Fluorescing inertinite macerals in Indian Gondwana coals with remarks on their genesis, terminology and coking potentiality

Abstract

The communication documents the presence of fluorescing structured inertinite macerals in the Indian Permian Lower Gondwana coals of Raniganj, Rajmahal and Singrauli Coalfields. However, quantitative assessment of the maceral has been carried out on the coals of Turra seam from Singrauli coalfield. It was observed that some of the semifusinite and fusinite fluoresced with dull reddish-brown to dark brown colour with almost identical intensity and colour as that of the associated perhydrous vitrinite. It seems that gymnospermous plants, chiefly responsible for the formation of Gondwana coals, were highly resinous and the tissues were also selectively impregnated with resins. The resin has an inherent tendency to get readily oxidized on aerial exposure and when such resin impregnated tissues were only partially oxidized, they produce the fluorescing inertinite maceral with well-preserved cellular structure. A critical analysis of published literatures on the reactivities of vitrinite and inertinite macerals in the Indian Gondwana coals during carbonization revealed that there are certain misconceptions not only about their identification but also coking behaviour. These aspects have also been discussed. The study of coals under fluorescence mode seems to hold promise for the proper assessment of reactive inertinite macerals in Indian Permian coals.