Experimental Studies to Evaluate Spontaneous Heating Liabilities of Coals: A Case Study

Abstract

Spontaneous heating of coal is a major problem worldwide and has been a great concern due to its potential to destroy precious coal resources and cause fire accidents in coal mines. Majority of fires occurring in different coalfields are started by spontaneous combustion of coal. So, extensive research work is being done to characterize the nature and causes of spontaneous heating to prevent its occurrence. In this paper, different properties of coal samples obtained from coal mines under Central Coalfields Limited (CCL) have been evaluated based on: proximate and ultimate analysis, calorific value, FT-IR spectroscopy and DTA. The data obtained was used to compare characteristics of different seams with respect to their tendency towards spontaneous heating susceptibility. From the experimental investigations, it was found that, in general the CCL coals have high ash content, low in moisture (below 2%), and have higher calorific value. The CHNS analysis showed that the sulphur content of the coals is less than 1% in all the cases. Among organic compounds alkane was found to be the most abundant functional group. Based on the transition temperature, it could be inferred that, seam 2 of Sarubera is least susceptible whereas seam 8 of Pindra opencast mine is most susceptible to spontaneous heating.