To thoroughly reveal the intrinsic relationships among coal gas adsorption-desorption characteristics, coal structure, and oxidation activity under deep high-temperature and high-pressure conditions, and optimize gas extraction schemes for high-gas mines, we performed a study. Coal samples from the 2201 mining face of No.2 coal seam in Xiaohuigou Coal Mine, China, were selected as the research object. A series of tests were systematically conducted under experimental temperature: 30-120℃, pressure: 0.5-2.5MPa, including proximate analysis, ultimate analysis, adsorption-desorption experiments, thermogravimetric analysis (TG), and Brunauer-Emmett-Teller (BET) pore structure test. The regulatory mechanism of coal gas adsorption and desorption under the coupling effect of temperature and pressure was clarified. The response mechanism between the pore structure of coal samples and their pyrolysis characteristics was determined. An optimization method for gas extraction parameters based on "synergistic regulation of pressure and desorption capacity" was established. This technology was successfully applied to the gas control scenario of the 2201 working face. After applying this technology, the average gas concentration at the upper corner of the working face decreased to 0.40%, with the maximum concentration controlled below 0.67%. The width of the goaf oxidation zone was reduced from the original 40-50 m to 25-30 m. The pure gas extraction flow rate per borehole reached 3.77 m3/min, equivalent to the extraction effect of 580 Φ113 mm reverse drilling holes. The cumulative pure gas extraction volume reached 7.01×105 m³, which effectively guarantees the safe production during the high-intensity mining of the working face.
Zou et al. (2025) studied this question.