DOC《露天塌陷坑底矿柱回收方法及空区处理方案研究》

露天塌陷坑底矿柱回收方法及空区处理方案研究 欧志成,向葵 (四川鑫源矿业有限责任公司,甘孜州,626000) 摘要:呷村银多金属矿为多层急倾斜薄至中厚矿体,在开采过程中,下盘银铜铅锌矿体和上盘独立铅锌矿体下降速度不平衡、后因地表塌陷采用露天开采回收上部矿柱矿量.

目前矿山存在采场垮塌严重、损失贫化大、积压三柱矿量大、空区未处理、安全隐患大等问题.为解决以上问题,结合充填系统的建设、矿体特征以及现场情况开展了采矿方法优化、三柱回收及采空区处理方案研究.通过研究选择合理的矿柱回收方法和空区处理方案,降低矿柱回收贫化、损失等技术经济指标,及时处理采空区、调整矿山开采顺序以降低矿山生产安全风险. 关键词:银多金属;

采空区;

矿柱;

充填;

回采方案;

安全 Research on the bottom pillar recovery method and goaf treatment scheme in an open collapse pit Ou Zhicheng,Xiang kui (Sichuan Xinyuan Mining Co., Ltd., Ganzi Prefecture, Sichuan, 626000) Abstract: The Gacun silver polymetallic deposit is a multilayer steeply inclined orebody of which thickness is thin to medium. During the mining process, the descent velocity of the footwall Ag Cu Pb Zn ore bodies and that independent Pb Zn ore bodies in the upper plate is not balanced. Soon after that, due to the surface subsidence, open pit mining method is adopted for the recovery of upper pillar. At present, there are many problems in the mine, such as serious collapse of stope, large loss and dilution, large backlog of three columns of ore, empty area is not handled, safety hidden trouble and so on. To solve these above problems, combining with the construction of filling system, orebody characteristics and site conditions, the optimization of mining method is carried out, the recovery of three columns and the treatment of mined out area was also studied. Through this research, the reasonable pillar recovery method and the empty area treatment scheme were selected, which can reduce the pillar recovery dilution and loss and other technical and economic indicators. Besides, timely treatment of mined out area and adjustment of mining sequence can reduce the safety risk of mine production. Keywords:silver polymetallic;

mined-out area;

filling;

stoping scheme;

security 呷村银多金属矿是一座资源丰富、品位高、难分选、工艺流程较复杂的银、铜、铅、锌、金等多金属矿床,分为银铜矿和独立铅锌矿,矿体为多层急倾斜薄至中厚矿体,以迭瓦式的形式平行存在,下盘银铜矿体与上盘独立铅锌矿体夹石薄,主要为流纹质凝灰岩.矿体走向整体呈南北走向,主要分布在5-6线之间,平均倾角70~75°,单层矿体厚度5~15m,最大达25m. 矿体下盘围岩为炭质板岩,上盘围岩为流纹质凝灰岩,其中炭质板岩稳固性差,流纹质凝灰岩较稳固,矿体为中等稳固,整体上矿体稳固性好于围岩.矿岩硬度系数:矿石f=6~10.灰岩及流纹质碎屑岩f=5~7.灰质千板岩f=4~7,绢云流纹质凝灰千板岩f=2~5.

1 开采现状 矿山现有4200m、4160m、4100m、4050m等4个生产中段,采用的采矿方法主要为浅孔留矿法,随着开采深度的下降,上部各中段留下大量采空区、矿柱未得到有效处理和回收,矿山开采现状主要为以下几方面: (1)4200m中段巷道受地压活动影响,变形较为严重,已不具备安全生产条件;

(2)开采顺序失调.下盘银铜矿体和上盘独立铅锌矿下降速度不匹配,上盘铅锌资源量远大于下盘高价值的银铜矿石资源量,即下盘银铜主矿体已开采下降至4050m中段且大部分已消耗,上盘铅锌矿体开采至4100m中段且只有少数几个矿房,绝大部分铅锌资源未动. (4)采场垮塌现象较为严重.4100m中段下盘银铜矿房均已垮塌至地表,部分矿房甚至垮塌至4050m中段,以致出矿损失贫化严重,同时使临近上盘的铅锌矿体开采技术条件受到破坏;