Comprehensive control technology of shaft fire area

Taking south No.2 shaft fire area of Gongwusu Coal Mine as the background, theoretical analysis and field practice are used to study the comprehensive control of shaft fire area. The results show that in the combustion process of coal body in coal field, coal oxidation reaction releases a lot of heat in the combustion center of coal body, the energy carried outside and internal energy of coal body overlying strata become unstable, and the gravity instability of overlying strata leads to deformation and failure, forming a large number of thermal fracture; under the action of thermal wind pressure, fresh air from the surface of the fracture field provides sufficient oxygen for coal combustion, and waste gas generated by combustion is also discharged into the atmosphere through these fractures. In order to control the large area of high temperature fire area in wellbore, the “area isolation method” is proposed. By pouring anti-fire materials into the borehole in the fire area, the temperature of the borehole showed a downward trend. However, due to the sealing has not been finished yet and there are air leakage passages, the temperature of some boreholes remains at 100 ℃ to 120 ℃ for a long time, and plugging measures should be taken in the later stage.