过去的几个月，大型矿业公司财富缩水幅度之大令人震惊，各矿业公司深受其苦。
BIG mining companies have suffered an astounding reversal of fortunes in the past few months.
为了实现煤矿安全生产，各矿必须建立稳定的矿井通风系统。
In order to realize safety production in coal mine, ventilation system must be set up.
由于各矿带矿物组合及含量的变化，使金的赋存状态及分布也发生相应改变。
The change of the mineral assemblage and content of every ore zone makes the change of the existing state and distribution of Au.
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