The developed theory of mineral disclosure makes it possible to calculate all the main parameters of the processing process to obtain products of a given quality, if the technological methods fully realize the effect of a given crushing depth. In fact, the qualitative and quantitative indicators of existing coal enrichment processes differ significantly from the theoretical ones. This is explained by the insufficiently clear separation of particles with similar specific gravity and the impossibility of reliable enrichment of small classes of coal. Therefore, it is important to choose the right demarcation weight, at which the enrichment will be optimal. Most coals, in particular, of the Donetsk basin, are usually enriched in a specific gravity of 1.5, however, in some concentrates the ash and sulfur content remains high...

Determination of the sizes of inclusions and the function of their size distribution in the mineral volume is an important task for practice. Since in the vast majority of minerals containing inclusions are opaque, it is not possible to experimentally measure the sizes of inclusions. Usually the sizes of inclusions cross-sections are measured on the slip, and by the picture on the slip we have to judge about the true sizes of inclusions in the mineral and about the size distribution of inclusions.

Parameters determining the results of gravity concentration of finely crushed coals. Disclosure of minerals, yields and compositions of fractions, quality of the obtained concentrate depend on the degree of crushing. The finer the coal is crushed, the greater the disclosure of minerals during crushing, the greater the amount of pyrite and mineral impurities (or rich in their aggregates) are extracted from the coal, the better the quality of coal obtained by gravity concentration of the crushed mass.

Methods for calculating yields and compositions of functions in gravity concentration have been developed for fine and coarse crushing. Calculation of coal crushing and its subsequent gravity concentration was carried out for coarse and fine crushing by different methods, which is a shortcoming of the theory. In addition, for some intermediate cases it is sometimes unclear which method should be used, and calculations by the coarse and fine crushing method give drastically different results.