According to the characteristics of spiral mining head for deep seabed cobalt-rich crust, the kinematic model, cutting loads model, quantity of cutting picks model of mining head, granularity distribution model and en...According to the characteristics of spiral mining head for deep seabed cobalt-rich crust, the kinematic model, cutting loads model, quantity of cutting picks model of mining head, granularity distribution model and energy consumption model were constructed. Based on these models, computer simulation program of cutting loads was developed with VB software. The mechanical parameters of mining head were obtained in the cutting depth range of 5160 mm. Making use of the simulation results, the effect of cutting depth of spiral mining head on the mining process was studied. The results show that the maximum force of single pick is 4.7051kN, the maximum force and torque of spiral drum of mining head are respectively 34.1668kN and 3.8795kN·m at the cutting depth of 160mm.展开更多
It took that the weight minimum and drive efficiency maximal were as double optimizing target,the optimization model had built the drilling string,and the optimization solution was used of the ant colony algorithm to ...It took that the weight minimum and drive efficiency maximal were as double optimizing target,the optimization model had built the drilling string,and the optimization solution was used of the ant colony algorithm to find in progress.Adopted a two-layer search of the continuous space ant colony algorithm with overlapping or variation global ant search operation strategy and conjugated gradient partial ant search operation strat- egy.The experiment indicates that the spiral drill weight reduces 16.77% and transports the efficiency enhance 7.05% through the optimization design,the ant colony algorithm application on the spiral drill optimized design has provided the basis for the system re- search screw coal mine machine.展开更多
This paper provides an improved understanding of the movement mechanisms of both bed-rock gully and sandy soil gully when underground mining occurs underneath,followed by systematic analysis of the contributing factor...This paper provides an improved understanding of the movement mechanisms of both bed-rock gully and sandy soil gully when underground mining occurs underneath,followed by systematic analysis of the contributing factors such as mining advance direction,gully slope angle,gully erosion coefficient and mining height.This paper presents the results from monitoring,theoretical analyses and up to date modeling based on the geological features in the gully affected area,and the implications of these results to the success of roof support trial.It was observed that when mining occurred towards the gully,sliding of slope block along the fracture surface occurred,which resulted in unstable roof condition;when mining progressed away from the gully,polygon blocks developed in the gully slope and rotated in reversed direction forming hinged structure;within the bed-rock slope,the hinged structure was unstable due to shear failure of the polygon block;however,within the sandy soil slope,the structure was relatively stable due to the gradual rotating and subsiding of the polygon block.The increase of the value of slope angle and mining height lead to a faster and more intensive fracture development within the gully slope,which had a pronounced effect on gully slope stability and underground pressure.Various remediation approaches are hence proposed in this paper including introducing more powerful support and reasonable mining height,setting up working face along or away from gullies,using room and pillar,strip mining and backfill instead of longwall mining.展开更多
Analyzed the situations and characteristics of thin coal seam mining and its mining technologies,and introduced the mining innovation technology used by Tianchen Coal Mine of Zhaozhuang Coal Company of China.This inno...Analyzed the situations and characteristics of thin coal seam mining and its mining technologies,and introduced the mining innovation technology used by Tianchen Coal Mine of Zhaozhuang Coal Company of China.This innovation technology combined the fully mechanized mining with individual props,and the working face of mining is over length,irregular form and double units.The rotational adjusting mining technology on thin coal seam is also practiced in this new mining technology.The detail technologies,such as outlays of working face and ways,mining methods,equipments of cutting,transporting and sporting,have been introduced.So that,using the synthetic and creative mining tech- nologies,Tianchen Coal Mine solves the mining problems of thin coal seam successfully.展开更多
The cyclonic static micro-bubble column flotation (FCSMC) is an effective separation device for fine particle treatment. The high mineralization rate and short flotation time of this equipment can be attributed to its...The cyclonic static micro-bubble column flotation (FCSMC) is an effective separation device for fine particle treatment. The high mineralization rate and short flotation time of this equipment can be attributed to its unique cyclonic force field. It also has been observed that the presence of a cyclonic force field leads to a lower bottom separation size limit and a reduction of unselective entrainment. The collection zone of the column is considered to consist of two parts,a column separation zone and a cyclonic zone. Total recovery of the collection zone was developed. For our study,we analyzed the particle movement in the cyclonic zone. Particle residence time equations for the cyclonic zone were de-rived by force analysis. Results obtained in this study provide a theoretical foundation for the design and scale-up of the FCSMC.展开更多
