Microscopic evaluation of coal and coke for metallurgical usage : A case study

The growing demands of the steel industry to import coking coals necessitates their optimal use by proper blending with indigenous coals. Petrographic assessment depicts the heterogeneity of the coals. Maceral composition and vitrinite reflectance per cent as a rank parameter are the basic outcomes of coal petrographic studies that are in frequent use for categorizing coals. The present study also gives an idea about the potentialities of petrographic techniques to decide the optimum blend proportion from coal type, rank and Vstep distribution pattern. Apart from this, coke microtextural studies can be used as an efficient tool not only to cross-check the predicted quality of the coke, but also to predict its behaviour during metallurgical operations. Attempts have been made here to predict coke quality from the microtextural study. Three indigenous coals and four imported coals with reflectance ranging from 0.81 to 1.23% have been used in the present study to illustrate the potentialities of microscopic techniques for the assessment of coal and coke for metallurgical usage