Oxidation of Pyrite by the Iron Bacteria Thiobacillus Ferrooxidans

By Iron Bacteria Thiobacillus ferrooxidans (ATCC 19859), the bioleaching of pyrite ore in shaker using mixed cultures has been studied. Ore microstructural analysis using X-ray diffraction, SEM and EDS permitted us to know the nature, distribution, size and morphology of pyrite after bioleaching. In SEM analysis, pyrites show needle and columnar shapes of pyrite, corrosion area on the surface of pyrite expanded with leaching time. Selective bioleaching in pyrite surface were confirmed by the XRD analysis. Temperature is one of the variables that has most influence on the metallic extraction processes and bioleaching. Different tests were performed with mixed cultures at 20, 30, 40 and 50℃. The maximum content of ferric ion were obtained with a temperature at 30℃ and that of ferrous ion was a temperature at 50℃.