn, In, Ga, Ge, Al and
mostly Ag). Argento-jarosite precipitation is a real problem for industrial application. It is
extremely difficult to recover the precious metal from the precipitate and subsequent silver losses
can be encountered [17].
Figure 2.11: Simplified flowsheet of the Jarosite Process [17]
2.4.3 The Hematite Process
The Hematite Process principle is used for the experimental development of this thesis. It
aims at removing soluble iron from zinc leach liquor solutions by precipitation.
2.4.3.1 General presentation
Hematite is one of the forms of ferric oxide, known for its ferromagnetic properties and
widely used in the steel industry as a source of iron. The Hematite Process has been introduced
by Akita Zinc Smelter of Japan in 1972 [20] and is currently used in several operations across
the world. As a result of hot acid leaching of a ferrite residue, ferrous iron and zinc are
solubilized in a sulfate solution, followed by selective precipitation of hematite (Equation 2.9). In
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the autoclave, typical oxygen partial pressure ranges from 15-60 psi and temperature is over
185°C (usually 200°C) [12].
2FeSO + ½O + 2H O → Fe O + 2H SO (Equation 2.9)
4 2 2 2 3 2 4
The presence of zinc sulfate has been shown to promote hematite precipitation at high
temperatures and high acid content [18]. For instance at 200˚C and 72-75g/L ZnSO , the limit
4
sulfuric acid concentration for hematite precipitation lies around 100g/L, against 65g/L when no
zinc sulfate is present [21]. Disadvantages of the Hematite Process are high capital and operating
costs due to the utilization of autoclaves. If pure enough, the hematite produced can be sold as a
pigment or for the cement industry to balance these expenditures. As for today, a very few
operations were able to produce marketable products.
2.4.3.2 The Akita Zinc Hematite Process
The Akita Zinc Process was developed by Dowa Mining Co., a Japanese nonferrous
metals manufacturer. It has been operated at the Iijima Zinc Refinery since 1972 and uses the
Hematite Process principle [20].
The ore treated at the Iijima Zinc Refinery contains Zn, Fe, Pb, Cu, Cd, Ag and Au along
with alkali elements (K, Na). The process consists of first leaching the roasted ore with neutral
solution and weak acid to eliminate the impurities (Figure 2.12). Then, the residue is leached
with spent electrolyte and SO at 105°C, in order to solubilize the metals. Copper is precipitated
2
by H S reduction. Most lead, gold and silver also report to this residue. A two-stage
2
neutralization with calcium carbonate eliminates free H SO , produces clean gypsum and Ga-In-
2 4
Ge-enriched gypsum. The neutralized solution is finally heated up to 200°C with an oxygen
overpressure of 15-45 psi to precipitate hematite. Contaminants include Zn, As, K and Na. Even
though some of these contaminants represent an issue and Zn, Mg and Mn remain in solution, the
Akita Zinc Process is successful extracting most of the iron out of the PLS.
Tables 2.2 and 2.3 compare the material balances for neutral leaching and hematite
precipitation steps. They account for the separation of metals and contaminants during the
process.
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2.4.3.3 Factors influencing the precipitation of iron in the Akita Zinc hematite process
The following factors are influencing the process, and thus will be of great importance in this
project:
- Acidity of the leach solution: as mentioned before, the acidity content controls the
chemistry of the iron precipitate. At 185°C, hematite is stable up to a sulfuric
concentration of 56g/L. At 200°C, the concentration increases up to 65g/L H SO . Above
2 4
these boundaries, the stable species are BIS and jarosite.
- CuSO and ZnSO : the presence of base metals as sulfates enhances hematite stability
4 4
over a wide range of acidity and temperature. This aspect will be further developed in
paragraph 3.4.
- Impurities: they usually prevent complete hematite precipitation. The elements which
have the most impact on the process are: K>Mg>Sb>As>Zn.
o K, Na, As and Sb most exclusively report to the precipitate. K and Na are part of
jarosite crystals which compete with hematite formation and lower the iron
concentration in the precipitate. As concentration in the precipitate increases
along with moisture content and thus alters filterability.
o Zn, Mg and Mn do not significantly report to the precipitate (less than 1%), but
change the solution physical properties. These elements tend to decrease the
particle size of the forming particles and consequently hematite has a tendency for
redissolution. Mg and Zn sulfates have a positive effect on solution viscosity and
density.
o When present in high concentration in the PLS, Ca and Al can decrease the iron
content in the precipitate by contamination (as an inclusion or nuclei).
o Ge, Ga and In can report to the precipitate as high as 80% for the former and 30%
for the latter, but their impact on hematite recovery is negligible. Elements such
as Cd, Co and Ni have no effect on the process as they do not precipitate.
o Lastly, high concentration of iron in the PLS tends to logically increase iron
content in the precipitate. It must stay within a reasonable range, to avoid
excessive iron content in the outlet solution.
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2.4.4 Comparison of the Goethite, Jarosite and Hematite Processes
None of the precipitates of the Goethite and Jarosite Processes is suitable for direct
commercialization as they are produced. Further refining is needed. In the production of
hematite, ferrite materials can be considered as marketable products if they are pure enough.
The following table summarizes and compares the characteristics of the three
precipitation processes (Table 2.4).
Table 2.4: Comparison of Goethite, Jarosite and Hematite Processes [14] and [22]
Goethite Jarosite Hematite
MFe [(SO ) (OH) ]
3 4 2 6
Compound formed FeO.OH Fe O
2 3
with Me=K, Na, NH
4
Temperature (°C) 70-90 90-100 >185
pH 2-3.5 1.5 Up to 2% H SO
2 4
Anion present Any SO 2- SO 2-
4 4
Cation added None Na+, K+, NH + None
4
Cationic impurities Medium Low Low
Anionic impurities Medium High Medium
Filterability Very good Very good Very good
Fe left in solution (g/L) <0.05 1-5 3
Zn 96 % Zn 96 % Zn 98.2 %
Metal recovery % Cu 90 % Cu 90 % Cu 98.2 %
Ag 85 % Ag 60-65% Ag 98.2 %
Fe 40-45 % Fe 25-30 % Fe 50-60 %
Residue composition % Zn 5-10 % Zn 4-6 % Zn 0.5-1 %
S 2.5-5 % S 10-12 % S 2-3%
Moisture 50 50 10
Amount produced/t ore 0.25 0.40 0.18
Zn loss in t/t slab 0.025 0.025 0.002
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Until recently, the Jarosite Process was prevailing. But jarosite residues are not only more
voluminous than hematite, but they also tend to host toxic metals such as Zn, Cd and Pb in their
crystal structure. Their stability over time is poor and represents environmental concern.
Additionally, zinc losses can be relatively high (Table 2.4). The Hematite Process has for long
been considered too difficult and costly to implement. However, progresses in high pressure
leaching technology as well as product quality appear to have addressed these issues. The Akita
Zinc Hematite Process is economical, and its products are clean enough from S and Zn to be
used in iron-steel making.
2.5 The iron hydroxysulfates problem
In numerous pressure leaching plants where the Hematite Process is used to purify the
leach liquors, iron hydroxysulfates have been forming in place of hematite. They are described
in this section.
2.5.1 Iron hydroxysulfates formation during iron precipitation processes
During HPOX processes, iron forms ferrous sulfate, which is then oxidized in ferric
sulfate. Hydrolysis of ferric sulfate then forms an iron precipitate. At T>185˚C in oxidative
environment, several iron species can form. Hematite is the desirable product as previously
presented in paragraph 2.4.3. The conditions of hematite formation are stringent and sometimes
difficult to control. It is likely that other iron solids (called iron hydroxysulfates) precipitate
along with hematite [5].
Iron hydroxysulfates are unwanted constituents in the residue for several reasons:
- Poor settling and filtering properties
- Relatively unstable compounds which represent an environmental impact if stockpiled
- Trapping of precious values in their crystal structure and thus lower recovery
- In the case of gold cyanidation circuits, high concentration of iron hydroxysulfates in the
autoclave residue means high lime consumption and difficulties to maintain pH > 10
during the cyanidation step. There is a risk of forming toxic HCN.
Several publications have shown that the total amount of free acid in solution determines
which iron species preferentially forms [2], [5], [17], [21]. Depending on the leaching
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conditions, the limit acid concentration for the formation of one or the other varies. Because
hematite is preferred over iron hydroxysulfates in the final product, the acid quantity is closely
monitored.
2.5.2 Iron hydroxysulfates characterization
The nomenclature of iron hydroxysulfate species vary depending on the authors. They
can also be referred as ferric hydroxysulfate, basic ferric sulfate or iron hydroxyl sulfate.
Early work by Posnjak and Merwin showed that there is a large number of ferric sulfate
salts but most of them are not actual crystalline species [23]. Our species of interest, the BIS, are
amorphous, metastable and often composed of mixtures. As a result, they are quite difficult to
characterize and very few data is available.
Posnjak and Merwin have identified three series of BIS. However, at the time, the authors
did not exclude that other hydrated species also exist. The three series were subdivided and
organized by the ratio Fe O to SO . The following table presents the BIS already identified at
2 3 3
the time of this study. Carphosiderite will later be identified as hydronium jarosite.
Table 2.5: BIS classified by Fe2O :SO ratio as they were first identified in 1922 [23]
3 3
Fe O :
2 3
Formula Crystal Color Name
SO ratio
3
3:4 3Fe O .4SO .9H O Rhombohedral Light-deep yellow Carphosiderite
2 3 3 2
Fe O .2SO .H O Orthorhombic Orange-yellow
2 3 3 2
Fe O .2SO .5H O Monoclinic Light yellow
2 3 3 2
1:2 2Fe O .5SO .17H O Orthorhombic Light-bright yellow Copiapite
2 3 3 2
Fe O .2SO .7H O Yellowish Amarantite
2 3 3 2
Fe O .2SO .8H O Yellowish Castanite
2 3 3 2
2:5 Fe O .2SO .10H O Yellowish Fibroferrite
2 3 3 2
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In the late 1970s, the iron hydroxysulfate minerals were divided in two series [24] and [25]:
- Elements with the general formula Fe(OH)SO .nH O, with the following members: basic
4 2
iron sulfate Fe(OH)SO , butlerite/parabutlerite (they are polymorphs) Fe(OH)SO .2H O
4 4 2
and fibroferrite: Fe(OH)SO .5H O. According to several publications, the non-hydrated
4 2
member of the BIS series is synthetic and has only been obtained in laboratory.
- Jarosites. The main jarosite species are presented in section 2.5.
In 1982, Lazaroff et al. also make the distinction between crystalline jarosites and amorphous
ferric hydroxysulfates, but refers of this last category as BIS [26]. In order to simplify the
nomenclature and avoid any confusions within the next sections, we will distinguish BIS
(Fe(OH)SO4 and its hydrated species) from the jarosite compounds. We will consider BIS and
jarosite as iron hydroxysulfates.
The following table presents the most common BIS encountered in high temperature
systems, using the most recent nomenclature.
Table 2.6: Selected hydroxysulfates of Fe [27]
Name Formula
Copiapite FeIIFe 4III(SO 4) 6(OH) 2.2H 2O
Fibroferrite FeIII(SO )(OH).5H O
4 2
Amarantite FeIII(SO )(OH).3H O
4 2
Butlerite FeIII(SO 4)(OH).2H 2O
- FeIII(SO )(OH)
4
2.5.3 Jarosite characterization
Jarosites are the compounds of formula: MFe (SO ) (OH) , where M can be H O+, Na,
3 4 2 6 3
K, NH +, Pb, Ag, Zn, Hg, Rb [17]. Silver-jarosite and potassium-jarosite are the two most stable
4
compounds of the family. Other extensive substitutions occur for Fe3+, SO 2-, OH-.
4
As for BIS, not all jarosites are naturally occurring. Out of ten species synthetized, six of
them only occur in minerals. The first mineral to be identified was potassium jarosite, in
Andalusia, Spain in 1852 [28]. Table 2.7 lists all known types of jarosites.
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Table 2.7: Chemical and mineral names of jarosites [29]
Formula Chemical Name Mineral Name
H OFe (SO ) (OH) Hydronium Jarosite Carphosiderite
3 3 4 2 6
NaFe (SO ) (OH) Sodium Jarosite Natrojarosite
3 4 2 6
KFe (SO ) (OH) Potassium Jarosite Jarosite
3 4 2 6
RbFe (SO ) (OH) Rubidium Jarosite None
3 4 2 6
AgFe (SO ) (OH) Silver Jarosite Argentojarosite
3 4 2 6
NH Fe (SO ) (OH) Ammonium Jarosite Ammoniojarosite
4 3 4 2 6
TlFe (SO ) (OH) Tallium Jarosite None
3 4 2 6
Pb Fe (SO ) (OH) Lead Jarosite Plumbojarosite
1/2 3 4 2 6
Hg Fe (SO ) (OH) Mercury Jarosite None
1/2 3 4 2 6
PbCuFe (SO ) (OH) Lead-Copper Jarosite Beaverite
3 4 2 6
2.5.4 Iron hydroxysulfates comparison
A spectroscopic analysis of the products of ferric sulfate hydrolysis was performed in
1996, with emphasis made on the amorphous species, which are compared to jarosite [30]. While
jarosite is inert, BIS are reactive in water. This difference is explained by the atomic arrangement
of each species: jarosites are trimers, and amorphous BIS are tetramers (Figure 2.13). The
reactivity of BIS is believed to be caused by the small separation of neighboring irons, short Fe-
O distance and strong hydrogen bonds (creating a large number of highly acid centers). This
would promote the oxidation of H O in O and thus explain BIS reactivity in water.
2 2
Figure 2.13: Molecular structures of jarosite (trimer) and BIS (tetramer) [30]
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BIS are also reactive in the atmosphere [23], decomposing either in ferric hydroxide and
gypsum (alkaline conditions) or ferric sulfate (acidic conditions). BIS can be formed by
precipitation, hydrolysis or evaporation but none of these processes yielded a product that fully
reaches equilibrium, producing mixtures.
In the case of pressure leaching, the main factors influencing BIS formation are acidity,
temperature and iron concentration. BIS readily precipitate at high acidity (>20g/L) and lower
temperatures (< 200˚C) [5]. As mentioned before, jarosite formation is favored by high acidity as
well and presence of some cations in relatively high concentration (Na+, NH4+, K+, Ag+ or
Pb+). Concerning the influence of initial ferric concentration, BIS seem to be promoted by
increasing ferric concentration. At 225˚C, within the stability region of hematite, Dutrizac and
Chen have observed that BIS becomes the predominant phase if the initial [Fe3+] exceeds
22.3g/L [31]. A more specific presentation of the factors influencing BIS formation is made in
section 3.3.
2.5.5 Methods to prevent BIS formation
Some attempts have been made to hinder the formation of BIS after autoclaving: the
Lime Boil Process and the Hot Cure Process.
The Lime Boil Process was developed by Sherritt to avoid silver losses due to iron
hydroxysulfate formation [32], [5]. It consists of treating the residue with lime to reach pH > 2.
Above 100˚C, hematite readily forms; under 100˚C, goethite is forming (assuming relatively
short residence time). Drawbacks of the process are related to consumption at industrial scale: up
to 200kg of lime per ton has to be used during a process which can last up to 24hrs. Additionally,
the slurry produced has many fines and represents handling issues.
The Hot Cure Process uses the acid and heat produced during the hydrolysis reaction to
break down the BIS into ferric sulfate (Figure 2.14). Neutralization of the remaining acid and
ferric sulfate formed can be achieved with limestone and not lime (Equation 2.10).
Fe (SO ) + 3CaCO + 3H O = 2Fe(OH) +3CaSO + 3CO (Equation 2.10)
2 4 3 3 2 3 4 2
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CHAPTER 3 PROCESS DEVELOPMENT
In this section, chemical and thermodynamic data relative to iron hydroxysulfates
precipitation is analyzed. The conditions of hydrolysis are used to best predict BIS formation.
3.1 Iron hydroxysulfates and hematite precipitation
This section details some of the chemical reactions and associated thermodynamics of iron
precipitation.
3.1.1 Reactions Equations
The overall mechanism of iron phase precipitation from sulfate is described in this
section. In sulfide ores, typical iron bearing species are chalcopyrite and pyrite. Chalcopyrite
oxidation yields ferric ions, while pyrite forms ferrous ions. Thus, for this project, ferrous sulfate
oxidation to ferric sulfate will be chosen as the starting species for the overall oxidation process.
Dissolution of chalcopyrite in ferric sulfate media is one of the processes used in copper sulfide
leaching operations (Equation 3.2). It will not be investigated in this thesis as no chalcopyrite
will be used during the experiments.
Iron sulfide oxidation:
2FeS + 7O + 2H O = 2FeSO + 2H SO (Equation 3.1)
2 2 2 4 2 4
4CuFeS + 17 O + 12 H SO = 4CuSO + 10 H SO + 2 Fe (SO ) + 2 H O (Equation 2.4)
2 2 2 4 4 2 4 2 4 3 2
CuFeS + 4Fe3+ = Cu2+ + 5Fe2+ + 2S (Equation 3.2)
2
Ferrous sulfate oxidation to ferric sulfate:
2FeSO + H SO + ½O = Fe (SO ) + H O (Equation 3.3)
4 2 4 2 2 4 3 2
Ferric sulfate hydrolysis to iron precipitates:
2Fe (SO ) + 6H O = 2Fe O + 6H SO (Equation 3.4)
2 4 3 2 2 3 2 4
2Fe (SO ) + 4H O = 4Fe(OH)SO + 2H SO (Equation 3.5)
2 4 3 2 4 2 4
3Fe (SO ) +14H O = 2H OFe (SO ) (OH) + 5H SO (Equation 3.6)
2 4 3 2 3 3 4 2 6 2 4
General equation for jarosite hydrolysis:
3Fe (SO ) + M SO + 12H O = 2MFe (SO ) (OH) + 6H SO (Equation 2.8)
2 4 3 2 4 2 3 4 2 6 2 4
(M = Ag+, NH +, K+, 1/2Pb2+)
4
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The following equations compare the sulfuric acid amount produced for each species.
Ferrous sulfate oxidation consumes half a mole of sulfuric acid for each mole of ferrous sulfate
produced. Hematite precipitation produces 1 mole of sulfuric acid for each mole of ferrous
sulfate oxidized. Jarosite formation releases 0.33 mole of sulfuric acid, against 0 moles for BIS.
The amount of sulfuric acid consumed or produced is paramount for this project as it allows
understanding the residue chemistry.
