Journals →  Eurasian mining →  2019 →  #1 →  Back

ArticleName Technology of extended pillar recovery in room and pillar mining in leading coal producing countries. Review
DOI 10.17580/em.2019.01.05
ArticleAuthor Prokopenko S. A., Sementsov V. V., Dobrovolsky M. S.

National Research Tomsk Polytechnic University, Tomsk, Russia:

Prokopenko S. A., Professor, Leading Researcher, Doctor of Engineering Sciences,


Scientific Center VostNII, Kemerovo, Russia:

Sementsov V. V., Head of laboratory, Candidate of Engineering Sciences
Dobrovolsky M. S., Senior Researcher, Mining Engineer


The room and pillar method (RPM) of coal extraction is used by Russian mines in areas unsuitable for longwalling while foreign mines apply it as the dominant technology at high cost–performance ratio. Evaluation of potential expansion of application domain for RPM in Russia needs in-depth study of foreign high-efficiency coal mining technologies. This article reviews process flow charts of coal extraction from pillars in the room and pillar mining technology in the USA, Australia, South Africa, etc. The technological advance is based mobile roof support applied since 1970 for ground control and to ensure safety of people and equipment. The structure and implementation variants of the support are discussed. There are two groups of the pillar recovery technologies with mobile roof support. The groups differ by conditions, parameters and sequence of mining operations. The first group includes variants of coal extraction from extended pillars between long rooms. The flow charts of one-side and two-side pillar recovery with different sets of MRS are discussed. The sequence of cutting entries in pillars, advancing the support and leaving support segments in the pillars are described. The second group of the process flow charts concerns square rib pillars. Such pillars left with initial parameters in mines resulted in high coal loss, and variants of partial coal extraction have been found therefore. Square pillars are recovered with mobile roof supports subsequently from four sides. The roof support is ensured by three MRS. The entries in the pillars are cut by the Christmas tree method, which shortens ferry time of cutter–loaders and improves coal production output. In hazardous conditions, pillars are cut by entries made along two sides. Diagonal entries can be used as well. Design and application of the advanced equipment for RPM has offered diverse technologies possibilities to miners in different countries to carry out safe extraction of coal from pillars and to increase the rate of of coal pillar recovery to 90 % and higher.

The article has been prepared ion the framework of the Competitive Recovery Program of the National Research Tomsk Polytechnic University.

keywords Mine, coal, room, mining, panel, pillar, roof, technology, mobile roof support, extraction, reserves

