LEACH OUT GOLD AND SILVER FROM SULFIDE CONCENTRATE CONTAINING COPPER WITH CYANIDE AND AMMONIA SOLUTIONS
(1.Institute of Chemical metallurgy, Academia Snica, Being 100080;
2.Royal Institute of Technololgy, Sweden)
2.Royal Institute of Technololgy, Sweden)
Abstract: A cyanidation leaching process for a sulfide concentrate containing gold and silver with ammonia and other complexes was investigated, and its potential in decrease of cyanide consumption was examined. The equilibria behaviors of copper and other metal ions in the CN-NH3 H2O system and the CN-NH3 EDTA-H2O system were analyzed by a microcomputer program. Experiments revealed that the leaching yield of gold in ammonia-cyanide solutions was raised from 86% to 99% from addition of EDTA in a certain concentration and its cooperative action with ammonia op the cyanidation of gold. Meanwhile，the leaching yield of silver was significantly increased From about 200% to 550% and the consumption of cyanide was decreased.
Key words: gold, silver, sulfide, cyanidation leaching