Role of Acidithiobacillus ferrooxidans in bioleaching of copper
氧化亚铁硫杆菌浸铜作用研究

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.