CHARACTERISATION OF IRON MINERALOGY IN JAMAICAN BAUXITE AND ASSOCIATED ASPECTS OF ALUMINA AND SODA LOSSES

摘要

The characterisation of bauxite ores, in particular the ironrnmineralogy, is critical when determining their processability. Inrnthis study, various Jamaican bauxite ores have been characterisedrnby Rietveld X-ray powder diffraction (XRD) and Mossbauerrnspectroscopy. The only forms of iron minerals found arerncrystalline hematite and crystalline alumino-goethite of relativelyrnsmall crystallite size. Within digestion, the apatite structurernformed is a sodium carbonate hydroxyapatite, and hence a sourcernof soda loss. No evidence of boehmite reversion was found.rnPost-digestion, the specific surface area of the bauxite residue isrnstrongly correlated with the goethite content, attributed to arndecreased particle size, rather than variations in porosity orrndensity. Possibilities for remediation have focussed on therntransformation of goethite to hematite, with thermal treatmentrnproving to be most encouraging to date.