Experimental study of change in physical and mechanical properties of anthracite under temperature exposure

The paper presents the experimental data of laboratory thermomechanical tests of anthracite specimens from the Gorlovsky Coal Basin (Novosibirsk Region). It is confirmed that the physical and mechanical properties of geomaterials undergo significant changes under conditions of higher temperature. The experimental results demonstrate a quite significant decrease in the ultimate uniaxial compressive strength σc and the static modulus of elasticity E of the anthracite samples. It is shown that anisotropy of mechanical properties accounts for differences in the temperature dependences of the strength characteristics and deformation behavior of the anthracite specimens subjected to heating. Consideration is given to such a fundamentally significant aspect of experimental geomechanics as the reliability of the results of laboratory tests of geomaterials. Importantly, our experimental investigation involved non-destructive laser ultrasonic diagnostics to qualitatively assess the degree of disturbances of the internal structure of anthracite specimens; subsequently some specimens were rejected («censored»). As a result, a statistically significant sample of specimens is created, having low variability in the physical and mechanical properties. Thus, it can be concluded that the efficiency of quantitative assessment of the strength characteristics and deformation behavior of geomaterials can be increased if both destructive and non-destructive (introscopic) methods are employed.

Ivanov P. N., Blokhin D. I., Zakorshmennyy I. M. Experimental study of change in physical and mechanical properties of anthracite under temperature exposure. MIAB. Mining Inf. Anal. Bull. 2021;(4-1):41—51. [In Russ]. DOI: 10.25018/0236_1493_2021_41_0_41.

Ivanov P. N.¹, PhD-student, pavelnivanov@mail.ru;
Blokhin D. I.^1,2, Cand. Sci. (Eng.);
Zakorshmennyy I. M.², Dr. Sci. (Eng.);
¹ National Research Technological University «MISiS» , Moscow, Russia;
² Institute of Comprehensive Exploitation of Mineral Resources Russian Academy of Sciences, Moscow, Russia.

1. Oparin V. N. Kiryaeva T. A. Usoltseva O. M. Tsoi P. A. Semenov V. N. On the features of the development of nonlinear deformation-wave processes in coal samples of various stages of metamorphism during their loading to failure in a changing temperature field. Fizikotekhnicheskiye problemy razrabotki poleznykh iskopayemykh. 2015, no. 4. pp. 3—24 [In Russ].

2. Yin T. B. Wang P. Li X. B. Shu R. H. Ye Z. Y. Effects of thermal treatment on physical and mechanical characteristics of coal rock. Journal of Central South University, 2016, Vol. 23, pp. 2336—2345. DOI: 10.1007/s11771-016-3292-9.

3. Fedorov V. A. Ushakov I. V. Shelokhvostov V. P. Effect of temperature on morphologic peculiarities of laser-induced calcite damage . Fizika i Khimiya Obrabotki Materialov. 1998, Vol. 1, pp. 37—40.

4. Kong B. Li Z. Wang E. Fine characterization rock thermal damage by acoustic emission technique. Journal of Geophysics and Engineering. 2018, no. 15 (1), pp. 1—12. DOI: 10.1088/1742—2140/aa9a54.

5. Hosseini M. Effect of temperature as well as heating and cooling cycles on rock properties. Journal of Mining and Environment. 2017, Vol. 8, no. 4, pp. 631—644. DOI: 10.22044/jme.2017.971.

6. Ivanov B. M, Faith G. N. Yanovskaya M. F. Mekhanicheskiye i fiziko-khimicheskiye svoystva vzryvoopasnykh ugol’nykh plastov [Mechanical and physico-chemical properties of coal from hazardous coal seams]. Moscow: Nauka, 1979, 195 p. [In Russ].

7. Kossovich Ye. L. Epshteyn S. A. Shkuratnik V. L. Minin M. G. Prospects and problems of using modern technology of microand nanoindentation for diagnostics of mechanical properties of coals. Gornyi Zhurnal. 2017, no. 12, pp. 25—30. DOI 10.17580/gzh.2017.12.05 [In Russ].

8. Dudchenko O. L. Fedorov G. B. Andreev A. A. Innovative method for the classification of coal slurries . Ugol’. 2018, Vol. 6, pp. 67—71. DOI: 10.18796/0041-5790-2018-6-67-71 [In Russ].

