One wedge-shaped microchannel was established,and the hydrodynamic properties of the wedge-shaped gas film were comprehensively investigated.The Navier-Stokes equations coupled with the full energy equation were adopt...One wedge-shaped microchannel was established,and the hydrodynamic properties of the wedge-shaped gas film were comprehensively investigated.The Navier-Stokes equations coupled with the full energy equation were adopted to mainly analyze the lubrication hydrodynamics of the gas film,as the horizontal plate was viewed as the adiabatic wall or the horizontal plate temperature was equal to the tilt plate temperature.A higher gas film temperature strengthened the rarefaction effect,and the more rarefied gas weakened the squeeze.Meanwhile,the vertical flow across the gas film could indicate the relation between the velocity vector and the gas film squeeze and expansion.The adiabatic horizontal plate could resist the heat conduction and enhance the rarefaction effect,and thus the direction of motion of the gas molecules was easier to be changed.展开更多
At the end of the open-pit mining process in large metal mines, the mining model must change from open-pit mining to underground mining, but the mutual interference between the two mining models leads to poor producti...At the end of the open-pit mining process in large metal mines, the mining model must change from open-pit mining to underground mining, but the mutual interference between the two mining models leads to poor production safety conditions and difficulties in production convergence during the transition period. To solve these technical problems of poor production safety conditions and difficulties in production convergence during the transition period, in this study, based on the case of the Dagu Mountain Mine, a new transition mode of wedge switching for collaborative mining is proposed and established, which is suitable for collaborative mining. This new mining process completely eliminates the boundary pillar and the artificial covering layer, combining the technology of the mining-induced caving method and the technology of deep mining at the bottom of the open-pit. The results show that 1） the optimization of the open-pit boundary reduces the amount of rock stripping, and 2） it achieves a stable transition of collaborative mining capacity. The study shows that the proposed method uses the technologies of the mining-induced caving method in underground mining and deep mining at the bottom of the open pit in open-pit mining, and the method then optimizes the open-pit mining in detail by comparing the advantages of open-pit mining and underground mining. This study provides true and accurate technical support for the transition from open-pit mining to underground mining.展开更多
基金National Science Foundation of China(51605447)Applied Basic Research Programs of Shanxi Province in China(201801D221370)
文摘One wedge-shaped microchannel was established,and the hydrodynamic properties of the wedge-shaped gas film were comprehensively investigated.The Navier-Stokes equations coupled with the full energy equation were adopted to mainly analyze the lubrication hydrodynamics of the gas film,as the horizontal plate was viewed as the adiabatic wall or the horizontal plate temperature was equal to the tilt plate temperature.A higher gas film temperature strengthened the rarefaction effect,and the more rarefied gas weakened the squeeze.Meanwhile,the vertical flow across the gas film could indicate the relation between the velocity vector and the gas film squeeze and expansion.The adiabatic horizontal plate could resist the heat conduction and enhance the rarefaction effect,and thus the direction of motion of the gas molecules was easier to be changed.
基金Projects(41371437,61473072,61203214)supported by the National Natural Science Foundation of ChinaProjet(N160404008)supported by the Fundamental Research Funds for the Central Universities,China
文摘At the end of the open-pit mining process in large metal mines, the mining model must change from open-pit mining to underground mining, but the mutual interference between the two mining models leads to poor production safety conditions and difficulties in production convergence during the transition period. To solve these technical problems of poor production safety conditions and difficulties in production convergence during the transition period, in this study, based on the case of the Dagu Mountain Mine, a new transition mode of wedge switching for collaborative mining is proposed and established, which is suitable for collaborative mining. This new mining process completely eliminates the boundary pillar and the artificial covering layer, combining the technology of the mining-induced caving method and the technology of deep mining at the bottom of the open-pit. The results show that 1） the optimization of the open-pit boundary reduces the amount of rock stripping, and 2） it achieves a stable transition of collaborative mining capacity. The study shows that the proposed method uses the technologies of the mining-induced caving method in underground mining and deep mining at the bottom of the open pit in open-pit mining, and the method then optimizes the open-pit mining in detail by comparing the advantages of open-pit mining and underground mining. This study provides true and accurate technical support for the transition from open-pit mining to underground mining.
