RECOVERING PRECIOUS METALS FROM METAL SULPHIDES

摘要

Gold, as well as copper, is recovered from copper bearing sulphidic material containing gold. The copper bearing sulphidic material is subjected to a main leach to provide a copper containing main leach liquor and a main residue. A secondary leach with ammonium thiosulphate solution is carried out on the copper bearing sulphidic material before the main leach, or on the residue from the main leach, to provide a gold containing secondary leach liquor and a secondary residue. Copper and gold are recovered from the respective leach liquors. Silver may also be recovered in addition to the gold.