Mine accidents and injuries are complex and generally characterized by several factors starting from personal to technical, and technical to social characteristics.In this study, an attempt has been made to identify t...Mine accidents and injuries are complex and generally characterized by several factors starting from personal to technical, and technical to social characteristics.In this study, an attempt has been made to identify the various factors responsible for work related injuries in mines and to estimate the risk of work injury to mine workers.The prediction of work injury in mines was done by a step-by-step multivariate logistic regression modeling with an application to case study mines in India.In total, 18 variables were considered in this study.Most of the variables are not directly quantifiable.Instruments were developed to quantify them through a questionnaire type survey.Underground mine workers were randomly selected for the survey.Responses from 300 participants were used for the analysis.Four variables, age, negative affectivity, job dissatisfaction, and physical hazards, bear significant discriminating power for risk of injury to the workers, comparing between cases and controls in a multivariate situation while controlling all the personal and socio-technical variables.The analysis reveals that negatively affected workers are 2.54 times more prone to injuries than the less negatively affected workers and this factor is a more important risk factor for the case-study mines.Long term planning through identification of the negative individuals, proper counseling regarding the adverse effects of negative behaviors and special training is urgently required.Care should be taken for the aged and experienced workers in terms of their job responsibility and training requirements.Management should provide a friendly atmosphere during work to increase the confidence of the injury prone miners.展开更多
Coal accounts for about 70% of the primary energy sources in China. The environmental pollution and resources waste involved with coal processing and utilization are serious. It is therefore urgent to develop highly-e...Coal accounts for about 70% of the primary energy sources in China. The environmental pollution and resources waste involved with coal processing and utilization are serious. It is therefore urgent to develop highly-efficient coal resources utilization theory and methods with low-carbon discharge. Based on our long-term basic research and technology development, the progress in beneficiation, cleaning, and trans- formation of coal, which includes dense phase fluidized bed dry beneficiation, deep screening of wet fine coal, micro-bubble flotation column separation, molecular coal chemistry, and transformation and sepa- ration of coal and its derivatives into value-added chemicals under mild conditions, is discussed.展开更多
Difficulties with soft coal seams having a high gas content and high stress levels can be addressed by a technology of pressure relief and permeability increase.Slotting the seam by auxiliary drilling with a water jet...Difficulties with soft coal seams having a high gas content and high stress levels can be addressed by a technology of pressure relief and permeability increase.Slotting the seam by auxiliary drilling with a water jet that breaks the coal and slots the coal seam during the process of retreat drilling achieves pressure relief and permeability increase.Improved efficiency of gas extraction from a field test,high gas coal seam was observed.Investigating the theory of pressure relief and permeability increase required analyzing the characteristics of the double power slotting process and the effects of coal pressure relief and permeability increase.The influence of confining pressure on coal physical properties was examined by using FLAC3D software code to simulate changes of coal stress within the tool destruction area.The double power joint drilling method was modeled.Field experiments were performed and the effects are analyzed.This research shows that there is an ''islanding effect'' in front of the joint double power drill and slotting equipment.The failure strength of the coal seam is substantially reduced within the tool destruction area.Drilling depths are increased by 72% and the diameter of the borehole is increased by 30%.The amount of powdered coal extracted from the drill head increases by 17 times when using the new method.A 30 day total flow measurement from the double power drilled and slotted bores showed that gas extraction increased by 1.3 times compared to the standard drilled bores.Gas concentrations increased from 30% to 60% and were more stable so the overall extraction efficiency increased by a factor of two times.展开更多
As is well known, deep mines are hot. As mining depth increases, the temperature of the surrounding rock also increases. This seriously affects mine safety and production and has restricted the exploitation of deep co...As is well known, deep mines are hot. As mining depth increases, the temperature of the surrounding rock also increases. This seriously affects mine safety and production and has restricted the exploitation of deep coal resources. Therefore, reducing the working face temperature to improve working conditions by controlling these heat hazards is an urgent problem. Considering problems in cooling deep mines both domestically and abroad along with the actual conditions of the Zhangshuanglou coal mine, we propose a HEMS technology that uses heat resources from deep mines in a stepwise manner. HEMS means a high temperature ex-change machinery system. Mine inrush-water is used as a source of cooling. Twice the energy is extracted from the mine inrush water. Heat is used for building heating in the winter and cold water is used for cooling buildings in the summer. This opens a new technology for stepwise utilization of heat energy in deep mines. Energy conservation and reduced pollution, an improved environment and sustainable economic development are realized by this technique. The economic and social effects are obvious and illustrate a good prospect for the application and extension of the method.展开更多
