Assessment of Spontaneous Ignition Lability and Gas Evolution of Coal-Bearing Rocks of Dumps and Sludges of the Coal Enterprises


Rock dumps of coal mining and coal processing enterprises contain coal, which is capable to absorbing oxygen to generate heat. Under favorable conditions, the heat generated is sufficient to increase the rock temperature and to form spontaneous fire seats. At the same time, coal-bearing rocks emit combustible and toxic gases generated during the coal decay and the oxidation of combustible elements. 
To assess the possibility of the development of spontaneous ignition processes in the coal-bearing rock agglomerates that were exposed to air for a long time, the samples were taken, the constant oxygen sorption rate and the duration of the spontaneous ignition incubation period were determined. Sampling was carried out on the surface of two dumps of the open pits, as well as at different depths of the slimepit of the processing plant, which were not in operation for decades. The experiment allowed to determine the concentration and intensity of the evolution of various gases from the coal-bearing rocks at natural ambient temperature. 
The uneven sorption activity of the rocks on the surface of dumps contributes to forming spontaneous fire seats in the areas that are most liable to this. In addition, rock dumps for decades continue to emit methane and carbon monoxide into the atmosphere at the natural temperature of the rocks, which negatively affects the surrounding nature. In the sludge settling tank, not operated for about 60 years, the sorption activity of the sludge in relation to oxygen changes not only on the surface, but also at different depths of the settling tank.
The revealed features of long-term storage of coal-bearing rocks in the dumps and slimepits should be taken into account when choosing the technologies for coal mining and processing, as well as storage of the overburden rocks and processing wastes.

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DOI: 10.24000/0409-2961-2021-3-74-80
Year: 2021
Issue num: March
Keywords : rock dump centers of spontaneous-combustion endogenous fire oxygen sorption rate oxidation tendency to spontaneous-combustion шлам coal-bearing rocks gas evolution
  • Portola V.A.
    Dr. Sci. (Eng.), Prof., T.F. Gorbachev Kuzbass State Technical University, Kemerovo, Russian Federation
  • Bobrovnikova A.A.
    Cand. Sci. (Chem.), Head of the Department T.F. Gorbachev Kuzbass State Technical University, Kemerovo, Russia
  • Protasov S.I.
    Cand. Sci. (Eng.), Director Innovative firm «KUZBASS-NIIOGR», Kemerovo, Russia
  • Seregin E.A.
    Chief Engineer Innovative firm «KUZBASS-NIIOGR», Kemerovo, Russia
  • Eremenko A.A.
    Dr. Sci. (Eng.), Prof., Deputy Director Institute of Mining of the Siberian Branch of the RAS, Novosibirsk, Russia