Percussive-rotary drilling technology was considered many years ago as one of the best approaches for hard rock drilling. It is a key for popularizing this technology on a large scale to design and make an impactor wi...Percussive-rotary drilling technology was considered many years ago as one of the best approaches for hard rock drilling. It is a key for popularizing this technology on a large scale to design and make an impactor with excellent performance. This paper presents a suit of method to design the percussive parameters for the oil or gas field by introducing the working principle of back-pressurod impactor, dividing the working periods of impaetor into three phases and establishing the computer emuiational model of percussive parameters. It draws a comparison between the results of model calenlation and experiment on the basis of analyzing the experiment results of impactor. The conclude provides credible foundation for designing and further ameliorating the impactor.展开更多
In this article, the authors propose the production of ethanol from cellulose as an alternative to oil. Cellulosic-ethanol will reduce greenhouse gas emissions, and provide a means to prevent forest fires. This liquid...In this article, the authors propose the production of ethanol from cellulose as an alternative to oil. Cellulosic-ethanol will reduce greenhouse gas emissions, and provide a means to prevent forest fires. This liquid dense fuel was selected because it： （1） easily transported and dispensed as a fuel; （2） can be handled by the existing fuel distribution infrastructure; and （3） unlike its commercial competitor, Me-OH （Methanol）, Et-OH （Ethanol）, is edible, thus being biodegradable and nontoxic. Forest residue ethanol is cheaper to produce and more environmentally friendly than other forms of ethanol fuel. Furthermore, forests would have less available ground fuel for fires. The potential decline of forest fires would then reduce the carbon footprint attributed directly to forest fires. In combination with ethanol fuel combustion, carbon emissions can be reduced by more than 70% compared to gasoline combustion. We used GREET （Greenhouse gases, Regulated Emissions, and Energy use in Transportation） software to assess the life cycles of different fuel pathways. In conclusion, cellulosic ethanol fuel is clearly an answer to decrease dependency on current oil imports and prevent forest fires.展开更多
Longwall mining is by far the most common method of underground coal extraction in Australia. The industry trends and expectations are placing increasing emphasis on the reliability and productivity of these operation...Longwall mining is by far the most common method of underground coal extraction in Australia. The industry trends and expectations are placing increasing emphasis on the reliability and productivity of these operations. The longwalls are becoming wider and longer while retreat rates are continuously increasing due to significant improvements achieved in longwall equipment reliability and automation.This increased longwall productivity is placing significant emphasis on the reliability of longwall panel development. Although there have been significant improvements in the reliability of continuous miners and hydraulic drill rigs,the traditional resin encapsulated bolt installation is still the principal method used in all major coal-producing countries around the world. Anglo American realised an opportunity existed to introduce an alternative roof bolt installation technique called ‘‘spin to stall" in Australia.Spin to stall was first introduced in Anglo American Coal in South Africa where it has been successfully used for over a decade,though implementation of South African spin to stall resin in Australia has proven to be near impossible due to a significant difference in geotechnical conditions,mining method,and,subsequently,roof bolting equipment. Therefore,a new spin to stall development project was initiated between Anglo American Coal and Jennmar Australia(SPIN2STALLò). This paper summarises the journey of this project,the results,and the successful implementation of spin to stall achieved at Grasstree Mine.展开更多
In this paper,a piezoelectric energy harvester based on spiral-shaped polyvinylidene fluoride(PVDF)cantilever is designed and fabricated for harvesting low frequency vibration energy in the environment.In this design,...In this paper,a piezoelectric energy harvester based on spiral-shaped polyvinylidene fluoride(PVDF)cantilever is designed and fabricated for harvesting low frequency vibration energy in the environment.In this design,the spiral-shaped PVDF cantilever is major for lowering the resonant frequency by increasing the length of the cantilever;Copper and silicon proof masses on both sides are working on further decreasing the resonant frequency and widen its bandwidth.Due to the high flexibility of the PVDF cantilever,this device is extremely sensitive to vibration and can harvest weak vibration energy.Both simulation and experimental results have approved that this device can operate at very low frequency which is about 20 Hz and can effectively harvest energy from 15–50 Hz.The peak of the output voltage can reach 1.8 V with the acceleration of 0.2 g.This is a promising harvester for powering the wireless sensors in the future.展开更多
基金Project(DY105 03 02 1) supported by the Deep Ocean Technology Development Itemproject(50474052) supportedby the National Natural Science Foundation of China
文摘According to the characteristics of spiral mining head for deep seabed cobalt-rich crust, the kinematic model, cutting loads model, quantity of cutting picks model of mining head, granularity distribution model and energy consumption model were constructed. Based on these models, computer simulation program of cutting loads was developed with VB software. The mechanical parameters of mining head were obtained in the cutting depth range of 5160 mm. Making use of the simulation results, the effect of cutting depth of spiral mining head on the mining process was studied. The results show that the maximum force of single pick is 4.7051kN, the maximum force and torque of spiral drum of mining head are respectively 34.1668kN and 3.8795kN·m at the cutting depth of 160mm.