Hematite precipitation:
2FeSO + H SO + ½O = Fe (SO ) + H O (Equation 3.3)
4 2 4 2 2 4 3 2
Fe (SO ) + 3H O = Fe O + 3H SO (Equation 3.4)
2 4 3 2 2 3 2 4
2FeSO + ½O + 2H O = Fe O + 2H SO (Equation 2.9)
4 2 2 2 3 2 4
BIS precipitation:
2FeSO + H SO + ½O = Fe (SO ) + H O (Equation 3.3)
4 2 4 2 2 4 3 2
Fe (SO ) + 2H O = 2Fe(OH)SO + H SO (Equation 3.5)
2 4 3 2 4 2 4
2FeSO + ½O + H O = 2Fe(OH)SO +0H SO (Equation 3.7)
4 2 2 4 2 4
Hydronium jarosite precipitation:
2FeSO + H SO + ½O = Fe (SO ) + H O (Equation 3.3)
4 2 4 2 2 4 3 2
Fe (SO ) + H O = H OFe (SO ) (OH) + H SO (Equation 3.8)
2 4 3 2 3 3 4 2 6 2 4
2FeSO + ½O ⁄+ H O⁄ = H OFe (SO ) (OH ⁄) + H SO (Equation 3.9)
4 2 2 3 3 4 2 6 2 4
⁄ ⁄ ⁄
3.2 Thermodynam ics
Thermodynamic evolution of the system was estimated using HSC Chemistry 7.1. Free
energy and reaction constant were calculated in order to predict the Fe-O-S system evolution.
Additionally, multi-components equilibrium compositions were calculated and plotted to
estimate the species consumption and production in the leach solution.
3.2.1 Oxidation of ferrous sulfate
The thermodynamics of ferrous sulfate oxidation help determine if the reaction is
complete at the conditions of leaching.
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of 3kmol O , 2kmol FeSO and H O was used. Increasing the total pressure to 50 bar (725 psi),
2 4 2
did not change the results. Some reasons for hydronium jarosite and BIS meta-stability are
presented in section 3.3.2.
Figure 3.2: Equilibrium composition for the precipitation of hydronium jarosite from ferrous
sulfate at 195˚C
3.3 Stability of iron hydroxysulfates
Because no data was available for modeling, experimental observations and models from
the literature were used to identify the main factors controlling iron hydroxysulfate precipitation
over hematite.
3.3.1 3D model of the Fe (SO ) -H SO -H O system
2 4 3 2 4 2
Based on Posnjak and Merwin‘s work, Tourre [17] produced a 3D model of the
hematite/sulfates system (see figures 3.3 and 3.4). According to this model:
- Hydronium jarosite is only stable up to 170˚C, i.e. below the operating temperature of
this project. Above this point, the only stable phases are hematite and BIS. Thus this
study should witness a simple system with only two coexisting species.
- Increasing sulfate content in the system favors the formation of BIS over jarosites.
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Figure 3.4: System Fe (SO ) -H SO -H O; polytherm 50˚C to 200˚C, 30 to 70% SO [17]
2 4 3 2 4 2 4
3.3.2 Experimental approach
In 1971, Babcan and al. defined the area of stability of iron hydroxysulfates in the Fe-O-S
system (Figure 3.5) [35]. In more recent studies, BIS have been proven to be also stable at
conditions which would normally lead to hematite formation [31], [36]. Cheng and al. refer to
Stranski‘s rule, also called Ostwald‘s step rule to explain this phenomenon [2]:
―If a reaction can result in several products, it is not the most stable state with the least amount
of free energy that is initially obtained, but the least stable one, lying nearest to the original state
in free energy‖ [37].
In the present case, if the oxidation conditions were maintained for a longer time, the
most stable phase would eventually form. As a result, from a thermodynamic point of view, iron
hydroxysulfates are metastable.
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Figure 3.5: Areas of stability of various compounds in the Fe-S-O system (modified after Babcan
[36])
Several hematite solubility studies have been conducted in order to identify the optimum
conditions for iron oxide precipitation. At equilibrium and room temperature, Umetsu and al.
proposed a linear relation between ferric concentration and free acidity (Equation 3.11) [21]:
Log[Fe(III)] = a*Log[H SO ] – b (Equation 3.11)
total 2 4 free
Where a and b are coefficient which depend on temperature and the presence of other metal
sulfates.
This linear model has been experimentally confirmed and modelled (Figure 3.6) [38].
The conditions used for this study were similar to the parameters used in the present thesis (170-
200˚C, 30-100 g/L free acidity) except for the fact that no oxygen overpressure was added.
Investigations on the hydrolysis of iron sulfate solution by the same authors highlighted the same
linear relation between ferric ion and free acid concentrations, but up to a certain point. The solid
phase equilibrium curve is actually made of two straight lines of different slopes (Figure 3.7). At
lower free acidity, the curve describes hematite equilibrium, and at higher acidity, the curve
describes BIS equilibrium.
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3.4 Effect of other sulfates on iron hydroxysulfates formation
This section details previous results obtained when leaching synthetic solutions prepared
with several different sulfate salts.
3.4.1 Selective precipitation of iron
Sulfide ores bear many different metals which can be leached along with iron. Common
sulfates in leaching solution are CuSO , ZnSO , Na SO . Assessing their impact on hematite or
4 4 2 4
BIS precipitation is paramount.
Figure 3.8: Relation between concentration of metal ion and pH at 25˚C and 200˚C [21]
The previous figure shows that the hydrolysis of ferric iron is favored at high temperature
and low pH (Figure 3.8) [21]. It can also be seen that for given conditions, only iron precipitates
and the other ions stay in solution. Hydrolysis is thus a very efficient way to selectively remove
iron from solution.
3.4.2 Effect of zinc sulfate
Because of the importance of the Hematite Process in the zinc industry, most studies
related to hematite precipitation thermodynamics have been performed in acidic ferric sulfate
solutions, with addition of zinc. The addition of zinc sulfate to the Fe-O-S system promotes the
formation of hematite over a wider range of temperature and free acidity [2], [21]. Sulfur content
in the precipitate decreases when zinc sulfate is present. Adding zinc sulfate to the leach solution
also shifts upward the critical concentration of sulfuric acid allowing hematite precipitation
(Figure 3.9) [39].
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Experiments have also been conducted with addition of sodium or magnesium sulfate.
Adding sodium sulfate resulted in the formation of sodium jarosite. Magnesium sulfate had a
similar effect on the system than zinc and copper.
Figure 3.10: Relationship between concentration of ferric ion and free sulfuric acid in the
presence of copper sulfate at 200˚C [39]
3.4.4 Buffering effect of metals sulfates
The hematite precipitation equilibrium can be rewritten as:
Fe 3+ + 1.5 H O = 0.5Fe O + 3H+ (Equation 3.12)
2 2 3
The reaction constant is K = and at first sight is independent of coexisting sulfates.
Yet, the upper acidity limit of hemat it e p recipitation is shifted at higher level when other sulfate
species are added to the system. The stabilizing effect of sulfates is due to the SO /HSO -
4 4
equilibrium (Equation 3.13), also referred as the ―buffering action of the second dissociation of
sulfuric acid‖ [39]. When adding sulfate, the free H+ form bisulfate ions HSO - , decreasing the
4
overall free acidity and thus allowing for wider hematite stability conditions (Equation 3.12).
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This theory is backed up by that bisulfate and undissociated sulfates are more stable at high
temperatures.
H+ + SO 2- = HSO4- (Equation 3.13)
4
3.5 Leaching of artificial solutions
This section details the preparation of the experimental phase. Using the previously
detailed observations, experimental work was subdivided in several steps. First, the conditions at
which BIS is precipitating from a simple Fe-O-S system were investigated, in the specific setup
allowed by Colorado School of Mines equipment. Several matrices which composition was
based on previous studies were tested. The operating parameters which could be modified were
composition (i.e. iron and acid concentration), temperature and oxygen overpressure. To be
considered suitable, the matrix needed to produce significant amount of BIS, and enough residue
to be tested by XRD and Leco.
Once BIS were effectively recovered in the residue, the acid concentration in the vessel
was slowly decreased to find the limit conditions yielding BIS over hematite. At this point, it was
paramount to keep initial ferrous sulfate concentration constant (22.3 g/L Fe). The range of
acidity tested was 5-98.6 g/L, and allowed to produce 9 samples which yielded from 100% to 2%
hematite, the rest of the samples being iron hydroxysulfates.
Keeping the same initial iron concentration and the autoclave‘s operating parameters
constant, three different matrices were then chosen:
- a low acid matrix yielding pure hematite ([H SO ] = 20g/L)
2 4 initial
- an intermediate acid matrix yielding a mixture of BIS and hematite ([H SO ] = 40g/L)
2 4 init
- a high acid matrix yielding mostly BIS ([H SO ] = 60g/L)
2 4 initial
The second experimental phase consisted in assessing the hindering effect of copper sulfate
on BIS precipitation. To do so, various amounts of copper sulfate ([CuSO ] =12.7-63.5 g/L)
4 initial
were added to the previously defined matrices ([H SO ] = 20-60 g/L) and the residues
2 4 initial
produced were compared.
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The third phase aimed at testing the impact of initial iron concentration on residue
composition, by using the same sulfuric acid and copper sulfate content in the previously tested
matrices, but changing the initial iron sulfate content. 3 batches of three different initial iron
compositions were tested:
- Batch A: 83.4g FeSO i.e. [Fe(II)] = 16.7g/L
4 initial
- Batch B: 111.2g FeSO i.e. [Fe(II)] = 22.3g/L
4 initial
- Batch C: 152.9g FeSO i.e. [Fe(II)] = 30.7g/L
4 initial
Finally, the influence of iron‘s initial oxidation state on the system was also investigated.
Within sulfides, the oxidation state of iron can be II or III and thus form ferrous or ferric sulfate
when leached in sulfuric acid. During the first phases of testing, the oxidation of ferrous ions to
ferric was believed to be complete because of favorable thermodynamics. However, most studies
conducted prior this thesis were based on the use of ferric sulfate for leach solution preparation
and it appeared necessary to verify the extent of iron oxidation in solution. As a result, two
batches of identical iron concentration (22.3g/L) were compared: one batch was prepared with
ferrous sulfate and the other with ferric sulfate.
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4.2 Experimental procedure
This section details the chemicals used, as well as the experimental procedure followed for
all tests.
4.2.1 Chemicals used for matrix preparation
Reagent grade chemicals and deionized water were used for all the experiments. Each
experiment was carried out using 1 liter of solution in the 2 liter vessel. The solutions were
prepared using:
- Ferrous sulfate heptahydrate FeSO .7H O
4 2
- Ferric sulfate hydrate Fe (SO ) .xH O
2 4 3 2
- Cupric sulfate pentahydrate CuSO .5H O
4 2
- Sulfuric acid H SO
2 4
Accounting for chemicals purity, initial iron concentration ranged from 16.7 to 30.7 g/L,
initial copper concentration varied between 0 and 63.6 g/L and sulfuric acid concentration varied
between 5 and 98.6 g/L. The sulfate salts were completely dissolved in 1 liter of deionized water
in a volumetric flask before being transferred into the vessel.
4.2.2 Preheating and retention phase
In order to reach the required temperature and pressure for hematite precipitation, the
vessel was preheated during ~60 min. During this time, neither oxygen nor agitation was applied.
After 60 min, the temperature in the vessel reached about 185˚C, which is the minimum required
temperature for the hematite process. The rotating drive was then started (500 rpm) and 40 psi
oxygen overpressure was added. Within 5 minutes, the temperature and pressure in the vessel
stabilized to the following conditions: 195ºC and 225 psi. The control range for the temperature
was ±2ºC. Retention time was 3 hours. Figure 4.3 presents the typical evolution of pressure and
temperature during a test.
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250
Pre-heating
phase
200
150
Process T
100
Process P
50
0
0 50 100 150 200 250
Time (min)
Figure 4.3: Temperature and pressure evolution during autoclave run
Table 4.1: Steam pressure values at 160, 185 and 195ºC
Temperature (ºC) 160 185 195
Steam Pressure (psi) 75.0 148.2 188.1
4.2.3 Cooling and samples handling
After 3 hours residence time, agitation and heater were stopped. Cooling took about 1h30
min to reach a temperature less than 100˚C in the reactor. The vessel was depressurized and
safely opened. Another 30 minutes of cooling were necessary for the vessel and the solution to
be safely handled. The solution was filtered on a Buchner vacuum filter using Whatman 50 filter
papers and washed with 1 to 2 liters of deionized water. The solutions were bottled for analysis
and the residues were dried at least 24 hours at 75˚C. Once bagged, residue samples were sent to
Newmont Metallurgical Services in Greenwood Village, CO for analysis.
4.3 Free Acidity measurement
Free acidity was measured using an auto titrator (model: DL15 Metler-Toledo) and a
Sigma Aldrich 0.5M NaOH titrant solution. The procedure is detailed in appendix A. Because of
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4.4 Flame Atomic Absorption Spectrometry
FAAS was chosen for analysis of the PLS because of its reliability for copper and iron. All
dilutions were made using a 2% nitric solution, in order to match the standard matrix
composition. Functional parameters of the machine are presented in table 4.2.
Table 4.2: Functional parameters used for atomic absorption analyses
Characteristic
Element Wavelength Lamp current Linear Range Slit
Concentration
Fe 302.1 nm 30 A 0.4 mg/L 10 mg/L 0.2 nm
Cu 216.5 nm 15 A 0.117 mg/L 20 mg/L 0.2 nm
4.5 X-Ray Diffraction
X-Ray Diffraction (XRD) analyses were performed at Newmont Metallurgical Services.
The XRD patterns helped identifying and quantify the phases in the residue.
Javed and al. used XRD patterns to make observations on the crystallinity of their hematite
residue [40]. Indeed, the intensity peaks shape provides information on the crystals. Sharp, well
delimited peaks are characteristic of well crystallized species. Poor crystallinity means wider
peaks. When possible, the XRD patterns produced in this project were compared. In mixtures,
peaks intensity and shape are related to phase abundance. As a result, only pure hematite samples
were used for pattern comparison (no pure iron hydroxysulfate residues were produced).
4.6 Sulfur content
Sulfur content measurements were performed at Newmont Metallurgical Services using a
Leco analyzer. This technology consists in heating less than 0.1g of sample at 1350˚C in an
induction furnace. During heating, oxygen is flowed through the machine, releasing sulfur
dioxide which is measured by an infra-red detection system [41].
Samples were analyzed for total sulfur content. They were compared to sulfur content in
the most common species encountered in this study (Table 4.3).
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Table 4.3: Sulfur content in hematite and iron hydroxysulfates
Hematite BIS Fibroferrite Jarosite
0 18.98% 12.39% 13.34%
4.7 QEMSCAN
A mineral characterization was performed at the Colorado School of Mines QEMSCAN
Facility, within the Department of Geology and Geological Engineering. Quantitative Evaluation
of Minerals by Scanning Electron Microscopy or QEMSEM is a recent method of analysis
designed to provide quantitative analysis of minerals or rocks. It is associating a scanning
electron microscope and energy dispersive x-ray spectroscopy detectors to integrated software
called QEMSCAN. Surface images of the samples are generated in function of their mineralogy,
integrating petrography data to the analysis.
A first recognition step gives an exhaustive list of present minerals. By grouping the
minerals into appropriate sections, a primary list is created. It allows narrowing the composition
to minerals of interest. Boundary zones between minerals were closely looked at. Mixed x-ray
spectra are common during acquisition and can lead to misidentification of the minerals.
Three samples susceptible to be representative of the various types of precipitates were
analyzed. The sample preparation procedure followed at Colorado School of Mines is presented
in appendix B.
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CHAPTER 5 RESULTS
This chapter presents the results obtained from the four experimental phases.
5.1 Leaching of a pure ferrous sulfate solution
This section presents the results obtained from the leaching of a solution of 22.3g/L initial
iron concentration (111.24g/L FeSO ) at varying initial free acidity.
4
5.1.1 Free acidity
Free acid generation/consumption in function of initial free acidity is presented in figure
5.1. At low initial sulfuric acid concentration, free acid is produced in solution. With increasing
initial free acid, less acid is released until it reaches equilibrium at [H SO ] = 40g/L =
2 4 initial
[H SO ] . Above this point, acid is consumed during the leaching process.
2 4 final
40
30
20
10
0
0 10 20 30 40 50 60 70 80 90 100
-10
-20
Initial Free Acid (g/L)
Figure 5.1: Free acid Consumed/Produced in function of initial free acid content
This pattern can be explained by the residue composition. At ―low‖ initial free acidity,
hematite is preferentially formed. For each mole of hematite precipitated, two moles of sulfuric
acid are formed. At intermediate initial sulfuric content, the residue is composed of hematite,
BIS and to a lesser extent jarosite. As mentioned in paragraph 3.1, jarosite precipitation produces
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noitcudorP/noitpmusnoC
ytidicA
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less acid than hematite, and BIS precipitation does not release any. Because the proportion of
hematite produced decreases, final acidity in the system drops as well. At high initial free
acidity, when BIS are predominant in the system, free acid is consumed for the oxidation of
ferrous sulfate. If the hydrolysis of ferrous sulfate to hematite is not complete, there is no acid
production to balance the initial consumption.
5.1.2 Final iron in solution
The following graph shows the relationship between final ferric concentration in solution
and final free acidity (Figure 5.2). At high free acid concentration, more iron remains in solution.
High sulfuric acid levels are promoting precipitation of BIS and jarosites, two species which
have lower iron content than hematite. Consequently, more ferric is remaining in solution at high
acidity.
At the point of initial sulfuric concentration of 40g/L, a breaking point in the curve is
seen. Above this point, BIS is the main phase (see Figure 5.3). Below this point, BIS content in
the precipitate gradually increase from 0 to 90%. The other stable phase is hematite. These
observations correlate previous publications [21], [39].
20
98.3
18 78.6
16
59.2 Initial free acid g/L
14
39.7
12
10
24.5
8 29.5
19.6
6
5.0
4
30 40 50 60 70 80 90
Final Free H SO (g/L)
2 4
Figure 5.2: Relationship between final ferric and free sulfuric acid concentrations
The numbers by the data points are the initial free acid concentration in g/L.
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)L/g(
noitulos
ni
)III(eF
laniF
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5.1.3 Residue characterization
The residue characterization by XRD and Leco is presented in this paragraph. The
percentage of hematite in the residue gradually decreases with increasing initial free acid
concentration. In parallel, the BIS content increases. Some hydronium jarosite has been detected
in one of the samples.
100%
90%
80%
70%
60%
50% Jarosite
40% BIS
30% Hematite
20%
10%
0%
5 20 25 29 40 59 79 98
Initial Free Acidity (g/L)
Figure 5.3: Effect of free acidity on residue composition
Figure 5.4 shows the relationship between the sulfur content in the residue and final
sulfuric acid concentration. It is correlated to the composition of the residue: a net increase above
41g/L initial free acidity marks the limit for BIS precipitation.
