梅山铁矿东南区破碎采场诱导冒落回采试验

梅山铁矿东南区破碎采场节理裂隙发育，矿岩稳固性较差，矿石回收率低，存在大量残矿。为了充分回收上部分段残矿，开展了诱导冒落回采试验研究。根据该区域的结构面调查和稳定性分级，-303和-318 m分段矿体稳定性分级处于不稳定 极不稳定范围，易冒落。基于拱形冒落的原理，分析了顶板围岩的受力状态，计算出引起回采空间顶板岩体破坏的持续冒落跨度为34.2 m。由此设计了诱导冒落法两步骤回采方式，先进行-303 m分段岩体诱导冒落，后进行-318 m分段冒落矿石的回收。为了减小炮孔的破坏程度，缩短-318 m分段回收分段炮孔的长度。设计在-303 m分段S5~S8正常回采进路中间补打加密进路。根据矿石的流动规律和残矿的空间位置，设计将-318 m分段S7和S8进路作为主堑沟回收巷道，S6和S9作为辅助回收巷道。根据现场回采试验，-303 m分段S5和S6进路视在回采率分别达到了151.18%和193.97%；-318 m分段S7和S8进路视在回采率分别达到了129.15%和134.05%，成效显著。

Test of Induced Caving Mining in Southeast Area Broken Stope of Meishan Iron Mine

The joints and fractures of the broken stope in the southeast area of Meishan Iron Mine are developed,the stability of the rock is poor,the ore recovery rate is low,and there are a lot of residual ores.In order to fully recover the residual ore in the upper levels,an experimental study on induced caving mining method was carried out.According to the structural plane survey and stability classification in this area,the stability classification of -303 m and -318 m level of ore bodies is in the unstable to extremely unstable range,and it is easy to fall.Based on the principle of arched fall,the stress state of the surrounding rock of the roof was analyzed,and the continuous fall span of the roof rock mass which caused the mining space was calculated to be 34.2 m.Therefore,a two step mining method of induced caving method was designed.Induced caving was adopted in -303 m level rock mass,and then the -318 m level ore was recovered.In order to reduce the damage of the blast hole,the length of the blast hole in -318 m level was shortened.According to the design,the middle of -303 m segment S5~S8 normal mining approach is reinforced to encrypted approach.According to the ore flow rule and spatial location of the residual ores,the -318 m level S7 and S8 approaches are designed as the main trench recovery lanes,S6 and S9 are used as auxiliary recovery lanes.According to the field mining test results,the apparent recovery rates of the S5 and S6 approaches in the -303 m level reached 151.18% and 193.97% respectively;the apparent recovery rates of the S7 and S8 approaches in the -318 m level reached 129.15% and 134.05% respectively,which further show that the application results are significant.