Abstract:In order to understand the occurrence regularity of mine gas and evaluate the possibility of gas emission, the gas parameters of No. 8+9 and No. 15 coal seams in Duanwang Coal Mine were tested, and the coal seam porosity, adsorption constant, gas content, gas pressure and initial gas desorption rate were analyzed. The results show that: (1) the gas content of coal seam is relatively high. The gas contents of No. 8+9 and No. 15 coal seams are 3.68m3/t and 8.98m3/t respectively. The gas pressures are 0.24MPa and 0.49MPa respectively. (2) The initial gas desorption rates of No. 8+9 and No. 15 coal seams are 10.7mmHg and 13.2mmHg respectively, indicating that coal seams have the risk of outburst. Gas pre-extraction shall be carried out during coal seam mining and gas prevention measures must be formulated. (3) The flow attenuation coefficients of drill holes in No. 8+9 and No. 15 coal seams are 0.017d-1 and 0.019d-1, and the permeability coefficients of coal seams are 4.412MPa2·d and 9.000MPa2·d. The comprehensive evaluation shows that the gas in No. 8+9 and No. 15 coal seams can be emitted. The measured results provided the basis and foundation for gas management and comprehensive utilization.
