The world's third largest zinc and eighth largest copper mine, Antamina, is located in the Andes Mountains in northern Peru, approximately 270 kilometres northeast of Lima, at an elevation of 4,300 metres. It is operated by a joint venture company, Compañía Minera Antamina S.A. The joint venture partners are Xstrata (33.75%), BHP Billiton (33.75%), Teck-Cominco Limited (22.5%) and Mitsubishi Corporation (10%). Xstrata acquired the partnership through its acquisition of Falconbridge in August 2006. Xstrata Copper and Xstrata Zinc are represented on the Board and Advisory Committee of the company.

Reserves are extracted by open pit mining followed by conventional grinding and flotation to produce concentrates. The concentrates are slurried and transported by a 300 kilometre pipeline to the Pacific coast, where they are filtered for shipment.

The Antamina deposit hosts total estimated Mineral Resources of 1.5 billion tonnes at an average grade of 0.84% copper. In March 2011, Antamina announced an 18% increase in its Mineral Reserves to 822 million tonnes at an average grade of 0.93% copper.

A  US$1.3 billion expansion to increase ore processing capacity at the mine site by 38% to 130,000 tonnes per day began commisioning in December 2011 and is targeted for completion in the first quarter of 2012.

Antamina began commercial production in October 2001 following two years of exploration and three years of construction at a capital cost of $2.3 billion, the most significant investment in Peruvian mining history.