Beneficiation potential of a low-grade coal from the Emalahleni (Witbank) coalfield

Abstract

The challenge of coal depletion has, among other resolutions, forced countries such as South Africa which depend heavily on coal-generated electricity to consider low-grade coal to meet their energy requirements. The Emalahleni Coalfield has an abundance of low-grade coal in-situ and in discards obtained from the No. 4 seam. This research thus seeks to give a technical assessment of the beneficiation potential of such coal for use in power stations linked to the coalfield. To that end, gravimetric and flotation beneficiation techniques were used, and their demineralisation capacities were assessed using physicochemical and petrographic analysis techniques. The results obtained showed that demineralisation of the coal was possible; with 29.1 and 33.6% ash obtained for an ~50% mass yield from gravimetric and flotation beneficiation techniques, respectively, against a thermal ash content requirement of 25-34% for coal-generated electricity.