ANISOTROPIC CRYSTALLINE GROWTH DEVELOPED IN BANGLADESHI COKING COAL DURING MESOPHASE TRANSFORMATION

The anisotropy of the mesophase spherules is developed during the carb onization of extracted coking coal in the temperature range 430 to 450 degrees C. Mesophase transition is observed by the differential scann ing calorimetric study. Enthalpy Delta H involved in the mesophase tra nsformation is found to be 46.26 J/g. The growth of mesophase spherule s, their coalesced structures, mosaic and flow type mosaic are observe d by the polarized light technique as the evidence of graphitizing car bon. The solvent extraction of coking coal is carried out using benzen e as a solvent at atmospheric pressure by Soxhlet apparatus.