Bioleaching silicon from five bauxite samples containing silicate minerals with different crystal structures were studied with Bacillus circulans CGMCC12.Decomposition of forsterite,kaolinite and orthoclase,which are the common silicate minerals in bauxite,and bauxite collected from Henan Province by Bacillus circulans CGMCC12 was stressed using X-ray diffraction and electron microscope.The results show that the ratios of Al2O3 to SiO2(A/S) in forsterite bauxite,kaolinite bauxite and quartz bauxite are incr...