柏杖子金矿多空区残矿开采技术研究

柏杖子金矿100-9#矿体为残矿,内部存在多个空区,矿岩稳定性差,岩移危害大,遗留有大量矿石散体,致使矿体回收困难。为此,提出多分段与底部双堑沟协同拉底的诱导冒落法回采方案,在分析矿岩可冒性、临界冒落跨度和冒落高度随采深的关系的基础上,结合矿体赋存特点及矿石流动特性,给出了诱导工程参数及爆破参数;采用矿体中部做切割向两端退采的方式,在满足上分段回采工作面超前下分段6~8个步距前提下,各分段拉底巷道同时施工,逐次诱导上部待冒矿体,由双堑沟整体回收,同时选用喷锚网联合支护方式,冒落垫层取3 m,可安全、经济、有效地回收残矿。

Study on Mining Technology of Residual Ore in Condition of Mined-out Area in Baizhangzi Gold Mine

No. 100-9 ore-body of Baizhangzi Gold Mine is the residual ore-body,it is difficult to recover the ore-body un-der the influence of the multiple mined-out zones,the poor ore and rock stability,the large rock movement,and a large amount of remained discrete ore. Therefore,the induced caving method with collaborative undercut of the multi-sublevel and double trenches on the bottom is proposed. By analyzing the relationship of caving,the critical caving span and height with the mining depth,and combined with the features of the existing conditions and the ore flow characteristics,the inducing engineering pa-rameters and blasting parameters are determined. The cutting layout in central orebodies and mining towards the ends are a-dopted. In the situation that the former sublevel mining working face is 6~8 steps ahead of the latter one,The piecewise under-cutting drifts are constructed at the same time, and the upper ore body are induced gradually and recovered by the double trenches. And then spray-bolt-mesh combining support is selected and the thickness of caving bedding is 3 m,by which the re-sidual ore can be recovered safely,economically and effectively.