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Coal is a brown to black, easily combustible rock, classified by rank. It is used mainly for electricity — thermal coal — and for steelmaking — metallurgical coal ("met coal," or coking coal). Met coal is baked in a coke oven into coke, a hard, porous, carbon-rich material that goes, with iron ore and limestone, into steel. This U.S. Geological Survey fact sheet sums up where U.S. met coal is, what makes coal suitable, and how it is produced, traded and consumed.

2023 at a glance

Million short tons
Produced in the conterminous United States66
Consumed domestically15.85
Exported51.1
Imported (all from Canada)0.712

The United States exports more than three times the met coal it uses, and is the world's second-largest exporter.

What makes coal "met coal"

Met coal is almost always bituminous and must meet strict chemical and physical specifications:

PropertyTarget or range
Ashunder 8.0%
Sulfurunder 1.0%
Phosphorus (P₂O₅)under 0.02%
Alkali (Na₂O, K₂O)under 3.0%
Volatile matterhigh-vol coal over 31%; medium-vol 22–31%; low-vol 14–22%
Fixed carbonhigh-vol under 69%; medium-vol 69–78%; low-vol 78–86%
Plasticity (Gieseler Plastometer)high-vol 5,000 to over 30,000 dial divisions per minute; medium-vol under 200–20,000; low-vol 20–1,000
Swelling (Arnu Dilatometer)high-vol +50 to over +300%; medium-vol +100–250%; low-vol −0–200%
Free Swelling Index5.5–9 (met coal potential); 3–5 marginal
Vitrinite reflectance0.65–1.90%

Ash and sulfur as received; volatile matter and fixed carbon on a dry, mineral-matter-free basis.

Single coal beds rarely meet every specification, so coke-oven feed is usually a blend — each coal adding strength, cutting impurities, or lowering cost by mixing expensive premium coal with cheaper coal.

Where it is

Map of the conterminous United States showing coal deposits by rank, with most met coal reserves and export ports in the East and large potential met coal resources in Colorado and Utah

Figure 1. U.S. coals by rank. Most met coal reserves and export ports are in the East; large potential resources lie in Colorado and Utah. USGS, modified from East (2013).

  • Most U.S. met coal lies in the Appalachian Basin, with large deposits in Pennsylvania, West Virginia, Virginia, Kentucky and Alabama. Low-volatile coal, usually preferred, runs along the basin's eastern edge; volatile matter rises westward.
  • Illinois Basin and central Great Plains bituminous coals are generally too high in sulfur.
  • Colorado, New Mexico and Utah have qualifying coal, but it is mined out or far from coke plants and ports — Colorado was the only Western state producing met coal in 2023.

Resources and reserves

The terms are often confused:

  • Coal resources: coal in the ground in forms and amounts that make extraction feasible now or later. Before mining, beds under 6,000 feet deep and — for bituminous and anthracite — thicker than 14 inches count as original resources.
  • Available resources: what remains after subtracting coal off-limits for land-use, environmental or social reasons, or unminable because of weathering, depth, stripping ratio, bed thickness or geology.
  • Reserves: coal that can be sold at a profit after mining and processing costs — a figure that shifts with costs, prices, demand and technology.

From mine to coke oven

Flow diagram of the five stages of the met coal supply chain

Figure 2. The met coal supply chain. USGS.

  1. Exploration and development: resources are leased or bought; reserves are defined by drilling, analysis and mapping.
  2. Mining — surface (contour, mountaintop removal, auger, highwall) or underground (room and pillar, longwall), depending on depth, thickness, stripping ratio, structure and extent.
  3. Processing and blending (optional): crushing, screening and sizing, removing rock partings, and separating minerals such as pyrite.
  4. Transport: by rail, barge or truck to coke ovens at home; for export, usually by train to a port and then by ship, sometimes via brokers, traders or terminals that blend further.
  5. Consumption at a coking facility.

The world market, 2023

ProducerMillion short tonsShare of world productionExported
China596.351.44%0.4
Australia183.815.85%180.5
Russia116.010.01%40.2
India71.66.18%0.03
United States66.05.69%51.1
Mongolia48.84.21%48.7
Canada34.12.94%33.8
World1,159.3100%372.4
  • These seven countries produce more than 96% of the world's met coal. China makes over half but uses nearly all of it, exporting only about 404,000 short tons; India exported about 26,000.
  • Australia, the United States, Mongolia, Russia and Canada supply over 95% of exports. Australia alone ships 48.47%; the United States 13.72%.

U.S. production

State, 2023Million short tonsShare
West Virginia30.345.83%
Alabama7.7811.77%
Virginia5.518.33%
Pennsylvania5.388.14%
Kentucky1.972.98%
Maryland0.3370.51%
Colorado0.0740.11%
Exports not attributed to a state17.226.02%
EIA adjustment−2.44−3.69%
Total66.11100%
  • All but Colorado are in the Appalachian Basin.
  • Output peaked at 90.0 million short tons in 2011, fell to 55.5 in 2020, then rose by about 10 by 2023 — as the average sales price climbed from $110.64 to $212.30 per short ton.
  • The Warrior coal field in Alabama is a major producer today, but the USGS has not assessed it since the 1960s, when it counted 11,905 million short tons of resources.

How much is left

Reserves at producing mines, end of 2023 (EIA): 3,151 million short tons in the Appalachian states — West Virginia 1,810, Pennsylvania 842, Alabama 170, Kentucky 147, Virginia 141, Ohio 33, Maryland 8. How much of it meets met coal specifications can't practically be calculated.

Available resources that may include met coal, from the USGS's National Coal Resource Assessment (1999–2001) and other studies:

AreaMillion short tonsNotes
Northern Appalachian Basin (Pa., W. Va., Ohio)46,500the Pittsburgh and Upper Freeport beds, long-time met coal sources
Central Appalachian Basin (W. Va., Va., Ky.)13,800the Pond Creek and Pocahontas No. 3 beds
Southern Piceance Basin34,000some meets met coal specifications
Kaiparowits Plateau (Utah)28,000much lies under Grand Staircase-Escalante National Monument and can't be mined
Somerset coal field (Colo.)3,100high-volatile A and B bituminous coal
Raton Basin (Colo., N. Mex.)5,500low sulfur, low to medium ash
Total130,900

Other Western fields — the Wasatch Plateau, Book Cliffs, Danforth Hills and Yampa — either don't meet the specifications or have produced no met coal, and Illinois Basin coal qualifies only when blended with Appalachian coal.

Sources

Based on "Metallurgical coal — Deposits, production, resources, market dynamics, and supply chain risks," U.S. Geological Survey fact sheet, drawing on U.S. Energy Information Administration data and earlier USGS assessments; a work of the United States government in the public domain. The fact sheet notes that the EIA's international and annual reports differ on 2023 U.S. production (66.0 and 66.11). It calls the reserve table's states "the six States producing met coal in the Appalachian Basin," though the table lists seven, including Ohio, which produced no met coal in 2023; it places the Piceance Basin in western Colorado in the text and in Colorado and Utah in its table; and its summary locates the 130,900 million short tons in the West, though its table includes the Appalachian basins. The figures here follow the tables.

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Licença: CC0 1.0 (domínio público) · Adaptado de pubs.usgs.gov

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