Study on Mineral Composition of Some Coal Samples by X-ray Analysis

Mineral composition of some Japanese and foreign coal samples and specific gravity fraction of these samples was studied by means of X-ray analysis. Minerals identified from X-ray diffraction patterns of these coal smples were quartz, calcite, dolomite, siderite, pyrite and clay minerals such as kaolin mineral, illite and montmorillonite. These clay minerals were identified from the behaviour of the diffraction profile after treatment with glycerol or hydrochloric acid. Calibration curves were made up from the pure standard minerals, using fluorite as internal standard, and quantitative estimation was done for quartz, calcite, dolomite, siderite, kaolin mineral and pyrite. Each mineral could be detected at least about 0.5% content in the sample. The mean deviation of the estimated value was about several percent for quartz and about 10-15 percent for carbonate mineral, kaolin mineral and pyrite. Quartz was generally found in all samples. Calcite and kaolin minerals were also dominant in most samples.