Physical Modeling of Cryogenic Treatment of Coal Seam with Liquid Nitrogen in Naked Hole
S. V. Serdyukov, L. A. Rybalkin, I. M. Serdyuk, T. V. Shilova
Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Coal seam, hole, cryogenic treatment, liquid nitrogen, physical modeling, rock pressure, temperature, thermal map, acoustic emission, spectral processing, oscillation strength, permeability
Abstract
The authors describe the research findings on cryogenic treatment of a physical model of face zone in a loaded coal seam containing a gas drainage hole. The treatment process included serial injection of liquid nitrogen in a naked hole drilled in the center of the model. Reactions of dry and water saturated coal were tested depending on hydrostatic compression. During the experiments, the change in temperature acoustic emission and permeability of coal was recorded at different distances from the hole. The engineering and methodical solutions used in observations and data processing are described. The influence of coal saturation with water on the velocity of cooling of the model medium and on the increase in its permeability is demonstrated. The utilization efficiency of liquid nitrogen in cryogenic treatment in a naked hole is estimated, based on the obtained results, the recommendations are formulated for the field tests at coal deposits.
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