A new technique of the long-hole blasting has been used in raising and prospecting of the rooms and the pillars.

一次钻孔分段爆破的新工艺已成功地应用到天井掘进和矿房、矿柱的回采方面。

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A new technique of the long-hole blasting has been used in raising and prospecting of the rooms and the pillars.

一次钻孔分段爆破的新工艺已成功地应用到天井掘进和矿房、矿柱的回采方面。

youdao