中高温浸矿菌结合对高砷铜精矿的浸出研究

利用自主选育的耐高砷中高温浸矿菌浸出以砷黝铜矿为主的高砷铜精矿(As 4%～5%, Cu＞20%)。采用前期中温浸矿菌, 后期高温浸矿菌的两段法生物浸出10 d, 总铜浸出率可达90.01%。对浸渣的铜物相分析可知: 高温菌对黄铜矿的浸出率可达78.45%, 是中温浸矿菌14.2%的5.5倍以上; 对砷黝铜矿的浸出率为33.42%, 约为中温浸矿菌17.48%的2倍。对原生硫化铜矿的浸出率总计为50.24%, 约为中温浸矿菌16.26%的3倍。高温菌对砷黝铜矿的氧化作用较黄铜矿差; 中温浸矿菌对As³⁺ 和As⁵⁺的耐受力比高温菌强。在两段法浸出前期添加2.0 g/L的 Fe³⁺ 或2.5%的黄铁矿精矿细菌培养液均能提高中温浸矿菌的浸出速率。

Study on Bioleaching of High Arsenic-bearing Copper Concentrate by Joint Use of Arsenic-tolerant Mutant of Thiobacillus Ferrooxidans and High Temperature-tolerating Thermoacidophilic Archae

Arsenic-tolerant mutant of thiobacillus ferrooxidans and high temperature-tolerating thermoacidophilic archae were combined to bioleach high arsenic-bearing copper concentrate (As 4%～5%, Cu>20%) which contains tennantite mainly. In the first stage and last stage of leaching process the thiobacillus ferrooxidans and the thermoacidophilic archae were used respectively, the total copper leaching rate could reach to 90.01% after 10 days' leaching. The leaching rate of chalcopyrite by thermoacidophilic archae could reach 78.45%, which is 5.5 times larger than that of 14.2% by thiobacillus ferrooxidans, while the leaching rate of tennanite by thermoacidophilic archae was 33.42%, which is 2 times larger than that of 17.48％ by thiobacillus ferrooxidans. The total leaching rate of primary copper sulphide ore by thermoacido philic archae was 50.24%, which is 3 times larger than that of 16.26% by thiobacillus ferooxidans. The oxidative ability of thermoacidophilic archae to tennantite was worse than to chalcopyrite. The As³⁺ and As⁵⁺to lerance of thiobacillus ferrooxidans was stronger than that of thermoacidophilic archae. The addition of 2.0 g/L Fe³⁺ or 2.5% pyrite inoculum in the early stage of leaching could intensify the bioleaching effect of thiobacillus ferrooxidans.