Extractive Metallurgy includes mineral processing, hydrometallurgy, pyrometallurgy, and electro metallurgy processes to separate commercially valuable metals from their ores. Mineral processing includes processes to break down the ore by crushing, grinding, sieving etc. which are often associated with dust generation. Hydrometallurgy involves aqueous solutions for leaching, precipitation, distillation, adsorption, and solvent extraction.
Smelting is the process whereby a high temperature process, and a chemical reducing agent is used to extract base metals from their ores. Pyrometallurgy includes smelting as well as calcining and roasting operations. Electrometallurgy includes processes that use some form of electrolytic cell.
Extractive metallurgy processes often result in the emission of NO2, CO, SO2, particulates and heavy metals (amongst other pollutants) into the atmosphere via stacks and as fugitive emissions. Groundwater and water released from site is usually closely monitored.
Extractive metallurgy industries and regulatory authorities are concerned about reduction and containment of unacceptable emissions.
