St. Petersburg Mining University, St. Petersburg, Russia:

M. Yu. Nazarenko, Cand. Eng., Associate Prof., Dept. of Chemical Technologies and Energy Recycling, e-mail: nazarenko_myu@pers.spmi.ru
S. N. Saltykova, Cand. Eng., Associate Prof., Dept. of Chemical Technologies and Energy Recycling, e-mail: saltykova_sn@pers.spmi.ru

For metallurgical and coke-chemical processes, the search for new carbon materials with the aim of partial or complete replacement of coking coals, the shortage of which is steadily coming, is topical. The influence of parameters of the semi-coking process (temperature, duration of the process, fineness of the initial material) of combustible shale from the Leningrad deposit on the quality of the resulting semi-coke was studied in order to determine the possibility of its further use in metallurgical and coke-chemical processes. The process of semi-coking oil shale was carried out on the developed laboratory plant for semi-coking solid fossil fuels with a closed system for cleaning gaseous products from ammonia, carbon monoxide and benzene. Process parameters: mode I – temperature 450–470 °C, holding time 3; 5; 8 h; mode II – 510–520 °C, holding time 3; 5; 8 h. Shale semi-coke samples were obtained with the following characteristics: ash content – from 50.60 to 54.20% (wt.); the yield of volatile substances – from 32.18 to 38.09% (wt.): density – from 1.71 to 1.99 g/cm³; microstructure – 1.5–2.2 points; sulfur content – from 3.9 to 6.6% (wt.). 
The work was supported by the grant of the President of the Russian Federation for young scientists and postgraduate students, project SP-1275.2021.1 "Establishment of physical and chemical laws, chemistry and mechanism of the process of semi-coking of low-grade types of solid fossil fuels (oil shale and brown coal)".

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