Effects of natural weathering on intrinsic properties of coal and coke quality

The degree of weathering of coking coal and its influence on coking potential of coal and coke strength after reaction depends on the various factors viz., climatic conditions, origin and types of coal. Results indicate that weathering of coking coal significantly affects the rheological properties, i.e. free swelling index, maximum fluidity, initial softening temperature, plastic temperature range and maximum expansion. Furthermore, the carbonization study confirms that the deterioration in coke strength after reaction also depends on the type of coals. It is therefore imperative to minimize weathering time of coking coals, and all-out efforts must be taken to cut down the cycle time from mining to its end use for techno-commercial utilization of a particular coal.