Assessment of Coal Permeability in Cyclic Treatment with Liquid Nitrogen
S. V. Serdyukov, I. M. Serdyuk, L. A. Rybalkin, T. V. Shilova, A. S. Serdyukov
Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: coal, cyclic treatment with liquid nitrogen, permeability, ultrasound velocity, jointing, optimization of number of treatment cycles
Abstract
The article describes the lab-scale tests of permeability of long-flame coal from the Mokhovsky Coal Mine in Kuzbass depending on the intensity of cyclic treatment of coal with liquid nitrogen. The freezing effect on jointing was assessed by a change in the gas flow and in the ultrasound velocity. It is found that permeability of the test coal in compression rises up to commercially significant values. To reach this effect, it is sufficient to implement three-four cycles of treatment with liquid nitrogen. The treatment decreases the ultrasonic P-wave velocity by up to 6%, which points at the increase in the volumetric density of microcracks.
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