Determination of sedimentation rate of coal dust depending on its size and form factor

A rationale for studying the mechanism of mass transfer and sedimentation of coal dust in mine workings is presented. The article also describes the Stokes and Newton laws, most commonly used to describe the settling velocity of dispersed systems over a wide range of particle sizes. Criteria for the applicability of modified equations based on the Reynolds number are formulated. It is shown that when calculating the sedimentation velocity of coal dust, it is necessary to consider that the resistance to its movement in the mine atmosphere is proportional to the first and second powers of the coal dust particle velocity. The change in the vertical component of the coal dust particle velocity depends on the particle form factor, that is, the ratio of its length to thickness. The obtained calculation results and graphical dependences of the sedimentation of coal dust particles explain the spread of coarse coal dust fractions in the mine workings with a size of 100 microns by 50–150 m, and practically non–precipitating fine fractions with a size of less than 10 microns, which are carried into the atmosphere by a ventilation jet. These statements are in good agreement with field observations.

Kubrin S. S., Kharchenko A. V., Zakharov V. N. Determination of sedimentation rate of coal dust depending on its size and form factor. MIAB. Mining Inf. Anal. Bull. 2026; (10-1):5-19. [In Russ]. DOI: 10.25018/0236_1493_2026_101_0_5.

S.S. Kubrin¹, Dr. Sci. (Eng.), Professor, Chief Researcher, Head of Laboratory, e-mail: s_kubrin@mail.ru, ORCID ID: 0000-0002-0490-9065,
A.V. Kharchenko¹, Cand. Sci. (Eng.), Assistant Professor, Senior Researcher, e-mail: av-kharchenko@yandex.ru, ORCID ID: 0000-0003-3036-6663,
V.N. Zakharov¹, Academician of the Russian Academy of Sciences, Dr. Sci. (Eng.), Professor, Chief Researcher, Scientific Advisor of the Institute, e-mail: val_zakharov@mail.ru, ORCID ID: 0000-0002-9309-2391,
¹ Institute of Comprehensive Exploitation of Mineral Resources, Russian Academy of Sciences, 111020, Moscow, Russia.

A.V. Kharchenko, e-mail: av-kharchenko@yandex.ru.

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