Home – Home – Jornals – Chemistry for Sustainable Development 2025 number 6

The results of laboratory coking are presented for GZh, Zh rank coal (two concentrates from different manufacturers), KZh + Zh, OS rank coal (two concentrates from different manufacturers) in the experimental furnace with 4 kg load, and the studies of resulting coke. The structural strength (S_s) of coke samples was determined according to GOST 9521-2017. Samples were studied by X-ray diffraction analysis, and the sizes of molecularly oriented domains in the coke were determined: domain height (L_c), domain length (L_a), interplanar distance (d₀₀₂), and the number of lamellas (N) in the domain package. The relationship between the structural strength of coke and the chemical-petrographic parameters of coal was studied (the yield of volatile substances per dry state, vitrinite reflectance index, the sum of lean components, the thickness of plastic layer). It has been determined that the structural strength of coke has a quadratic dependence with respect to the chemical-petrographic parameters of coal. According to the experimental results, it is demonstrated that for coke obtained from the OS rank coal, the 0.4 nm difference in L_c and 0.3 nm difference in L_a correspond to a 50 % change in the structural strength of coke. For coke obtained from the Zh rank coal, the 0.28 nm difference in L_c and 0.46 nm in L_a corresponds to a 23 % change in the structural strength of coke. It is concluded that the L_c and L_a indicators make it possible to differentiate the quality of coke by structural strength, unlike for the chemical-petrographic indicators of coal. The general trend of changes in the L_c and L_a domain sizes depending on the structural strength of coke and the stage of coal metamorphism in the sequence GZh, Zh, KZh + Zh, OS is given.