ELECTROWINNING

"An electrochemical process that produces metals from their ores. Most metals occur in nature in oxidized form in their ores. While numerous ways exist to reduce the ores, for many metals electrochemical reduction is the most practical. The ore is dissolved (often following some chemical purification or preprocessing) in an acidic aqueous solution or in a molten salt and the resulting electrolyte solution is electrolyzed. The metal is deposited on the cathode (either in solid or in liquid form), while the anodic reaction is usually oxygen evolution. Copper and zinc are two metals that are often produced by aqueous electrolysis. Aluminum, magnesium, and sodium are some metals that can be produced by molten salt electrolysis. For aluminum, this is the only practically used production process (see an Encyclopedia Article). Also called ""electroextraction."" "