downward mining 中文意思是什麼
downward mining
解釋
下行開采-
Application of large - scale downward cementation - filling mining method in jinchuan nickel mine
大規模下向膠結充填采礦法在金川鎳礦的應用 -
Discussions on pseudo - ceiling in downward piling access back - filling mining method
下向分層進路式充填采礦法假頂護頂途徑探討
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