孝义铝矿民采空区矿体安全高效开采技术研究

【作者】 吴安福；

【导师】 吴超；

【作者基本信息】 中南大学 ， 采矿工程， 2011， 硕士

【摘要】 我国铝土矿山周边环境复杂,矿区内存在大量民采巷道和空硐,严重破坏了矿体的原生结构,给矿山安全生产带来巨大的隐患。民采过程中,为了追求利润最大化,采富弃贫,矿柱间隔尺度随意性大,顶柱形状不规则。为了减少掠夺开采的成本,大量废石和贫矿被随意丢弃在采空区,导致正规开采的矿石损失率、贫化率和围岩混入率居高不下。孝义铝矿五大矿区均存在大量的采空区,大型设备在作业过程中,经常发生挖掘机械陷落采空区的事故,造成设备的损坏、人员伤亡,给正常采矿生产带来的重大安全隐患。因此,开展民采空区安全开采技术研究,提高矿石的回采率,降低贫化率,具有十分重要的经济价值和社会效益。论文以中铝山西分公司孝义铝矿民采空区矿体开采为研究对象,在综合分析国内外资料的基础上,通过现场调查、理论研究、数值分析、模拟开采和试验开采,研究孝义铝矿民采空区矿体安全高效开采技术和方法,消除开采隐患,实现铝土矿资源的综合回收利用。论文取得成果如下：(1)基于Reissner厚板理论,分析了矿岩自重、地面超载、等效移动荷载、自重和等效移动荷载等4种条件下,安全系数为1.0或1.3,岩体分别为灰岩、页岩、铝土矿、砂岩等,空区跨度为14.9m,18.7m,21.9m情况下的采空区顶板的安全临界厚度。(2)基于三维数值分析,研究了沉积型铝土矿民采空区顶板、间柱等关键部位受力与跨度的关系,探明了空区最大主应变与最大主应力的分布特征,指导了矿山的安全生产。(3)优化了大面积高效回采民采空区矿体的开采工艺及技术参数,提出了高效作业回采民采空区矿体的技术指南和标准。通过试验开采研究,民采空区试验区共回采高品位A/S铝矿石23788t,实际回采率为92.7%,贫化率为6.5%；同比条件下,新工艺的回采率比原来提高了3.06%以上。该技术现已在孝义铝矿推广应用,成为民采空区矿体安全高效的主要方法,成功解决了民采空区矿体开采过程的高损失率、高贫化率和安全生产等难题,取得了良好的经济效益和社会效益。更多还原

【Abstract】 A large number of civil mined-out areas exsit in the mining stops for the complex surrounding environments of bauxite mine in China, not only bring about serious damages to primary ore structure, but also pose a great threat to safety production of bauxite mine.In order to seek maximum profit and reduce cost of predatory exploitation, the rich resources are exploited while the poor are abandoned and the irregular pillars and roofs are left,waste rock and lean ore were discarded everywhere in the mined-out areas,which brings in high loss and dilution rate.In all five diggings of Xiaoyi Aluminum Mine,there are a quantity of mined-out areas. Large scale equipments often fall into these areas in the production process, causing damages to equipments and casualties to working staffs, which brings in great security risks to safety production. Thereby,studying on the safety mining technology of civil-mined-out areas to increase the recovery rate and decrease the dilution rate shows high economic value and social benefit.Based on comprehensive analysis of literature and information both home and abroad, it studies on the mining technology of Xiaoyi Aluminum Mine of Shanxi Branch China Aluminium Company, and brings foword safety and highly-efficient mining technology to remove mining risks and realize comprehensive recovery and utilization of bauxite resource,by field investigation,academic research, simulation mining and testing mining.The main results are as follows:(1) Based on Reissner thick plates theory,the cirtical thickness of roof in limestone, shale,bauxite and sandstone mined-out areas under self-weight, ground overloading,equivalent moving loads and combined action of self-weight and equivalent moving loads are ananlyzed, with spans are 14.9m,18.7m and 21.9m and the safety factor is 1.0 and 1.3 respectively.(2) Relying on three dimensional numerical analysis, relation between stress and span at key position such as roof and pillar is studied in sedimentary Bauxite mine, distribution characteristics of maximum principal strain and stress are pointed out, providing guidence to safety production of Xiaoyi Aluminum Mine.(3) Mining technology and parameter in large civil mined-out areas are optimized, technical guide and standard of highly-efficient mining are brought forward. By testing mining,23788t high-grade bauxite are recovered, practical recovery rate and dilution rate reaches 92.7% and 6.5% respectively, recovery rate is above 3.06% than previous technology.This technology as the chief safety and highly-efficient mining method, has been popularized in Xiaoyi Aluminum Mine. Problems such as high loss rate, high dilution rate and safety production are successfully solved, as well as good economical and social effects are obtained.更多还原