Isolated in Chile’s northern Atacama Desert, the open-pit Escondida Mine is the world’s largest source of copper. Escondida means “hidden” in Spanish, and hidden it was. The copper ore was buried under hundreds of meters of rock. The only way it was found was by drilling along a line of other known copper finds that stretched hundreds of kilometers. Copper represents a substantial part of Chile’s economy. In 2013, copper mine production was valued at just over $30 billion. Chile is the world’s leading producer of copper, accounting for nearly 32% of world copper production (Escondida Mine, Chile | EROS, n.d.).
Rio Tinto (30%), JECO Corporation (10%), JECO 2 (2.5%), and BHP (57.5%) own the Escondida mine. Minera Escondida Limitada (MEL), a joint venture between BHP, Rio Tinto, and JECO, is in charge of running it.
The mineral deposits in the property are related to multiphase biotite Granodiorite Porphyry stocks. The early porphyry phases host the highest-grade copper (Cu) mineralisation consistently. The two active Escondida and Escondida Norte are porphyry copper deposits, similar to majority of Chilean/Andean copper deposits. The deposits exhibit supergene-enriched copper porphyries with primary mineralisation associated with several phase intrusions of monzonite to granodiorite composition into host volcanics. Before mining, copper mineralisation used to start at approximately 150m to 200m depth below surface. Copper oxide minerals are primarily brochantite, antlerite, and chrysocolla along with iron oxides. Supergene zone minerals include copper mineral chalcocite with lesser covellite and chalcopyrite occurring with iron sulphide mineral pyrite (“Escondida Mine, Chile,” n.d.).
In 2023, the Escondida mine, operated by BHP in Chile, produced 1,055,000 metric tons of copper. This marks a 5% increase from the previous year, primarily attributed to a higher concentrator feed grade of 0.82% compared to 0.78% in 2022. However, the production faced challenges due to road blockades and geotechnical issues that affected ore mining and processing (Biggest Copper Mines Produced 20% Less Copper in 2023 – Richard Mills, 2024).
Escondida is among the largest copper mines in the world, playing a pivotal role in the global copper supply. BHP’s production guidance for Escondida in 2024 was estimated at between 1,080,000 and 1,180,000 metric tons, with the fourth-quarter results still awaited.
Reference
Biggest copper mines produced 20% less copper in 2023 – Richard Mills. (2024, April 10). https://aheadoftheherd.com/biggest-copper-mines-produced-20-less-copper-in-2023-richard-mills/
Escondida Mine, Chile. (n.d.). NS Energy. Retrieved December 3, 2024, from https://www.nsenergybusiness.com/projects/escondida-mine-chile/
Escondida Mine, Chile | EROS. (n.d.). Retrieved December 3, 2024, from https://eros.usgs.gov/earthshots/escondida-mine-chile
