Market Survey on Copper - Indian Bureau of Mines

2020. In the meantime the mill will be kept up to its 182,000 tonnes per day capacity
with sulphides from Radomiro Tomic and Alejandro Hales. The underground mine
will start up in 2018 and when it reaches full capacity of 120,000 tonnes per day in
2030, the balance of the tonnage will come from the Alejandro Hales underground
mine. It is estimated that extractable underground reserves below the present pit total
1,150 million tonnes of ore gradeing 0.76% copper and 0.052% molybdenum.
This remarkable mine was for many years the world's largest annual producer
until overtaken recently by Escondida and it is one of the largest ever copper mining
excavation. It has produced over 29 million tonnes of copper in total, far more than
any other mine.
ii) Radomiro Tomic
The Radomiro Tomic deposit, 5 km north of the main pit, was discovered in
1952 after an extensive churn drilling programme to explore for oxidised ore to the
north of the Chuquicamata pit. It was named Chuqui Norte but they did not develop it,
largely because the technology had not been developed, particularly SX/EW. Two
smaller areas of interest were found and the overall results showed that the
Chuquicamata complex of mineralised porphyries is no less than 14 km long.
The deposit is covered with some 100 metres of alluvium and in 1993/94
Codelco estimated a resource base for the operation of 802 million tonnes of oxide ore
grading 0.59% copper and 1,600 million tonnes of refractory (sulphide) ore. The
deposit covers an area of 5 km x 1.5 km.
Mining started in 1997 and is again a conventional truck and shovel operation
followed by crushing, pre treatment and stacking before acid leaching. Copper is
extracted by SX/EW. Leached ore is removed by bucket wheel excavator followed by
secondary leaching. It is likely that the 'refractory' sulphide ore will be mined and
used to keep the Chuquicamata mill full during the changeover to underground
mining.
Northern Expansion of Mina Sur
Between the main pit and Mina Sur there remains a substantial tonnage of socalled
exotic copper in the channel of paleogravels (ancient gravels) between the two
and which were mined in Mina Sur. The minerals, thought to be deposited by
colloidal copper solutions leached from the main deposit, included manganese bearing
copper pitch and copper wad, along with other impurities which made the ore difficult
to leach in the original vats and produced a substandard cathode. The 'exotic' ore is
now being heap leached and the copper extracted by SX/EW which leaves the
impurities behind in the leach solution. It is expected that this operation will produce
129,000 tonnes of good quality copper cathode annually.
Secondary Waste Dump Leach
This is the leaching of certain copper bearing waste dumps and is expected to produce
26,000 tonnes of copper annually.
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