Volatile displacement of Meghalaya coals — A pointer to explore low sulphur coals

Volatile displacement, which measures the difference between calculated and experimental volatile matter, is indicative of abnormality in coals which may be related to petrological or chemical parameters. The volatile displacement (δυ) values of Meghalaya coals were calculated from their chemical analyses. Correlations of volatile displacement (δυ) with parameters such as carbon, hydrogen, moisture, oxygen, oxygen plus sulphate sulphur, oxygen plus pyritic sulphur, oxygen plus organic sulphur and total sulphur were studied. An approximately linear relationship exists only between δυ and moisture, and δυ and total sulphur, and not between other parameters. Plots on Seyler’s chart indicate the coals as perhydrous to orthohydrous. The linear relationship with total sulphur indicates that the coals may have become abnormal mainly due to the marine environment of deposition and weathering.