During the 11th century, China developed sophisticated technologies to extract and use coal for energy, leading to soaring iron production.

A few miners are still extracting coal from the mines.

In other forms, Canadian industry has a long history of extracting large coal and natural gas reserves.

Mining is the only way to extract coal, a vital source of energy.

In the west side of the county there are mines for extracting coal and bauxite.

Consider two companies that extract coal of identical quality.

Company X operates at a production site where it is very easy to extract coal.

Company Y operates at a site where it is relatively difficult to extract coal.

It was the last deep mine in the UK to extract coal from right under the sea.

Some mines still extract coal with explosives, a technique that has changed little in 100 years.