By comparing XRD patterns, Javed et al. observed that increasing sulfuric acid
concentration is negatively influencing hematite crystallinity [40]. For this project, at constant
copper and iron concentration, increasing free acidity readily forms BIS or jarosite in the residue.
Only one sample yielded 100% hematite, thus it was not possible to compare a significant
number of patterns.
XRD patterns for hematite, BIS and a mixture of jarosite-hematite are presented in
figures 5.5 and 5.6.
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eudiseR
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70000
FeO
60000 2 3
(HO)Fe(SO)(OH)
3 3 42 6
50000
40000
30000
20000
10000
0
0 10 20 30 40 50 60 70 80
2θ
Figure 5.6: XRD pattern for a mixture of hydronium jarosite – hematite
5.2 Effect of copper sulfate
Using the same initial matrices composition (in terms of Fe(II) and H SO concentrations),
2 4
copper sulfate was increasingly added in the system.
5.2.1 Free Acidity
Figure 5.7 shows the influence of copper sulfate on final free acidity. Three initial free
acidity compositions were investigated: 20g/L, 40g/L and 60g/L, as they were respectively
expected to yield hematite, a mixture, and BIS. In presence of copper sulfate, the amount of acid
produced increases. At high copper sulfate concentration (63.5g/L Cu), the limit is shifted up to
point where there is no acid consumption at 60g/L initial free acid.
5.2.2 Final iron in solution
The effect of copper sulfate on final iron remaining in solution is presented in figure 5.8.
The breaking point in the curve is observed for copper concentrations below 25.4g/L (appearance
of BIS in the residue). At 38.1g/L and above, there is no visual shift and final free acidity
steadily increases. This correlates well to the residue composition: there is no BIS in the samples
prepared from ―intermediate‖ free acidity solutions. From figure 5.8, it can also be seen that
copper sulfate helps decreasing the iron left in solution only at low initial sulfuric concentration.
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5.2.3 Final copper in solution
Figure 5.9 presents the concentration of copper in the rinse solution with increasing final
free acidity and various initial copper contents. Above a limit of approximately 53g/L H SO ,
2 4
copper concentration increases in the rinse solution. There obviously is an effect of the initial
copper concentration on the copper remaining in the rinse. But free acidity seems to have an
influence as well since batches with same initial copper content show different final copper
concentrations.
Copper sulfate solubility is influenced by the amount of free sulfate ions in solution
(Equation 5.1). Higher sulfuric acid concentration means more sulfate ions are available. The
solubility of copper sulfate can be decreased to the point where some copper sulfate precipitates
along with hematite/BIS. When the residue is washed with distilled water, copper sulfate
dissolves and is transferred to the rinse solution.
CuSO = Cu2+ + SO 2- (Equation 5.1)
4 4
4
3.5 ♦ 12.7 g/L Cu
3 ■ 23.4 g/L Cu
2.5 ● 38.1 g/L Cu
2 ▲ 63.5 g/L Cu
1.5
1
0.5
0
40 45 50 55 60 65 70
Final free acidity (g/L)
Figure 5.9: Influence of free acidity on copper concentration in the rinse solution
5.2.4 Residue characterization
Copper sulfate influences the residue composition by hindering the formation of BIS, as
shown in figure 5.10. Looking at the sulfur content as a function of acidity, it is seen that copper
sulfate shift upwards the free acidity limit for hematite vs. BIS precipitation (Figure 5.11 and
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)L/g(
noitulos
esnir
ni
noitartnecnoc
uC
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Table 5.1: Influence of copper sulfate on free acidity upper limit for hematite precipitation
Initial [Cu] 0g/L Cu 12.7g/L Cu 25.4g/L Cu 38.1g/L Cu 63.6g/L Cu
Limit [Free Acid] 41 g/L 46 g/L 50.5g/L 56 g/L >61g/L
As mentioned in paragraph 3.5., three initial free acidity conditions were tested. At 20g/L
initial free acid and [Cu]>12.7g/L, the residue produced is 100% hematite. The XRD patterns of
these samples were compared in order to assess a potential influence of copper sulfate on
hematite crystallinity (see appendix C). Residues precipitated from high copper sulfate solutions
seem to be better crystallized (sharper peaks). This observation needs to be taken with caution
and would need to be confirmed with additional testing.
5.3 Effect of increasing iron concentration
In this third phase, 3 batches of three different initial iron compositions were tested:
- Batch A: 83.4g FeSO i.e. [Fe(II)] = 16.7g/L
4 initial
- Batch B: 111.2g FeSO i.e. [Fe(II)] = 22.3g/L
4 initial
- Batch C: 152.9g FeSO i.e. [Fe(II)] = 30.7g/L
4 initial
For each batch, three different copper concentrations (0, 12.7 and 38.1 g/L) and three
different sulfuric acid concentrations were tested (20, 40 and 60g/L).
5.3.1 Free Acidity
Free acid generation/consumption in function of initial free acidity is presented in figure
5.12. The same previously reported trend is observed for batch A, B and C:
- low initial free acidity is correlated to the highest acid production (>15g/L)
- high initial free acidity is correlated to acid consumption
- intermediary initial free acidity leads to acid production or consumption depending on the
copper sulfate concentration in the system
Increasing the initial iron concentration in solution yielded unclear results. One could expect
an increase in acid production because more iron is available for hydrolysis. It cannot be
confirmed here since batch B sulfuric acid concentrations are higher than batch C.
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5.3.2 Final iron in solution
The three graphs in figure 5.13 illustrate the final amount of iron left in solution over free
acidity. It shows that:
- An increasing copper sulfate concentration is associated with a decrease in the final free
acid content. As a result, more iron precipitates out of solution when copper is present.
- It is unclear how initial iron concentration is influencing the conversion % to hematite.
For batch A and B, there is no (or very little) shift in the curve at high copper sulfate
concentrations. This is related to hematite being the main component in the residue under these
conditions.
For Batch C, it is unclear why the concentration of iron remaining in solution is higher at
intermediate initial free acidity. The corresponding residues do not show high amounts of BIS
which could have explained such pattern.
5.3.3 Final copper in solution
Figure 5.14 compares the concentration of copper in the rinse solution for batch A, B and
C. Again, because of sulfate concentration, higher free acidity is related to greater amount of
copper in the rinse solution.
Less data was available to analyze batch A and C. As a result, the observations made for
these two batches must be analyzed with caution. One could expect that increasing iron
concentration would lower the solubility of copper sulfate and thus increase the amount of
copper in the rinse solution for batch C. It is not the case since batch A shows higher levels of
residual copper in the rinse solution than B and C. The rinsing step was overall consistent, but
some small variations in the volume of DI used to rinse the precipitates might explain these
results.
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5.3.4 Residue characterization
Figure 5.15 compares the effect of copper sulfate on residue composition for batch A, B
and C. As noticed in paragraph 5.2, copper sulfate hinders the formation of BIS and jarosite.
The following observations are made for the influence of iron concentration:
- The proportion of hydronium jarosite in the residue decreases with increasing iron
concentration. No jarosite was detected in batch C
- When no copper sulfate is added in the initial solution, the influence of iron sulfate
concentration is unclear
- When copper sulfate is present, batch B and C show similar trends. However, batch A has
much lower BIS content, indicating that low initial iron concentration hinders BIS
formation
Plotting the sulfur content in the residue against final free acidity shows the limit for BIS
formation (Figure 5.16). Table 5.2 summarizes the influence of initial iron concentration on this
limit.
Table 5.2: Upper free acidity limit for the precipitation of hematite
Initial Fe 0g/L Cu 12.7g/L Cu 38.1g/L Cu
Batch A - 16.7 g/L 35 g/L 38 g/L > 45 g/L
Batch B - 22.3 g/L 41 g/L 46g/L 56 g/L
Batch C - 30.7 g/L 37 g/L 42 g/L 54 g/L
Each limit was defined with only three points, which led to a probable error of ±2g/L.
When the residue formed at high free acidity did not yield BIS, the limit was considered to be
above the highest point measured. As seen earlier, copper sulfate shifts upward the limit free
acid concentration for the precipitation of BIS.
When increasing the iron content in the leach solution from 16.7 to 22.3g/L, the free acid
limit is moved forward. At 30.7g/L, it moves back to a slightly lower value. Thus batch B shows
an optimum iron concentration to shift up the free acidity limit. There is no clear correlation
between figures 5.14 et 5.15 to make a definitive conclusion on the effect of iron concentration.
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XRD patterns of 100% hematite samples were also compared. No clear trend could be
identified for the effect of initial iron concentration on the residue crystallinity.
5.4 Effect of initial iron oxidation state
In this section, the effect of initial oxidation state of iron on the system is investigated.
5.4.1 Ferrous ion titration
Following the process presented in appendix D, the remaining ferrous iron was titrated in
the cooled solutions right after leaching (Table 5.4). All the solutions were initially composed of
22.3g/L iron and 25.4g/L copper.
Table 5.3 Ferrous iron titration data
Initial H SO Fe(II) titrated in final Fe(III) in final %Fe(II) not oxidized
2 4
(g/L) solution (g/L) solution (g/L) from initial
Initial 20 0.25 7.5 1.12
Iron: 40 0.25 11.2 1.12
Fe(II) 60 0.2 13.5 0.9
Initial 20 0.05 15.3 -
Iron: 40 0.025 17.1 -
Fe(III) 60 0.05 21.3 -
When titrating the solution prepared from ferric sulfate, a color change happened after
two or three drops added. Because leaching takes place in an oxidative environment, the
possibility for ferrous ions to be in solution is null. Thus the residual potassium dichromate
added before saturation of the solution (<0.05g/L) was not accounted for. Instead, a ±0.05g/L
error on ferrous titration was considered.
Titration of the solutions prepared with ferrous iron revealed that a very little portion of
the total iron was not oxidized (1% or less). As a result, it was considered that all the iron
originally dissolved in solution was available for hematite or BIS precipitation.
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5.4.2 Free Acidity
At low and intermediate initial free acidity, liquors prepared from ferric sulfate produced
less free acid than liquors prepared from ferrous sulfate (Figure 5.16). When using ferric sulfate,
the first oxidation reaction does not take place (Equation 3.3). Yet, this reaction consumes most
free acid in solution. The resulting large excess of free acid in solution hinders hematite
precipitation and as a result sulfuric acid production. At 60g/L initial free acidity, when BIS are
stable, there is no acid consumption. Because of high sulfuric concentration in solution, acid
consumption has stabilized.
30
25
20
15
Initial Fe(II)
10
Initial Fe(III)
5
0
0 10 20 30 40 50 60 70
-5
Initial Free Acid (g/L)
Figure 5.17: Comparison of free acid consumed/produced after leaching of ferric and ferrous
sulfate solutions
5.4.3 Final iron in solution
Comparison between solutions prepared with ferric or ferrous iron in terms of final iron
concentration is shown in figure 5.18. Ferric iron yielded much less residue than ferrous iron.
Additionally, the characteristic curve shift related to BIS formation is not seen when using ferric
iron.
This increase in ferric iron remaining in solution can be explained by the excess of free
acid. Hydrolysis reactions for BIS and hematite precipitation produce sulfuric acid. Thus, at
higher concentrations, the hydrolysis reactions are shifted backwards.
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5.4.5 Residue characterization
Figure 5.20 compares the residue composition of solutions prepared with ferrous or ferric
sulfate. The following observations can be made:
- For solution prepared from ferrous sulfate, increasing the initial free acid concentration
promotes the formation of BIS
- Residues from solutions prepared from ferric sulfate do not seem to be influenced by the
initial free acid concentration
- No specific trend explains the episodic formation of jarosite in the residue
The results for the batch prepared from ferric sulfate suggest that the free acidity limit for
precipitation of BIS is already reached at 20g/L.
Fe(II) Fe(III) Fe(II) Fe(III) Fe(II) Fe(III)
100%
90%
80%
70%
60%
Jarosite
50%
BIS
40%
Hematite
30%
20%
10%
0%
20 20 40 40 60 60
Initial Free Acidity (g/L)
Figure 5.20: Effect of iron oxidation state on residue composition
When looking at the sulfur content in the residues (Figure 5.21), the limit free acidity is
logically higher in the ferrous sulfate case where the system is not saturated by sulfate ions. The
lower limit is unclear for the Fe(III) solutions since none of the residues majority yielded BIS. It
was set at 41 g/L or lower (Table 5.4).
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Table 5.4: Free acidity limit for the precipitation of BIS
Initial Fe Fe(II) Fe(III)
Free Acid Limit 50.5 g/L <41 g/L
25
20
15
Fe(II)
10
Fe(III)
5
0
30 35 40 45 50 55 60 65 70
Final Free Acidity (g/L)
Figure 5.21: Relation between sulfur content in residues and free sulfuric acid concentration
5.4.6 Discussion
The previous results were presented in terms of free acidity. This choice was made since
the literature review and the results obtained in paragraph 5.1 indicated that free acidity is the
main factor influencing the precipitation. In this specific case, at equal initial iron concentrations,
the ratio Fe:S is quite different when preparing a solution from ferric sulfate or ferrous sulfate. It
becomes more difficult to compare tests which molar ratios are very unalike. As a result, the
effect of iron oxidation state on the residue chemistry must be confirmed by leaching solutions
with similar molar ratios before making a definitive conclusion.
5.5 Stat-Ease model
Design-Expert® by Stat-Ease® is a software providing statistical modelling on design of
experiment (DOE) for process development optimization. In this project, it was used to generate
a prediction of the system‘s behavior. Two different analyses were performed.
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A first approach consisted in using a regular two-level factorial design. Two-Level
factorial design is useful for estimating main effects and interactions. The second approach
consisted in using a general factorial design, which allowed analyzing three factors, with three
levels for each of them. The factors analyzed where [FeSO ], [CuSO ] and [H SO ]. The
4 4 2 4
response factor analyzed was %BIS (=%FeOHSO + %(H O)Fe (SO ) (OH) ) in the residue. A
4 3 3 4 2 6
model separating BIS and jarosite as response factors was produced, but was not conclusive.
More details about Stat-Ease® plots interpretations can be found in appendix F.
5.5.1 First approach
Table 5.5 presents the factors and levels used. The model is performed based on the
extreme values for each factor. A two-level design using three factors gave 8 runs.
Table 5.5: Factorial DOE – first approach
Factor 1 Factor 2 Factor 3 Response 1
Run A:[FeSO4] B:[CuSO4] C:[H2SO4] %BIS
g/l g/l g/l
1 83.40 0.00 20.00 18.6
2 152.93 0.00 20.00 12.3
3 83.40 150.08 60.00 16.8
4 152.93 150.08 20.00 0
5 152.93 150.08 60.00 90
6 152.93 0.00 60.00 98.8
7 83.40 0.00 60.00 95.1
8 83.40 150.08 20.00 0
According to the Box-Cox Plot recommendations, a square root transform was used. The
Half-Normal Plot (Figure 5.22) and Pareto Chat (Figure 5.23) determined that [CuSO ] and
4
[H SO ] had the most effect on the %BIS.
2 4
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Table 5.8: ANOVA for selected factorial model – Second approach
Sum of Mean F p-value
Source Squares df Square Value Prob > F
Model 412.34 8 51.54 24.06 < 0.0001 significant
B-CuSO4 78.46 2 39.23 18.31 < 0.0001
C-H2SO4 294.56 2 147.28 68.76 < 0.0001
BC 39.32 4 9.83 4.59 0.0099
Residual 38.55 18 2.14
Cor Total 450.90 26
Because of the complexity of the response to [CuSO ] and [H SO ], the 3D surface
4 2 4
model is symbolized by columns. The model errors seem to be related to the intermediate values
which were not accounted for in the first approach. The fact that the intermediate values used are
not actually equidistant from the extreme values likely is a partial reason for the differences
between the prediction and the actual values. As for approach 1, changing [FeSO ] had a very
4
few influence on the 3D model (Figure 5.26).
Design-Expert® Software
Factor Coding: Actual
Original Scale
%BIS (%)
Design points above predicted value
Design points below predicted value
140
X1 = B: CuSO4
X2 = C: H2SO4 120
Actual Factor 100
A: FeSO4 = 83.405
80
60
40
20
0
60
40 150.083
C: H2SO4 (g/L)
50.03
20
0
B: CuSO4 (g/L)
Figure 5.26: 3D surface model for the second approach
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5.6 Ternary diagrams
In order to visualize the influence of PLS composition on the Fe-Cu-S system,
experimental data was plotted in ternary graphs, using the software OriginLab®. The purpose is
to obtain a continuous approach of the results, and complete to the discrete data described in the
experimental paragraph.
5.6.1 Residue composition
First, the XRD data was plotted within the Fe-Cu-S ternary diagram to observe the
species distribution. One example (Batch B) is shown figure 5.27, where the stability area of BIS
and hematite have been extended for better reading. The original plots for batches A, B and C are
shown in appendix F. The switch between BIS and hematite seems to occur in limited
conditions, with a very small area in the diagram where the two species are coexisting. The limit
is not as clear for batches A and C, but this is most likely related to the fact that less data points
were available to draw the diagram.
For batches A, B and C, this small ―coexisting domain‖ was represented as a line, and the
result is compiled in figure 5.28. It appears that an increasing initial iron concentration shifts this
limit to the lower part of the graph.
%BIS
?
Figure 5.27: Ternary plot showing hematite vs. BIS stability in the Fe-Cu-S system
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After processing the data, seven mineral categories were brought out:
- Hematite, and more generally all the pixels detected as iron oxides species
- BIS, including the synthetic product FeOHSO and one of its hydrated species fibroferrite
4
(FeOHSO .5H O)
4 2
- BIS-Hematite interphase, which describes all the areas where the beam shot was directed
at a boundary between the two phases without being able to detect which one was
dominant
- Jarosite, as hydronium jarosite
- Elemental sulfur, i.e. the pixels characterized by an unusually high sulfur content when
compared to the other elements
- Ferric Sulfate
- Other minerals i.e. quartz, which has been found contaminating a couple samples.
Tests 42 and 43 are mainly composed of hematite, with BIS and jarosite in traces. Test 44
mostly shows BIS with less than 5% of hematite and jarosite. The images as well as composition
of each samples is presented in appendix G.
QEMSCAN percentages are matching the XRD data up to a ±5% difference. The reason for
this difference relies in the detection limit of QEMSCAN (5µm). When analyzing a pixel, an
average measurement from the whole pixel area is produced, but it does not account for the
heterogeneity of the pixel. All intermediary pixels were associated with the closest category
matching their global composition, which means that part of each pixel could have actually
belong to another category.
