Pulverization patterns of coal from outbursts

The article presents the studies on fracture mechanics of outburst-hazardous coal and on coal pulverization from coal and gas outbursts. The coal samples fractured in outbursts are analyzed at a lab scale. The regular patterns of coal pulverization and coal particle-size distributions are discussed. A procedure is proposed to determine energy input of coal fracture using a modification of Von Rittinger’s and Charles’s laws. The obtained equation is a basic equation defining dependence of linear sizes of fractured particles on the specific work input A and on the mechanical properties of material R (i.e. expression of a law of crushing). The behavior of the distribution function of weak crushed coal particles is revealed empirically. Coals of different damage categories (from I to V) differ by an order of magnitude in crushability at close values of the equivalent radius and are described by the same cumulative curve. The energy input of coal fracture from coal and gas outbursts was investigated on outburst coal samples. The particle-size distribution in coal fracture from outbursts has no difference from the particle-size distribution of coal after mechanical crushing. The investigations show that in terms of energy, pulverization of outburst-hazardous coal has a more complex nature, which is due to the damage ratio of coal, nonuniform distribution of cracks and their different-size opening in coal.

Grechishkin P. V., Sokolov K. V., Malova S. A. Pulverization patterns of coal from outbursts. MIAB. Mining Inf. Anal. Bull. 2024;(12):18-28. [In Russ]. DOI: 10.25018/0236_ 1493_2024_12_0_18.

P.V. Grechishkin, Cand. Sci. (Eng.), Director, Kemerovo branch of JSC Scientific Research Institute of Mining Geomechanics and Surveying-Interdisciplinary Scientific Center «VNIMI», 650002, Kemerovo, Russia, e-mail: pv_grechishkin@mail.ru, ORCID ID: 0009-0003-3974-2685,
K.V. Sokolov, Chief Engineer, Chertinskaya-Koksovaya Mine, MMK-Ugol LLC, 652607, Belovo, Russia, e-mail: office@mmk-coal.ru,
S.A. Malova, Specialist in Educational and Methodological Work, NUST MISIS, 119049, Moscow, Russia, e-mail: malova.sa@misis.ru, ORCID ID: 0009-0009-7045-8694.

P.V. Grechishkin, e-mail: pv_grechishkin@mail.ru.

1. Shadrin A. V. Justification of the functional diagram of the subsystem for forecasting sudden coal and gas emissions. Vestnik of safety in coal mining scientific center. 2022, no. 3, pp. 6—15. [In Russ].

2. Kanin V. A., Piven Yu. A., Rozhko M. D. Assessment of the rock burst hazard of coal and anthracite seams in the mines of the Donetsk coal basin. Proceedings of RANIMI. 2024, no. 2(40), pp. 43—59. [In Russ].

3. Osipova I., Gospodinova V. Representation of the process of sudden outbursts of coal and gas using a knowledge graph. E3S Web of Conferences. 2020, vol. 192, no. 83, article 04022. DOI: 10.1051/ e3sconf/202019204022.

4. Lama R., Saghafi A. Overview of gas outbursts and unusual emissions. Wollongong, 2020, 16 p.

5. Li T., Cai M. F., Cai M. Earthquake-induced unusual gas emission in coalmines — A km-scale in-situ experimental investigation at Laohutai mine. International Journal of Coal Geology. 2007, vol. 71, no. 2—3, pp. 209—224.

6. Chen Y., Liu R., Xuan P. A calculation method of gas emission zone in a coal mine considering main controlling factors. Scientific Reports. 2021, vol. 11, article 23597. DOI: 10.1038/s41598-021-03090-5.

7. Romanchenko S. B., Devlikanov M. O. Influence of the dispersed composition of coal dust on explosion hazard indicators. Vestnik of safety in coal mining scientific center. 2019, no. 2, pp. 16—23. [In Russ].

8. Borisenko A. A. Destruction of the bottomhole zone of the formation during a sudden outburst. Tekhnika bezopasnosti, okhrana truda i gornospasatel'noe delo [Safety, labor protection and mine rescue], Moscow, Nedra, 1968, pp. 26.

9. Shpurgalova Yu. A., Shpurgalova M. Yu. Methodology for optimizing the parameters of the rock crushing process. System analysis and applied information science. 2015, no. 1, pp. 53—58. [In Russ]. DOI: 10.21122/2309-4923-2015-1-53-59.

10. Segarra P., Sanchidrian J. A., Navarro J., Castedo R. The fragmentation energy-fan model in quarry blasts. Rock Mechanics and Rock Engineering. 2018, vol. 51, pp. 2175—2190. DOI: 10.1007/ s00603-018-1470-9.

11. Fadeenkov N. N., Trufakin N. I. On the quantitative assessment of energy consumption for rock disintegration. Fiziko-tekhnicheskie problemy razrabotki poleznykh iskopaemykh. 1982, no. 3, pp. 58—61. [In Russ].

12. Charles R. I. Energy-size reduction relationships in comminution. Trans. A.I.M.E. 1957, vol. 208, pp. 80—88.

13. Borisenko A. A. Energy intensity of coal destruction in outburst-hazardous seams. Fiziko-tekhnicheskie problemy razrabotki poleznykh iskopaemykh. 1979, no. 5, pp. 96—101. [In Russ].

14. Borisenko A. A., Tkachenko E. S. Work of coal destruction during sudden outbursts. Ugol'. 1978, no. 12, pp. 20—23. [In Russ].

15. Khalkechev R. K. Application of the theory of multifractal modeling of deformation and destruction processes of rock masses for the purpose of short-term forecasting of sudden coal and gas outbursts. Ugol'. 2019, no. 7 (1120), pp. 48—50. [In Russ]. DOI: 10.18796/0041-5790-2019-7-48-50.

16. Borisenko A. A. Conditions of occurrence and mechanism of sudden outbursts and other gasdynamic phenomena in mines. Nauchnye soobshcheniya Instituta gornogo dela im. A.A. Skochinskogo. 1979, no. 182, pp. 3—11. [In Russ].

17. Cherepanov G. P. Mekhanika khrupkogo razrusheniya [Mechanics of brittle fracture], Moscow, Nauka, 1974, 640 p.

18. Kouzov P. A. Osnovy analiza dispersnogo sostava promyshlennykh pyley i izmel'chennykh materialov [Fundamentals of analysis of dispersed composition of industrial dusts and crushed materials], Leningrad, Khimiya, 1971, 280 p.

19. Khodot V. V. Vnezapnye vybrosy uglya i gaza [Sudden emissions of coal and gas], Moscow, Gosgortekhizdat, 1961, 362 p.