Impurities in the particle are also present in anhydrite due to magnesium content, which can be explained according to Table , where anhydrite has an MgO content of 0.3 %. In general, the leaching kinetics of magnesium from anhydrite is slower, which is shown by the steady increase in the ion concentration. Leaching is therefore not completed after 24 hours. Likewise, no significant difference can be observed between the stoichiometric ratios. Thus, there is no advantage for anhydrite with increased acid addition. A similar process can be seen with talc as a magnesium source. A stationary state is also not reached after 24 hours of leaching. However, a greater discrepancy can be seen between the stoichiometric ratios. After 24 hours of leaching, the magnesium content for 𝑆𝑡 = 1.0 is 277.6 mg L -1 and 24% higher than for 𝑆𝑡 = 0.2. For MgCl2 the solubility is with 543 g L -1 as with CaCl2 much higher than the measured values. This means that only the chemical equilibrium is the limiting factor . However, this is not appropriate in relation to the 5-fold acid quantity. It is therefore also true for talc that the higher acid content does not increase the magnesium yield to the same extent as the amount used. A lower acid input therefore has a higher efficiency. A comparison of the leaching times with calcium in Figure shows a more sluggish behavior. Even after 24 hours, there is still no stationary leaching state. It is irrelevant whether the magnesium ions are dissolved from the mineral anhydrite or talc. The curve is identical for both minerals. The relationship between the minerals can be analysed in more detail by means of regressions using equation (6). The regression parameters are shown in Table . When comparing the different parameters of calcium leaching from anhydrite, it can be seen that the values differ only in the stationary concentration 𝐶 ∞,𝐶𝑎,𝐴𝑛ℎ𝑦𝑑𝑟𝑖𝑡𝑒 . The rate 𝑘 𝐶𝑎,𝐴𝑛ℎ𝑦𝑑𝑟𝑖𝑡𝑒 is identical for all stoichiometric ratios, which underlines the independence of 𝑘 𝐶𝑎,𝐴𝑛ℎ𝑦𝑑𝑟𝑖𝑡𝑒 from the amount of acid added. For talc, the regression shows no significant differences for any stoichiometric ratio. This proves that calcium leaching is independent of the amount of acid used. Overall, the calcium leaching process can be modeled by equation ( ) independent of the particles used, and the solubility in distilled water, the final concentration and the rate can be derived directly from the regression.