Steep slope mining 陡帮开采

along slope mining 顺坡开采

slope mining method 斜坡采煤法

steeper slope mining 陡帮开采

inverse slope mining 逆坡开采

sharp slope mining technology 陡帮开采技术

mining slope 矿山边坡 ; 采矿边坡

slope of mining area 矿区坡面

open mining slope 露天矿边坡