Colliery:
Coal mining is the process of extracting coal from the ground. Coal is valued for its energy content and since the 1880s has been 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 Kingdom and South Africa, a coal mine and its structures are a colliery, a coal mine is called a ‘pit’, and the above-ground structures are a ‘pit head‘. In Australia, “colliery” generally refers to an underground coal mine. [Wikipedia]
Noted in “Why the UK doesn’t need a new coal mine,” Mark Peplow, NewScientist (4 September 2021):
The colliery’s coal wouldn’t fuel polluting power stations. Instead, the mine would supply “coking coal” to the steel industry in the UK and Europe. Coke is a dense form of carbon that plays three vital roles in steel-making. Inside a blast furnace, carbon chemically removes oxygen from iron oxide ore to create crude iron. Burning coke also raises the temperature to 2000°C or more, allowing molten iron to be tapped from the bottom of the furnace. Finally, a dash of carbon in the iron strengthens the metal, helping it to become steel inside a second furnace.
