| Experimental research on bacterial oxidation of refractory gold concentrates was carried out. The effects of several factors such as pulp density, oxidation time, dissolved oxygen, stirring speed and culture medium dosage on the removal rate of Fe/As/S, oxidation rate of sulfide and the extraction rate of gold were investigated. By cyaniding CIL gold extraction, the extraction rate of gold increased from 15.53% in the absence of bacterial oxidation to 95.82%. Furthermore, the Eh, pH diagrams and the behavior of Fe were also analysed. |