顶底板均不稳固的古采区残矿回收实践研究

Practice study on residual ore recovery in ancient mining area with unstable roof and floor

某矿山银硐子银多金属矿生产探矿过程中遇到大量明清古采区,使得矿山开采条件更加困难。初步查明古采区位于矿体中部,上盘剩余矿体厚4~7 m,下盘剩余矿体厚6~8 m。为保证矿山的安全开采和经济效益,本文设计采用下盘矿体与上盘矿体分采合出连续采矿法,分两步回采古采区剩余矿体。首先,采用抛掷爆破方式将古采区下盘剩余矿体崩入古采区内;其次,崩落上盘剩余矿体和一部分上盘围岩覆盖在下盘崩落矿石上;最后,采用截止品位放矿的方式,将崩落的上盘围岩废石永久留在采空区内。该方案能充分利用矿山正常开采时的采准切割系统,在减少采切工程量的同时也避免了残矿回收与正常开采之间的互相干扰;由于人员不进入采空区,因此保证了开采的安全性;上盘剩余矿体、下盘剩余矿体均可沿走向连续回采,生产效率高。试验采场应用期间,上盘矿体与上盘矿体分采合出连续采矿法采出古采区残矿资源量23000 t,创造经济价值181万元,应用效果较好。

During the production prospecting process of Yindongzi silver polymetallic mine,it encountered a large number of ancient mining areas in the Ming and Qing dynasties,which made mining technical conditions more difficult.It is preliminarily identified that the ancient mining area is located in the middle of the ore body,the remaining roof ore body thickness is 4 m to 7 m,and the remaining floor ore body thickness is 6 m to 8 m.In order to ensure the economic benefits and safe mining of the mine,a continuous mining method that separates the floor ore body and the roof ore body is designed to recover the residual ore in the ancient mining area.First,the remaining floor ore body is collapsed into the ancient mining area by throwing blasting;after that the remaining roof ore body and part of the roof surrounding rock are collapsed and covers the collapsed floor ore.The cut-off grade is adopted to draw the ore,and finally the collapsed roof surrounding rock is permanently left in the mined area.This scheme makes full use of the tunnel system during normal mining of the mine,greatly reduces the amount of work,and also avoids mutual interference between the recovery of residual ore and normal mining.All tasks of residual ore recovery are carried out in the tunnel,which is safe;each all ore bodies can be continuously mined along the strike,with high production efficiency.During the application of the test stopped,the continuous mining method that separates the floor ore body and the roof ore body extracted 23000 t residual ore in the ancient mining area,creating economic value of 1.81 million yuan,and the application effect is excellent.