5.7.2 Particle Size and shape
PSD of the three samples is presented in Figure 5.30. Test 42 and 43 show similar fine
particle sizes (inferior to 150µm) and are quite homogeneous overall. Test 44 shows a much
wider distribution ranging from the detection limit 7µm up to over 1mm. The bigger particles do
not seem to have agglomerated: they are round and show concentric hematite and jarosite growth
rings. The intermediary particles show stretched out, irregular shapes.
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CHAPTER 6 PROPOSED ECONOMIC ANALYSIS
A general analysis was performed in order to assess which economic indicator would be the
most impacted by a decrease of the BIS content in the autoclave discharge.
6.1 Assumptions
The following economic evaluation will be based on a simplified flowsheet where pressure
oxidation is used Leach/Solvent Extraction/Electrowinning circuit for copper and cyanidation for
gold. The following assumptions were made:
- Feed head grade is presented in table 6.1
- Overall recovery is presented in table 6.3 and based on the assumptions concerning the
residue presented in table 6.2
- Capital and operating costs are calculated for the circuit presented in Figure 6.1
- 560,660 tonnes of concentrate feed per annum and 800,940 tonnes of feed per annum
- Grinding circuit functioning at full capacity
- The concentrate mineral composition is 60% chalcopyrite, 35% pyrite, 5% gangue
- At this stage, the income related to gold production will not be included in the analysis
- Conditions of leaching: 220˚C, 40 psi oxygen overpressure
- Operating costs do not include neutralization of the leach solution. Sulfuric acid is
considered to be reused for heap leaching
- Capital costs include the expenditures related to building a new mill, they do not include
refining costs for Cu cathode if needed
- The mill is operating 325 days/year to account for maintenance shutdowns
- Pressure leaching and solvent extraction – electrowinning circuits are located on the same
site; therefore, no transportation costs were included
- By-products are not marketable
- 10 year cash flow
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Recalculating the percentages within Fe-Cu-S system, the compositions of the
concentrates in the ternary diagram are the following: 21.6% Cu, 41.5% S, 36.9% Fe.
Implementing the feed composition in the ternary plots (paragraph 5.6), we can predict the
percentage of BIS in the residue as well as the percent of iron recovered in the residue (Table
6.2).
Table 6.2: Composition of the residue and %Fe recovered
%BIS in residue %Fe recovered in residue
10 90
Table 6.3: Overall %Recovery assumptions based on residue composition
Au Cu
90% 98%
Accounting for table 6.2, we will also assume that:
- %Fe recovered in residue has an influence on the overall copper recovery during the
solvent extraction and electrowinning stages
- We will neglect the impact of other contaminating ions in solution such as Zn, Pb or
alkali metals
Costs estimates for actualization of the costs were used following equation 6.1 and table 6.4:
2014 Cost = [Year] Cost * Equation 6.1
Table 6.4: Cost indexes for CAPEX and OPEX estimation [44]
Year CAPEX OPEX
1995 80.1 83.0
2014 101.5 98.5
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6.2 Copper pressure leaching circuit
The estimation of operating and capital costs for the copper recovery circuit was made
using the Proceedings of COPPER 95-COBRE 95 International Conference [44]. The detailed
tables are presented in appendix H.
Table 6.5: Total Operating Costs for production and marketing of cathode copper per
annum in M$
Parameter 1995 Cost 2014 Cost
Autoclaving concentrates 30.75
SX/EW 30.86
Copper losses, tailing disposal, freight, 21.61
marketing, etc
Total operating costs 83.22 98.76
Table 6.6: Total Capital costs for hydrometallurgical treatment of copper concentrate per annum
in M$
Parameter 1995 Cost 2014 Cost
Direct capital costs 170.14
Indirect capital costs 65.00
Total capital costs 235.14 297.78
6.3 Grinding and flotation mill
The estimation of operating and capital costs for the primary grinding and flotation circuit
was based on the Flotation Mill Model of CostMine 2014 [42]. The values for a 2,500 tpd feed
throughput were extrapolated from values for 1,000 and 2,000 tpd feed throughput. The detailed
calculation can be found in appendix H.
Table 6.7: Total Capital and Operating Costs for grinding and flotation Mill
Parameter 2014 Cost
Capital Costs in M$ 37.60
Operating Costs in $ per tonne of feed 13.81
Operating Costs in M$ per annum 11.06
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6.5 Sensitivity Analysis
Figure 6.2 shows NPV sensitivity for CAPEX, OPEX and gross revenue. The later has the
most influence on NPV, since fluctuating copper price have a considerable impact on the
revenue made from a 100,000 tonnes annual production. Operating costs have more influence on
NPV than capital costs, which could be explained by the operating challenges associated with
Pressure Leach/SX/EW circuits.
2500
2000
1500
1000
500
0
-20 -15 -10 -5 0 5 10 15 20
%change
gross revenue opex capex
Figure 6.2: Sensitivity analysis
Within a copper leach operation where iron contamination is a major issue, diminishing the
amount of BIS in the residue would have two main financial consequences:
- Slightly decrease operating and capital costs (because of tailing disposal and filtering
savings)
- Highly increase the gross revenue by improving copper recovery
For this estimation, a copper recovery increase of 1% would represent a NPV increase of
$30M. Again, it is likely that some costs have been underestimated in this analysis. But the
previous remark shows that effectively hindering BIS allows a significant increase of NPV.
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CHAPTER 7 CONCLUSIONS AND RECOMMENDATIONS
This project aimed at better understanding the influence of leaching solution composition on
the precipitate chemistry during high pressure oxidative leaching. It was achieved by leaching
artificial solutions of varying compositions at temperature and pressure usually implemented in
copper sulfide POX circuits. The main application to the observations made in this thesis would
be to predict the response of any copper-iron sulfide concentrate and change the solution
chemistry to hinder the formation of BIS. This is, of course, a theoretical approach since
synthetic solutions prepared from sulfates were used to recreate a certain concentrate
composition. Contaminants and conditions of leaching would deeply complicate the system‘s
response. However, the statistical model and ternary plots can be used to predict some general
trends which can be expected during leaching of copper sulfides.
7.1 Summary
The literature review highlighted the importance of sulfuric acid concentration in the PLS
on residue composition. In the conditions of this study, in a simple Fe-O-S system at 22.3g/L Fe,
the upper limit for hematite precipitation over BIS is 41g/L. Hematite precipitation is associated
with great production of sulfuric acid, whereas BIS formation is consuming it. This explains why
high acidity promotes the formation of BIS. Applied to the industry, this suggests that a possible
solution to an excessive BIS content in the autoclave discharge would be to decrease the overall
sulfuric acid concentration. Of course, this has to be done with caution to avoid diminishing
overall recovery.
When progressively adding copper sulfate to the system, the precipitation limit for
hematite is shifted upward. At 63.5 g/L Cu, hematite is stable up to 61g/L sulfuric acid. Copper
sulfate is thus actively hindering BIS formation. The specific effect of copper on the limit is
depending on the matrix composition (i.e. iron concentration and initial acid concentration) and
the operating conditions of leaching as well. The results presented here sometimes show great
difference with what has been reported in the literature. Overall, this thesis‘ results mean that
adding copper sulfate to an existing circuit could help improving the residue‘s chemistry.
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According to several authors, the stabilizing effect of copper sulfate is a due to the
buffering action of the ion sulfate. The type of metal in solution is certainly influencing the
process as well since different metal sulfate in comparable concentration yield slightly different
results.
The effect of initial iron concentration in solution was investigated over the range 16.7-30.7
g/L. Discrete experimental results did not allow to draw definite conclusions regarding its
influence on BIS content in the residue or %Fe left in solution. However, two trends can be
highlighted:
- BIS seems to be hindered by low initial iron concentrations.
- Increasing copper sulfate concentrations help reducing the iron left in solution after
leaching.
The influence of initial oxidation state of iron was tested by leaching identical solutions
prepared from ferric or ferrous sulfate. Ferric sulfate seems to promote BIS formation and
increase the amount of iron left in the PLS, no matter the initial free acidity concentration. This
can be explained by the consumption of acid for ferrous oxidation to ferrous, which does not
happen when using ferric sulfate as reagent. In practice, this would mean that the acid leach
concentration can be optimized to fit the type of minerals in the ore, and the oxidation state of
iron in these minerals.
Hydronium jarosite was shown to be precipitating along with hematite and BIS. There is no
specific trend which could help explaining its stability, besides the fact that it disappears at low
initial iron concentration.
Statistical modelling by Stat-Ease® and extrapolation using OriginLab® confirmed that
sulfuric acid was the main parameter controlling hematite precipitation, along with copper
sulfate to a lesser extent. An equation to predict the model‘s response was produced, but needs to
be used with extreme caution when operating at intermediate free acidity levels. The system does
not seem to fit as well when BIS and hematite are coexisting.
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Plotting the data into ternary diagram (Fe-Cu-S system) has shown the following points:
- Increasing iron concentrations diminishes the stability area of hematite
- The coexistence area for hematite and BIS is very limited
- %Fe effectively extracted from solution by precipitation correlates well to final residue
chemistry. This is logical regarding to higher %Fe in hematite than BIS.
Finally, QEMSCAN analysis is correlating XRD data, and is showing that BIS particles are
much coarser and more irregular than hematite.
7.2 Recommendations for future work
- Develop an experimental procedure to thermodynamically characterize BIS and model
the data. Missing this information prevented any preliminary analysis and led to
estimations based on experimental models only.
- Investigate the reproducibility of the results. A few tests were performed twice and
yielded residues showing some composition difference.
- Broadening the range of initial iron concentration tested. Leaching of the three batches
highlighted a trend for hematite to become less stable at higher [Fe] . This would need
initial
to be confirmed to see the evolution of the stability limit delineated in the ternary plot.
- Conduct additional ―intermediary‖ acidity leaching tests to better understand the reasons
for low iron recovery when BIS and hematite are coexisting.
- Working at larger scale. Many areas of the ternary diagrams could not be investigated
because of insufficient amounts of residues formed. They were not suitable for XRD
analysis.
- Investigate the influence of other metal sulfates on the system. Especially, ZnSO ,
4
MgSO , Na2SO , K SO . Priority should be given to the most common metal
4 4 2 4
contaminants, as well as alkalis, which readily form jarosites.
- Conduct and analyze tests with actual concentrates, which compositions are similar to
those tested in this project. The comparison would provide precious information on the
prediction reliability.
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APPENDIX SECTION
APPENDIX A: FREE ACIDITY TITRATION PROCEDURE (MODIFIED AFTER JOSEPH
GROGAN)
Solution Preparation
30wt.% (1.6M) Potassium Oxalate Solution
Weigh out 150g of potassium oxalate and mix with 450mL of solution in a beaker. Heat and stir
until dissolved. Allow to cool and make up to 500mL in a volumetric flask.
Analytical Method
Procedure:
1. Pipette 1mL of sample into sample beaker
2. Dilute sample with approximately 50mL distilled water.
3. Add 5mL of the oxalate solution (should contain ≈ 8mmol oxalate).
4. Wait to allow oxalate complexes to form (solution will become turbid).
5. Run Method 668. (Input sample info and print report)
6. Titrate with 05n NaOH (ensure tower is filled with NaOH pellets) to pH endpoints of 3.5 and
8.5.
7. The characteristic ‗S‘ curve should be between these two pH values. Use the equivalence point
to determine mL titrant used. The equivalent point is where the curve is steepest on the pH vs.
vol titrant plot, or the highest value/peak corresponding to the ‗S‘ curve for the plot of the first
derivative (dpH/dvol. titrant) vs. vol. titrant.
Calculation:
Free H SO (g/L) = =
2 4
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APPENDIX B: QEMSCAN SAMPLE PREPARATION PROCEDURE
Source: Colorado School of Mines QEMSCAN facility (Dr Katharina Pfaff)
To make a grain mount:
1. Measure the total sample weight into a beaker (zero the scale to the beaker‘s weight).
Write the total sample weight in the column.
2. If the sample is too large, cut and quarter it until there is a reasonable amount of material.
3. Riffle the samples until each test tube has one gram of sample material.
4. Choose one test tube of material and measure it into a plastic tube with a label taped
around it. Use the test tube opposite the first to create a duplicate sample, again measured
and labeled.
5. Add graphite to the sample. Choose graphite size by the closest estimation to the grain
size of the sample. If the sample is heterogeneous, choose several graphite sizes. Measure
out the graphite in a 3:1 ratio of graphite to sample in the plastic tube by the scale then
pour it in with the sample material.
6. Mix up the epoxy in an 8:1 resin to hardener ratio. Mix enough to have ~3-3.5 grams of
epoxy per sample, plus some extra just in case.
7. Measure the epoxy into the sample and stir thoroughly with a toothpick.
8. Place the sample into the pressure cooker, close the lid securely, and flip the switch up to
create a vacuum. Let the epoxy sit for 12 hours.
9. Remove the samples from the pressure cooker, fix the labels on the top, and backfill the
sample with more epoxy, ~1 mm. Place back into the pressure cooker to let sit for another
12 hours.
Polishing:
1. For grain mounts, attach the sample holder to the head of the polisher.
2. Polish the tops of the samples (label side) on the 80 grind with water until flat. Use the level
by the QEMSCAN to check the samples before moving on. Once flat, use the 1200 grind on
the tops to polish a sheen and make the label readable.
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3. Polish the sample side using the sequence 80, 220, 1200, 6 µm, 3 µm, 1 µm. For hard rock
samples, use water. For shales or water soluble minerals, use alcohol. After each grind, rinse
the samples with water (or methanol for alcohol polished samples) and change the sample
holder to make sure there is no granular material remaining during the lower grinds.
4. The 80, 220, and 1200 are grinding pads and the 6, 3, and 1 µm are polishing pads that use a
diamond polishing fluid along with water or alcohol lubricant.
5. After the 1 µm, wash the samples in methanol well, dry them with compressed air, and place
them in the oven for at least 30 minutes. Use gloves to handle the clean samples from this
point on.
Carbon coating:
1. Place the glass ring on the machine, close it, and turn on the vacuum. Wait for the
vacuum to reach 10-4 (or as close as possible) before turning on the voltage with the
Start/Stop button. Crank up the voltage using the knob next to it until the carbon rods
begin to spark.
2. Watch the brass piece change color. Stop at red for SEM work, purple/blue for
QEMSCAN. Turn down the voltage with the knob before hitting the Start/Stop button
again and then turning off the vacuum. Color of the brass piece corresponds to carbon
coat thickness (darker=thicker).
3. Carbon coating allows for an electrically conductive surface for the electron beam in the
QEMSCAN.
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APPENDIX D: FERROUS IRON TITRATION – PASMINCO CLARKSVILLE
LABORATORY PROCEDURE
Scope: This procedure is used to determine the amount of ferrous iron in sulfate solutions
Principle: The ferrous salts in cold acid solution are quantitatively oxidized to the ferric
oxidation state by potassium dichromate
Reagents: 1. Potassium dichromate solution: 4.4g/L
2. Potassium dichromate solution: 0.44g/L
3. Sodium diphenylaminesulfonate: 10g/L
4. Acid buffer solution: 15% H2SO4, 15% H3PO4 to 1liter with water
Procedure: 1. Pipette 5 or 50mL filtered sample into a 250mL Erlenmeyer flask
2. Add 50mL acid buffer solution and 10 drops diphenylamine sulfonate indicator
3. Titrate with potassium dichromate solution until color changes to purple or
violet
Calculation: 5mL sample:
mL 0.44g/L K Cr O *0.1 = g/L Fe2+
2 2 7
mL 4.4g/L K Cr O *1.0 = g/L Fe2+
2 2 7
50mL sample:
mL 0.44g/L K Cr O *0.01 = g/L Fe2+
2 2 7
mL 4.4g/L K Cr O *0.1 = g/L Fe2+
2 2 7
Interferences: Cu in quantities > 1mg assists the oxidation of Fe2+ by air. As(III) raises results as
if oxidized to As(VI) by dichromate.
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APPENDIX F: STAT-EASE DATA®
Analysis method provided by Stat-Ease® [45].
1. Compute effects. Use half-normal probability plot to select model. Click the biggest
effect (point furthest to the right) and continue right-to-left until the line runs through
points nearest zero. Alternatively, on the Pareto Chart pick effects from left to right,
largest to smallest, until all other effects fall below the Bonferroni and/or t-value limit.
2. Choose ANOVA and check the selected model:
a. Review the ANOVA results.
i. Model should be significant based on F-test:
1. (Prob > F) is < 0.05 is significant (good).
2. (Prob > F) is > 0.10 is not significant (bad).
ii. Curvature and Lack of Fit (if reported) should be insignificant:
1. (Prob > F) is < 0.05 is significant (bad).
2. (Prob > F) is > 0.10 is not significant (good).
b. Examine the F tests on the regression coefficients. Look for terms that can
beeliminated, i.e., terms having (Prob > F) > 0.10. Be sure to maintain hierarchy.
c. c. Check for ―Adeq Precision‖ > 4. This is a signal to noise ratio.
d. d. Verify the ANOVA assumptions by looking at the residual plots.
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"Large" is the value of the red line which is set as the minimum of 1 or the F critical value at
alpha of 0.5 using p and n-p degrees of freedom, where p is the number of terms in the model
including the intercept and n is the number of runs. =min(finv(0.5,p,n-p), 1).
Cook's Distance
1
0.8
0.6
0.4
0.2
0
1 2 3 4 5 6 7 8
Run Number
Figure F. 6: Cook‘s Distance – First Approach
Leverage
Numerical value between zero and one that indicates the potential for a design point to influence
the model fit. A value of one means that the predicted value will be forced to be exactly equal to
the actual value, with zero residual. The sum of the leverage values across all cases equals the
number of parameters fit by the model. The maximum leverage an experiment can have is 1/k,
where k is the number of times the experiment is replicated. Values larger than 2 times the
average leverage are flagged. A high leverage point is "bad" because if there is a problem with
that data point (unexpected error) that error strongly influences the model.
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ABSTRACT
This PhD project investigates the mining regulatory framework (MinReF) of Western Australia
(WA), and the environmental protection it provides during the lifecycle of mining operations.
The MinReF—a construct developed for this study is defined as the Federal and State mining
laws consisting of numerous legislation, regulations, policies and other administrative tools
implemented by government agencies. It covers century-old legislation as well as more recent
Acts.
The study was conducted using qualitative research methods to analyse the effectiveness of
the environmental regulations based on an investigation of the overall MinReF, two case
studies and interviews with regulators, lawyers, academics, researchers and stakeholders.
This research is grounded in sustainable development principles but also draws from other
disciplines such as public policy, legal doctrines and environmental law, regulation theory,
theories of bureaucracy, and discourse analysis to understand relevant theoretical
approaches concerning the study. The two case studies include a uranium mine which
received approval in January 2017 but is not yet operational, and coal mining operations in
the Collie Region of Western Australia.
