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%.

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.

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.

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

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