CHUQUICAMATA

mining and smelting centre, Antofagasta region, northern Chile. It lies at 9,350 feet (2,850 m) above sea level and is the largest open-pit mine in the world. Large-scale operations started in 1915. Tapping one of the world's largest-known copper deposits, it produces more than one-fourth of the nation's copper, which is carried by rail to Antofagasta, 140 miles (225 km) southwest, for export. Flotation and smelting facilities were installed in 1952; and an expansion of refining facilities in 1968 made possible 500,000 tons annual copper production in the late 1970s. Ore bodies at nearby La Extica are also being mined. The controlling interest in these mines passed from foreign to Chilean hands in 1969; the mines were completely nationalized in the early 1970s. Pop. (1983 prelim.) 29,959.