某铁矿矿柱回采安全性研究

某铁矿二采区一中段采用空场采矿法进行采矿，经过多年开采该中段未处理采空区体积已经达到40万m3，遗留矿柱矿量超过26万t，为了充分回收矿产资源矿山计划回采矿柱。由于现场未处理的采空区体积较大，而矿柱又是维持采空区稳定性的关键要素，可能部分矿柱的回采或破坏就会诱发一定规模的地压活动，威胁矿山的正常安全生产。所以在矿柱回采之前，对回采区域的矿柱进行安全性研究，可以指导矿柱回采的实施，进而保障矿柱的正常安全回采。结合矿山的现场实际情况，以应力增量理论为基础，采用工程地质调查、室内试验结合数值模拟的方法，对矿山二采区一中段需回采矿柱的安全性进行研究，确定了各回采矿柱的安全系数大小。研究结果表明矿山二采区一中段的矿柱处于安全状态，可以进行部分矿柱回收。

Stability of Pillars Recovery in an Iron Ore

The open stope mining method was adopted in the first section of No.2 mining area in an Iron Mine.The untreated goaf has reached 400,000 m3 and the ore quantity of remained pillar is nearly more than 26 million tons after years of exploitation.In order to fully recover the mineral resources，the mine is planning to recover the pillars.As the untreated mined-out area is large and the remained pillar is the key support for maintaining the stability of mined-out area，the recovery or destroy of part of pillars may induce a certain scale of ground pressure activities which will threaten normal safe production of mine.So before the pillar stoping，the research on security of pillar mining area can guide the implementation of the pillar stoping，and ensure the pillar mining in safety.Combining with the actual situation in an iron mine and based on the theory of stress increment，the combination of engineering geological investigation，laboratory test with numerical simulation is adopted to research the pillar′s security about the first section in No.2 mining area and to determine the safety factor of each pillar.The research results showed that the pillars in the first section of No.2 mining area is in safety，and parts of pillars can be recovered.