Prevention and Origin of Exceptional Deleterious Gas Compositions in Coal Mine

The abnormal content of gas compositions of H2S, CO2, CO and N2 under coal mine has close relationship of safe production and comprehensive utilization of coal gas. According to original analyses of anomalous accumulation characteristics of the above-mentioned gas in China, the paper suggests that abnormal thermochemistry effect, osmosis effect of surface water, sealed effect of coalseam floor, coal types and coal metamorphose degree are the main factors which contribute to abnormity of deleterious gas compositions. Based on study of gas origin, primary measures for prevention and control of deleterious gas in coal excavating course were brought forward. The research has guiding significance for safe production of coal mine.