Method for ensuring safe stoping of working face under old fire area of shallow-buried close-distance coal seam group

Abstract

The invention relates to the field of fire prevention and control, in particular to a method for guaranteeing safe stoping of a working face under an old fire area of a shallow-buried short-distance coal seam group. Comprising the following steps. And S100, digging a stope face of the lower coal group of the shallow-buried close-distance coal seam group, and drilling a plurality of groups of observation-exhaust holes towards the old fire area in the air inlet crossheading, the air return crossheading and the open-off cut of the lower coal group after the stope face is arranged. S200, before working face stoping, a plurality of sets of ground nitrogen injection-grouting holes are formed in the position, located between an air inlet way and an air return way, over the working face from the ground to the old fire area. And S300, before working face stoping, liquid nitrogen is poured into the old fire area from the ground nitrogen injection-grouting holes, fire sources possibly existing in the old fire area are extinguished through liquid nitrogen injection, the goaf is inerted, and the pressure difference between the goaf and the ground is balanced. And S400, after exhausting is finished, working face stoping is conducted, slurry is poured into the old fire area from the ground nitrogen injection-grouting hole, grouting is stopped till the ground nitrogen injection-grouting hole is located above the goaf suffocation zone, and stope cracks are blocked through the slurry.

Description

technical field [0001] The invention relates to the field of fire prevention and control, in particular to a method for ensuring safe recovery of a working face under an old fire area of ​​a shallow-buried coal seam group at a short distance. Background technique [0002] For the working face of shallow buried coal seam group mining, due to the shallow buried depth of the coal seam, the overlying strata collapsed and deformed after the mining of the working face, forming a gas conduction zone in the vertical direction, and the gas conduction zone is connected to the ground. Because mines generally adopt negative pressure ventilation, there is a pressure difference between the ground and the underground, which intensifies the air leakage from the ground to the goaf, which makes the goaf very prone to natural fire disasters. After the spontaneous combustion of the overlying coal seam, it is necessary to implement fire extinguishing measures such as sealing, but after the fire ...

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Problems solved by technology

[0003] The invention aims to solve the problem that the gas in the old fire area overlying the mining layer of shallow buried close-distance coal seam group pours into the working face of the lower layer, causing the poisonous and harmful gas in the working face of the lower layer to exceed the limit and the goaf to spontaneously ignite, and provides a method to ensure shallow burial The method of safe mining in the working face under the old fire area of ​​the close-distance coal seam group

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