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- Stability of boundary pillar of open pit and underground mine 露天地下开采隔离层稳定性研究
- open pit and underground mine 露大地下开采
- Necessity for reconstructing Anjialing mine from an open pit into a combined opencast and underground mine 谈安家岭项目由单一露天变更为露井联合开发的必要性
- Transfer from open pit to underground mine 露天转地下
- Transition from Open Pit to Underground Mine 露天转地下
- Changing from open pit mine to underground mine 露天转地下
- open pit mine turns into underground mine 露天转井下
- Transfer from open pit to underground mining 露天转地下
- turning open pit into underground mining 露天转地下
- Its extracting method includes surface well drilling and underground mine tunnelling.The tunnelling method is suitable for many mine areas in our country. 开发煤层气的方法有地面钻井开采和井巷开采两种，其中井巷开采方法适用于我国许多矿区。
- underground Mining and Open Pit mining 井露开采
- underground mining from open pit 露天转地下开采
- Transition from open pit to underground mining 露天转地下开采
- changing open pit mining into underground mining 露天转地下
- Transition mining from open pit mine to underground mine 露天转地下
- Study of Two Methods For Pit and Fissure Sealing. 窝沟封闭剂的封闭性研究
- This paper summarizes the experiences of the existing uranium open pits and analyzes the questions in design,erection and production. 本文通过总结已建成投产的露天铀矿,经过对设计、施工与生产中出现的问题分析。
- If the buses and underground go on strike, business in London will grind to halt. 如果公共汽车和地铁续继罢工，伦敦的商业就会逐渐瘫痪。
- Following the sparse Alexandrite veins through pegmatite rock with hand dug trenches, open pits and small tunnels, mining was very primitive to say the least. 他们赤手掘出壕沟，在伟晶岩石层中寻觅稀疏的亚历山大石矿脉，开坑打洞，开采无比原始。
- transferring open pit mining into underground mining 露天转地下开采
