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In order to control the extremely complex +1 030 m horizontal fourth mining fire area with a wide spread concealed smoldering state at 4238 working face of Huashan Mine, combine active fire-fighting with partition isolation and fire control as the basic idea, comprehensive fire-fighting techniques, such as remote sealing after shrinkage, inorganic material filling, liquid carbon dioxide cooling, nitrogen injection inerting, flyash slurry filling in the roadway and filling in the surrounding roadway in smoldering fire areas, have been successively adopted for treatment. The results show that the fire in 4238 working face has been extinguished, after a long time of high intensity treatment, the fire has been gradually extinguished, the concentration of carbon monoxide gas is controlled below 1×10-5, at present, the management of the fire area is at the end stage.

To solve the problem of controlling concealed fire source of typical small kilns in Datong Mining Area, the combination method of experimental analysis and infrared thermal imaging technology is adopted to study the detection and control technology of concealed fire source, i.e. through the programmed heating experiment, it is found that compared with the traditional grouting fire-proof material, the large aggregate accumulation isolation materials is more effective in inhibiting the increase of coal temperature and reducing the concentration of spontaneous ignition signature gas, and the infrared thermal imaging and drilling techniques are used to delineate concealed fire sources. The large aggregate accumulation filling materials are injected into the area suspected to be the fire source, and the materials have the characteristics of fast coagulation, easy formation and high strength, so the isolation strip is quickly constructed to gradually suffocate the fire area. The results show that the infrared thermal imaging technology can be used as an effective method for detecting and delineating concealed fire sources. At the same time, large aggregate accumulation and isolation filling materials can not only effectively prevent small kiln fire from invading the main mining face, but also cut off oxygen supply in the fire area to achieve the purpose of asphyxiating the fire area.

In the southeastern part of Datong Mining Area, the minefield is seriously damaged by the disorderly mining of small kilns, and the distribution of small kiln fires is wide spread, which has become the main factor threatening the safety of mine production. On the basis of adhering to the principle of“first detection and then governance”, the concealed fire scope of small kilns is preliminarily delineated by adopting the detection method combining surface drilling with underground drilling. In order to lay a foundation for the follow-up targeted control measures, and in combination with the actual conditions of mine production technology, after further adopting regional isolation and pressure equalization techniques, the concentration of CO gas in the borehole was observed to drop to 20 ppm, and the temperature was below 25 ℃, effectively controlling the serious situation of the small kiln fire in the lower coal seam on the coal seam working face. The interference ensures the smooth progress of mine safety production.