The government of Western Australia regulates over 1000 mine sites, covering more than fifty
different minerals, including coal, copper, iron ore, lithium, mineral sands, and uranium. As a
result of the legacies of the past, there are 17,000 abandoned mines spread across Western
Australia, and the MinReF needs to address issues relating to their rehabilitation. The existing
MinReF has evolved over 100 years with several government agencies responsible for its
implementation. It is characterised by complexity concerning both, regulations and
administrative structures which have evolved to facilitate and regulate mining operations in
the State. A distinctive feature of the WA’s MinReF is its dichotomy allowing some of the
mining operations to be carried out under the Mining Act 1978 while others are based on
purposefully designed State Agreements. The two case studies are examples of the use of
State Agreements but are also subject to other legislation related to the issuing of mining
tenements, land access, and mine closures.
The study identified seven challenges with the MinReF of WA. They are (i) inherent
weaknesses of key legislation; (ii) unclear demarcations and overlap of legislation; (iii)
ambivalence and dichotomy of the mining regulatory framework; (iv) lack of coordination of
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ACKNOWLEDGEMENTS
The research and writing of this thesis would not have been accomplished without the
attention, support and encouragement of many people whose names do not appear in this
acknowledgement. I will continue to extend my gratitude to them in this life, and beyond if that
becomes a reality with my current consciousness.
First, I want to acknowledge my principal supervisor Professor Dora Marinova, who has been
my teacher, mentor and friend for over 25 years. Her love and care for teaching and research,
complemented by her gentle, patient and professional manners, helped me to maintain
motivation over the journey of this research project and finally writing this thesis. Her
encouragement, reminders, insights provided and advice to explore new ideas are very much
appreciated. Dora’s suggestion to consider case study methods for my investigation helped
me to find facts and evidence that I would never have found, had I followed my pre-conceived
notions of research methods when I enrolled in the PhD program. Dora’s guidance made all
the difference in conducting the research and finally writing the thesis.
My co-supervisor, Mr Peter McCafferty always found time to discuss matters relating to the
key issues of this thesis. Peter always emphasised the need to find empirical evidence and
helped me to develop alternative insights, and sometimes challenged me about the
parameters and limitations of qualitative methodologies. He allocated time generously to read
my early drafts and provided feedback.
Dr Talia Raphaely was one of my co-supervisors until she left Curtin University, and the
support and encouragement she provided during the early stages of this research are warmly
appreciated.
My friend, mentor, and former teacher, Professor John Phillimore, Director, John Curtin
Institute of Public Policy, Curtin University supported me by providing references and books
upon request. I am grateful for his support, and encouragement.
Russel Clemens, a former colleague, was always available to chat over the phone, and
person-to-person meetings to debate on public policy issues and other matters pertaining to
sustainability issues by sharing his knowledge, and practical work experience in the public
sector.
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I thank Dr Myo Nyunt, a former colleague, scholar, and dear friend for sharing his wisdom,
and offering me the best home-made coffee every time I visited his home.
I acknowledge my dearest elder sister, Dr Pushpa Wickramasuriya, an eminent physician who
has acquired the highest academic and professional qualifications in our family, with deep
respect and affection for her constant support and encouragement.
I thank my youngest sister, Ms Manohari de Zoysa ((Chuti) who is an educator, and my dearest
friend, and brother-in-law Wimal de Zoysa, for their support and in particular sending me key
books on social research methods from the USA to enable me to refer the most recent
references in the methodology chapter.
My son Upulmal helped me throughout this research by supporting, and keeping me motivated
by asking the questions: “Dad how is it going? When are you going to complete your thesis
ah!”. I thank him for his invitations to share meals and watch the episodes of House of Cards
at his warm apartment.
My daughter, Sunili Uthpalawanna, a feminist, an eminent lawyer, and Human Rights
advocate supported my research work by providing insights on some legal matters despite her
busy schedule, and feminist activities.
My dear young friend, Melbourne-based Dr Tharanga Dandeniya, was always available for
chats about attacking procrastination, and tips for writing regularly. His suggestions of finding
a comfortable chair in the corner of the house, and how to write continuously based on his
successful PhD journey at Monash University, were most beneficial.
I also learnt much about research skills during my PhD journey by continually watching the
vlogs by Professor Tara Brabazon, Dean of the Graduate Research.
My life-long friend, Dr Sarath Gunathilake, Professor of Public Health at State University, Long
Beach, California was a good role model for my academic journey. His kind invitation to join
his research team to conduct field research for the WHO Bangladesh in late 2016 was useful
to refine my qualitative research and interviewing skills.
I must acknowledge three of my beloved friends based in Sri Lanka, the eminent bi-lingual
writer Daya Dissanayake, poet Udeni Sarathchandra who always encouraged me to finish this
project, and Sachitra Mahendra for his support and encouragement.
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My life-long mentor and friend, Professor Wimal Dissanayake’s encouragement is much
appreciated. When I last wrote to him, complaining about winter weather in Perth, and asking
for forgiveness for not writing a promised review of his latest poetry collection, Wimal
immediately replied and encouraged me to finish writing my thesis as a priority.
I must acknowledge Melissa Pilkington, of ‘To the Letter Transcripts’, for providing a
professional transcription of interviews in the most professional manner. Melissa also proof-
read the first draft of the abstract and first chapter, and I record my gratitude and appreciation
for her services.
I must extend gratitude for many of my peers including several “CUSPians” who shared their
time, food and friendship throughout the journey of this research project. There are too many
to acknowledge by name. However, I must share my gratitude to all of them, and for the
support extended in particular to Aditya Nugraha who has always shared his librarian skills
whenever I had a question about references, Laura Kittle, Lucas Marie, Daniel Jukes, and
Achmad Room Fitrianto for friendship and support and words of encouragement throughout
my PhD journey. Bohan Wang, dear young friend was an excellent inspiration for sharing her
study skills and goal settings for academic excellence.
I must also acknowledge the time given by all the research participants, whose names I cannot
divulge in this thesis due to Curtin University’s Code of Ethics.
I must record my gratitude to Chintana and Max Gerreyn for converting my concept of
representing ‘Western Australian Mining Regulatory Symphony” (WAMRS) into a visual and
their contribution and time is much appreciated.
The staff of Curtin University’s Graduate Research School helped me throughout from the
beginning to the final submission of this thesis. I must acknowledge the support received from
Ms Zalila Abdul Rahman, Ms Doreen Phan and Ms Catherine Martin for their prompt and
professional responses to my questions. Ms July Lunn’s support and all the hard work she
has done for all graduate students must be acknowledged. Ms Marylin Coen, Humanities
Librarian’s, assistance and the support extended to graduate students is warmly.
I am grateful to my dear Sri Lankan friends in Perth, especially, Banudla and Vinitha Rodrigo
for their support, humour and a frequent invitation to social events at their home. Chintana
and Chandima Meegamarachchi not only extended their warm friendship but offered me a
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place to sleep after late nights spent working at the Curtin University ‘Hub’, saving me the long
drive home.
Finally, but not least, I am grateful to my long-time friend Marilyn Beech who proof-read the
abstract, chapters three, five, six, a part of chapter eight, and ten of this thesis
I must acknowledge the stipend I received through the post-graduate scholarship provided by
the Australian Government supplemented by Curtin University for three and half years to
support my survival during this PhD journey. I have neither received nor sought any financial
support from any mining company in Perth, or elsewhere for this research.
I must finally declare that I had no conflict of interest in doing this research. I did not use any
privileged or confidential information from any of the government agencies I have worked prior
to become a full-time post-doctoral student in March 2014. If there is any sensitive information
appearing in this thesis, the sources are the anonymous research participants who were
contacted, and interviewed according to the Guidelines of Ethics as stipulated by the Code of
Ethics of the Curtin University.
Sunil K Govinnage,
Curtin University Sustainability Policy Institute
2 October 2018
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DEDICATION
I dedicate this thesis to:
Present and past generations of Whadjuk - Noongar people who lived and preserved a
precious land and environment for over 60,000 without destroying our unique eco-system;
Professor Dora Marinova, my principal supervisor and Mr Peter McCafferty my co-supervisor
for mentoring, and support extended to complete this research project;
And to the following ladies and gentlemen whom I met during academic, seminars, meetings
and through follow up with them on their insightful writing on various subjects on mining-
related work in Australia and elsewhere:
Dr Gavin Mudd, who has written some of the best peer-reviewed journal articles on a variety
of subjects on Australian mining industry;
Dr Sara Bice, for her effortless research and academic contributions to areas such as
responsible mining, corporate social responsibility and licence to operate;
Piers Verstegen, for being the other voice on environmental protection in Western Australia;
Charlie Roche for his effortless work and research on mining rehabilitation work in Australia
and elsewhere;
Ms Mia Pepper for her tireless work on environmental protection and mine rehabilitation
work;
16 anonymous research participants who gave their time and shared their insiders’ stories to
add value to this research project,
My two beloved children; Sunili Utpalawanna and Upulmal Govinnage,
Sachitra Mahendra who will one day soon write a better thesis than this work, and,
All present and future researchers who will continue to investigate environmental issues
relating to mining in Australia and elsewhere.
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ABBREVIATIONS
ABC – Australian Broadcasting Corporation
ABS – Australian Bureau of Statistics
ACF – Australian Conservation Foundation
ADMINREF – Adaptive Capacity for the improvement of the Mining Regulatory Framework of
Western Australia
AFR – Australian Financial Review
AER – Annual Environmental Report
AFR – Australian Financial Review
ANAO – Australian National Audit Office
ALCP – Australian Government’s Landcare Program (“ALCP”)
AusIMM – Australian Institute of Mineral and Mining
BHP – The Broken Hill Proprietary Company Limited (BHP), an international mining first
incorporated in 1885 and commencing mining silver and lead at Broken Hill, in New South
Wales, Australia.
BHPB – BHP Billiton Limited and BHP Billiton, a multinational mining, metals and petroleum
public company headquartered in Melbourne, Australia
CEEC – Coalition for Energy Efficient Comminution
CERES – Coalition for Environmentally Responsible Economies
CFCs – Chlorofluorocarbons
CSR – Corporate Social Responsibility
CSIRO – Commonwealth Scientific and Industrial Research Organisation
CSRP – Centre for Sustainable Resource Processing
DBCA – Department of Biodiversity, Conservation and Attractions
DDT – Dichlorodiphenyltrichloroethane
DBCA – Department of Biodiversity, Conservation and Attractions
DIA – Department of Indigenous Affairs (WA)
DPLH – Department of Land Administration
DME – Department of Mines and Energy
DMP – Department of Mines and Petroleum
DMIRS – Department of Mines, Industry, Resources, and Safety (See also DMP)
DSD – Department of State Development
DJTSI – Department of Jobs, Tourism, Science and Innovation (See also DSD)
DWER – Department of Water and Environmental Regulation
ENB – Earth Negotiations Bulletin
EPBC – Environment Protection and Biodiversity Conservation Act 1999
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EIA – Environmental Impact Assessment
EIR – Extractive Industries Review
EDF – Environmental Defense Fund (USA)
EMS – environmental management system EMS.
FoE – Friends of the Earth
FoEA – Friends of the Earth Australia
GEF – Global Environment Facility
GSWA – Geological Survey of Western Australia
GDP – Gross Domestic Products
GMI – Global Mining Initiative
GRI – Global Reporting Initiative
GRO – Gold Regulation Ordinance1854
GSP – Gross State Products (WA)
GSSB – Global Sustainability Standards Board
ICMM – International Council of Mining and Minerals
IEA – International environmental agreement
ISO – International Standard Organization
IISD – International Institute for Sustainable Development
IUCN – International Union for the conservation of nature and natural resources
IIED – International Institute for Environment and Development
LA Act – Land Administration Act 1997
LGA – Local Government Areas
NRDC - Natural Resources Defense Council (USA)
NTA – Native Title Act 1993
MCA – Minerals Council of Australia
MCP – Mine Closure Plan
MEA – Millennium Ecosystem Assessment
MRF – Mining Rehabilitation Funds
MMSD – Mining, Minerals and Sustainable Development
MMSDP – Mining, Minerals, and Sustainable Development (MMSD) Project
OECD – Organisation for Economic Co-operation and Development
SAs – State Agreements
SDD – Sustainability Disclosure Database
SDIMI – Sustainable Development Indicators for the Australian Minerals Industry
SMEs – Small and medium-sized enterprises
SMI – Sustainable Minerals Institute
SLO – Social Licence for Operation
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GLOSSARY OF TERMS
Abandoned mines - “abandoned mine site means land declared to be an abandoned mine
site” (MRF Act, section 9(1).
Act - An Act of Parliament. “A statute, what a parliament enacts when it makes laws. The
term ‘statues’ and ‘Acts’ are interchangeable (Mann, 2013, p.15)
Legislation
(1) Making LEGAL something that was not legal…
(2) Another usage treats legislation as roughly synonymous with JURISDICTION or
JUDICIALISATION. (ibid. p.445).
Adaptive Capacity for the improvement of Mining Regulatory Framework of Western
Australia—A concept developed in this thesis for the improvement of the Mining Regulatory
Framework of Western Australia.
Discourse Analysis - “study of conversation or language in use” and consists of an “array of
analytic approaches” (Stubbe, Lane, Hilder, Vine, Vine, Marra, Holmes & Weatherall, 2003,
p.351).
Mining Regulatory Framework of Western Australia (MinReFWA) - A construct developed to
define the Western Australian and Federal legislation on mining, consisting of numerous
regulations, policies and other administrative tools managed by several State government
agencies.
Regulation - “Broadly, mechanisms of social control, typically based in law and including the
enforcement strategies of government agencies and public authorities.
(1) In its narrow sense, a form of delegated legislation, referring to a single rule, (a
regulation) or set of rules (regulations) made law by being authorised as DELEGATED
LEGISLATION made under a PARENT ACT. (Mann, 2013, p.617).
State Agreements (SAs) – “State Agreements [are] contracts between the State and a
company seeking to develop a project have traditionally been the vehicle used to conduct
major resource projects in Western Australia. They are comprehensive documents, designed
to establish ‘an integrated regime for approval, management and monitoring of all stages of
the project’ under ministerial supervision” (Hillman, 2006, p.293).
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PROLOGUE
What follows are reflections on my journey that led me to undertake this research project, after
having worked for over twenty years as a career civil servant in the public service in Western
Australia. First, I want to write about the factors that influenced me to embark on an academic
journey to undertake this research project and write this thesis. It all started not as an
epiphany, but due to a calling which is linked to my new sense of place: Perth, Western
Australia.
I arrived in Perth on 29 May 1988 as a skilled migrant, with my Sri Lankan heritage as a cultural
identity and with the intention of adopting Australia. I wanted to adopt Perth as my new home
with two children (two years and four years of age respectively), help them to be good citizens,
and support my partner; a medical officer who wanted to continue her further studies to
become a paediatric surgeon. Perth was very different from the country where I was born and
grew up, Sri Lanka, and where I had worked in a university; the Asian Institute of Technology,
Thailand where the Asian Disaster Preparedness Centre was then located.
Since arriving in Perth, despite the economic, social, cultural and geographical differences
from my native country, Sri Lanka, I have fallen in love with Perth and come to understand the
history, culture, social and economic background of Western Australia where we have a
prosperous mining industry which has a history of over 160 years. As part of my reflections
of life in Perth and also due to my interest in literature, I have published five poetry books in
Sinhala, my native language, and two English poetry collections in which I have described my
journey, the long struggle to settle down, and the adjustments made to our lifestyle to develop
roots in Perth. Though some of my reflections are written in Sinhala, my second collection of
English poetry titled “Perth: My Village Down Under (2011) includes more insights about my
journey to Australia and the settlement process as a first-generation migrant.
The first six months of our life in Perth were consumed by uncertainty, amidst fear of racism
against Asian migrants, which was at its peak during the time of our arrival, the dilemma of
losing of my native language, and the uncertainty of not knowing ways to settle down in a new
place that was both familiar and unfamiliar. I was concerned about how to develop new roots
in a new place without even knowing the names of trees in our surroundings. During this
period, much energy was spent on searching for jobs and trying to find out the Australian ways
of presenting my skills to secure a job based on my qualifications. When I arrived in Australia,
I had a bachelor’s degree in humanities, a diploma in business management and professional
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qualifications in public health and journalism, with significant work experience in community
health, rural development, project management, and journalism in Sri Lanka. I later worked
in the fields of disaster management and information technology in Thailand before my arrival
in Australia. However, despite my background and experience, I was unsure how to apply for
employment, let alone to secure a job to earn a regular income and settle down and raise our
two small children in Perth.
The first five months were devoted to searching for jobs. At one point, I even thought of doing
a second university degree specialising in social work at the University of Western Australia.
To follow this idea, I met and consulted the then head of Social Work and Social
Administration, Professor Laksiri Jayasuriya, whom I had heard of through my Sri Lankan
network of contacts. After carefully perusing my resume, his first and firm reaction was that
my desire to pursue a degree in social work to embark on a new career was futile. He said
some words to the effect: “Sunil, you must try and secure a job in the civil service here. You
are more than qualified to find a good job in the public sector in Perth. We need skilled
migrants like you in this Lucky Country!” By that time, I had applied for several jobs in various
fields with no results or even an opportunity for an interview. A few days after my conversation
with Professor Jayasuriya, I secured my first successful Australian job interview for a position
in disaster management and international relief work advertised by a non-governmental
agency in Melbourne.
My job interview took me to Melbourne where I had my first unsuccessful job interview in
Australia. I returned home by a Greyhound bus, crossing a vast stretch of land in my new
country, travelling through two States and crossing the famous, 1,100 kilometres long
Nullarbor Plain. My first journey back from the eastern seaboard to Perth, not only gave me
some insights into the arid nature of my adopted country, but also motivated me to read further
on the environmental issues that have impacted the ecosystem of Australia. While in
Melbourne, I found a brochure that described the work of a voluntary group organising a
unique conference titled “Pathways to the Future” in Perth. As soon as I arrived in Perth, I
telephoned a contact person listed on the brochure and eventually joined the group as a
volunteer. Professor David Blair, a physicist, was one of the distinguished persons amongst
the diverse professionals who formed that group. I became friends with a retired civil servant
in the group, one Mr Max Throbjonsen, a son of an immigrant, who understood my struggle to
adapt to a new way of life in a new country. My involvement with the group gave me profound
insights into environmental, social and economic issues in my adopted “home” that many
migrants might take decades to learn or perhaps never fully understand during their lifetime.
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By early December 1988, I managed to secure a civil service job successfully as an
Information Technology Planning Officer to support a new information system developed by
the Health Department of Western Australia. After six months of employment, I had the
privilege of securing a tenured position that gave me a regular income and enables to begin a
comfortable life in Perth. Though I was professionally engaged in technocratic work, I never
gave up my interest or the association with the Pathways to the Future Group as a volunteer.
