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。

youdao

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。

youdao

The power run steadily, and its brake function was improved apparently, and satisfied with require of safety in production of coal mine.

改进后的制动电源制动性能有了明显提高，运行稳定，能满足煤矿安全生产的要求。

youdao

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.

WSJ: Teenager Films Afghan Child Labor