The original block caving system with floor pillar exists many effects,such as development work large,constraction difficult,production efficiency lower and ore loss great.

 
  • 原采用有底柱崩落法底板漏斗方案,存在采準工程量大、施工困難、生產(chǎn)效率低和礦石損失貧化大等問(wèn)題。
今日熱詞
目錄 附錄 查詞歷史
国内精品美女A∨在线播放xuan