Copper extraction is the multi-stage process of obtaining copper from its ores. The conversion of copper ores consists of a series of physical, chemical, and electrochemical processes. Methods have evolved and vary with country depending on the ore source, local environmental regulations, and other factors. The copper smelters with the highest production capacity (metric tons of copper yearly) lie in China, Chile, India, Germany, Japan, Peru and Russia. China alone has over half of the world's production capacity and is also the world's largest consumer of refined copper.
Precious metals and sulfuric acid are often valuable by-products of copper refining. Arsenic is the main type of impurity found in copper concentrates to enter smelting facilities. There has been an increase in arsenic in copper concentrates over the years since shallow, low-arsenic copper deposits have been progressively depleted.
