Escondida

Escondida is a large open-pit copper mine at 3,100 m (10,200 ft) elevation in the Atacama Desert in Antofagasta Region, Chile. It has for decades been one of world's most productive copper mines and is the mine that leads in copper and gold production in Chile. In 2019 it was estimated that the mine and its ancillary industries generated 2.5% of Chile's GDP. The mine's produce is largely exported to China as ore concentrate that contained as of 2020 an estimate of 4% chalcopyrite, 35% chalcocite and 46% pyrite.

As of 2024 Escondida has each year been the most productive copper mine in Chile since 1996 more than doubling the produce of the next largest mine, Collahuasi, in four of the last ten years up to 2024.

Geology

The Escondida deposit is one of a cluster of porphyry coppers in an elongated area about 18 km (11 mi) north–south and 3 km (1.9 mi) east–west and is associated with the West Fissure (Falla Oeste) system, which is in turn associated with most of the major Chilean porphyry deposits. A barren, leached cap, in places up to 180 m (590 ft) thick, overlies a thick zone of high grade secondary supergene mineralisation of the main orebody, largely chalcocite and covellite, which in turn overlies the unaltered primary mineralisation of chalcopyrite, bornite and pyrite.

Reserves

At mid 2007, Escondida had total proven and probable reserves of 34.7 million tonnes of copper, of which 22.5 million tonnes is estimated to be recoverable. Total resources (including reserves) were 57.6 million tonnes of copper, of which 33.0 million tonnes should be recovered. Exploration continues. As of 2019, the known resource is 21.7 Billion tonnes at 0.54 percent Copper including Escondida and adjacent deposits.