The most common approach to extracting metal-bearing ore from a porphyry copper deposit is by open-pit mining, although such mines also typically include some underground activities.

从斑岩含铜矿床开采含金属的矿石，最主要的方式是露天开采，尽管这种矿床常会伴随一些地下的地质活动。

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Mobility between surface mining, underground mining, coal or metal mining sectors may be limited by differences in production technologies and licensing requirements.

表面开采，地下开采，煤或金属采矿行业之间的流动性可能会因生产技术和许可要求的差异而受限制。

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The stability of horizontal pillars in deep mining is one of the common technical challenges that should be solved urgently for underground metal mines.

深部水平矿柱开采的稳定性问题，是地下金属矿山迫切需要解决的共性技术难题之一。

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