SEPARATION OF MINERAL MATTER FROM INDIAN COAL BY USING SOLVENTS

Abstract

Coal resources have been estimated at over 861 billion tone globally. India accounts for 236 billion tonne of coal. Coal meets around 30.3 % of global primary energy needs and generates 42% of the world's electricity. Indian electricity capacity has a rapid growth from 1350MW in the year 1947 to more than 140,000MW presently. Wide spectrum of coal is required ranging from power generation to steel production, infrastructure and commercial purposes. Indian coals contain high in ash content ranging from 15% to 55% [1] but low in sulphur content. Power plants complain of high ash content, inconsistent quality and size. Research and process development to produce the ash-free coal (Hyper-coal, HPC) has been carrying out since 1999 [5]. To improve the quality of coal by washing to reduce the environmental impact, enhance coal quality and increase process efficiency. Coal washing and coal beneficiation processes are the major thrust in terms of developing strong research cells for developing better practices, suiting requirements of all the coalfields of India. The extraction yield depends strongly on the coal particle size, solvent and extraction conditions. Experimental investigation for removal of mineral matter from Indian coal by using three different solvents such as Tetrahydrofuran, 1,4 Dioxane and Diethyl ether. Comparative study on reduction of ash content of Indian coals having different average particle sizes(0.126mm,0.258mm and 0.403mm) using different solvents reveals that Tetrahydrofuran is the best solvent with respect to these used solvents. The maximum reduction of ash content is found to be 23.16%. Experimental studies also highlighted how ash removal of coal by using solvents is increased with the decrease of particle size due to the easy liberation of ash bearing components from coal particles [16].