Collahuasi produces copper concentrate, copper cathodes and molybdenum concentrate from three open-pit mineral deposits in the Andean plateau of the far north of Chile.
The company produces principally copper concentrate. This semi-processed raw material accounts over 90% of the company's output and is shipped to customers for the final stage of processing.
In 2009, Collahuasi produced a record 535,853 tonnes of copper content, representing an increase of 15.4% on 2008. This comprised 492,727 tonnes in the form of concentrate and 43,126 tonnes in cathodes. The company accounted for 9.9% of Chile's total copper output in 2009, consolidating its place as one of the country's main producers and positioning the company to become a leading international player.
The mine has a staff of 978 and there are 1497 contractor personnel. The facilities at the mine site include the open pit at Ujina, the permanent accommodation complex, the concentrator plant, the solvent extraction-electrowinning (SX-EW) plant, and a 200 kilometre pipeline to transport concentrate from the mine to the port of Punta Patache, 60 km south of Iquique. Punta Patache has a de-watering plant, a concentrate storage dome and port facilities.
It is an open pit truck/shovel mine with reserves of 3.1 billion tons, 2 billion tons of which is accessible. It is has been the mine with the largest single investment in Chilean history of approximately 1.8 billion dollars.
Collahuasi is a joint venture between Anglo American (44%), Falconbridge (44%). and a Japanese consortium, lead by Mitsui and Co. Ltd. (12%). Blizzards and lightning storms occur and there are active volcanoes.
The Collahuasi Mine is located in northern Chile 4,800 meters above sea level in the Andes surrounded by the barren Atacama Desert. Access to the mine is by paved road. There is also an airstrip.
Geology and Mineralization
The Collahuasi property contains two separate porphyry copper deposits known as the Ujina and Rosario, each with important secondary enrichment zones, and the exotic copper deposit Huinquintipa located downstream from the Rosario deposit and contains 9 million tonnes grading 1.35% copper. The deposits are estimated to contain 3.1 billion tonnes of geological resources grading 0.82% copper to an initial mining depth of about 500 m at Ujina and 600 m at Rosario. The property also includes high grade copper-silver vein systems at the adjacent deposit of La Grande.
The Collahuasi district is situated within a major north-south structural feature known as the West Fissure system. This system controls most of the large Tertiary porphyry deposits in Chile.
The property covers 380 exploitation concessions over 110,710 hectares (Dec/02) and 85 exploration concessions over 41,800 hectares. The property is located in northern Chile, about 180 kilometres southeast of the port of Iquique.
Collahuasi is based on a typical low-grade copper porphyry, comprising three ore zones: the major Ujina and Rosario deposits consisting of secondary, enriched sulphides and oxides and the Huinquintipa oxide deposit.
The Ujina and Rosario deposits are large porphyry deposits developed on two separate intrusive and hydrothermal systems of similar age. The two porphyry deposits exhibit a typical profile: a leached cap, a copper oxide horizon, a secondary enrichment blanket and a primary sulphide protore. The Huinquintipa deposit is a small gravel-hosted exotic copper deposit where the contained copper is present as copper oxides, probably derived during the erosion of the Rosario porphyry.
Mining & Operation
The Collahuasi facilities include a 60,000 tonne per day concentrator at Ujina, a copper oxide leaching plant, an oxide solvent extraction/electrowinning plant, a concentrate pipeline, dewatering plant and port at Punta Patache, 65 kilometres south of Iquique, and other project infrastructure. Initial annual yield expected to be 350,000 tonnes of copper in concentrate and 50,000 tonnes of copper cathode.
The Ujina and Huinquintipa zones were mined first, with a transition to the Rosario orebody completed during 2004. Stripping at Rosario began in 2002. The stripping ratio at Ujina averages 4.4:1 (waste: ore) with a 15m bench height. Huinquintipa is somewhat smaller. The design mining rate of 360,000t/d of rock was achieved in Year 1, involving the blasting of 750,000t of material every two days.
Equipment used at Collahuasi includes five Bucyrus-Erie 49R III electric drills and a Drilltech T60KL diesel drill, 40 Komatsu 830E haul trucks and five Bucyrus-Erie 495BI electric rope shovels. Two Krupp Fördertechnik 6,000t/hr semi-mobile crushing plants, one used in each pit initially, provide substantial in-pit haulage cost savings.