Assessment of auto-oxidation potential of some Indian coals by differential thermal analysis (DTA) technique

Abstract

It is a well-known fact that coal when exposed to air, undergoes oxidation, even at ambient temperature conditions.The process is exothermic in nature. If the amount of heat liberated during the process is not dissipated, it leads to an increase in temperature, which in turn enhances the rate of reaction, ultimately culminating in open fire. These fires are the major causes of accidents resulting in loss of lives and property across the globe. Apart from loss of valuable coal reserves, blockage of resources and capital, reduction of heating values and coking properties; it also causes serious environmental pollution. However, all coals are not susceptible to auto-oxidation to the same extent. Therefore, accurate assessment of the oxidative tendency is essential to plan the production and storage capabilities in mines. There are different innovations and technologies available in various parts of world to assess and control spontaneous heating tendency, till date there is no unanimity to adopt single method for its assessment. In this study, an attempt has been made to study the auto-oxidative tendency of Indian coal seams by using different thermal technique (DTA). For this purpose 48 coal samples were collected from all major coalfields of the country. The intrinsic properties of these samples were determined using proximate analysis and bomb calorimeter. Correlation study between the intrinsic parameters and susceptibility indices indicate that DTA can be a better method for assessment of the auto-oxidation potential of coal. © 2018 Books and Journals Private Ltd. All rights reserved.