Behavior of Fe and S in bioleaching of pentlandite

The reaction behavior of Fe and S in bioleaching of pentlandite with Thiobacillus ferrooxidans was investigated. The results of leaching experiments and XRD pattern show that pentlandite can not be oxidized easily by 2.8 g/L Fe(3+) at 35 degreesC, and H(+) was released while Fe(3+) precipitates to form jarosite. Bacteria oxidize the sulfide in the mineral to produce element sulfur, meanwhile, H(+) in the solution is consumed and this process results in pH value increasing about 0.3 everyday in the solution, and this process is supported by SEM morphology and EDS patterns.