Rietveld refinement and microstructure analysis of red mud

Abstract

The post product material of the alumina industry, i.e. the bauxite residue called red mud is a matter of concern keeping in view the waste product management and its environmental implication. The disposal and maintenance of red mud is a serious problem for the industry. This waste product contains many important materials, which of course depends on the quality of the ore used for extraction of the aluminium. In this present study, the x-ray diffraction and microstructure analysis were emphasized in details for the first time. At the same time the different phases present were analyses using rietveld analysis and found out the different structural parameters. It is found that, the major component of the waste product is hematite and magnetite and the others are, SiO 2 , TiO 2 , Al(OH) 2 etc. which are very less percentage wise. The Bragg R parameters for hematite is found out to be 8.80, with magnetic R factor (=7.57). The space group is R-3C with rhombohedral crystal structure. The cell parameters are a=b= 5.0373, c= 13.7388 with cell volume (=301.91). The Gof for the structure is calculated to be 55.234. Lastly with the available preliminary information a structure is generated with different co-ordinate positions of the atoms, their bond lengths and bond angles.