Importance of petrographic study of non-coking coals from Talcher coal field, Orissa in coal utilisation

Abstract

Talcher coal is non-coking and high ash type and presently used for thermal power generation, sponge iron making, cement and chemical industry. Coal beneficiation is being carried out by size reduction followed by washing and gravity separation to reduce the ash content and improve other chemical parameters. Poor washability characteristics of Indian coals in general and Talcher coal in particular and presence of high near gravity materials do not support the conventional washing techniques resulting in below expected quality yield. The role of detailed petrographic studies during processing /beneficiation needs special attention in order to improve the quality of coal and competitiveness of the product in the open market. This paper provides general information on petrographic findings of coal from different seams presently exposed in Talcher coalfield in terms of lithotype, maceral, microlithotype, mineral matter and rank (vitrinite reflectance). Importance of lithotype, mineral matter and oxidation characteristics of coals with respect to coal preparation /beneficiation and maceral /microlithotypes in combustion has been discussed in detail.