关键词: 露天矿, 分期开采, 设计, 境界圈定, 采剥计划, 效益

Abstract: In the design of the technical renovation project of the Xigou Mine，the eastern hilltop is enclosed into the mining boundary.But after the production practice，it is proved that the mining of the eastern hilltop seriously threatened to the safe production of the 3 100 meter industrial site by adopting the complete boundary mining technology.Therefore，the proposal for solving the issue of production safety of the eastern hilltop mining by the phased mining is put forward.In the design of stage mining，the final boundary is divided into two stages by temporary non-working slope.The eastern hilltop is divided into the second phase of mining.According to the design standard for open-pit mine，the length of service of the phased mining，the temporary slope formation elements and the advancing sequence of each step are determined.Through the preparation of medium-term and long-term mining plan，the feasibility of the phased exploitation scheme is verified theoretically.From the first phase mining plan execution in the past two years，the designed scheme can guarantee that the annual production capacity is not reduced after the technological transformation with the final mining boundary not changed，and also can avoid the hidden danger of the eastern hilltop with considerable economic benefits obtained.

Key words: Open-pit mine, Stage mining, Design, Mining boundary delineation, Stripping plan, Benefits