How coal is mined
Nine of every ten coal beds on Earth date from just two periods, the Carboniferous and the Permian.
- stations
- 3
- things downstream
- 406
The short version
Coal is the buried remains of swamp forests, pressed and heated over millions of years into black seams. Shallow seams are exposed by stripping off the overburden and digging with shovels and draglines. Deep seams are cut underground, often by longwall machines. Many coals are washed in a preparation plant before shipping.
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Strip the overburden
Where a seam lies close to the surface, the rock and soil above it are drilled, blasted and removed in long strips. Draglines and electric shovels do the heavy lifting.
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Cut the deep seam
Underground, the most economical method is longwall mining. Two spinning drums fitted with carbide bits run back and forth along a long section of the seam, and the roof is allowed to collapse behind the machine.
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Wash the coal
Many coals from both surface and underground mines go through a preparation plant, which washes away rock and other impurities.
Worth repeating
- In 2020, coal supplied about a quarter of the world's primary energy and over a third of its electricity.
- Longwall mining accounts for about 50 percent of underground coal production.
Where it comes from
Share of world coal mined, as given in the Wikipedia coal article.
Where it goes next
Coal feeds 6 lines directly and reaches 406 things in total.
Further down the line
Keep walking
Sources
Cite this page: "How coal is mined." Assembly Line, 2026-11-03. https://assemblyline.org/make/coal