Vibration classification screen is the key to ensure the quality of washing raw coal and product raw coal in the process of changing from run-of-mine coal to washing raw coal.

振动分级筛在矿井毛煤转化为入洗原煤过程中是保证入洗原煤和产品原煤质量(粒度合格)的关键设备。

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This text explains to Xutuan coal mine west breeze well and main well a method, error margin for of run-through measuring analysis with anticipate.

介绍了许疃煤矿西风井与主井之间的贯通测量的方法、误差分析和预计。

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According to characteristics of the coal mine production, the article analyses the power supply system in coal mines and discusses the economic run mode of the transformers and the lines.

根据煤矿生产的特点，对煤矿供电系统进行了分析，对变压器、线路的经济运行方式进行了探讨。

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China Metallurgical Group, the Chinese state-run company slated to take control of the coal deposits, said it had no idea children were used to mine coal in the area.

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