Characterization of potential acid leachate from raw coal, discard coal, and slimes from a Colliery in the Witbank Coalfield, Mpumalanga Province, South Africa

摘要

Geochemical static and kinetic tests were conducted on raw and discard coal and slimes from a colliery in the Witbank coalfield, to characterize the potential leachate. Raw coal was found to be potential non-acid producers, whereas discard coal had the potential to produce acid. Based on column leaching tests, raw coal and slimes did not produce significant leachate, whereas discard coal produced acidic and sulphate rich leachate, especially at the initial stages of experiment, followed by cyclic buffering. The study recommended that there should be long-term environmentally acceptable strategies to treat discard coal in order to meet the regulatory requirements.