宜昌晒旗河磷矿条带充填法采场结构及回采顺序研究

复杂地形条件下矿体安全高效开采研究对于释放矿山资源产能有着重要意义。为解决目前房柱法开采对地表扰动程度大且矿柱难以回收等问题,基于条带充填开采技术,从采场结构及回采顺序两个方面对宜昌晒旗河磷矿展开了适应性研究,以期在提高矿石回收率的同时减少地表扰动。首先依据晒旗河高山河谷地形下地应力特征,在盘区内划分了高低应力采区,构建了分区采场结构,并引入极限强度理论得到条带矿柱的合理宽度;然后设计了高应力采区"隔一"、低应力采区"隔一采一"的条带回采顺序,运用FLAC3D数值软件优选出高、低应力采区间的回采顺序,研究矿体在开挖过程中围岩应力变化特征及地表变形特征。结果表明:①从低应力采区向高应力采区的回采顺序优势明显,可缓解高低应力采区的应力不均匀程度;②在整个回采及充填过程中,采场围岩较稳定,矿柱所受的垂直压应力均小于抗压强度;③高山河谷地形下地表沉降曲线演化特征为"U→V→U→W",地表沉降得到了有效控制;④所设计的条带充填法与传统房柱法开采相比,矿石开采效率得到了大幅提升,可为晒旗河磷矿及类似高山河谷地形下矿床开采提供技术指导。

Study on the Optimization of Mining Scheme for Gently Inclined Thin Orebody of Shaiqi River Phosphorite Mine in Yichang City

The study of safe and efficient mining of orebodies under complex topographic conditions is of great significance for releasing the productivity of mine resources.In order to solve the problems of large disturbance to the surface and difficult recovery of pillars caused by room-and-pillar mining，the adaptability of Yichang Shaiqi River Phosphate Mine is studied from two aspects of stope structure and mining sequence based on strip filling mining technology，so as to improve ore recovery and reduce surface disturbance.Firstly，according to the characteristics of in-situ stress under alpine valley terrain，the high and low stress mining areas in the pan area are divided，the zoned stope structure is constructed，and the reasonable width of strip pillars is obtained by introducing the ultimate strength theory；secondly，the strip mining sequences of “two-mining-one” in high stress mining areas and “one-mining-one” in low stress mining areas are designed，and the high and low stress mining is optimized by using FLAC3D numerical software.The mining sequence of the interval is studied，and the stress variation characteristics and surface deformation characteristics of the surrounding rock during the mining process are studied.The study results show that:①the mining sequence from the low stress mining area to the high stress mining area is relatively good，which can alleviate the stress non-uniformity in the high and low stress mining area；②during the whole mining and filling process，the surrounding rock of the stope is relatively stable，and the vertical pressure stress on the pillar is less than its extreme limited compressive strength；③the evolution characteristics of surface subsidence curve under alpine valley topography can be described as “U→V→U→W”，and surface subsidence is effectively controlled；④compared with the traditional room-pillar mining method，the designed strip filling method can effectively increase the ore mining efficiency，it can provide technical guidance for the mining of Shaiqi River Phosphate Mine and the deposits under similar alpine valley terrain.