The Contents and Some Related Aspects of Trace Elements in Coals

The contents of trace elements in coals are clearly relevant to any environmental aspect during mining, beneficiation and usage. There are published data for 66 trace elements in coals, surely not a surprising fact ‘for a naturally occurring material formed under varying conditions over a long period’ (Swaine, 1985). There is a comprehensive account of trace elements in coals, including tabulated data for the 24 elements of environmental interest (Swaine, 1990). Results should be stated on a coal basis and in order to avoid the error of inferring that ash is an inherent part of coal, reference should be made to mineral matter in coal and to ash yield, a product of the heating of coal under stated conditions at a specific temperature.