leaching plant which was planned to produce 50,000 tons of electrolytic copper annually. Amongst the equipment purchased were steam shovels from the Panama Canal. A port and oil-fired power plant were built at Tocopilla, 90 miles to the west and an aqueduct was constructed to bring water in from the Andes. Production started on May 18, 1915. Actual production rose from 4345 tonnes in the first year to 50,400 tonnes in 1920 and 135,890 tonnes in 1929 before the Depression hit and demand fell. The Guggenheims gave up control of the mine in 1923 when they sold 51% to Anaconda Copper, which acquired most of the remainder in 1929. Anaconda ran the mine until the 1960s when the Chilean state acquired a 51% holding in the "Chilenization" of the copper industry. In 1971 the mine was nationalised and in 1976 was incorporated into Codelco. Production from the capping of oxidised minerals, which required mere leaching in sulphuric acid to dissolve the copper and the recovery of the copper by electrolysis was the sole means of production until the 1950s. However their gradual depletion forced the construction of a mill and flotation plant in 1961 to treat the underlying secondary sulphides. These have been steadily expanded until recently the pit was producing over 600,000 tonnes of copper annually, though this has now fallen with the lower grades as the richer secondary mineralisation is also depleted in the three porphyries that make up the orebody. The present mine is a conventional truck and shovel operation, with a large proportion of the ore crushed in-pit and transported by underground conveyors to the mill bins. The 182,000 tonnes p.a. concentrator is also conventional and is primary crushing followed by SAG mills and ball mills with cyclone classification. The flotation section produces both copper and molybdenum concentrates. The 1.65 million tonnes p.a. of concentrate are smelted in one Outokumpu flash smelter and one Teniente converter with electric furnace and cylindrical slag cleaning followed by four Pierce Smith converters. The blister copper goes to six anode furnaces which feed three anode casting wheels. The anodes go on to the 855,000 tonnes p.a. electrolytic refinery. The future of Chuquicamata Plans to go underground and mine the rest of the Chuquicamata orebody by block caving are now well advanced. At the SIMIN conference in 2007 in Santiago Codelco engineers detailed a possible future mining plan. The open pit