1. Mark C., Gauna M. Preventing roof fall fatalities during pillar recovery: A ground control success story. International Journal of Mining Science and Technology. 2017. Vol. 27. рр. 107–113.
2. Baskakov V. P., Rozenbaum M. A., Kalinin S. I., Sementsov V. V., Dobrovolsky M.S. Shortwall mining of thick coal seams in the conditions of gas dynamic event hazard. Ugol. 2015. No. 11. pp. 17–20.
3. Sementsov V. V., Dobrovolsky M. S., Nifanov E. V., Shabalin M. P. Use of the shortwall system in coal seams prone to dynamic phenomena. Vestnik NTS VostNII. 2017. No. 2. pp. 27–31.
4. Filatov Yu. M., Sementsov V. V., Prokopenko S. A., Ermolaev A. M., Sobolev V. V. Improvement of safety and efficiency in pillar recovery in room and pillar method of coal seam mining. Ugol. 2018. No. 12. pp. 16–20.
5. Sementsov V. V., Dobrovolsky M. S., Nifanov E. V., Shabalin M. P. Analysis of pillar recovery technology in room and pillar mining in Russia. Vestnik NTS VostNII. 2018. No. 4.
6. Trubetskoy K. N., Galchenko Yu. P. Nature-like mining technologies — Prospect for global conflict resolution in development of mineral resources of the lithosphere. Vestnik RAN. 2017. Vol. 87. No. 7. pp. 655–662.
7. Trubetskoy K. N., Rylnikova M.V., Klebanov D. A., Makeev M. A. Research and technology in reorganization of open pit mining management using robotic machinery. Gornaya Promyshlennost. 2017. No. 5. pp. 27–31.
8. Prokopenko S. A. To coal power—high technologies. Ugol. 2005. No. 7. pp. 55–57.
9. Prokopenko S. A., Ludzish V. S., Li A. A. Recycling possibilities for reducing waste from cutters on combined cutter-loaders and road builders. Waste Management & Research. 2017. Vol. 35(12). pp. 1278–1284.
10. Poderi R. Yu., Klementeva I. N., Lyapin D. G. Peculiarities of interaction between rotary bucket wheel excavator tool and rocks in their contact friction zone. Ugol. 2016. No. 12. pp. 20–22.
11. Khalevin A. A., Shotter A. V. Import substitution and development of high-speed drivage system. Ugol. 2017. No. 5. pp. 42–44.
12. Prokopenko S. A., Ludzish V. S., Kurzina I. A., Sushko A. V. Results of industry testing of multiple-use rock-cutting picks. Gornyi Zhurnal. 2015. No. 5. pp. 67–71. DOI: 10.17580/gzh.2015.05.14.
13. Chernikova A. A., Petrov V. L. Training of mining engineers at the Russian research universities. Gornyi Zhurnal. 2015. No. 8. pp. 103–106. DOI: 10.17580/gzh.2015.08.22
14. Makarov A. M. Expansion of the mechanical supervisor functional. Ugol. 2015. No. 1. pp. 56–57.
15. Uvarova V. A., Baskakov V. P. Fire and toxic safety control over polymeric materials in mines. Bezopasnost truda v promyshlennosti. 2015. No. 3. pp. 45–50.
16. Artemev V. B., Galkin V. A., Makarov A. M., Kravchuk I. L., Galkin A. V. Mechanism of hazardous production situation prevention. Ugol. 2016. No. 5. pp. 73–77.
17. Wilson H. G. Mobile roof support for retreat mining. Proc. 10th International Conference on Ground Control in Mining. S. Peng (Ed.). WV Univ., 1991. pp. 103–114.
18. Howe L. A Decade of mobile roof support application in the United States. Proc. 10th International Conference on Ground Control in Mining. S. Peng (Ed.). WV Univ., 1998. pp. 187–201.
19. Howe L. Two Decades of Mobile Roof Support Applications. Available at: (accessed: 17.11.2017).
20. Lind G. H. Key success elements of coal pillar extraction in New South Wales. The Journal of the South African Institute of Mining and Metallurgy. May/June 2002. рр. 199–205.
21. Mark C., Chase F. E. Analysis of retreat mining pillar stability (ARMPS). Proc. Seminar on New Technology for Ground Control in Retreat Mining. Pittsburgh. U.S. Bureau of Mines, 1997. рр. 17–34.
22. Mark C., Zelanko J. Sizing of final stumps for safer pillar extraction. 20th International Conference on Ground Control in Mining Morgantown, Virginia, USA, 2001. рр. 59–66.
23. Maleki H., Owens J., Endicott M. Field evaluation of mobile roof support technologies. Proc. 20th International Conference on Ground Control in Mining. Morgantown, WV. West Virginia University, 2001. рр. 67–77.
24. McTyer K., Sutherland T. The Duncan method of partial pillar extraction at Tasman Mine. Proc. 11th Underground Coal Operators’ Conference, University of Wollongong & the Australasian Institute of Mining and Metallurgy, 2011, рр. 8–15.
25. Galvin J. M. Pillar extraction. Ground Engineering–Principles and Practices for Underground Coal Mining. Springer, 2016. рр. 309–358.
26. Galvin J. M. Strata Control for Coal Mine Design Project. Research report no. 2/96. Sydney : UNSW School of Mining Engineering/Joint Coal Board OH&S Trust, 1996. р.107.
27. Beukes J. S. Pillar and rib pillar extraction in South African collieries. Part 1–RR No. 3/89, Part 2–RR No. 20/89, Part 3–RR No. 8/90. Johannesburg: Chamber of Mines of South Africa Research Organisation, 1990. рр. 340.
28. Galvin J. M. Pillar extraction–Buried continuous miners. Iss. 3. Strata Control for Coal Mine Design Newsletter. School of Mines, University of New South Wales, 1993. рр. 2–3.

Full content Technology of extended pillar recovery in room and pillar mining in leading coal producing countries. Review