基金the Liaoning Technical University Outstanding Youth Science Foundation(jx09-10)
文摘It took that the weight minimum and drive efficiency maximal were as double optimizing target,the optimization model had built the drilling string,and the optimization solution was used of the ant colony algorithm to find in progress.Adopted a two-layer search of the continuous space ant colony algorithm with overlapping or variation global ant search operation strategy and conjugated gradient partial ant search operation strat- egy.The experiment indicates that the spiral drill weight reduces 16.77% and transports the efficiency enhance 7.05% through the optimization design,the ant colony algorithm application on the spiral drill optimized design has provided the basis for the system re- search screw coal mine machine.
基金provided by the National Natural Science Foundation of China (Grant No.51004101,No.51264035)the Science Foundation for Young Scholars of China University of Mining &Technology (Grant No.2009A001)+1 种基金the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)the Fundamental Research Funds for the Central Universities (2012QNA35)
文摘This paper provides an improved understanding of the movement mechanisms of both bed-rock gully and sandy soil gully when underground mining occurs underneath,followed by systematic analysis of the contributing factors such as mining advance direction,gully slope angle,gully erosion coefficient and mining height.This paper presents the results from monitoring,theoretical analyses and up to date modeling based on the geological features in the gully affected area,and the implications of these results to the success of roof support trial.It was observed that when mining occurred towards the gully,sliding of slope block along the fracture surface occurred,which resulted in unstable roof condition;when mining progressed away from the gully,polygon blocks developed in the gully slope and rotated in reversed direction forming hinged structure;within the bed-rock slope,the hinged structure was unstable due to shear failure of the polygon block;however,within the sandy soil slope,the structure was relatively stable due to the gradual rotating and subsiding of the polygon block.The increase of the value of slope angle and mining height lead to a faster and more intensive fracture development within the gully slope,which had a pronounced effect on gully slope stability and underground pressure.Various remediation approaches are hence proposed in this paper including introducing more powerful support and reasonable mining height,setting up working face along or away from gullies,using room and pillar,strip mining and backfill instead of longwall mining.
基金the Natural Science Fund of China(70771060)the Production Safety and Supervision of Management Bureau of China(04-116)+3 种基金the National Soft Science Planed Program(2004DGQ3D090)and(2006GXQ3D154)the Natural Science Fund of Shandong Province(Y2006H10)the Social Science Planning Program of Shandong Province(06BJJ005)the Soft-science Planed Program of Shandong Province(2007RKA134)
文摘Analyzed the situations and characteristics of thin coal seam mining and its mining technologies,and introduced the mining innovation technology used by Tianchen Coal Mine of Zhaozhuang Coal Company of China.This innovation technology combined the fully mechanized mining with individual props,and the working face of mining is over length,irregular form and double units.The rotational adjusting mining technology on thin coal seam is also practiced in this new mining technology.The detail technologies,such as outlays of working face and ways,mining methods,equipments of cutting,transporting and sporting,have been introduced.So that,using the synthetic and creative mining tech- nologies,Tianchen Coal Mine solves the mining problems of thin coal seam successfully.
