Sulfur speciation on the surface of pyrite leached by moderate thermophiles

Leaching processes and sulfur speciation on the surface of pyrite leached by the moderate thermophiles of Sulfobacillus thermosulfidooxidans were investigated by scanning electron microscopy,X-ray diffraction and sulfur K-edge X-ray absorption near edge structure spectroscopy.The results show that Sulfobacillus thermosulfidooxidans can significantly improve the leaching of pyrite and the leaching rate is up to 5.3 g·L^-1 after the process for 24 d.The surface of the mineral is obviously corrupted after leaching for 24 d with microbes and on the surface there are some visible crystalline floccules.Leaching products were found accumulating during the leaching process and the main composition is jarosite.The sulfur K-edge spectra indicates that the sulfur components are composed by pyrite and jarosite,whose mass fractions are 34.8% and 65.2%,respectively.