Abstract
M.Sc. (Geology)
The purpose of this study was to assess the MLA’s ability to characterise (e.g. modal
mineralogy, elemental assay, particle size distribution, particle density distribution and
mineral associations) a coal product from New Vaal Colliery, with the aim to determine any
liberation and beneficiation characteristics. In general the MLA assessment on coal is
comparatively new and novel, especially at Spectrum (University of Johannesburg), hence
research in this regard is required. For the first time New Vaal coal product was
characterised with the MLA 600 FEG SEM. The coal product supplied to Lethabo Power Station for the study’s samples, consisted of Top Seam and Middle Seam coal from New Vaal Colliery which is located in the Cornelia subbasin of the Vereeniging-Sasolburg coalfield, South Africa. The proximate analysis characterised the coal as a high-ash (42.25% air-dried) and low calorific value (13.92 MJ/kg air-dried) product. Chemically SiO2 was the most abundant oxide followed by Al2O3 for the XRF analysis, which was mostly derived from the abundant kaolinite clay mineral (determined by petrography, XRD and MLA analysis). Mineralogically inertinite was the most abundant coal maceral encountered during the petrographic analysis. With geochemical characterisation, chalcophile, siderophile, lithophile and radioactive trace elements were found to be mostly comparable to the global average.