4. Industrial sources

Selenium was initially a by-product of sulfuric acid, as long as it was produced by the lead chamber process. Then, anode slimes from copper electrorefining became its main source (90% of production [10] ). It also contains tellurium, as well as other impurities such as Cu, Pb, As, Sb, Au, Ag, etc., [M 2 241] Pyrometallurgy and electrorefining of copper. The recovery of selenium from these sludges takes precedence over that of tellurium, as Se toxicity is one of the hazards of the copper industry. Moreover,...