氧化亚铁硫杆菌浸铜作用研究

为研究氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,简称A.f)对铜浸出的作用,从某煤堆积水中分离得到A.f菌,利用该菌对铜进行浸出实验,设置3个处理,3个处理的浸出液分别为9 K培养基(简称S),成熟菌液(简称MS)和过滤除菌液(简称FS)。结果表明,3个处理中铜都得到了浸出,浸出铜浓度按S、FS和MS依次递增分别为4 433、5 377和6 296 mg/L;浸出初期,MS中的铜,浸出速度最快,过滤除菌液中次之,而培养基中的速度比较稳定,比前两者均慢,24 h后三者浸铜速度趋近一致;三者中pH、Eh变化相似,pH均先升高至3.4左右保持相对稳定,Eh均先迅速下降至280 mV后保持稳定。由实验可知,氧化亚铁硫杆菌主要在浸出初期促进了铜的浸出,且菌液中溶解氧氧化Fe2+以及酸性条件下氧化Cu0对铜的浸出作用不容忽视。

Role of Acidithiobacillus ferrooxidans in bioleaching of copper

Copper leaching in the presence and absence of Acidithiobacillus ferrooxidans( A. f) cultivated from coal mine water are carried out, in 3 leaching solutions: 9 K substrate(S), the solution without bacteria(FS) and the solution with bacteria(MS). The experimental results show that: (1) copper leached in all three solutions, and the concentrations of leached copper in different solutions increases by the order: S, FS, and MS, which are 4 433 mg/L,5 377 mg/L,6 296 mg/L, respectively; (2) in the initial stage of the experiments, the copper leaching rate is the fastest in MS, followed by the solution without bacteria then by substrate(FS), and after leaching for 24 h, the leaching rates approach the same in all three solutions; (3) the changes of pH and Eh in the three solutions are similar. The pH values increase from 2.5 to 3.4 then maintain relatively steady; and the Eh values maintain relatively steady after decreasing sharply to 280 mV. The study shows that indirect bioleaching took the dominant place in the leaching of copper and the dissolved oxygen(DO) effect on copper leaching in solution MS could not be ignored.