The surface subsidence basin is the result of underground coal mining.

地下采煤会导致地表下沉盆地的形成。

youdao

In the early days of underground coal mining, pit canaries often had short but valuable lives.

早期地下采煤的时候，矿井中的金丝雀常常拥有短暂而有价值的一生。

youdao

This paper introduces the design method for a kind of the explosion-division intelligent electromagnetic starter specially used in the fans of the underground coal mining district.

介绍了一种煤矿井下对旋式风机专用隔爆型电磁启动器的设计方法。

youdao

And while it's true that's shrinking as a percentage of Alpha's business, because we're exporting a lot more coal this year than we have in the past, our domestic steel companies are scrambling to get coal since metallurgical coal comes mostly from underground mining.

FORBES: Magazine Article

Coal mining accounts for 90% of sales at Joy's underground division and 33% at its surface-mining unit (copper and other ores account for the rest).

FORBES: The Big Dig

Louis-based Patriot Coal agreed to phase out its mountaintop excavationsand redirect its efforts back to underground mining.

FORBES: A Turning Point for Mountaintop Removal Coal?