Bacterial Oxidation and Cyanide Leaching Process of Gold Concentrate Containing Arsenic and Sulphur

Gold concentrate containing arsenic and sulphur is first oxidized with thiobacillus ferrooxidans , then gold is leached with cyanide. The influences of some factors, such as ore size, slurry concentration, bacterial inoculation amount , oxidation temperature and time, removal rate of sulphur, iron and arsenic on gold leaching rate are examined. Gold leaching rate can reach 87.7%, which is higher than that of cyanide leaching directly, when slurry concentration is 10% and oxidation for 10 days at 32 ℃ and removal rate of sulphur, iron and arsenic are 70.5%, 58.7% and 41.1 %, separately .