Mechanism on biooxidation of arsenopyrite with Thiobacillus ferrooxidans strain SH-T

Bacterial oxidation tests of the polished sections of gold bearing arsenopyrite and pure arsenopyrite powder were conducted with a fine thiobacillus ferrooxidans named SH T. The arsenopyrite polished sections during the whole process of bacterial oxidation were observed and analyzed at 12 h intervals under the microscope in order to study the surface character of arsenopyrite at the every phase and the formation course of oxidation film on the crystal surface. The compositions of oxidation film which could restrain biooxidation of arsenopyrite were indicated as jarosite and arsenolite by XRD. After the arsenopyrite crystals are oxidized, As state of the arsenopyrite crystal are transformed from [AsS] 2- and As(Ⅲ) to As(Ⅴ), which reveals the oxidation regularity of the arsenopyrite surface and its inner relation. [