However, as to refractory sulfide gold concentrates, the effect of heavy metals is not apparent.

Biometallurgy, roasting and pressure oxidation are generally used to pretreat the refractory gold containing sulfide ores or concentrates. The advantages of biooxidation were presented in the paper.

The properties of Yun Long refractory silver-copper ore are summarized. The feasibility as well as the pilot test result of the acid leaching-sulfide precipitation flotation process is demonstrated.