Assesment of Ammoniacal Ammonium Sulphate Leaching as a Pretreatment Process for Copper Bearing Gold Ores Bas, A.D,, Kucuk, A.,, Yazici, E.Y.,, Deveci, H Proceedings of XIIIth International Mineral Processing Symposium-IMPS 2012; 10/2012

In the current study, ammoniacal ammonium sulphate leaching (AASL) and pre-aeration as a pretreatment step before the cyanidation of a copper-bearing gold ore was studied. Direct cyanide leaching of the ore resulted in only a ~10% extraction of gold indicating the refractory character of the ore. The ammonia/ammonium sulphate leaching as a pretreatment process was shown to substantially improve the gold extraction (>90%) in subsequent cyanide leaching with a significant reduction in the consumption of cyanide. This could be linked with the ready dissolution/removal of copper in the pretreatment stage by ammonia/ammonium sulphate leaching. The pre-aeration of the ore ahead of cyanidation was also observed to enhance the extraction of gold, albeit, to a limited extent (i.e. from ~10% to ~30%). These findings have demonstrated that ammonia/ammonium sulphate leaching prior to the cyanide leaching can be used suitably for the pretreatment of refractory copper-bearing gold ores.