Coal in South Africa

Abstract

South Africa has more than 70 per cent of the coal resources of Africa, and coal forms the back-bone of the South African industry. In terms of the norms generally accepted for the Carboniferous coals of the Northern Hemisphere, South African coal has long been regarded as “abnormal”. However, these apparent abnormalities can be adequately explained in terms of the petrography which in turn reflects the conditions of peat formation and the subsequent metamorphism under a steep palaeogeothermal gradient. In common with other Gondwana coals South African coals are generally rich in material transitional between vitrinite and inertinite ( sensu stricto). This transition material is partly reactive during technological processes like carbonisation, and is therefore regarded as semi-reactive. South African coals are generally low in sulphur, nitrogen and phosphorus, and in the case of the first two the contents are dependent on maceral composition and rank. On account of the low basisity of the coal ash the ash fusion temperatures are generally high and this is an advantage in most areas of coal utilisation. A review is given of adverse geological conditions affecting coal exploitation, and of methods that can possibly be used to recognise and predict of even eliminate these conditions for purposes of mine planning.