Mercury control in the cyanidation of gold ores

Journal ArticleThe control of mercury during gold cyanidation is of particular interest to the gold mining industry. Typically, mercury(II) is released as cyano complexes during leaching and follows gold through the solution concentration and purification step (carbon adsorption and electrowinning or zinc cementation). Ultimately, prior to the production of dor6 metal, elemental mercury is removed by retorting. Process alternatives for mercury control are considered; not only the isolation and removal of mercury from the system but also the stabilization and fixation of mercury in the ore so that it is not released during cyanide leaching. Li this regard, a number of different chemical processes for mercury control are reviewed and their usefulness discussed based upon their characteristic features. These processes include precipitation, adsorption, solvent extraction, ion exchange and cementation