Proper room and pillar sizes are both critical factors for safe mining and high ore recovery rate in shrinkage stoping mining of underground metal mines.The rock masses of Tangdan copper mine of China are fractured,wh...Proper room and pillar sizes are both critical factors for safe mining and high ore recovery rate in shrinkage stoping mining of underground metal mines.The rock masses of Tangdan copper mine of China are fractured,which needs much reinforcement and support prior to mining.Cement-sodium silicate grout technology was selected,then its related parameters such as grout pressure,diffusion radius and time were calculated and proposed.In order to test the effect of the pressured grout in the fractured No.4 ore block,field experiments were conducted.To optimize stoping configuration,three-dimensional numerical simulation with ANSYS and FLAC 3 D softwares was proposed.The results show that the drilling porosity and mechanical properties of the rock masses are increased obviously.After grout,ore recovery rate is increased by 10.2%employing the newly designed stoping configuration compared with the previous.Last,analyzed from the surface movements,roof subsidence and the maximum principal stress of the pillars,the mining safety is probable of being ensured.展开更多
基金Projects(51374034,51674012)supported by the National Natural Science Foundation of ChinaProject(2013BAB02B05)supported by the China National Science and Technology Support Program during the 12th Five-Year Plan Period
文摘Proper room and pillar sizes are both critical factors for safe mining and high ore recovery rate in shrinkage stoping mining of underground metal mines.The rock masses of Tangdan copper mine of China are fractured,which needs much reinforcement and support prior to mining.Cement-sodium silicate grout technology was selected,then its related parameters such as grout pressure,diffusion radius and time were calculated and proposed.In order to test the effect of the pressured grout in the fractured No.4 ore block,field experiments were conducted.To optimize stoping configuration,three-dimensional numerical simulation with ANSYS and FLAC 3 D softwares was proposed.The results show that the drilling porosity and mechanical properties of the rock masses are increased obviously.After grout,ore recovery rate is increased by 10.2%employing the newly designed stoping configuration compared with the previous.Last,analyzed from the surface movements,roof subsidence and the maximum principal stress of the pillars,the mining safety is probable of being ensured.
文摘通过试验与数值模拟相结合的方法,系统探究了液氨在高温(690~1100 K)和高压(1.0~4.0 MPa)条件下的喷雾特性,旨在构建精准的液氨喷雾预测模型。试验采用高速阴影摄影技术,捕捉喷雾的动态过程;数值模拟则基于拉格朗日–欧拉耦合方法,重点分析了喷雾的速度场、索特平均直径(Sauter mean diameter,SMD)和概率密度分布函数(probability density function,PDF)等关键参数。研究结果表明,随着环境压力升高,喷雾的轴向扩展减弱,径向扩展增强,喷雾贯穿距缩短,尖端速度降低,锥角增大(最大增幅达86.13%);环境温度升高可显著促进喷雾的蒸发和扩散效果,但对喷雾贯穿距和锥角的影响不显著。试验发现,在环境温度690 K、环境压力1.0 MPa的情况下,由于氨处于闪沸状态,喷雾显著膨胀,锥角变大。此外,喷雾的速度场和液滴分布对压力变化高度敏感,随着压力增加,SMD显著减小(最大降幅达42.83%),PDF向小液滴偏移,提升了雾化效果。研究验证了所建立模型在液氨喷雾预测中的可靠性。