I also helped the group to organise a conference targeted at high school students,
policymakers, and politicians (as keynote speakers) on topics relating to sustainable
development.
By the mid-1990s, due to organisational changes in the government sector in Perth, my first
job was made redundant. However, as I was a tenured civil servant by then, I managed to
secure another position in the same agency relating to information system development
projects. Though I was fond of technology planning work and computers, I had a strong desire
to move into other areas of interest and focus on the environment. Further, I was interested
in learning more about various environmentally friendly pathways to the future, particularly in
a State where the so-called notion of “prosperity” was entrenched, based on the success of
the mining industry. My interest and curiosity to learn further led me to undertake graduate
studies in a new field that was emerging as an academic discipline described as sustainable
development.
In early 1990, I enrolled in a master’s degree program at the Institute of Science and
Technology Policy at Murdoch University in Perth, Western Australia, where I commenced my
studies as a part-time student. By the end of the first semester, I completed two units that
taught me various issues related to science and technology policy and a second unit, a
semester-long workshop on sustainable development. Though I never had high academic
grades during my undergraduate and overseas studies, I received high distinctions for my first
two units. Perhaps it was due to my enthusiasm for learning new subjects relating to
environment-centric topics. For a new migrant who wanted to study a post-graduate course
in a new discipline with two primary school children and a partner trying to get back to her
career in medicine was not an easy task. However, we all did what we were required to do,
with our new sense of place, and I was able to complete my master’s degree with distinctions
in 1995 and continue my civil service career.
While continuing my studies and working in the field of information technology, I managed to
find employment through secondments to the Department of Transport and Perth Zoo. The
latter agency was one of the fascinating workplaces I have ever worked. Perth Zoo was then
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led by a very inspiring and future looking leader, Ms Ricky Burges. Although my primary tasks
at Perth Zoo were to develop information technology infrastructure in support of the agency’s
business plans, I had the opportunity of meeting various experts and learning about
conservation programs developed by Perth Zoo. I was fascinated by the dedicated team of
employees and volunteers who worked so hard to preserve vanishing species native to
Western Australia, such as numbats, chuditches and long-neck turtles. My experience at
Perth Zoo confirmed that the colonisation process of Australia on top of over 60,000 years of
civilisation had impacted the environment including the native ecosystem. These epiphanies
and learning various complex subjects relating to sustainable development for my master’s
degree program led me to continue to read more about the Australian environment, its fragile
ecosystem and the mining industry.
In February 1999, I received a promotion and found a new job as a Senior Consultant, System
and Technology Architecture, in the Department of Mines and Energy (DME). Over the years,
I found various public information resources about the Australian environment, and my
engagement in various personal conversations with many experts had exposed me to hitherto
unknown public information sources on the Western Australian environment. One such source
was the knowledge of various public information repositories on the mining industry and
legislation on mining. DME was one of the key government agencies, with over 100 years of
history and responsibility for regulating the mining industry in Western Australia.
The history of the department was associated with the functions it had to perform, such as
granting exploration and mining tenements for mining minerals, gas and petroleum, and
collecting Royalties. The department was established during the colonial era, first to facilitate
the development of the gold sector and collect Royalties (Spillman, 1993, Hunt, 2009). Over
the years, the agency has developed an administrative structure and, among other functions,
at present promotes and regulates the mining industry and is responsible for the development
of resources in Western Australia. By the time I went to work at the DME, a former head of
the Department had commissioned a book titled A Rich Endowment: Government and Mining
in Western Australia 1829 -1994 (Spillman,1993). The book provided me with knowledge and
information on the history of the mining industry in Western Australia, and how not only the
mining industry but the legislation and an administrative system that had evolved over a period
of 100 years. A few years later, I had the opportunity to read an audit report titled ‘Ensuring
compliance with conditions on mining’ by the Western Australian Auditor General (WAAG,
2011) and tabled in the Western Australian Parliament in 2011. According to the Auditor
General’s report, the mining regulatory compliance in WA had not functioned effectively. The
report further states that “legislation and powers are in place to enable agencies to monitor
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and enforce compliance with mining conditions. However, the way agencies have
implemented this framework means they do not provide assurance on the overall levels of
compliance with conditions, or whether the conditions deliver the desired outcomes” (p.7).
This passage in the Auditor General’s report raised many questions in my mind, as I had an
interest and some knowledge of the Australian environment by then, including a commitment
to the principles of sustainable development. The information I was gathering outside of work
helped me to develop a natural curiosity to find some answers as an independent researcher
outside the government agency framework. Three years later, this curiosity influenced me to
leave my tenured public service position to find answers to the questions in my mind about
the issues impacting Western Australia, focusing on the environment and its protection. I
wanted to explore the nature of mining laws and how they have been implemented to ensure
environmental protection in my sense of place that I had begun to call home.
There is a variety of public information sources in the mining industry in Western Australia.
Along with a few other agencies, the Department of Mines, Industry Regulation and Safety
has a rich repository of public information that also includes the evolution of the agency
structure for over a century. Its website provides the annual reports submitted to the Western
Australian Parliament. I also learned that Hansard of the State Parliament has all the debates
on legislation, including mining legislation, dating back to more than a century. In my civil
service career, I held many positions and performed a variety of roles by supporting
information systems, managing information technology projects, carrying out corporate risk
management tasks, including occupational health and safety work, except environmental
regulatory work on mining at my last place of work, then known as the Department of Mines
and Petroleum (DMP). I retired early in March 2014 from my job as I wanted to follow up on
my over two decades of interest in the environmental issues and policies informing the nature
of Western Australia and my new sense of place. This led me to ask the question: what could
an independent researcher do to identify environmental issues according to the principles of
sustainable development? I thought it was a relevant question to answer in a State where the
mining industry still plays a significant role in generating income and providing employment.
What follows is my humble best attempt to answer the research question of my independent
research in an academic environment under an excellent team of mentors in one of the best
universities in Australia: “How is the mining regulatory framework in Western Australia being
implemented legislatively to ensure environmental protection during the lifecycle of mining?
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CHAPTER ONE – RESEARCH PUZZLE
1.1 Introduction
Mining operations are inherently intertwined with economic, social and environmental issues
(Brueckner, Durey, Mayes & Pforr, 2014; Petrova, 2012; Mudd, 2007 & 2014). The current
practices of mineral extraction could have significant impact on local communities (Brueckner
et al. 2014; Brereton & Moran, 2010; Worrall, Neil, Brereton & Mulligan, 2009; Bice, 2014),
and environment (Bruckner et al. 2014; Mudd, 2010a, Mudd, 2007; Azapagic, 2004). Further,
the extent of such impacts is rising due to the need for production increases and therefore,
will contribute to the deterioration and decline of ore grades (Giurco and Petrie, 2007; Mason,
Prior, Mudd & Giurco, 2011). Declining ore grade means that more substantial amounts of
minerals of lower metal content need to be extracted to deliver each tonne of processed metal,
and contribute to lower the productivity (Topp, Soames, Parham & Bloch, 2008), causing
higher waste and generation of greenhouse gas per tonne of product (Mudd, 2009), thus,
contributing to negative environmental impacts (Mudd and Patterson, 2010).
Mining companies across the globe now use new technology and employ innovative systems
for mine operations (McLellan, Corder, Giurco, & Green, 2009), and adopt concepts such as
‘responsible mining’ (Bice, 2014), and ‘mining sustainability’ (Mudd, 2013, 2010 & 2010a) to
justify mining practices. The concept of mining sustainability has also influenced the global
mining industry. The importance of adopting sustainable mining practices is highlighted in a
report titled "Mining, Minerals and Sustainable Development" (MMSD) published by the
International Institute for Environment and Development (IIED) in 2002. The IIED report also
identifies the need for ‘social licences’ to operate mining. The MMSD report states that the
mining industry had ‘‘failed to convince some of its constituents and stakeholders that it has
the ‘social licence to operate' in many parts of the world'' (IIED, 2002, p. xiv). Further,
Danielson (2002), who presented the key issues of the MMSD report to the Extractive
Industries Review (EIR) of the World Bank highlighted the shortcomings of the initial findings:
“MMSD found that many broadly shared ideas about sustainable development in
the minerals sector simply are not correct. The only way to avoid falling into this
trap is to ensure that the EIR’s findings are based on reliable and publicly
checkable evidence” (Danielson, 2002, p. 3).
The concept of mining sustainability emerged in literature after the initiatives of the MMSD
project and critiques against some of its findings and approaches. Several academics (Hilson
& Murck, 2002; Mudd, 2013, 2010 & 2010a; Azapgic, 2004), and other organisation (GRI.
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n.d.). World Resource Institute (n.d.) have contributed to sustainable mining practices, and
reporting initiatives of the new approach (Chapter Two, Table 2.2).
Long before the identification of the need for global mining sustainability initiatives, Western
societies have introduced mining legislation to manage various aspects of mining operations
across the globe (General Mining Act 1872 (USA); State Coal Mines Act 1901 (New Zealand),
Legal Information Institute “nzlii.org”(1901). Western Australia (WA) was no exception with
the enactment of the State’s first mining law—the Gold Regulation Ordinances 1854— in the
mid-nineteenth century (Hunt, 2009, p.7). Since 1854, subsequent governments
progressively introduced mining legislation by enacting several mining laws (Mineral Lands
Act 1892; Mining Act 1904; Abstraction of Groundwater: Water and Irrigation Act 1914; Mining
Act, 1978; Environmental Protection Act, 1986; Mining Rehabilitation Fund Act, 2012). Further
to the mining legislation, now regulatory agencies in WA frequently use discourses such as
“responsible exploration” and “development of mineral and energy resources” (DMP, 2017).
However, the references to concepts such as ‘mining sustainability’, ‘corporate social
responsibility’ and ‘licence to operate’ discussed in Chapter Three are not mandatory
regulatory requirements, hence, not embodied in key legislation and regulations that come
under the mining regulatory framework (MinReF) in WA.
This chapter consists of eight sections including the preceding introduction. The second
section outlines the scope of the research project. The third section outlines the focus of the
study.1 The fourth section provides an overview of the mining industry in WA. The fifth section
states the research question and the objectives of this PhD study. Section six provides the
justification and the rationale for the research. The seventh section outlines the significance
of this research. The eighth section provides the chapter outline of the thesis.
1.2 Scope of the research project
This study investigates “how the mining regulatory framework in Western Australia being
implemented legislatively to assure environmental protection during the mining life cycle?”
The term mining regulatory framework (MinReF)—a construct developed for this study, is
defined as State and Federal legislation consisting of numerous Acts, regulations, policies and
other administrative tools implemented by government agencies. It covers century-old
legislation (Abstraction of Groundwater: Water and Irrigation Act 1914), as well as more recent
mining laws (Biodiversity Conservation Act 2016).
1 Throughout this thesis, I used the terms ‘study’, ‘research project’, ‘PhD study’ and ‘PhD project’ are
used interchangeably, and they convey the research undertaken to submit this thesis.
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This research is grounded in sustainable development principles, but it draws from other
disciplines such as public policy, mining law, theories on legal doctrine and environmental law,
regulation theory, theories of bureaucracy, and discourse analysis to understand various
theoretical approaches relevant to this study. Firstly, this thesis identifies the environmental
legislation, regulations and policies that come under the MinReF to map the scope of the
study. Secondly, the study traces the origin of mining legislation in WA which commenced in
1854, and how the regulatory framework has evolved over the years to understand the drivers
that shaped and formed the current mining laws in WA. However, the timeline of this study is
limited to an analysis of the environmental regulations of the MinReF since the enactment of
a key mining legislation; namely, the Mining Act 1978, and three State Agreements ratified in
the State Parliament in 1979. Thirdly, this study analyses the strengths and weaknesses of
the MinReF using data from a group of research participants who represent regulators,
lawyers, academics, researchers and stakeholders supported by a literature review. Fourthly,
the study reviews the problematics of defining the term of ‘best practice’ and examines how
two regulatory agencies in WA has used the terminology and provides five examples that
could be described as best practice methods examining emerging innovative practices of re-
using difficult to rehabilitate mine sites for productive human use. Finally, having identified
both the strengths and weaknesses of the MinReF, this study proposes the need to introduce
a new theoretical framework—“Adaptive Capacity for the improvement of the Mining
Regulatory Framework of Western Australia” (ADMINREF). This thesis also includes a future
research agenda, and identify, a few key areas that are important, but fall outside the scope
of this study.
This study is a phenomenological investigation exploring the evolution, the scope, and the
strengths and weaknesses of the mining regulatory framework of WA. The study, using
qualitative research methods, investigates how environmental regulations have been
implemented legislatively by examining two case studies.
1.2.1 Limitation of the research
The impact of mining operations could be examined by analysing economic, social and
environmental aspects under the principles of sustainable development as outlined in the
Brundtland Report (1987). However, this study focuses only on the environmental sphere of
sustainable development and examines only the environmental compliance of two types of
minerals, i.e. uranium and coal. The study does not examine either economic or social issues
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of “the triple bottom line” 2 concerning mining operations in WA. Through the research lenses
of case study methodology, this study investigates only a slice of the MinReF focusing on the
environmental compliance of two types of minerals, i.e. coal and uranium mining in WA. Thus,
the research does not examine legislation and regulations on other minerals such as iron ore,
mineral sands, nickel, lithium, and gas and oil (petroleum).
The MinReF that operates in its current form has evolved over a century. It has complex
regulations and not being implemented through a well-coordinated regulatory framework
(Western Australia’s Auditor General, “WAAG,” 2011). One research project cannot study
multi-faceted and complex regulatory framework examining its economic, social and
environmental impacts. Therefore, this research project investigates explicitly the
environmental regulations and compliance focusing on two case studies and the strengths
and weaknesses of the MinReF. However, it is assumed that insights gain from the findings
of the analysis of the MinReF by investigating issues such as the implementation of legislation,
mine rehabilitation and mine closure plans would help identify broader policy issues on
regulations of other minerals, and gas and oil.
1.3 The focus of the research project
Further to the analysis of MinReF, this research project focuses on the compliance of
environmental regulations of two case studies during the ‘life cycle of mining’ (Hartman, and
Mutmansk, 2002). The first case study examines the regulatory framework employed to
approve one of the four uranium mines in WA as the operation phase is yet to commence
(Cameco Australia, 2015). The Yeelirrie uranium mine is located “660km north-east of Perth
in the Goldfields region (mining-technology.com. n. d). The primary reason for selecting the
Yeelirrie uranium project is to investigate the reasons for approving this particular mine in
January 2017 under a State Agreement ratified in 1978. The other three uranium mines,
namely Kintyre, Wiluna, Mulga Rock were approved under the Mining Act 1978 (DMP, 2017)
during the Barnett Liberal government (2009 – 2017). However, the fourth uranium mine,
Yeelirrie, examined in the second case study was approved under a State Agreement (“SA”),
(Cameco Australia, 2015, p.66). The SAs are “contracts between the State and a company
seeking to develop a project, have traditionally been the vehicle used to conduct major
resource projects in Western Australia” (Hillman, 2006). Using two sets of legislation to
approve uranium mines reflects a dichotomy of mining legislation in the uranium mine approval
process of WA. Hence, it was chosen to investigate the rationale of adopting two sets of
2 The phrase “the triple bottom line” was first coined in 1994 by John Elkington, the founder of a
British consultancy called SustainAbility (Economist.com (2009).
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mining regulations to approve the same mineral. The second case study examines the
environmental compliance and consequences of coal mining in the Collie Region in South-
West Australia and managed through a State Agreement. The rationale for selecting coal
mining for one case study is due to the availability of extensive literature suggesting various
environmental impacts due to coal mining in the Collie Region (McCafferty, 2017; McCullough
& Lund, 2016; Doupé & Lymbery, 2005, Johnson & Wright, 2003). In both case studies, I also
examine other legislation relating to the issuing of mining tenements, land access, and mine
closure plans examining the environmental regulations that come under the MinReF.
The timeline of this study is limited to an analysis of the legislation, regulations and policies
since the enactment of a key mining legislation; namely the Mining Act 1978 up to 2018. The
end date of this study, February 2018, represents a judgment of the WA Supreme Court that
upheld an appeal against the approval of the uranium mine chosen for the study. The timeline
of this research project also covers two mining regulatory reform programs, first in 2009, and
the second carried out from 2012 - 2015, with the objective of improving the environmental
regulations by amending the Mining Act 1978. These two mining reform agendas helped to
gain insights into how changes to existing legislation are made, and why new ones are added
to the framework. The recent legislation added to the MinReF the Mining Rehabilitation Fund
Act 2012, was also examined to find out its jurisdiction and the effectiveness as the very first
mining rehabilitation regulation introduced after over 100 years of mining operations in WA.
1.4 An overview of the mining Industry in Western Australia
"The resource sector (mining and petroleum) is the key economic driver for the Western
Australian and Australian economy" (Government of Western Australia, 2017, p.4). There are
over 2000 approved mining tenements issued under the Mining Act 1978, and more than 1000
operating mine sites, and these have generated around A$93 billion worth of commodities
during 2016 (ibid).
Western Australia’s mining industry directly employed an average of 108,769 people during
2016–17, up from 104,553 the previous year (ibid). This figure included people employed in
mineral exploration, mine site infrastructure construction, mineral processing, mine site
surveying, transport and catering. During 2016 –17, an area of 42.5 million hectares of land
was released for mining tenements, representing “an increase of 13 per cent from 37.6 million
hectares in 2015–16” (ibid). Exploration licences accounted for about 80 per cent of the area
covered by mining tenements (ibid).
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WA is considered one of the prime investment destinations for investment in mining projects,
and has been listed among the top three jurisdictions at a global level (Fraser Institute, org.
2017). The Fraser Institute also assesses how mineral endowments and public policy factors,
including taxation and regulatory uncertainty affect mining investments. According to the
Frazer Institute’s survey, WA is the third most attractive jurisdiction for mining investments
behind Canada’s Manitoba and Saskatchewan provinces (ibid).
The economic benefits of WA's mining boom have been widely publicised and are often
emphasised (Barnett, 2014; Department of Mines and Petroleum, 2017). The vital role of the
resource sector contributes to the prosperity of the State WA is considered "one of the world's
most diverse resource jurisdictions, producing more than 50 different commodities, making it
a leading contributor to the State economy" (Smith, 2017, p. 4).
1.5 The objectives
The research question and the objectives of this PhD study examine the legislation,
regulations, and other administrative tool come under the MinReF and two case studies
focusing on the environmental sphere of the sustainable development principles as outlined
in the concept of ‘triple bottom line’ of sustainable development (Figure 1).
