Sorokin E. The development of the scientific foundations of the internal structure and properties of coal to expand the coking raw material base.

In the dissertation, the scientific and technical problem of expanding the coking raw material base by developing scientific foundations and ideas about the molecular and supramolecular structure of coals of various grades was solved, which made it possible to use low-sintering DG grade coal in coking coal and produce metallurgical coke with the necessary set of desired properties. The results of calculating the fractal dimension of the surface of the cleavage of density fractions of weakly sintering (DG grade) and well-sintering (grade K) coal obtained using atomic force microscopy showed for the first time that conglomerates of nanostructured and supramolecular formations in the analysis of samples of different densities and the transition from a less dense to a denser fraction have a structure with a developed configuration of supramolecular compounds located on the surface. The changes in the coals of the middle and low stages of metamorphism are identical. When studying the change in the density of groups of coal macerals by the petrographic method, it was found that both when moving from one brand of coal to another and by studying different density fractions of a separate brand, the macrostructure of supramolecular formations changes. Inertinite group macerals have a density change rate of 0.19 units. Іn a series of metamorphism, and vitrinite groups of 0.009 units. Having determined the content and distribution of heteroatoms, as well as the formation in the organic mass of coals of various grades and their density fractions, it was found that both with an increase in the degree of coal metamorphism and with a change in the density of coal fractions, the role of carbon atoms in the structure of the macromolecular structure increases. Moreover, both coals with a sufficiently high stage of metamorphism and fractions with a high density contain macromolecules with a high degree of aromaticity and a low content of aliphatic side chains. The central orthogonal compositional planning was carried out and multicriteria optimization of coal blends containing a fraction of low-caking DG grade coal with a density of 1.25-1.3 g/cm3 was carried out, the optimal content region of the density fraction of low-metamorphosed coal in the charge for coking was determined. The studies on planning and optimization are confirmed by pilotindustrial coking at the Dneprovsky Coke Chemical Processing Plant. The developed technological recommendations for obtaining the density fraction (1.25-1.3 g/cm3) of low-caking coal are implemented by using a four-product cascade heavy medium hydrocyclone in the processing line for enrichment. Key words: low-caking coal, low-metamorphosed coal, coking charge, coke, atomic force microscopy, fractal dimension, coal maceral groups.