Bacterial Pre-oxidation of Refractory Gold Concentrate from the High Altitude Areas and Cyanidation Leaching of Gold
高海拔地区难处理金精矿的细菌氧化预处理及氰化浸金

Bacterial pre-oxidation of refractory gold ore from the high altitude areas was studied.The removal rates of Fe,S,As and cyanidation leaching rate of Au were examined under the different conditions.And the gold concentrate,oxidizing slag,and leaching residue were analyzed by XRD and SEM.The results indicated that the removal rates of Fe,S and As were up to 85% and the leaching rate of gold was 88.09%.Feasibility of bio-oxidation pretreatment in the high altitude areas was proved.Based on the experimental results,the bacterial oxidation mechanism of gold concentrates and acid solution neutralization were analyzed briefly.The bacterial oxidation of gold concentrate occurred under cooperative direct and indirect mechanism.Removal of the arsenic and heavy metal ions of liquid phase in the form of ferric arsenate and hydroxide precipitation was the main purpose of acid solution neutralization.