The giant Collahuasi open pit operation is the world's fourth largest copper mine and is located in the Andean plateau of northern Chile's Tarapacá Region. The mine is operated by a joint venture company, Compañía Minera Dona Inés de Collahuasi SCM. The joint venture partners are Xstrata (44%), Anglo American (44%), and a group of Japanese companies headed by Mitsui & Co. Ltd (12%). Xstrata acquired its interest through the Falconbridge acquisition in August 2006. Xstrata Copper is represented on the Board and Executive Committee of the company.

The operation consists of two major porphyry copper deposits – Ujina and Rosario – located at altitudes of 4,000 metres to 4,600 metres above sea level. Collahuasi has an expected mine life of 50+ years and mines and processes both copper sulphide and oxide ores to produce copper concentrates and cathodes respectively.

The facilities at the site include the Ujina and Rosario open pit mines, permanent accommodation complex, concentrator plant, solvent extraction-electrowinning (SX-EW) plant, and a 200 kilometre pipeline to transport concentrate from the mine to the port of Punta Patache, 60 kilometres south of Iquique.

One of the world’s largest copper deposits Collahuasi hosts total estimated Mineral Resource of 7.6 billion tonnes at an average grade of 0.8% copper using a 0.3% cut-off grade. 

An expansion to increase the concentrator plant's processing capacity to 150ktpd was completed in October 2011. A further expansion project  to reach 160 ktpd remains on schedule for commissioning during 2013. Aprefeasibility study into a major expansion of the concentrator plant to over 1 million tonnes per annum was approved in June 2011.

Brief History of the Operation

Collahuasi's environmental impact studies were approved in 1995, construction and development began by the end of 1996, and commercial production commenced in 1999.