Reasons of efficiency of surface miners in selective coal cutting under low temperatures

The article discusses feasibility of selective coal cutting by surface miners under conditions of permafrost. The strength test data on splitting irregularly shaped coal samples by opposite-directed spherical indenters after preliminary freezing of the samples in a climate cell are presented. The testing conditions were: minimal and maximal treatment temperatures -40 °C and +23 °C, respectively; relative humidity up to 60%. The coal failure envelopes are plotted. It is found that with decreasing temperature down to critical values (-20 °C and lower), the ultimate uniaxial compression and tension strengths, and the failure envelope parameters grow essentially. The capacity of Wirtigen SM surface miner is related with the strength characteristics of the test coal under different ambient temperatures (0, -10 °C, –20 °С, –30 °С, –40 °С). From the analysis of the resultant relationships, it follows that reduction in the surface miner capacity in frozen rock cutting can reach 43.0%.

 

Keywords: coal, failure envelope, brittleness ratio, spherical indenters, permafrost zone, selective cutting, capacity, surface miner.
For citation:

Yakubovskiy M. M., Mikhailova E. A., Mikhailova E. A., Bazhukov A. A. Reasons of efficiency of surface miners in selective coal cutting under low temperatures. MIAB. Mining Inf. Anal. Bull. 2021;(10):42-57. [In Russ]. DOI: 10.25018/0236_1493_2021_10_0_42.

Acknowledgements:
Issue number: 10
Year: 2021
Page number: 42-57
ISBN: 0236-1493
UDK: 622.33, 622.063.44
DOI: 10.25018/0236_1493_2021_10_0_42
Article receipt date: 31.12.2020
Date of review receipt: 19.02.2021
Date of the editorial board′s decision on the article′s publishing: 10.09.2021
About authors:

M.M. Yakubovskiy1, Cand. Sci. (Eng.), Assistant Professor, e-mail: yakubovskiy_mm@pers.spmi.ru,
E.A. Mikhailova1, Student, e-mail: elena_mikhailova96@mail.ru,
A.A. Bazhukov1, Engineer, Scientific Center for Geomechanics and Mining Problems, e-mail: alex.bajukov2016@yandex.ru,
1 Saint-Petersburg Mining University, 199106, Saint-Petersburg, Russia.

 

For contacts:

E.A. Mikhailova, e-mail: elena_mikhailova96@mail.ru.

Bibliography:

1. Moskalev A. N., Pigida E. Yu., Kerekilitsa L. G., Vakhalin Yu. N. Razrushenie gornykh porod pri termotsiklicheskom vozdeystvii [Destruction of rocks under thermocyclic effects], Kiev, Naukova dumka, 1987, 250 p.

2. Kurilko A. S., Zakharov E. V. Experimental studies of the effect of negative temperatures on the energy intensity of carbonate rock destruction. MIAB. Mining Inf. Anal. Bull. 2011, no. S10, pp. 154—162. [In Russ].

3. Epshtein S. A., Nikitina I. M., Agarkov K. V., Nesterova V. G., Minaev V. I. Effects of cyclic freezing and thawing on coals quality indices. MIAB. Mining Inf. Anal. Bull. 2019, no. 6, pp. 5—18. [In Russ]. DOI: 10.25018/0236-1493-2019-06-0-5-18.

4. Będkowski T., Kasztelewicz Z., Sikora M. Technical and economic analysis of mechanical rock extraction based on 'Raciszyn' deposit. Inzynieria Mineralna. 2016, vol. 17, no. 2, pp. 107—112.

5. Ordin A. A. Schwabenland E. E. Evaluation of technological parameters for apatite extraction by surface miners. Journal of Mining Science. 2016, vol. 52, no. 2, pp. 293—299.

6. Volk H. Wirtgen drives the development of surface mining. Procedia Engineering. 2016, vol. 138, pp. 30—39.

7. Kramadibrata S., Simangunsong G. M., Widodo N. P., Wattimena R. K., Tanjung R. A., Wicaksana Y. Rock excavation by continuous surface miner in limestone quarry. Geosystem Engineering. 2015, vol. 18, no. 3, pp. 1—13.

8. Korshunov V. A., Petrov D. N., Yastrebova K. N. Design method for building a rock strength certificate based on the results of tests of samples by spherical indentors. Innovatsionnye napravleniya v proektirovanii gornodobyvayushchikh predpriyatiy: geomekhanicheskoe obespechenie proektirovaniya i soprovozhdeniya gornykh rabot. VIII Mezhdunarodnaya nauchnoprakticheskaya konferentsiya. Sbornik nauchnykh trudov [Innovative directions in the design of mining enterprises: geomechanical support for the design and maintenance of mining works. VIII International Scientific and Practical Conference. Collection of scientific works], Saint-Petersburg, SPbGU, 2017, pp. 256—265. [In Russ].

9. Korshunov V. A., Kartashov Yu. M. A new method for determining the ultimate tensile strength of rocks. Journal of Mining Institute. 2011, vol. 190, pp. 202—206. [In Russ].

10. Korshunov V. A., Kartashov Yu. M., Kozlov V. A. Determination of rock strength passport indices by the method of destruction of samples by spherical indentors. Journal of Mining Institute. 2011, vol. 185, pp. 41—45. [In Russ].

11. Pavlovich A. A., Korshunov V. A., Bazhukov A. A., Melnikov N. Ya. Assessment of the strength of the rock mass during the development of deposits in an open way. Journal of Mining Institute. 2019, vol. 239, pp. 502—509. [In Russ].

12. Neskoromnykh V. V. Razrushenie gornykh porod pri provedenii geologorazvedochnykh rabot: uchebnoe posobie [Destruction of rocks during exploration: Educational aid], Krasnoyarsk, SFU, 2015, 396 p.

13. The official website of the Wirtgen Group, available at: https://www.wirtgen-group.com (accessed 27.12.2020).

14. Primenenie kompleksa gornogo oborudovaniya Wirtgen Group v slozhnykh gornotekhnicheskikh usloviyakh Pikalevskogo kar'era, available at: https://mining-media.ru/ru/article/ ogr/336-primenenie-kompleksa-gornogo-oborudovaniya-wirtgen-group-v-slozhnykh-gornotekhnicheskikh-usloviyakh-pikaljovskogo-karera (accessed 27.12.2020).

Подписка на рассылку

Раз в месяц Вы будете получать информацию о новом номере журнала, новых книгах издательства, а также о конференциях, форумах и других профессиональных мероприятиях.