出典:Wiktionary
coalmining (uncountable)
出典:Wikipedia
出典:『Wikipedia』 (2011/07/04 20:31 UTC 版)
The goal of coal mining is to remove coal from the ground. Coal is valued for its energy content, and since the 1880s is widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron from iron ore and for cement production. In the United States, United Kingdom, and South Africa, a coal mine and its structures are a "colliery". In Australia, "colliery" generally refers to an underground coal mine.