Market Survey on Copper - Indian Bureau of Mines

2. Corporacion Nacional del Cobre de Chile (Codelco) or National Copper
Corporation of Chile
Codelco Norte
Codelco Norte is a division of Codelco that is made of the Chuqicamata and
Radomiro Tomic mining areas.
i) Chuquicamata
Copper has been mined for centuries at Chuquicamata as was shown by the
discovery in 1898 of "Copper Man", a mummy dated at about 550 A.D. which was
found trapped in an ancient mine shaft by a fall of rock. However mining on any
scale did not start until the later years of the XIX Century and these early operations
mined the high grade veins (10-15% copper) and disregarded the low grade
disseminated ore.
The Modern Mine
Chilex (The Chile Exploration Company) then went ahead with the
development and construction of a mine on the eastern section of the Chuquicamata
field - it acquired the remainder gradually over the next 15 years - and a 10,000 tons
per day leaching plant which was planned to produce 50,000 tons of electrolytic
copper annually.
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 is becoming
gradually uneconomic and it was estimated that mining would slow down and stop by
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