Effect of washing and stamping on coke making of a low-grade Indian coal: correlation between various properties

Abstract

Huge reserves of low-grade coals with low volatile in India have not yet secured their entry in iron and steel industries due to their poor caking characteristics, thereby establishing their suitability for coke making with specified requirements is a big challenge. Beneficiation and pre-treatment technology like stamping of coal mass prior to carbonisation are considered to be effective in producing such coke. The obtained results on a low volatile poor caking coal show that coal washing improves the properties of washed coal and its coke; washing followed by stamping improves the strength and reactivity of coke. Correlation developed evinces a linear dependence of (i) coke properties on stamping weight and of (ii) coke properties from washed coal on the coke properties from unwashed coal with significant R2 value (range 0.704–0.990). The properties of coke (except Shatter index) from washed coal evince the correlation CSR′ = 191.4 + 1.712 GI′ − 1.3622 CRI′ − 2.686 − 0.495 , where GI′, 61.44–75.23; CRI′, 16.09–29.20; , 82.82–89.13 and 7.82–9.92 (R2 = 0.993).