Iron Ore Characterisation during High Temperature Thermal Processing

Abstract

AbstractIronmaking essentially involves different ways of combining iron ores and energy sources to produce metallic iron. The thermal properties of the iron ores determine the amount of energy required for processing. Investigating and understanding these thermal properties is thus extremely important with respect to controlling the ironmaking processes.Using experimental and mathematical techniques, six iron ores from different origins were thermally characterised in this study. Chemical and structural changes in the iron ore during heating were investigated using SEM, EDS, and XRD analysis. Throughout the process, a number of transformations and reactions were apparent, and these have been quantified for each ore.Goethite was found to decompose between 250‐350 d̀C. This endothermic reaction was found to be the most important stage with the energy requirement to heat iron ore samples dependent upon the amount of goethite in the iron ore. The endothermic kaolinite decomposition occurred at 600 d̀C while the exothermic partial reduction of hematite to magnetite occurred at 850 d̀C. Differences between the raw and sintered iron ores were investigated.