含砷锑金精矿的生物预氧化-氰化浸金研究

采用嗜酸性氧化亚铁硫杆菌对含砷锑金精矿的生物预氧化-氰化浸金进行了研究。预氧化结果表明最佳生物氧化工艺参数为: 初始pH值范围为1.8～2.0, 矿石粒径-0.074 mm, 氧化温度为25～30 ℃, 摇床转速为140 r/min, 细菌接种量为20%, 液固比100∶2, 矿浆浓度1%～2%, 氧化时间12 d。浸出结果表明, 含砷、锑分别为10.37%和36.81%的金精矿如不经生物预氧化处理, 金浸出率仅41%左右;而经过12 d的生物氧化预处理, 金浸出率可达76.55%左右, 提高了35.62个百分点。生物预氧化可以脱除金精矿中的砷, 金的浸出率与砷的氧化率成正相关关系。研究结果能为生物预氧化含砷难处理金矿氰化浸金提供理论和技术指导。

Study on Leaching of Gold Concentrate Bearing Arsenic and Antimony by Bio-preoxidation and Cyanidation

Studies  were carried out on leaching of gold concentrate bearing arsenic and antimony with acidithiobacillus ferrooxidans by bio-preoxidation and cyanidation. Results of preoxidation showed that the optimum bio-oxidation technical parameters were as follows, the initial pH value was  in the range of  1.8～2.0, the particle sizes of ore was  -0.074 mm, oxidation temperature was  25～30 ℃, rotating speed of the shaking table was 140 r/min, the bacterial load was 20%, the liquid-solid ratio was 100∶2, the pulp density was 1%～2% and oxidation time was 12 d. The leaching results showed that the leaching rate of gold from concentrate bearing 10.7% arsenic and 36.81% antimony was only about 41% without bio-preoxidation treatment. The leaching rate of gold can reach about 76.55% with bio-preoxidation stage for 12 days, up 35.62 percentage points. Bio-preoxidation can remove arsenic from gold concentrate, with gold leaching rate being a positive correlation with arsenic oxidation rate. The results can provide theoretical and technological supports for leaching refractory arsenic-bearing gold ores by bio-preoxidation and cyanidation.