Application of Liquid CO₂ Fire-extinguishing Technique in Gongquan Coal Mine

In order to control the spontaneous combustion in 2272 goaf of Gongquan Coal Mine and resume the safety production of 2273 working face as soon as possible, liquid CO₂ direct injection and fire-extinguishing technique was adopted, and liquid CO₂ was transported to the vicinity of 2273 working face by using KRM-1200 liquid carbon dioxide fire-extinguishing device. Through high pressure hose connected to the fire prevention drilling, liquid CO₂ was directly injected into spontaneous combustion zone of 2272 goaf. The concentration of CO decreased sharply in 2272 goaf, and the index gases such as C₂H₂ and C₂H₄ disappeared.