More than 80 million metric tons of fly ash is produced annually in the U.S. as coal combustion by-product. Coal fly ash can be converted to value-added products if unburned carbon is reduced to less than 2.5%. Howeve...More than 80 million metric tons of fly ash is produced annually in the U.S. as coal combustion by-product. Coal fly ash can be converted to value-added products if unburned carbon is reduced to less than 2.5%. However, most of fly ash is currently landfilled as waste due to lack of efficient purification technologies to separate unburned carbon from fly ash. A rotary triboelectrostatic separator has been developed and patented recently at the University of Kentucky with unique features. Several fly ash samples have been used to understand the effects of major process parameters on the separation performance. The results show that compared to existing triboelectrostatic separators, the rotary triboelectrostatic separator has significant advantages in particle charging efficiency, solids throughput, separation efficiency, applicable particle size range.展开更多
On June 16,2016 the technical achievement of the Shaanxi Yanchang Oil Group relating to ＂the integrated process technology for comprehensive utilization of coal,oil and gas and their commercial application＂ has pass...On June 16,2016 the technical achievement of the Shaanxi Yanchang Oil Group relating to ＂the integrated process technology for comprehensive utilization of coal,oil and gas and their commercial application＂ has passed the experts’appraisal in Beijing.It is said that this achievement has shattered the traditional precedent and engineering paradigm of using coal or natural gas to simplistically manufacture methanol and has carved out a new mode for comprehensive utilization of coal, oil and gas resources, featuring apparent emissions reduction ef-fects with innovative nature to command a leading posi-tion internationally.展开更多
In this paper,the designed features of a W-flame coal-fired boiler are introduced.A scheme of joint primary air for two boilers is made and technical measures are also taken based on corresponding analyses and studies...In this paper,the designed features of a W-flame coal-fired boiler are introduced.A scheme of joint primary air for two boilers is made and technical measures are also taken based on corresponding analyses and studies.The scheme and the measures provide a reference for technicians to improve the efficiencies and reduce the startup costs of other similar large boilers.展开更多
文摘Mine accidents and injuries are complex and generally characterized by several factors starting from personal to technical, and technical to social characteristics.In this study, an attempt has been made to identify the various factors responsible for work related injuries in mines and to estimate the risk of work injury to mine workers.The prediction of work injury in mines was done by a step-by-step multivariate logistic regression modeling with an application to case study mines in India.In total, 18 variables were considered in this study.Most of the variables are not directly quantifiable.Instruments were developed to quantify them through a questionnaire type survey.Underground mine workers were randomly selected for the survey.Responses from 300 participants were used for the analysis.Four variables, age, negative affectivity, job dissatisfaction, and physical hazards, bear significant discriminating power for risk of injury to the workers, comparing between cases and controls in a multivariate situation while controlling all the personal and socio-technical variables.The analysis reveals that negatively affected workers are 2.54 times more prone to injuries than the less negatively affected workers and this factor is a more important risk factor for the case-study mines.Long term planning through identification of the negative individuals, proper counseling regarding the adverse effects of negative behaviors and special training is urgently required.Care should be taken for the aged and experienced workers in terms of their job responsibility and training requirements.Management should provide a friendly atmosphere during work to increase the confidence of the injury prone miners.
基金support from the National Natural Science Foundation of China(No. 50921002)
文摘Coal accounts for about 70% of the primary energy sources in China. The environmental pollution and resources waste involved with coal processing and utilization are serious. It is therefore urgent to develop highly-efficient coal resources utilization theory and methods with low-carbon discharge. Based on our long-term basic research and technology development, the progress in beneficiation, cleaning, and trans- formation of coal, which includes dense phase fluidized bed dry beneficiation, deep screening of wet fine coal, micro-bubble flotation column separation, molecular coal chemistry, and transformation and sepa- ration of coal and its derivatives into value-added chemicals under mild conditions, is discussed.
