Preventing the propagation of methane or coal dust explosions through the use of active explosion-suppression systems remains one of the most underutilised explosion controls in underground coal mines. As part of the ...Preventing the propagation of methane or coal dust explosions through the use of active explosion-suppression systems remains one of the most underutilised explosion controls in underground coal mines. As part of the effort to develop better technologies to safeguard mines, the use of active barrier systems was investigated at Kloppersbos in South Africa. The system is designed to meet the requirements of the European Standard （EN 14591-4 2007） as well as the Mine Safety Standardisation in the Ministry of Coal Industry, Coal Industrial 1 Standard of the Peoples Republic of China （MT 694-1997）. From the tests conducted, it can be concluded that the ExploSpot System was successful in stopping flame propagation for both methane and methane and coal dust hybrid explosions when ammonium phosphate powder was used as the suppression material. The use of this barrier will provide coal mine management with an additional explosion control close to the point of ignition and may find application within longwall faces further protecting mines against the risk of an explosion propagating throughout a mine.展开更多
Based on the equation of the gas flow continuity and state, Darcy law and Langmuir equation, the law of methane seepage in the wall of drainage roadway was studied. The governing equation of methane one-way seepage in...Based on the equation of the gas flow continuity and state, Darcy law and Langmuir equation, the law of methane seepage in the wall of drainage roadway was studied. The governing equation of methane one-way seepage in the seam was founded. By solving the equation, the calculation of methane seepage velocity in the coal wall was worked out. The result has really applied worth and will give beneficial references to re-lated research, it provides preventing coal and gas outbursts with theoretical gist.展开更多
Methods of exploitation drainage, which is presently applied in polish hard coal mines in Upper Silesian Coal Basin(Poland), are not effective enough, high risk of methane hazard can be observed, and production capaci...Methods of exploitation drainage, which is presently applied in polish hard coal mines in Upper Silesian Coal Basin(Poland), are not effective enough, high risk of methane hazard can be observed, and production capacity of the mining plant is not fully used. Methane hazard, which may occur during planned coal exploitation, is presented in this paper. Following parameters are taken into consideration in the forecasts: coal extraction parameters, geological and mining conditions, deposit's methane saturation degree and impact of coal exploitation on the degasification coefficient of the seams, which are under the influence of relaxation zone. This paper presents the results of the analysis aiming to verify applicability of drainage ahead of mining of the coal seams by using surface directional wells. Based on the collected data(coal seams' structural maps, profiles of the exploratory wells, geological cross-sections), the lab tests of drilling cores and direct wells' tests, static model of the deposit was constructed and suitable grid of directional wells from the surface was designed. Comparison of forecasted methane emission volume between the two methods is investigated. The results indicated the necessity of performing appropriate deposit's stimulations in order to increase effectiveness of drainage ahead of mining.展开更多
文摘Preventing the propagation of methane or coal dust explosions through the use of active explosion-suppression systems remains one of the most underutilised explosion controls in underground coal mines. As part of the effort to develop better technologies to safeguard mines, the use of active barrier systems was investigated at Kloppersbos in South Africa. The system is designed to meet the requirements of the European Standard （EN 14591-4 2007） as well as the Mine Safety Standardisation in the Ministry of Coal Industry, Coal Industrial 1 Standard of the Peoples Republic of China （MT 694-1997）. From the tests conducted, it can be concluded that the ExploSpot System was successful in stopping flame propagation for both methane and methane and coal dust hybrid explosions when ammonium phosphate powder was used as the suppression material. The use of this barrier will provide coal mine management with an additional explosion control close to the point of ignition and may find application within longwall faces further protecting mines against the risk of an explosion propagating throughout a mine.
文摘Based on the equation of the gas flow continuity and state, Darcy law and Langmuir equation, the law of methane seepage in the wall of drainage roadway was studied. The governing equation of methane one-way seepage in the seam was founded. By solving the equation, the calculation of methane seepage velocity in the coal wall was worked out. The result has really applied worth and will give beneficial references to re-lated research, it provides preventing coal and gas outbursts with theoretical gist.
文摘Methods of exploitation drainage, which is presently applied in polish hard coal mines in Upper Silesian Coal Basin(Poland), are not effective enough, high risk of methane hazard can be observed, and production capacity of the mining plant is not fully used. Methane hazard, which may occur during planned coal exploitation, is presented in this paper. Following parameters are taken into consideration in the forecasts: coal extraction parameters, geological and mining conditions, deposit's methane saturation degree and impact of coal exploitation on the degasification coefficient of the seams, which are under the influence of relaxation zone. This paper presents the results of the analysis aiming to verify applicability of drainage ahead of mining of the coal seams by using surface directional wells. Based on the collected data(coal seams' structural maps, profiles of the exploratory wells, geological cross-sections), the lab tests of drilling cores and direct wells' tests, static model of the deposit was constructed and suitable grid of directional wells from the surface was designed. Comparison of forecasted methane emission volume between the two methods is investigated. The results indicated the necessity of performing appropriate deposit's stimulations in order to increase effectiveness of drainage ahead of mining.
