Research And Engineering Application Of Hydrogen Sulfide Treatment By Injecting Lye Into Coal Seam In Tiexin Coal Mine

Hydrogen sulfide is one of the toxic and harmful gases in coal mine, man will appear severe poisoning symptom when the concentration of hydrogen sulfide in the air current reaches 0.2～0.3%, when the concentration reaches 0.1-0.2%, one can die in a few seconds. In recent years, the number of coal mines that have abnormal emission of hydrogen sulfide is increasing with the increase of mining scope and depth, safety production and workers’health are seriously affected. At present, the main methods of treating hydrogen sulfide in coal mine are to increase the amount of wind in the working face, spraying alkali lime, shielding water curtain and some monitoring measures, although they have made some achievements, the effect is not ideal, therefore, it is urgent to study the root of abnormal emission of hydrogen sulfide, and explore effective treatment methods to reduce or eliminate the hazard of hydrogen sulfide in coal mines.Based on the previous research, the method of alkali injection in coal seam to treat hydrogen sulfide is proposed, theoretical analysis, laboratory tests, field tests and numerical simulation are used to study the source and emission laws of hydrogen sulfide, content of hydrogen sulfide in coal seams and the feasibility and effect of treating hydrogen sulfide by injecting alkali solution into coal seams. The main study aspects are as follows:The Tiexin Coal Mine that exists abnormal emission of hydrogen sulfide is treated as study object, the causes, sources and occurrence laws of hydrogen sulfide in coal seams are studied; in order to determine the content of hydrogen sulfide in every ton of coal, the method of testing content of hydrogen sulfide is proposed; the method of alkali injection in coal seam is used to treat hydrogen sulfide, the feasibility of alkali injection in coal seam is demonstrated by testing physics mechanics parameters of rock; parameters of alkali injection are studied, including alkali solution, injection pressure, injection quantity, borehole length, spacing and hole sealing method; the alkali solution seepage and treatment effect of hydrogen sulfide are studied by numerical simulation software; the alkali injection tests are performed in E902 and W910 working face, the effect of treating hydrogen sulfide by alkali injection in coal seam is researched.The content of hydrogen sulfide is tested in 9# coal seam in Shanxi Baoli Tiexin Coal Mine, and industrial test of alkali injection is carried out, the reasonable alkali injection parameters are determined through the theoretical analysis and alkali injection test, and the control method is applied in this mine, through measuring the emission content of hydrogen sulfide before and after alkali injection in the working face, the concentration of hydrogen sulfide does not appear overrunning phenomenon, this treatment method is proved to be good.