Study On Gas Emission Law Of Full-mechanized Working Face In Steep Thick Coal Seam

Gas accident is of importance in coal mine disasters. In coal mines,gas disasters mainly including gas (dust)explosion accidents, coal and gas outburst accidents. According to the statistics of state administration of work safety state administration of coal mine safety, a total of 123 gas accidents in all mines in China resulted in 1052 deaths from January 2008 to December 2009. Gas accidents and deaths accounted for 58.6% and 80.3% of total coal mine accidents. The proportion of gas accidents in coal accidents is growing, it has become the No.1 killer of production safety in coal mines.The reserves of steep thick seam accounted for 4% of total reserves in China and 80% of the southern mines has steep thick seam. The specificity of mining methods and technology in steep thick seam causes the gas emission more complex than nearly level, gently steep coal seam. The analysis of sources and the law of gas emission, the choice of gas emission prediction methods and the construction of prediction model which predictthe gas emission volume are supplement to the gas emission law and the gas emission prediction and is security of achieving gas control targeted.Combining with the flow theory of gas in the coal seam and the mining technology specificity of sub-level caving mining method in steeply inclined thick coal seam, the source of gas emission of the full-mechanized mining working face in steep thick seam is analysis identified. On this basis, the sub-prediction method is selected to project the volume of gas emission in working face. The gas monitoring data in past working face and in working face being mined are analyzed comprehensively with a theoretical analysis combined with field experiments and field monitoring means. By comparing and studying the data which from a variety of functions in regression analysis, the law of gas emission of every gas emission source of the full-mechanized mining working face in steep thick seam is identified. On the basis of the law of gas emission of every gas emission source, the prediction model of gas emission volume in steep thick seam is constructed. Finally, the model is applied to 3537 working face of zhaogezhuang mine. The result verifies that the model is accurate through tunnel assay.The study of gas emission law and the prediction model construction of gas emission volume in steep thick seam provides a science and effective way for mines to reduce or eliminate gas disasters.