基金supports provided by the National Key Basic Research and Development Program of China (No. 2011CB201205)the National Natural Science Foundation of China (No. 51074161)the Independent research of State Key Laboratory of Coal Resources and Mine Safety of China University of Mining & Technology (No. SKLCRSM08X03)
文摘Difficulties with soft coal seams having a high gas content and high stress levels can be addressed by a technology of pressure relief and permeability increase.Slotting the seam by auxiliary drilling with a water jet that breaks the coal and slots the coal seam during the process of retreat drilling achieves pressure relief and permeability increase.Improved efficiency of gas extraction from a field test,high gas coal seam was observed.Investigating the theory of pressure relief and permeability increase required analyzing the characteristics of the double power slotting process and the effects of coal pressure relief and permeability increase.The influence of confining pressure on coal physical properties was examined by using FLAC3D software code to simulate changes of coal stress within the tool destruction area.The double power joint drilling method was modeled.Field experiments were performed and the effects are analyzed.This research shows that there is an ''islanding effect'' in front of the joint double power drill and slotting equipment.The failure strength of the coal seam is substantially reduced within the tool destruction area.Drilling depths are increased by 72% and the diameter of the borehole is increased by 30%.The amount of powdered coal extracted from the drill head increases by 17 times when using the new method.A 30 day total flow measurement from the double power drilled and slotted bores showed that gas extraction increased by 1.3 times compared to the standard drilled bores.Gas concentrations increased from 30% to 60% and were more stable so the overall extraction efficiency increased by a factor of two times.
基金Financial support for this project, provided by the National Basic Research Program of China (No. 2006CB202200)the National Major Project of Ministry of Education (No.304005) the Program for Changjiang Scholars and Innovative Research Team in University of China (No.IRT0656), is gratefully acknowledged
文摘As is well known, deep mines are hot. As mining depth increases, the temperature of the surrounding rock also increases. This seriously affects mine safety and production and has restricted the exploitation of deep coal resources. Therefore, reducing the working face temperature to improve working conditions by controlling these heat hazards is an urgent problem. Considering problems in cooling deep mines both domestically and abroad along with the actual conditions of the Zhangshuanglou coal mine, we propose a HEMS technology that uses heat resources from deep mines in a stepwise manner. HEMS means a high temperature ex-change machinery system. Mine inrush-water is used as a source of cooling. Twice the energy is extracted from the mine inrush water. Heat is used for building heating in the winter and cold water is used for cooling buildings in the summer. This opens a new technology for stepwise utilization of heat energy in deep mines. Energy conservation and reduced pollution, an improved environment and sustainable economic development are realized by this technique. The economic and social effects are obvious and illustrate a good prospect for the application and extension of the method.
文摘More than 80 million metric tons of fly ash is produced annually in the U.S. as coal combustion by-product. Coal fly ash can be converted to value-added products if unburned carbon is reduced to less than 2.5%. However, most of fly ash is currently landfilled as waste due to lack of efficient purification technologies to separate unburned carbon from fly ash. A rotary triboelectrostatic separator has been developed and patented recently at the University of Kentucky with unique features. Several fly ash samples have been used to understand the effects of major process parameters on the separation performance. The results show that compared to existing triboelectrostatic separators, the rotary triboelectrostatic separator has significant advantages in particle charging efficiency, solids throughput, separation efficiency, applicable particle size range.
文摘On June 16,2016 the technical achievement of the Shaanxi Yanchang Oil Group relating to ＂the integrated process technology for comprehensive utilization of coal,oil and gas and their commercial application＂ has passed the experts’appraisal in Beijing.It is said that this achievement has shattered the traditional precedent and engineering paradigm of using coal or natural gas to simplistically manufacture methanol and has carved out a new mode for comprehensive utilization of coal, oil and gas resources, featuring apparent emissions reduction ef-fects with innovative nature to command a leading posi-tion internationally.
文摘In this paper,the designed features of a W-flame coal-fired boiler are introduced.A scheme of joint primary air for two boilers is made and technical measures are also taken based on corresponding analyses and studies.The scheme and the measures provide a reference for technicians to improve the efficiencies and reduce the startup costs of other similar large boilers.
