Precautionary Measures in Determining Volatile Matter in Natural Coke Washability Fractions

Industrial utilization of heat-altered coal, especially natural coke derived from coking coal, has become a challenge. As such approximately 3,500 million tones (Mt) reserves of baked coals are available in different coalfields of India. In the present investigation, a natural coke sample (03 tone) was collected from a huge dump of seam XIV of Burragarh colliery under leasehold of Bharat Coking Coal Ltd., a subsidiary of Coal India Ltd, situated in Dhanbad district of Jharkhand state. It was observed that the volatile matter in the washability fractions of different size ranges (50 to 0.5mm) at specific gravity 1.40 to 1.80 showed erratic distribution with respect to ash. To check the abnormality, the subsamples were subjected to microscopic (petrographic) study and chemical analysis including CO2 determination. The high concentration of CO2 is related to high concentration of carbonate minerals generated due to igneous intrusions in coal seams. Based on above observations, it was concluded that the volatile matter can be corrected through determined CO2 content in each fraction. Since efforts are being made to use natural coke in different industries such as steel, power, cement, carbon artifacts, etc., a careful investigation of volatile matter distribution in natural coke washability fractions would be of immense help in planning its bulk use.