9. Melnikov N. N. Mesyats S. P. Ostapenko S. P. Cherepetskaya E. B. Shibaev I. A. Morozov N. A. Kravcov A. N, Konvalinka A. Investigation of disturbed rock zones in open-pit mine walls by seismic tomography. Key Engineering Materials, 2017, Vol 755, pp 147—152. DOI: 10.4028/www.scientific.net/KEM.755.147.

10. Dudchenko O. L. Fedorov G. B. Vibroacoustic technique for intensification of coal preparation . Ugol. 2019, Vol. 4, pp. 62—66. DOI: 10.18796/0041-5790-2019-4-62-66 [In Russ].

11. Shkuratnik V. L. no.vikov E. A. Physical modeling of the grain size influence on acoustic emission in the heated geomaterials. Journal of Mining Science. 2012, Vol. 48, no. 1, pp. 9—14. DOI: https://doi.org/10.1134/S1062739148010029.

12. Beron A. I. Vatolin Ye. S. Koyfman M. I. Mokhnachev M. P. Chirkov S. Ye. Svoystva gornykh porod pri raznykh vidakh i rezhimakh nagruzheniya [Properties of rocks under different types and modes of loading]. Moscow: Nedra. 1984, 276 p. [In Russ].

13. Zakharov V. N. Malinnikova O. N. Investigation of the structural features of coal from outburst-hazardous seams. Zapiski Gornogo instituta. 2014, no. 210, p. 43. [In Russ].

14. Kossovich Ye. L. Epshteyn S. A. Dobryakova N. N. Minin M. G. Structural features and mechanical properties of anthracite, metaanthracite and graphite . Gornyi Zhurnal. 2020, no. 4. pp. 25—29. DOI: 10.17580/gzh.2020.04.05. [In Russ].

15. Victorov S. D. Kochanov A. N. Pachezhertsev A. A. Experimental study of the microstructural characteristics of the surfaces and volumes of granite samples . Bulletin of the Russian Academy of Sciences: Physics. 2018, Vol. 82, no. 7, pp. 786—788.

16. Han Y. Wang J. Dong Y. Hou Q. Pan J. The role of structure defects in the deformation of anthracite and their influence on the macromolecular structure. Fuel. 2017, Vol. 206, pp. 1—9. DOI: 10.1016/j.fuel.2017.05.085.

17. Shibaev I. A. Morozov D. V. Dudchenko O. L. Pavlov I. A. Estimation of local elastic moduli of carbon-containing materials by laser ultrasound. Key Engineering Materials, 2018, Vol. 769, pp. 96—101. DOI: 10.4028/www.scientific.net/KEM.769.96.

18. Bychkov A. S. Cherepetskaya E. B. Karabutov A. A. Makarov V. A. Laser optoacoustic tomography for the study of femtosecond laser filaments in air. Laser Physics Letters. 2016, Vol. 13 (8), no. 085401. DOI: 10.1088/1612-2011/13/8/085401.

19. Zarubin V. Bychkov A. Simonova V. Zhigarkov V. Karabutov A. Cherepetskaya E. A refraction-corrected tomographic algorithm for immersion laser-ultrasonic imaging of solids with piecewise linear surface profile. Applied Physics Letters, 2018, Vol. 112, no. 214102. DOI: 10.1063/1.5030586.

20. Karabutov A. A. Podymova N. B. Cherepetskaya E. B. Determination of uniaxial stresses in steel structures by the laser-ultrasonic method. Journal of Applied Mechanics and Technical Physics. 2017, no. 58 (3), pp. 503—510. DOI: 10.1134/S0021894417030154.

21. Cherepetskaya E. B. Karabutov A. A. Makarov V. A. Mironova E. A. Shibaev I. A. Vysotin N. G. Morozov D. V. Internal structure research of shungite by broadband ultrasonic spectroscopy. Key Engineering Materials. 2017, Vol. 755, pp. 242—247. DOI: 10.4028/www.scientific.net/KEM.755.242.

22. Shibaev I. A. Vinnikov V. A. Stepanov G. D. Determining elastic properties of sedimentary strata in terms of limestone samples by laser ultrasonics. MIAB. Mining Inf. Anal. Bull. 2020, Vol. 7, pp. 125—134. DOI: 10.25018/0236-1493-2020-7-0-125-134.