The Escondida (Spanish "hidden") mine is the copper open-pit mine with the largest production in the world, representing 8 percent of all world production located in the Atacama Desert of Chile, nearly 160 kilometers southeast of Antofagasta.
Escondida produces copper concentrate, by means of a flotation process of sulphide ore, and copper cathodes, using a leaching process of oxide ore. All of the ore is extracted from the open pit mine, which moves approximately 350 million tons of material per year.
Construction of the mine started in August 1988, and the first batch of ore was processed in November 1990. After successive phases of expansion, total investment in Escondida since that time has been approximately US$ 4 billion. Between 1990 and 2002, annual income tax paid to the Chilean government averaged US$ 140 million.