黄铜矿精矿中等嗜热微生物浸出过程及其优化

Bioleaching of chalcopyrite concentrate with moderate thermophilic bacteria and its optimization

采用3种中等嗜热微生物:喜温硫杆菌(Acidithiobacillus caldus,A.c)、嗜铁钩端螺旋菌(Leptospirillum ferriphilu,L.f)、嗜热氧化硫化杆菌(Sulfobacillus thermosulfidooxidans,S.t)对黄铜矿精矿进行浸出。探讨浸出过程中的微生物生长优化及搅拌反应器浸出条件优化。微生物最佳生长条件如下:生长温度为45℃、初始p H为1.5。驯化过的浸矿细菌的生长及浸出率明显高于未驯化的,驯化后浸出率在矿浆浓度为50 g/L时达到最大,为94.00%;当矿浆浓度达到100 g/L时,铜的浸出率稳定在80%左右。搅拌反应器的最优化浸出条件如下:搅拌速度350 r/min,充气强度500 m L/min。在此条件下,对黄铜矿精矿进行浸出,浸出时间为30 d时,最终铜离子浓度为17.36 g/L,铜的浸出率为85.60%。

The bioleaching of chalcopyrite concentrate in the presence ofthreedifferent moderate thermophilic bacteria such asAcidithiobacillus caldus（A.c）,Leptospirillum ferriphilu（L.f） andSulfobacillusthermosulfidooxidans（S.t）, including the optimal conditions of microbial growth and the optimization of stirred reactor during the bioleaching process, wasinvestigated. The resultsshow that the best growth conditions of bacteria areas follows,temperature of 45℃and initial pHof1.5.The microbial growth of the domesticated bacteria and the bioleaching rate using themare significantly higher thanthose of thenon-domesticated bacteria. The leaching rate usingthedomesticated strains reaches the maximum94.00%with the pulp density of 50 g/L. The leaching rate of copper stabilizesat about 80% when the pulp density reaches100 g/L. The optimal parametersof stirred reactors areas follows：stirring speed of 350 r/minand aeration intensity of 500 mL/min. The final concentration of copper ionsis17.36 g/L and the leaching rate of copperis 85.60% for the chalcopyrite bioleachingfor 30 d under these conditions.