noun
coal miner
A worker who extracts coal from a mine. This is a straightforward occupational term.
彼の祖父は炭鉱労働者だった。
His grandfather was a coal miner.
炭鉱労働者たちは過酷な環境で働いていた。
The coal miners worked under harsh conditions.
Compound of 炭鉱 (coal mine) + 労働者 (worker).