Studies on blending of coals for coking using solvent refined coal

Acute shortage of prime coking coal in India has resulted in increased use of imported low ash coking coal in the steel plants. In this context, to maximize use of indigenous coking coal and to enhance the coking properties of the blend, a suitable coking agent was developed by solvent refining of coal. Studies on the influence of solvent refined coal (SRC) addition on the coking properties of various ranks of Gondwana coals of Indian origin are presented. SRC from non-coking coal, when used as an additive in the coal blends, enhanced the coking and plastic properties of the parent coals/blends. In laboratory scale studies, the beneficial effects of the additives were assessed by the change in coking, swelling and plastic properties. For bench scale studies, 2 kg coal blend was carbonized and the strength of the resultant coke was determined by micro-tumbler test. The test revealed that in corporation of 10% SRC in the blend can replace 20% of imported coking coal. Further, pilot scale coking test were also conducted in 250-300 kg capacity electrically heated ovens. The structural characteristics of the coke produced were investigated by X-ray and polarized light microscopy. It is observed that the co-carbonisation of SRC with coking blends increases the size of the optical texture as well as the degree of structural ordering of coke