露ろ天てん掘ぼり炭たん鉱こう

noun

open-pit coal mine; open-cut coal mine

A coal mine where mining is conducted from the surface, not underground.

• この地ち域いきには大だい規き模ぼな露ろ天てん掘ぼり炭たん鉱こうがある。

  There is a large open-pit coal mine in this area.

• 露ろ天てん掘ぼり炭たん鉱こうは地ち下か採さい掘くつより安あん全ぜんな場ば合あいが多おおい。

  Open-pit coal mines are often safer than underground mining.