This paper analyzes the preconditions for small and medium-sized coal mines to increase coal recovery rate, and puts forward some paths and measures for the second mining of the coal resources.

分析了中小煤矿提高煤炭资源回收率的前提保障条件，提出了复采煤炭资源的途径和措施。

youdao

Vale is the world's second largest mining company and the planet's biggest iron ore producer.

作为世界第二大矿业公司，“谷”也是全球最大的铁矿石出产地。

youdao

Komatsu is the world's second-largest maker of construction and mining equipment, trailing Caterpillar.

小松是世界第二大建筑及采矿设备制造商，仅次于卡特彼勒。

youdao

Vale is the second-largest mining company in the world that produces a wide range of metals, the largest being iron ore and nickel.

FORBES: By Alex L��tourneau

One is for the large mining companies, which have excellent safety standards, and the second is for the medium-sized and small mining operations, which have lower standards.

CNN: After a final day together, miners begin to disband

The Gillard government has anticipated a second mining boom, he says, and allocated spending in anticipation.

CNN: Australia: Losing 'know-how' economy?