Abstract: In order to validate mixed strains have more biooxidation effect on of refractory arsenic gold ore, At.f, At.t, L.f and all three mixed bacterium was Cultivated and domesticated separately. The results showed that: compared with single bacteria, the mixed bacterium has the strongest ability of oxidation and leaching, the leaching rate of arsenic was up to 70.1% for 35 days; the leaching rate of ferrum for mixed bacterium is a little lower than L.f; Since gold was mainly wrapped by arsenic sulfide minerals, interaction between mixed strains can improve biooxidation. Fermentation tank expanding experiments indicated that: the influence of solution pH by mixed bacterium make the gold leaching more easily, and reduce the dosage of added acid; increase of Eh and maintain in a higher state can help the oxidation operation of pyrite and arsenopyrite.

Key words: Mixed strains, Arsenic, Ferrum, Leaching rate, Biooxidation