Characterization of complex bauxite ore: Part III

Abstract

This paper presents the microstructural and micro-chemical characterization of a complex bauxite ore using Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (SEM-EDS). The experimental methodology involved high-precision sample embedding, grinding, and diamond polishing followed by quantitative spot analysis and elemental mapping at an operating voltage of 20 kV. The EDS results across multiple spectra successfully identified the key mineral phases, confirming that the ore matrix is dominated by oval and elliptical grains of aluminum hydroxides, specifically boehmite or diaspore, ranging from 20 to 400 µm. Furthermore, the microanalysis reveals extensive structural intergrowth, where the primary aluminum phases regularly enclose and incorporate tight fine-grained impregnations of iron oxides, predominantly hematite, alongside titanium dioxide modifications such as rutile or anatase, and localized calcite inclusions. These detailed microstructural features and encapsulation characteristics provide critical mineralogical data necessary for understanding phase distribution and predicting mineral liberation behavior in industrial utilization.