FIGURE 1 - THE TRIPLE BOTTOM LINE OF SUSTAINABLE DEVELOPMENT
ECONOMIC SOCIAL
ENVIRONMENTAL
Source: Elkington (1994)
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This study examines only the environmental issues relating to sustainable development
principles. It does not focus on the economic or social aspects of sustainable development
principles. The theoretical framework of mining sustainability in this thesis is supported by the
works by Bruntland (1987), Azapagic (2004); Mudd, (2010); who have examined and identified
various elements of “mining sustainability” and “sustainbility practices”. These practices
include strategies to preserve biodiversity and reduce carbon footprints, prevention of air,
water, noise pollution, and mine rehabilitation (Azapagic, 2004). However, all of these
parameters are yet to appear as mandatory conditions in mining legislation. Although this
research project is grounded in sustainable development principles, it also draws from other
disciplines such as public policy, mining laws examining legal doctrines of environmental law,
regulation theory, and discourse analysis, and the theory of bureaucracy in sociology to
understand various theoretical discourses relevant to this study.
The research undertaken for this project was carried out exploring multiple facets of the mining
regulatory framework of WA, enabling various issues to emerge through an epistemological
investigation focusing on the genesis, the evolution, its scope, and the strengths and
weaknesses of the MinReF. During the early phase of the literature review and before the
data gathering phase of the project, the complexities associated with the project became clear.
The main reasons for the complexity of this study could be attributed to four issues. First over
the existence of over one hundred mining legislation and regulations (see Chapter Five, Table
5.2 & 5.3). Second, the evolutionary nature of the State and Federal legislation, regulations
and policies that have evolved over 100 years. Thirdly, the evolutionary nature of the
framework also reveals that it is not static, and has been subjected to various changes due to
the needs of the society (Hunt, 2009, p.9). Hunt explains:
“That so many amendments have been made to the mining laws over… the years is not
an indication of massive and continuing errors in the legislation but is simply a reflection
of the willingness of the Department [DMP] and successive governments to listen to the
mining industry and make amendments of the mining laws” (ibid).
The fourth issue is, the genesis of mining laws in WA which has a direct link to the State’s
Colonial history when it was determined that the Crown own all the minerals. According to
Hunt (2009), the mining laws in Australia differed substantially from the mining laws in other
common law countries; with the most important differences arising from the policy decision
that the Crown should own all minerals (ibid, p.1). The current legislation and the formation
of agencies such as Department of Mines have also linked to the Colonial administration
(Spillman, 1993, State Records Office, n. d).
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WA’s first mining legislation, namely, the Gold Regulation Ordinance1854 was enacted to fill
a gap in the colonial administration enabling the Colonial Governor “to make regulations
concerning gold fields and [issuing] licences for working for gold” (Hunt, 2009, p.2). When the
gold was discovered, there were no laws for “governing the disposal of mineral lands” (ibid).
This need was addressed by enacting the Mineral Lands Act 1892 (ibid), and the legislation
was then owned by the then Crown Lands and Surveys Department (State Records Office,
n.d. para two).
The mining regulatory framework that exists in its present form (see Chapter Five, Table 5.2)
has evolved progressively by removing redundant legislation (Mining Act 1904, Wildlife
Conservation Act 1950), and adding new legislation on mining operations, (Mining Act 1978);
environmental protection (Environmental Protection Act 1986); land administration (Land
Administration Act 1997); and, water (Water Agencies (Powers) Act 1984). The current
legislation and regulations are assigned to different agencies carrying out various tasks
relating to mining operations. These include issuing of exploration licences, mining tenements
under the Department of Mines, Petroleum, Industry, Regulation and Safety, granting access
to land through the Department of Land, and providing licences for water and ensuring
environmental protection through the Department of Water and Environmental Regulation.
The administrative structures responsible for implementing the MinReF and the agency-
centric roles are described in Chapter Five (sections 5.6 to 5.8.1). Therefore, it is essential
to examine whether the mining regulatory framework is working in a coordinated manner, as
a number of different agencies managing various aspects of legislation and regulations come
under the MinReF. These issues will be examined by addressing the research question and
the objectives of this research projects.
1.5.1 Research question and the objectives:
1.5.1.1 The research question:
‘How is the mining regulatory framework in Western Australia being implemented
legislatively to assure environmental protection during the mining life cycle?’
The main objectives of the research are as follows:
1.5.2 Analyse the strengths and weaknesses of the current mining regulatory framework
in relation to environmental protection in Western Australia.
1.5.3 Analyse how the mining regulatory framework is being implemented in two case
study locations.
1.5.4 Identify Australian and global best practices of environmental protection relating to
mining operations and rehabilitation work.
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1.5.5 Propose ways and means of improving the Western Australian mining regulatory
framework to assure environmental protection.
In this research project, the term ‘environmental protection’ is used to denote "the prevention,
control and abatement of pollution and environmental harm, for the conservation,
preservation, protection, enhancement and management of the environment and for matters
incidental to or connected” (Government of Western Australia, 1986, p.1).
1.6 The rationale and justification of the research project
This section provides an overview of several previous works that have examined various
aspects of mining and sustainability-related research. There have been numerous studies
and research work on WA mining operations and sustainability related subjects (Pope, 2007;
Hillman, 2006; Govindarajalu, 2000). Further, there have been two State audit reports and
one Federal audit report (Western Australian Auditor General Western 2004 & 2011;
Australian National Audit Office, 2014) that have identified gaps and deficiencies of the mining
regulatory framework of WA. However, these reports have not examined either the research
questions or objectives of this study. The audit findings are discussed in Chapter Five (section
5.10.1).
Govindarajalu's (2000) research is based on a survey of a sample of mining companies, and
evaluates whether they have followed the environmental guidelines of the Department of
Minerals and Energy (DME) from the pre-mining to post-mining stages. However,
Govindarajalu's study does not examine the functionality or the effectiveness of the overall
mining regulatory framework or the environmental regulations external to the DME such as
Environmental Protection Act 1986, Environment Protection and Biodiversity Conservation Act
1999. Further, Govindarajalu's research does not include in-depth case studies investigating
the effectiveness of the environmental compliance of mining regulations.
Pope's research (2007) focuses on the sustainability assessment and policy lessons of the
Gorgon project which deals with the extraction of natural gas from the off-shore North-West
Shelf project in Western Australia. Pope’s work, therefore, out of the scope of this research.
Petrova’s research (2012) investigates the social sustainability aspects of a mining town in the
South-West region of Western Australia. Petrova's research is limited to an analysis of the
social sustainability of a mining town in WA. Flugge’s (2012) doctoral research examines the
effects of the senior manager’s performance on sustainable development. There are a few
other works on the environmental regulations of Western Australia (Chandler, 2014. Roche &
Mudd, 2014). These works appear as chapters in a monograph (Brueckner et al., 2014) on
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WA's mining operation, but it has not explicitly focused on the research question or the
objectives of this research project (Chandler, 2014. Roche, & Mudd, 2014).
This PhD study also investigates a unique set of regulations called ‘State Agreements’ (SAs)
specially designed to support large mining projects (Barnett, 1996, 2014), by granting special
benefits to companies. There are sixty four SAs, (Table 5.3), and three of them are analysed
in the two case studies in Chapter Seven. Chapter Five includes information on the merits
and demerits of SAs (Tables 5.4 & 5.5). A few previous research studies have examined the
roles and functions of the State Agreements (Hillman, 2006; Margetts, 2001; Fitzgerald, 2005
& 2002). Of the previous research, Hillman (2006) has examined the roles and future of the
SAs from a legal perspective, but did not address issues on environmental compliance through
case study methods. Fitzgerald (2005 & 2002), has researched on the use and application of
SAs in Australian States and Territories. Fitzgerald’s research work includes her doctoral
research (2002), but it does not investigate the environmental regulations of State Agreements
of WA, or their environmental compliance. Margetts' thesis (2001) examines SAs in the
context of competition policy and public interest and does not cover legislative compliance of
environmental compliance. In summary, the previous research on SAs have neither covered
any aspects of the research objectives of this study nor have examined environmental
regulations of SAs used to support large resource projects in Western Australia.
This PhD research proposes policy recommendations and includes a sample of Australian
and overseas best practices examining what lessons could be learned on environmental
protection including the re-use of difficult-to-rehabilitate abandoned mines for human use.
Although this study focuses only on Western Australian legislation and regulations, addressing
environmental compliance, the findings have national, as well as global applications. This
study contributes to policy development on environmental regulations by providing new
insights into local, national and global applications of mining practices based on the lessons
learned from WA.
In summary, previous research findings on mining sustainability-related issues have not
addressed the main research question or the objectives of this research project. This study
investigates how the MinReF being implemented as a regulatory mechanism to assure the
conditions of environmental protection during the life cycle of mining through two in-depth case
studies which have not been the focus of previous research on WA’s mining and sustainability-
related research. Therefore, undertaking an analysis of the strengths and weaknesses of the
MinReF in WA is of vital importance.
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1.7 The significance of the research
Southalan (2012) identifies three vital aspects of environmental regulations and policy issues.
They include, (a) "the inability or unwillingness of government agencies to monitor
requirements under the mining law; (b) "concerns about regulatory burdens; and (c)
"complexities (that) arise from other restrictions or controls placed … by other agencies"
(p.205). This research, while considering the above three critical issues on "environmental
regulation and policy matters" as a running thread, investigates other issues. First, this study
explores issues unique to WA mining operation and regulatory practices covering the
administration of environmental regulations through a multi-agency system. Secondly, this
study examines the effectiveness of State Agreements that are unique to Western Australia
through two case studies analysing how the uranium mines are approved, and how coal
mining operations are regulated and whether the legislation and regulations assure
environmental protection by analysing the strengths and weaknesses of the MinReF. Further,
this research study explores the effectiveness of the recently introduced mine rehabilitation
legislation (Mining Rehabilitation Fund Act 2012).
Of the issues identified in this study, I have examined them in the context of gaps in
environmental compliance of mining regulations as identified by the Western Australian
Auditor General (WAAG, 2011). The Auditor General’s report entitled Ensuring compliance
with conditions on mining (2011) notes that the “legislation and powers are in place to enable
agencies to monitor and enforce compliance with mining conditions. However, the way
agencies have implemented this framework means they do not assure the overall levels of
compliance with conditions” (p.7). This PhD project investigates the reasons for the absence
of the overall level of compliance with environmental regulations through two case studies
(Chapter Seven), supplemented by an analysis of the strengths and weaknesses of the
MinReF (Chapter Eight), as research objectives. The analysis of the MinReF examines how
the environmental regulations have been implemented through multiple agencies, and
whether the current implementation system presents complexities and restrictions, or whether
controls are placed by other agencies as highlighted by Southalan (2012, p.205). Further,
such an analysis also provides an opportunity to propose specific policy recommendations by
examining the current gaps and deficiencies of existing regulations in a policy context and why
the regulatory framework does not provide evidence to assure the overall levels of compliance
as noted by the Auditor General (WAAG, 2011, p.7).
This thesis not only examines the reasons for the lack of overall assurance of compliance but
also proposes ways and means of improving the gaps and deficiencies of the existing
regulations. Thus, this research project is relevant and significant in a State which is highly
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dominated by mining for its income from the Royalties from mining companies. For example,
WA's gross state product (GSP) of $247.7 billion during 2016 – 17 contributed to 14% of
Australia's gross domestic product (GDP), (Government of Western Australia: Department of
Jobs, Tourism, Science and Innovation, 2018, para two). The revenue from mining Royalties
collected accounted for 29% of GSP in 2016 - 17 (ibid).
The mining industry in WA has entered into new mining ventures such as ‘fracking". Studies
have been commissioned, examining scientific approaches to measure the effectiveness of
emerging mining activities (EPA, 2014). Although this study only focusses on the regulatory
framework regarding coal and uranium, the findings provide new and independent insights
would be valuable to supplement existing knowledge on the effectiveness of the overall mining
regulations in WA and elsewhere.
The thesis also analyses the notion of best practices to explore innovative ways to restore the
health of the land affected by mining as WA has 17,000 abandoned mines (Government of
Western Australia: Media Statement, 2014) due to the legacies of the past mining activities.
Concerning theory development, this research contributes in two ways. First, it examines
relevant theories such as public interest policy (Ogus, 2004 & 2004a); legal doctrines (Hoecke,
2013), discourse analysis (Stubbe, Lane, Hilder, Vine, Vine, Marra, Holmes & Weatherall,
2003), and regulatory design principles (Gunnigham and Sinclair, 1999) to examine various
facets of the environmental legislation and regulations come under the MinReF. Second, this
study contributes to a new theoretical framework—Adaptive Capacity for the Mining
Regulatory Framework of Western Australia (ADMINREF) to address the current gaps and
deficiencies of the MinReF and is discussed in detail in Chapter Eight (Section 8.11 and Figure
8.4). This thesis includes a series of recommendations and a future research agenda.
Insights gained from this study would be useful to examine other mineral and petroleum (gas
and oil) regulations that are not addressed in this study. However, the findings and insights
gained from this PhD study would be useful to investigate other projects operated under State
Agreements and legislation not analysed in this research.
1.8 Thesis structure
Chapter One: Introduction summarises the background and the context, the theoretical
framework, scope and the research objectives, limitation of the research, the justification and
significance of the study.
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Chapter Two: Review of the global policy drivers on mining focuses on the first two
transdisciplinary areas outlines the literature on sustainable development that shapes the
overall environmental policy drivers at a global, and Australian levels.
Chapter Three: Theoretical background discusses some key theoretical approaches and
introduces concepts such as corporate social responsibility, and licence to operate the theory
of bureaucracy, legal doctrine, the rule of law and discourse analysis.
Chapter Four: A literary review addresses several theoretical approaches covering mining
law, environmental law, public policy, politics of resource development and regulation theory
that helped to examine various facets related to this study to gain insights into the mining
regulatory framework in Western Australia.
Chapter Five: History of mining legislation in Western Australia and key issues
describes the genesis, evolution of the mining regulatory framework including a description of
legislation and regulations concerning environmental compliance.
Chapter Six: Methodology and methods, describes the methodology of this study with
details on qualitative research and case study method, the techniques used for data collection,
coding, and analysis.
Chapter Seven: Two case studies investigate issues relating to the approval of a uranium
mine, and coal mining in Western Australia focusing on how the environmental regulations
have been implemented to approve, operate and development of mine closure plans.
Chapter Eight: Strengths and weaknesses of the mining regulatory framework analyse
the mining regulatory framework. The chapter also includes the findings of the research
project, and a theoretical model proposed to address the gaps and weaknesses of the
framework.
Chapter Nine: Best practice models and environmental regulatory strategy of Western
Australia discusses the problematics of defining the terminology and examines WA
environmental strategies against the regulatory design principles. The second part of the
chapter provides five examples of Australian and European ‘best practice’ cases that could
successfully function outside government regulatory systems.
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CHAPTER TWO REVIEW OF LITERATURE ON GLOBAL POLICY DRIVERS ON MINING
2.1 Introduction
In this study, a systematic literature review was carried out to identify previous research,
relevant peer-reviewed academic journals and other literature including legislation, regulations
and policies that form the Mining Regulatory Framework (MinReF) of Western Australia (WA).
This literature review identifies various State and Federal legislation (See Tables 5.2 and 5.3),
and other vital theoretical discourses relevant to this study. The literature review in this
chapter also includes sections providing several theoretical discourses to understand the WA
bureaucracy3 responsible for implementing legislation and regulations that fall within the
MinReF. The literature review also provides insights into the complexities of mining legislation
which cannot be examined using a single discipline. Thus, this literature review includes
multidisciplinary subjects covering theories on sustainable development, public policy,
regulation theory, mining laws encompassing legal doctrines and environmental law. It also
provides insights into the discourses represented by agencies responsible for the
implementation of the MinReF. The agency narratives are examined using theoretical frames
and disciplines drawing from literature on critical discourse analysis (Stubbe et al., 2003 &
Fairclough, 1995) and theories of bureaucracy (Weber, 2015). Using multidisciplinary
approach is in alignment with Pezzoli (1997), and Todorov & Marinova (2010) ]who emphasise
the requirement “to break the silos of disciplinary research”, highlighting the need to adopt
“methodologies and techniques that allow transdisciplinarity” (ibid, p.3) to examine issues
relating to sustainable development.
The literature and theories relevant to this research project cover five transdisciplinary areas:
(i) sustainable development (ii) public policy; (iii) regulation theory; (iv) mining law
encompassing legal doctrines and environmental law, and (v) sociology focusing on the
theories of critical discourse analysis and bureaucracy. This chapter deals with the first two
disciplines that shape the overall environment policy drivers at a global, Australian and
Western Australian level. The following two chapters discuss the theoretical background and
legal frameworks for understanding the link between mining and environmental protection in
WA.
3 I am using the term “bureaucratic/bureaucracy” in this study in the context of the work of German
sociologist Max Weber (2015) Weber, M. (2015) "Bureaucracy" in Weber's Rationalism and Modern
Society, translated and edited by Tony Waters and Dagmar Waters, Palgrave-Macmillan. p. 114.
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2.2 Sustainable development
This section first identifies key literature on the genesis of sustainable development as a
development paradigm and the emergence of concepts such as mining sustainability. It then
identifies the origins of global drivers on sustainability agreements and frameworks that led to
the incorporation of sustainable development principles into the mining industry examining
global drivers. The terms ‘sustainable development’ (SD), and ‘sustainability’ are used
interchangeably throughout the text with both concepts conveying the principles of SD. The
literature on corporate social responsibility and social licence to operate is reviewed to position
mining within the changing conceptual environment. Finally, global drivers of sustainable
development which have influenced the Australian mining activities are examined.
2.2.1 Genesis and emergence of sustainable development as a new paradigm
The genesis and the emergence of the term “sustainable development” could be traced back
to the United Nations Conference on Human Environment (UNCHE), held in Stockholm in
1972 (Dresner, 2012). The UNCHE led to the formation of the World Commission on
Environment and Development (WCED). The report published by the WCED commonly
known as ‘Our Common Future’ (1987) defined sustainable development as “development
that meets the needs of the present without compromising the ability of future generations to
meet their own needs” (United Nations General Assembly, 1987, p. 43). Since then, hundreds
of alternative definitions of sustainable development have emerged (Zeijl‐Rozema, Cörvers,
Kemp & Martens, 2008; Dempsey, Bramley, Power, & Brown, 2011; Kommadath, Sarkar, &
Rath, 2012). They aim to apply SD principles to a variety of established and emerging
disciplines as a new paradigm (Pearce and Walrash, 2001). Following the scope of this
research, SD “requires a nation to consider and protect the environment and natural resources
on which its current and future development depend. The connections between the
environment and development thus provide a powerful rationale for environmental protection:
enlightened self-interest” (Dernbach, 1998, p.20).
