Structural characterization of coking component of an Indian coking coal

Abstract

Coking coal is used for coke making owing to its inherent swelling and thermoplastic properties. Non-coking coal on the other hand lacks these coking properties and hence coke making from non-coking coal is a challenging task. In the present study, we isolated the “coking component” present in an Indian coking coal by density separation followed by solvent extraction method and elucidated its chemical structure using XRD, Raman, XPS, FT-IR, NMR and mass spectrometry techniques. The coking component was found to have turbostatic graphitic structure similar to that of expandable graphite. Finally, we synthetically induced coking properties in four non-coking coals of Indian origin using expandable graphite and molasses following a simple heat treatment process. The resultant modified coal produced G1-G2 grade coke in low temperature Gray King (LTGK) assay.