短語(yǔ)詞組短語(yǔ)longwall actual mining 走向長(zhǎng)壁回采longwall advancing mining system 長(zhǎng)壁采煤法longwall advancing mining stope 長(zhǎng)壁式回采工作面longwall advancing mining workings 長(zhǎng)壁開(kāi)采法longwall shrinkage mining method 留礦全面法longwall advancing mining stoping 長(zhǎng)壁采礦法longwall advancing mining slicing 長(zhǎng)壁分層采礦longwall advancing mining retreating 長(zhǎng)壁后退式回采longwall advancing mining mining 長(zhǎng)壁式開(kāi)采 返回 longwall mining