Abstract

Coal sulphur content is a major consideration in coal marketing. To predict sulphur content and distribution in a coal basin, a sulphur geochemical model needs to be developed. A series of questions are posed regarding coal sulphur distribution, forms and origins. Salient aspects of literature on coal sulphur content and distribution are reviewed to establish a framework for developing a sulphur geochemical model.

Some coal sulphur originates from peat-forming processes. Sulphate, ferrous iron, and microorganisms are key ingredients for the origins of coal pyrite and organic sulphur. Hydrogen sulphide is an important intermediate for pyrite and organic sulphur formation in peats. Sulphur isotope values for peat sulphate, plant sulphur, peat pyrite and peat organic sulphur corroborate the hypothesis that microorganisms reduce sulphate to hydrogen sulphide, which in turn reacts with available ferrous iron or organic matter to produce pyrite and organic sulphur respectively.