基金Project 50425414 supported by the National Outstanding Youth Science Foundation of China
文摘The cyclonic static micro-bubble column flotation (FCSMC) is an effective separation device for fine particle treatment. The high mineralization rate and short flotation time of this equipment can be attributed to its unique cyclonic force field. It also has been observed that the presence of a cyclonic force field leads to a lower bottom separation size limit and a reduction of unselective entrainment. The collection zone of the column is considered to consist of two parts,a column separation zone and a cyclonic zone. Total recovery of the collection zone was developed. For our study,we analyzed the particle movement in the cyclonic zone. Particle residence time equations for the cyclonic zone were de-rived by force analysis. Results obtained in this study provide a theoretical foundation for the design and scale-up of the FCSMC.
基金Supported by the Science Foundation of China National Petroleum Corporation (990407 - 06 - 02)
文摘Percussive-rotary drilling technology was considered many years ago as one of the best approaches for hard rock drilling. It is a key for popularizing this technology on a large scale to design and make an impactor with excellent performance. This paper presents a suit of method to design the percussive parameters for the oil or gas field by introducing the working principle of back-pressurod impactor, dividing the working periods of impaetor into three phases and establishing the computer emuiational model of percussive parameters. It draws a comparison between the results of model calenlation and experiment on the basis of analyzing the experiment results of impactor. The conclude provides credible foundation for designing and further ameliorating the impactor.
文摘In this article, the authors propose the production of ethanol from cellulose as an alternative to oil. Cellulosic-ethanol will reduce greenhouse gas emissions, and provide a means to prevent forest fires. This liquid dense fuel was selected because it： （1） easily transported and dispensed as a fuel; （2） can be handled by the existing fuel distribution infrastructure; and （3） unlike its commercial competitor, Me-OH （Methanol）, Et-OH （Ethanol）, is edible, thus being biodegradable and nontoxic. Forest residue ethanol is cheaper to produce and more environmentally friendly than other forms of ethanol fuel. Furthermore, forests would have less available ground fuel for fires. The potential decline of forest fires would then reduce the carbon footprint attributed directly to forest fires. In combination with ethanol fuel combustion, carbon emissions can be reduced by more than 70% compared to gasoline combustion. We used GREET （Greenhouse gases, Regulated Emissions, and Energy use in Transportation） software to assess the life cycles of different fuel pathways. In conclusion, cellulosic ethanol fuel is clearly an answer to decrease dependency on current oil imports and prevent forest fires.
文摘Longwall mining is by far the most common method of underground coal extraction in Australia. The industry trends and expectations are placing increasing emphasis on the reliability and productivity of these operations. The longwalls are becoming wider and longer while retreat rates are continuously increasing due to significant improvements achieved in longwall equipment reliability and automation.This increased longwall productivity is placing significant emphasis on the reliability of longwall panel development. Although there have been significant improvements in the reliability of continuous miners and hydraulic drill rigs,the traditional resin encapsulated bolt installation is still the principal method used in all major coal-producing countries around the world. Anglo American realised an opportunity existed to introduce an alternative roof bolt installation technique called ‘‘spin to stall" in Australia.Spin to stall was first introduced in Anglo American Coal in South Africa where it has been successfully used for over a decade,though implementation of South African spin to stall resin in Australia has proven to be near impossible due to a significant difference in geotechnical conditions,mining method,and,subsequently,roof bolting equipment. Therefore,a new spin to stall development project was initiated between Anglo American Coal and Jennmar Australia(SPIN2STALLò). This paper summarises the journey of this project,the results,and the successful implementation of spin to stall achieved at Grasstree Mine.
基金supported by the National Natural Science Foundation of China(Grant Nos.61176103,91023045 and 91323304)National Ph.D.Foundation Project(Grant No.20110001110103)Global Research Outreach Program of Samsung Advanced Institute of Technology
文摘In this paper,a piezoelectric energy harvester based on spiral-shaped polyvinylidene fluoride(PVDF)cantilever is designed and fabricated for harvesting low frequency vibration energy in the environment.In this design,the spiral-shaped PVDF cantilever is major for lowering the resonant frequency by increasing the length of the cantilever;Copper and silicon proof masses on both sides are working on further decreasing the resonant frequency and widen its bandwidth.Due to the high flexibility of the PVDF cantilever,this device is extremely sensitive to vibration and can harvest weak vibration energy.Both simulation and experimental results have approved that this device can operate at very low frequency which is about 20 Hz and can effectively harvest energy from 15–50 Hz.The peak of the output voltage can reach 1.8 V with the acceleration of 0.2 g.This is a promising harvester for powering the wireless sensors in the future.
