Comparative stability analyses of traditional and selective room-and-pillar mining techniques for su

来源 :矿物冶金与材料学报 | 被引量 : 0次 | 上传用户:sun18903827600
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The stability and productivity concerning a modification on the traditional room and pillar for a new selective technique at the Portuguese Panasqueira Mine have been described.The traditional room-and-pillar stoping uses 5.0-m wide rooms with 3.0 m×3.0 m pillars,while the selective room-and-pillar mining technique consists in stoping with rooms of 4.0 m wide and pillars of 4 m×4 m with a subsequent selective cutting of the quartz veins at the mid pillar of approximately 0.5 m high,to obtain a pillar section with an area of 3.0 m×3.0 m The stability and productivity analyses indicate that the selective technique obtains smaller average pillar safety factor,more rock mass displace-ment,more extraction and selectivity ratios,and ore grade improvement,compared with the waditional technique.These results show that the selective technique is also more convenient.This proposed selective room-and-pillar mining technique is applicable to any sub-horizontal narrow quartz veins with wolfram,gold,etc.such as the famous La Rinconada gold mine in the Peruvian Andes.
其他文献
Ti-6.5Al-3.5Mo-1.5Zr-0.3Si (TC11) alloy impeller is an important part in the airspace engine that serves under severe working conditions, and it requires excell
The development and prospect of rare earth functional biomaterials (REFB) was discussed. From 1979 to 1985, the simple REFB (salts) has been developed, and the
SiC substrates grown by the sublimation method still have high densities of structural defects such as dislocations, micropipes, low-angle grain boundaries, mac
The spring-back of a bending metal tube was studied through extensive experiments and finite element method (FEM) analysis. An approximate equation for the spri
在电力市场环境下,发电商的策略性投标行为关系到电价风险、市场稳定、市场力滥用行为及发电商自身利润等诸多问题.文中在对发电机组成本/需求的微观经济分析基础上,建立了机
在电力市场环境下,利用柔性交流输电系统FACTS(Flexible AC Transmission System)设备解决网络阻塞问题,获取更大的经济效益已经越来越引起人们的重视.提出基于FACTS的现货市
在讨论模糊综合评价方法的基础上,提出了家具产品设计方案的多级模糊综合评价方法,并利用所提出的方法,针对SOHO家具产品绿色效能,从产品材料、结构、功能三方面的绿色因素进
介绍了一种通过改变电极上的驱动电压来测量和调控入射光偏振态的液晶器件,同时模拟了该器件的液晶分子指向矢分布。众所周知,液晶分子的倾斜角较容易控制,却常忽视其扭曲角同样
设计了一种采用共面TEM馈电结构的抛物反射面超宽谱脉冲辐射天线,分析了该种馈电结构的阻抗特性与辐射特性。实验表明当馈入电压为3kV、前沿180ps的超宽谱脉冲时,该天线主轴