block caving coal mining method [矿业] 大块崩落采煤法
fully caving coal mining method 全部垮落采煤法
fully mechanized caving coal mining 综采放顶煤
coal caving mining 放顶煤开采 ; 放顶煤
Roof coal caving mining 放顶煤回采
coal caving mining methods 放顶煤采煤法
longwall top-coal caving mining 放顶煤开采
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