Coking coal
The coal that becomes coke for blast furnaces: hard to replace in primary steelmaking, so the EU and US rate it critical.
Natural sources · Fossil stores · No. 12
- EU critical 2023
- US critical 2025
- HHI 2,849 · highly concentrated
This coal does two jobs inside a blast furnace: it burns for heat and rips oxygen out of iron ore.
Chart: Illustration: Coking coal
Where it comes from
Chart: Map of where it comes from
Coking coal is a special bituminous coal that softens, swells and fuses into hard porous coke when baked. Key seams lie in Queensland's Bowen Basin, Canada's Elk Valley, Appalachia, Kuzbass and the South Gobi.
Three things to know
- In 1709 Abraham Darby first fired a blast furnace with coke instead of charcoal, freeing ironmaking from forests.
- A tonne of coking coal yields about 0.77 tonnes of coke, with the rest captured as gas and chemicals.
- Steel made from scrap in electric arc furnaces needs almost no coal, about 16 kg per tonne.
The journey
- 1 Bituminous seamLow ash, low sulphur, right volatility
- 2 WashingMined and cleaned to coking grade
- 3 BlendingCoals of different volatility mixed
- 4 Coke ovenBaked without air at about 1,100 °C
- 5 Blast furnaceCoke charged with ore to make iron