ABSTRACT
The size distribution of the coal obtained from mechanized face effect directly coal preparation parameters such as variation in crushing size, relative density of froth flotation, and equipment required to obtain maximum washability of coal. Coal preparation processes are dependent on the differences in physical properties between the coal components or macerals. The major differences between the lithotypes, which are dependent on their macerals, are in toughness, relative density, and crushability. Vitrain and fusain are more brittle and lighter in density than that of other lithotypes. The effect of petrographic composition on coal breakage is evident in preparation plant as well as in the mine. Cutting of coal is automatically a natural separation and results in selective concentration of certain macerals, group macerals, and lithotypes. Significant petrographic variations may therefore be recognized by screening, sizing, oil flotation, and relative density separations. In other words, the vitrain, which is best coking component, has low density, clarain and clarodurite, is best for coal conversion and the heavy fraction (inertinite and durain) is best for power plants (Falcon 1978, Falcon and Falcon 1987a, 1987b).
