Volatile parts of the coal, such as water, gas, and tar, are driven off by baking. This is done in an airless furnace or oven (kiln) at temperatures as high as 2,000 °C (3,600 °F) but usually around 1,000–1,100 °C (1,800–2,000 °F).
Although coke is more expensive than coal, it can be used in households as a clean fuel, relatively free of smoke and impurities. At the present day its use in domestic heating has been less than oil or gas, but in the 20th century it was often used in kitchen stoves.
References[change | change source]
- "Coal and Steel". World Coal Association. http://www.worldcoal.org/coal/uses-of-coal/coal-steel/.