SULFUR SPECIATION OF DESULFURIZED COALS BY XANES SPECTROSCOPY

Least square analysis of the X-ray absorption near edge structure (XAN ES) region of sulfur K edge X-ray absorption fine structure (XAFS) spe ctra can provide a quantitative analysis of both the organic and inorg anic functional forms of sulfur in coal. In the current article, this method is applied to speciation of the sulfur forms in a number of des ulfurized coals. The samples investigated include biologically desulfu rized coals, samples subjected to selective chemical reactions, sample s subjected to molten caustic leaching and specimens treated with boil ing perchloroethylene. In all cases, analysis of XANES provides a reas onably quantitative speciation of the changes in the sulfur forms resu lting from the various treatments.