Quantitative X-Ray Diffraction as a Tool for Smelting Optimisation of Kalahari Manganese Ores

摘要

The Kalahari Manganese Deposit in South Africa accounts for 80 per cent of the world's land-based mineable Mn reserves. Although the ores are primarily mined for export, South Africa is the world's third largest producer of ferromanganese and ferrosilicomanganese alloy, both of which are derived from the smelting of these ores. Mineralogical analysis has traditionally been forsaken for bulk chemical assaying in quality control of smelter feeds, principally because quantitative data could not be easily produced. Yet, mineralogy plays a vital role in determining smelting behaviour, which in turn has economic implications when aspects such as energy and reductant consumption are considered. Smelting is an endothermic process, and the amount of energy input required is dependent on the minerals present in the ore, as well as their relative proportions. Further, knowing the bulk Mn oxidation state in the ores allows for calculation of the amount of oxygen that must be driven off to produce alloy, and hence the amount of reductant required.