Twenty-four coal samples representing the four major rank types were analyzed by the X-ray RIM methodology which includes mass absorption analysis by X-ray transmission and quantitative X-ray powder diffraction. Twenty-three separate mineral species were observed in the samples, many of which could be quantified in the whole coal analysis. Several mineral species at levels of 5 weightpercent or less were observed only in the ashed scans. Some dehydration and reconstitution reactions were observed in the ashing process, including the combination of organically bound alkaline-earth elements and sulfur to form bassanite and magnesium sulfates. Quartz and kaolinite dominated the silicate mineral portion of the mineralogy, whereas calcite and siderite represented the carbonate; pyrite with associated sulfate oxidation products were generally present as well. The X-ray transmission studies were successful in estimating the carbonaceous matter in the whole coal samples and comparison of the chemical oxides derived from the X-ray data with direct analyses from the Penn State data sheets revealed good correlations, although significant departures occurred for some species and a systematic underestimation of aluminum oxide from the X-ray clay peaks was observed. This study suggests that the RIM procedure can be applied to coal mineral and amorphous component analysis on a routine basis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.