The original definition of SD is not sufficient for the mining industry which is dependent on
non-renewable resources. However, WCED highlights that “fossil fuels and minerals, their
use reduces the stock available for future generations. However, this does not mean that
such resources should not be used” (United Nations General Assembly, 1987, pp.45-46). It is
important to recognise that even before the publication of the WECD (1987), there had been
significant initiatives on environmental and ecological preservation. This trend could be traced
back to Rachel Carson’s classic ‘Silent Spring’ (1962) first published as three serialised
essays in the New Yorker Magazine (Carson, 1962). Table 2.1 lists the emergence and
evolution of the sustainable development concept at the global level. It provides evidence to
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work that has gone into identifying and contributing to numerous initiatives on SD goals and
strategies since Rachel Carson’s ‘Silent Spring’ was published. After the publication of
Carson’s work, many global initiatives commenced. In 1971, the International Institute for
Environment and Development (IIED) was established in the United Kingdom which
developed IIED strategies promoting programs for countries to make economic development
without destroying the natural environment. (www.iied.org). In 1972, the United Nations (UN)
held a conference on the Human Environment where the term “sustainable development” was
adopted (Dresner, 2002). The following year, the UN established the United Nations
Environment Program (UNEP), and it remains as the UN’s primary policy coordinating agency
on the environment (www.unenvironment.org). Amidst UN endeavours, the non-governmental
agencies also emerged in the West, initiating various programs focusing on the environment.
For example, the Greenpeace movement was established in Canada in 1971, and the
Worldwatch Institute was established in the United States in 1975.
In 1987, the UN published its pathfinding report, commonly known as Our Common Future,
on sustainable development. In 1988, the UN initiated the Intergovernmental Panel on
Climate Change (IPCC). Another two landmark events initiated by the UN were the Earth
Summit held in Rio de Janeiro and development of the Kyoto Protocol both of which took place
in 1992 (United Nations Framework Convention on Climate Change “unfccc”, 1998). The
importance of the Earth Summit was the development of a treaty committing member nations
to reduce individual nations’ greenhouse gas emissions through national level action plans
and strategies which came to know as Agenda 21. Agenda 21 highlighted the threat of
greenhouse gas emissions and its contribution to climate change due to anthropocentric
activities. (sustainabledevelopment.un.org, June 1992). Further development of such global
action led to the initiatives of the development of the UN Sustainable Development Goals and
the Paris Agreement (United Nations Framework Convention on Climate Change, n.d).
These global initiatives marked a global consensus about the importance of sustainability as
a pragmatic philosophy for development. Reporting on sustainability performance also
emerged through establishing systems of indicators and targets. Decarbonising the economy
became a primary concern as well as an opportunity for new business initiatives within the
framework of the green economy. This led to the World Economic Forum’s 2018 report on
the importance of the environment in the creation of global value chains (wefrom.org, n.d.).
These global milestones are listed in Table 2.1.
Within the new paradigm of sustainable development as the integration of economic, social
and environmental issues, there are numerous arguments for and against its applicability to
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the mining industry (IIED, 2002). The 2004 framework for sustainable development indicators
for the mining and minerals industry (Azapagic, 2004) was followed by specific reporting
guidelines (GRI, 2010). Although the SD principles and frameworks have been applied to a
variety of other fields, including planning and forecasting, public transportation, measuring
urban sustainability, automobile dependency in global cities, planning urban landscapes,
fostering sustainable behaviour in social marketing and environmental protection (McKenzie-
Mohr, 2000), the challenges for the mining industry remain. By its nature, these activities rely
on extracting unrenewable resources. Many argue that the original definition of SD as
articulated in the WCED (1987) report has been distorted (Holden, Linnerud & Banister, 2014)
and question its applicability to mining.
Irrespective as to how sustainability is being reconciled with the mining of natural resources,
what this thesis analyses is specifically the environmental provisions associated with the
operation of mines. This particular perspective within the broad spectrum of sustainability
issues related to mining is of high importance, particularly given the fact that all mines operate
within a life cycle (Hartman, and Mutmansk, 2002). The legal frameworks that ensure
environmental protection during and after the mining operations are the particular focus of this
study and they are rooted within broader conceptual principles of sustainable development.
Before tackling environmental protection in the case of mining in Western Australia, it is helpful
to shed light on the emergence and evolution of the sustainable development concept. (Table
2.1).
.
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1987 The UN published the “development that meets the needs of the present without compromising the
WCED Report commonly ability of future generations to meet their own needs” (United Nations General
known as ‘Our Common Assembly, 1987).
Future.
1987 The International Court of A milestone legal judgment by the then head of the International Court of Justice
Justice based in the Hague based in the Netherlands. The ruling was made on the relationship between the
made a landmark judgement ‘right to development’ and the concept of sustainability
relating to sustainability. (Source: Singh, 1988)
1988 The Intergovernmental The IPCC began to evaluate up-to-date scientific, technical and socio-economic
Panel on Climate Change research data on global climate change effects.
(IPCC) was established. (Source: www.ipcc.ch).
1990 International Institute for The IISD commenced publishing the “Earth Negotiations Bulletin” (ENB); the first
Sustainable Development report was published in 1992.
(IISD) was established in (Source: International Institute for Sustainable Development, n.d.)
Canada.
1991 Global Environment Facility The Global GEF began its operations in 1991 as a three-year pilot project
(GEF), a functional unit of sponsored by the United Nations Development Programme, the United Nations
the World Bank, was Environment Programme, and the World Bank.
established. (Source: www.gefweb.org; www.worldbank.org)
1992 United Nations Conference, The UN Framework Convention on Climate Change (UNFCCC) is an international
Earth Summit was held in environmental treaty, and it was adopted on May 9, 1992. The treaty was
Rio de Janeiro from 3 to 14 available for signature at the Earth Summit in Rio de Janeiro from 3 to 14 June
June 1992. 1992 and enforced on 21 March 1994. The treaty commits member nations to
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reduce individual nations greenhouse gas emissions through national level action
plans and strategies. Agenda 21 was adopted.
(Source: www.un.org)
1993 The first meeting of the UN A key follow-up of the conference was to ensure international cooperation through
Commission on Sustainable intergovernmental decisions to promote national SD work.
Development (SD) was (www.un.org/esa/sustdev)
established.
1994 The Global Environment The objective of the GEFWEB was to enable effective decision-making power to
Facility (GEFWEB) was developing countries by granting billions of aid dollars to initiate projects on
established. biodiversity, water, climate change, land degradation.
(Source: www.gefweb.org)
1994 China published a white The white paper identified the country’s development, population, environment.
paper titled, Agenda 21 on China’s example was considered as a global example for developing national
the country’s challenges on strategies for SD.
SD. (Source: www.iisd.org)
1995 The World Trade The agenda for the WTO included environmental linkages to global trade on
Organization (WTO) was environment and development.
established. (Source: worldtrade.org)
1996 The International Standard The ISO 14001 is a voluntary international standard to facilitate corporate
Organisation (ISO) 14001 environmental management (Source: www.iso.org)
was formally adopted.
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concept first introduced by
John Elkington.
2005 The International Mineral The presentations of the conference are published as a book titled A review of
Processing Council (IMPC) indicators of sustainability for the minerals extraction industries
meeting held in Antalya, (Source: Bôas, Shields, Šolar, Anciaux, & Önal, 2005)
Turkey, (October 13-14,
2005). Chaired by Professor
Dr Güven Önal of the
Istanbul Technical
University.
2005 The initial Millennium The MEA report with input from 95 countries provided scientific information on the
Ecosystem Assessment consequences of ecosystem changes and the impact on human well-being.
(MEA) was published. (Source: www.millenniumassessment.org)
2008 The Green economy National governments commenced investing a portion of their national income as
concept entered the a stimulus for environmental and low-carbon initiatives.
mainstream. (Source: www.oecd.org)
2009 Copenhagen climate The conference participants were unable to reach an agreement on the emissions
negotiations conference reductions of new GHG levels beyond 2012.
was held. (Source: www.iisd.ca)
2010 Global Reporting Initiative The Mining and Metals Sector Supplement was released including reporting tools
(GRI) for the mining industry.
(Source: www.globalreporting.org)
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2.2.2 The emergence of the mining sustainability concept
The sustainable development principles and framework outlined in the WCED (1987), and
endorsed by the United Nations have influenced governments, global corporations and non-
governmental agencies to respond to the challenges and adopt new strategies on protecting
the environment. After the 1992 Rio Earth Summit, several global bodies responded jointly to
the “pressure to improve” strategies on sustainable development and the mining industry
(Mining, Minerals and Sustainable Development program. n.d., para five). The Mining,
Minerals and Sustainable Development program was one of them (ibid). As a result, nine of
the largest global mining companies embarked on a new initiative in late 1998 aimed at
achieving a series of changes to the way the industry operates including global reporting on
corporate sustainability reporting.
The academic world also responded to this global trend. For example, Professor Warhurst
(2002) of the University of Warwick produced a pathfinding report on Sustainability Indicators,
and Sustainability Performance Management. Further, Azapagic (2004) highlighted the need
to measure the “environmental and economic integrated indicators” under the umbrella of
sustainability. Specifically, he argued for the need for reporting on “per unit mass of mineral
various/products sold and per unit value-added, respectively” (Azapagic 2004, p 661). Private
sector business enterprises and governments also considered the need for incorporating
sustainability principles into their strategies and work plans (globalreporting.org, n.d). These
considerations were supported by a milestone legal judgment made by the then head of the
International Court of Justice based in the Netherlands in 1987. The ruling was made on the
relationship between the ‘right to development’ and the concept of sustainability:
“The imperative of sustainability has to be recognised in relation to any right to
development. Given these considerations, there would seem to be three broad elements
of sustainability which qualify the right to development, and which can be listed as
follows:
(i) sustainability in relation to resources available for present and future
generations;
(ii) Sustainability in relation to an adequate and healthy environment;
(iii) Sustainability in relation to the community – the concept of ‘international
commons’ and safeguarding the “common heritage of mankind” (Singh, 1988,
p. 5).
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Judge Singh’s ruling is considered a landmark decision as it provides a legal basis for
sustainability and the “common heritage of mankind”. The concept of ‘mining sustainability’ is
relatively a new and diverse interpretation with different opinions, views and controversies
(Fonseca et al.; 2013; Azapagic, 2004; Mudd, 2007). Fonseca et al. (2013) highlight the
presence of “20 records of frameworks” to measure mining sustainability citing the Global
Compendium of Sustainability Indicators Initiatives (p. 180). Azapagic (2004) further
highlights the need to measure sustainability activities embracing concepts such as a ‘licence
to operate’. On the other hand, Mudd (2007) raises the question: “How on earth do we really
assess the sustainability of mining and move beyond rhetoric and policy to really understand
this debate?” (Mudd, 2007, p. 27). It is evident that there are unanswered issues and further
questions to examine the concept of mining sustainability. Mudd (2007) notes:
“At first 'Sustainable Mining' is often perceived as a paradox - minerals are widely held
to be truly finite resources with rising consumption causing pressure on known
resources. The true sustainability of mineral resources, however, is a much more
complex picture and involves exploration, technology, economics, social and
environmental issues, scientific knowledge and so on – predicting future sustainability is
therefore not a simple task.” (Mudd, 2007, p.1).
Kirsch (2010) provides critical views on the concept of sustainable mining stating that the term
is used too often as a corporate oxymoron and one of the key strategies corporations use to
justify their activities:
“The mining industry moves more earth than any other human endeavour. Yet mining
companies regularly claim to practice Sustainable Mining. Progressive redefinition of the
term sustainability has emptied out the concept of its original reference to the
environment. Mining companies now use the term to refer to corporate profits and
economic development that will outlast the life of a mining project. The deployment of
corporate oxymorons like Sustainable Mining is one of the key strategies corporations
use to conceal harm and neutralize critique” (Kirsch, 2010. p. 88).
Nevertheless, the International Council on Mining and Metals (ICMM) disagrees on academic
debates on mining sustainability. The ICMM argues that the global mining sector has a vital
role in promoting sustainable development. According to the Council, mining, similar to many
other anthropocentric activities should be “undertaken in such a way that the activity itself and
the products provide a net positive long-term contribution to human and ecosystem well-being”
(International Council on Mining and Metals, 2012, p. 5). The ICMM’s ethos on sustainable
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development is stemming from a framework that explains ten principles of sustainable
development declared in 2003 (see Table 2.2). Two of these principles, namely the principles
six and seven relate directly to environmental protection and should guide mining activities as
well as the legislative frameworks that support them.
TABLE 2.2 PRINCIPLES OF MINING SUSTAINABILITY
Principle GOAL
Principle Apply ethical business practices and sound systems of corporate
1 governance and transparency to support sustainable development
Principle Integrate sustainable development in corporate strategy and decision-
2 making processes
Principle Respect human rights and the interests, cultures, customs and values
3 of employees and communities affected by our activities
Principle Implement effective risk-management strategies and systems based
4 on sound science and which account for stakeholder perceptions of
risks
Principle Pursue continual improvement in health and safety performance with
5 the ultimate goal of zero harm
Principle Pursue continual improvement in environmental performance issues,
6 such as water stewardship, energy use and climate change
Principle Contribute to the conservation of biodiversity and integrated
7 approaches to land-use planning
Principle Facilitate and support the knowledge-base and systems for
8 responsible design, use, re-use, recycling and disposal of products
containing metals and minerals
Principle Pursue continual improvement in social performance and contribute
9 to the social, economic and institutional development of host countries
and communities
Principle Proactively engage key stakeholders on sustainable development
10 challenges and opportunities in an open and transparent manner.
Effectively report and independently verify progress and performance
(Source: International Council on Mining and Metals, 2003)
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TABLE 2.3 A SUMMARY OF THE EVOLUTION OF GRI AS A GLOBAL DRIVERS OF SUSTAINABLE REPORTING
YEAR INITIATIVES COMMENTS
1997 GRI was founded in Boston, the USA in 1997. The genesis of the GRI goes back the US NGO; the Coalition for
Environmentally Responsible Economies (CERES) and the Tellus Institute.
1998 GRI established a multi-stakeholder Steering Steering Committee agreed to focus on activities to do more than on
Committee to develop the organization’s environment.
guidance.
2000 GRI launched the first version of the GRI This Guideline incorporated the first global framework for comprehensive
Guidelines. sustainability reporting.
2001 GRI became an independent organization.
2002 Ernst Ligteringen was appointed as the Chief The GRI was relocated to Amsterdam, the Netherlands.
Executive, and
the GRI Board of Directors was appointed.
The second generation of the Guidelines, G2,
was launched. The G2 Guidelines also
included the public feedback received from
the first version of the GRI’s technical
guidelines.
2003 GRI’s Organizational Stakeholders Program The GRI Stakeholder Council was formed – the formal stakeholder policy forum
was launched, enabling core supporters to to advise the Board of Directors.
champion GRI’s mission and contribute their
expertise to GRI’s work.
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2005 GRI formed an advisory committee to provide
high-level technical advice and expertise to
maintain the overall quality of the Framework.
2006 GRI G3 Guidelines were launched with an This year marked developing formal partnerships with the UNGC and the
emphasis on the materiality principle. OECD.
GRI’s first Global Conference on
Sustainability and Transparency took place:
‘Reporting: A measure of Sustainability’.
2007 A Regional Hub in Brazil was established. GRI activities were expanded to South America.
2008 GRI held its second Global Conference titled A regional hub in Australia was established.
‘Sustainability Reporting Today: The Readers’
verdict’.
GRI Governmental Advisory Group was
established.
2009 GRI expanded its services by providing A GRI Regional Hub in China was established, the first of its kind in Asia.
certified software and tools, i.e. GRI certified
software and tools program.
2010 GRI published: (a) GRI and ISO 26000: How One of the outcomes of the third GRI conference was the signing a
to Use the GRI Guidelines in Combination memorandum of understanding between GRI and the UN Global Compact that
with ISO 26000; (b) Carrots and Sticks – was signed during the conference.
Promoting Transparency and Sustainability.
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2014 Launched GRI’s content index services to The following (GRI) organizational changes took place:
facilitate validation of accuracy and alignment
of G4-based reports. The creation of a new organizational entity was established.by separating GRI
standard-setting work and all other organizational activities.
A publication titled Ready to Report? aimed at The new organisational entity led to the creation of a new Global Sustainability
SMEs to consider the relevance for Standards Board and, an oversight committee, and also an independent
sustainability reporting in the SMEs appointments committee.
Independent public funding solely for
standards-setting activities was established.
Continued the expansion of global activities
by setting up the GRI’s seventh focal point in
Colombia.
A new Chief Executive (Michael Meehan) was
appointed.
2015 GRI developed improved certification of The GRI certification exam is offered in more than 70 countries.
reporting procedures.
Launched an exam for G4 formulated 60 The report explores materiality from the SD reporter’s perspective, using data
multiple choice questions enabling individuals from fields covering technology hardware & equipment, and banking issues.
to gain accreditation and evaluate the ability
to use GRI’s G4 Guidelines.
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2.4 The impact on the global sustainability drivers in the Australian mining
sector
The development of global reporting initiatives had an impact on mining sustainability
work in Australia. For example, several organisations associated with the mining
industry have developed dialogues through regular conferences to discuss further
exploring how Australian mineral sector could contribute to global initiatives on
sustainable development through the work of The Australasian Institute of Mining and
Metallurgy (AusIMM), the Sustainable Minerals Institute (SMI), and the Centre for
Sustainable Resource Processing (CSRP).
Founded in 1893 and with a current membership of 13,000 members drawn from all
sections of the industry and supported by a network of branches and societies in
Australasia and internationally (AusIMM, n.d., para one), the Australasian Institute of
Mining and Metallurgy provides services to professionals engaged in all areas of the
global resources sector. It is the national peak body working towards a culture of
promoting and increasing the knowledge of sustainability among the practitioners.
Rather than viewing sustainability from purely a company perspective, the AusIMM
sees it as a requirement for all professionals within the industry (Keogh, 2009, p.90)
in response to the changing times and new opportunities.
The Coalition for Energy Efficient Comminution (CEEC) is another independent body
established by a group of leaders of the mining industry. The CEEC provides a forum
for effective communication about the latest technical findings to its members
(Coalition for Energy Efficient Comminution, n.d.). These new technological findings
raise awareness and provide programs on improved engineering designs covering a
range of subjects such “improved blasting, crushing and grinding techniques” that
helps to “lower project costs, and improve energy efficiency.” (Ibid, n.d., para two &
three).
These organisations have developed and contributed to sustainable development
practices and training for the Australian minerals industry (AMI, 2009, CCEE, n.d).
Regular industry events, such as conferences, awareness and training programs
emphasise improving “the capacity of the [Australian] minerals sector to contribute to
the global goal of sustainable development.’’ (AusIMM, n.d, second para) are held for
the benefits for the members regularly.
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