Extraction and Beneficiation of Ores and Minerals; Volume 4: Copper

Mining Industry Profile: Copper(U.S. EPA 1987). The dumps contain over 600 million tons of oxide ore, and only 10 to 15 percent areactive at any given time (U.S. EPA 1989e).Low-grade, mine-run ore is used in the leach dumps. Ore having an oxide copper content of at least 0.07percent, but not having sufficient copper to justify mining, is generally deposited on the leach dumps (CyprusMinerals Company 1992). The dumps have been built directly on the existing topography, utilizing thenatural drainage created by the contours of several canyons located on the property to divert and collect thePLS (U.S. EPA 1989e). "Leach dump site preparation has been minimal. Convenient, comparativelynarrow, steep-walled canyons are selected. They are then subjected to critical examination for majorfractures, etc." (Weiss 1985).Haulage trucks carry the ore from the pit to a leaching area where it is dumped and spread by a bulldozer.Lift heights range from 40 to 300 feet depending on the particular topography of the land.1-157