Underground coal mining activities in the Quangninh coal basin (in the North ofVietnam) have been carried out at a depth of-130 m to-150 m,and in the near future thismining depth will become-300 m and-500 m.Together w...Underground coal mining activities in the Quangninh coal basin (in the North ofVietnam) have been carried out at a depth of-130 m to-150 m,and in the near future thismining depth will become-300 m and-500 m.Together with the increasing coal output,the quantity of methane and other mine gases emitted from coal beds during mining activitieswill grow bigger and bigger.According to the forecast of the coal mining industry,ifmines go deeper downward,all underground coal mines in the Quangninh basin will beclassified into the mine group with the dangerous level of methane bearings.Mine gascontrol and management operations with conventional ventilation are less effective andentail high expenses.One of the main solutions is to carry out short,medium and longboreholes for controlling and recovering methane and other mine gases from coal bedsbefore mining activities.Efficiency of drilling activities for methane gas recovery from coalseams with horizontal bore holes at underground coal mines depends on many factors includingthe mine gas draining borehole layout at the roadways,gas content in the coalbeds,technologies for mine gas draining boring activities,and so on.Methane gas existsin the coal beds under the adhesive state with stable physical and chemical bonds.In orderto recover these gases,it is necessary to carry out boreholes and create artificial joints(collecting pits) in coal beds with the impulse method (hydraulic separation method).展开更多
Multi-factor productivity(MFP) in underground coal mining has been on the decline for the last decade.The mining industry requires a viable and sustainable approach to overcome the current downtrend. This is only poss...Multi-factor productivity(MFP) in underground coal mining has been on the decline for the last decade.The mining industry requires a viable and sustainable approach to overcome the current downtrend. This is only possible by concurrently focussing on productivity improvement and operating costs reduction,delivered through both incremental and step change technology development. Four technologies are presented in this paper: fibre optic borehole sensing has been demonstrated to reveal detailed information about gas flow influx, water level and borehole blockage events occurring along the length of a surfaceto-inseam lateral. Fibre optic gas sensing has also been investigated, and this technology promises a remote, intrinsically safe, distributed solution. Recent developments in continuous water jet drilling technology have demonstrated a step change increase in drilling rates and flexibility for coal seam degassing,applicable in both surface-to-inseam and underground in-seam applications. The application of water jet technology to the cable bolt drilling problem offers potential to address a serious health and safety and productivity issue in the roadway development process.展开更多
文摘Underground coal mining activities in the Quangninh coal basin (in the North ofVietnam) have been carried out at a depth of-130 m to-150 m,and in the near future thismining depth will become-300 m and-500 m.Together with the increasing coal output,the quantity of methane and other mine gases emitted from coal beds during mining activitieswill grow bigger and bigger.According to the forecast of the coal mining industry,ifmines go deeper downward,all underground coal mines in the Quangninh basin will beclassified into the mine group with the dangerous level of methane bearings.Mine gascontrol and management operations with conventional ventilation are less effective andentail high expenses.One of the main solutions is to carry out short,medium and longboreholes for controlling and recovering methane and other mine gases from coal bedsbefore mining activities.Efficiency of drilling activities for methane gas recovery from coalseams with horizontal bore holes at underground coal mines depends on many factors includingthe mine gas draining borehole layout at the roadways,gas content in the coalbeds,technologies for mine gas draining boring activities,and so on.Methane gas existsin the coal beds under the adhesive state with stable physical and chemical bonds.In orderto recover these gases,it is necessary to carry out boreholes and create artificial joints(collecting pits) in coal beds with the impulse method (hydraulic separation method).
基金Australian Coal Association Research Program (ACARP)CRCMining’s Coal Technologies and Fugitive Emissions Research programThe University of Queensland
文摘Multi-factor productivity(MFP) in underground coal mining has been on the decline for the last decade.The mining industry requires a viable and sustainable approach to overcome the current downtrend. This is only possible by concurrently focussing on productivity improvement and operating costs reduction,delivered through both incremental and step change technology development. Four technologies are presented in this paper: fibre optic borehole sensing has been demonstrated to reveal detailed information about gas flow influx, water level and borehole blockage events occurring along the length of a surfaceto-inseam lateral. Fibre optic gas sensing has also been investigated, and this technology promises a remote, intrinsically safe, distributed solution. Recent developments in continuous water jet drilling technology have demonstrated a step change increase in drilling rates and flexibility for coal seam degassing,applicable in both surface-to-inseam and underground in-seam applications. The application of water jet technology to the cable bolt drilling problem offers potential to address a serious health and safety and productivity issue in the roadway development process.
