metalextraction

Metal extraction, or extractive metallurgy, is the branch of metallurgy that focuses on obtaining metals from natural ores and secondary materials. It covers the sequence from mining and mineral processing to purification and refining. Primary production begins with ore extraction, followed by dressing to concentrate metal-bearing minerals by crushing, grinding, and separation.

After concentration, the material is treated by pyrometallurgical or hydrometallurgical methods. Pyrometallurgy uses high-temperature processes such as roasting, smelting, and reduction to convert oxides into metal, often with fluxes and reductants. Hydrometallurgy relies on aqueous chemistry to leach metals, then solvent extraction and electrochemical deposition (electrowinning) to obtain purified metal.

Metal production varies by element. Iron is produced mainly via blast furnaces or direct reduction, yielding iron and, after refining, steel. Aluminum is produced from bauxite via Bayer to alumina, then Hall-Héroult electrolysis. Copper is obtained from sulfide concentrates by smelting and refining; zinc, lead, nickel, and other metals follow similar routes. Gold and silver are recovered by flotation or cyanidation, refined to high purity.

Environmental and social considerations include energy use, emissions, water treatment, tailings management, and land disturbance. Modern practice emphasizes waste minimization, remediation, and responsible sourcing. Recycling of metals, or urban mining, reduces energy needs and expands resource availability.

Historically and economically, metal extraction has driven technological development from ancient smelting to modern hydrometallurgy. Today it remains essential for infrastructure and electronics, with ongoing research into more sustainable, efficient, and diversified methods.