The use of Protodiakonov and Hardgrove methods to determine the effect of coal quality on its grinding ability.

The factors affecting the mechanical strength of coal and coal charges, deviations of the crushing capacity coefficients' actual values of coal charges from their calculated values, and the possibility of categorizing coal in relation to the degree of its resistance to crushing have been explored. The dependence permitting satisfactory precognition of the HGI value of the coal charge placed on the data of the crushing capacity coefficients of its ingredients was settled. The effect of the grinding ability of coal on its quality indicators, namely the degree of metamorphism, petrographic and elemental composition has been examined in this article.