Coking coal: Extraction
The rare coals that swell and fuse into coke
What this tab covers How it is mined, drilled or grown, and processed into a tradeable form: the main methods compared, their unit economics, by-products, and the companies that do this work globally and in India.Coking coal is bituminous coal that softens, swells and resolidifies into strong, porous coke when heated without air. Good seams need low ash, low sulphur and the right volatility. Key sources include Australia's Bowen Basin, Canada's Elk Valley, Appalachia, Russia's Kuzbass and Mongolia's South Gobi. Much is mined underground or from deep pits, then washed. In coke ovens, blended coal is baked at about 1,100 °C for 15-18 hours (Smil). Each tonne of coal gives about 0.77 tonnes of coke; the rest becomes gas and tar used as fuel or chemical feedstock (Smil).
Coking coal (metallurgical coal) is mined with the same machines as thermal coal but sold on quality. Grades run from premium hard coking coal (strong coke, low ash, low volatile matter), through semi-hard and semi-soft coking coal, to PCI coal used for injection. Most seaborne supply comes from open-cut and underground mines in Australia, Canada, the US and Russia; China and Mongolia supply China's mills overland. After mining, washing plants raise quality, and coke ovens at or near steel plants turn the blend into coke. The step that makes it tradeable is washing to a guaranteed specification.
Methods compared
| Method | Share of supply | Typical scale | Recovery / efficiency | By-products | Unit cost |
|---|---|---|---|---|---|
| Open-cut mining (Bowen Basin, Elk Valley, Tavan Tolgoi) | most seaborne supply (indicative; basis: typical industry range, not checked against a sourced 2025 figure) | large mines 5-15 Mt a year (indicative; basis: typical industry range, not checked against a sourced 2025 figure) | wash-plant yield often 60-80% of raw coal (indicative; basis: typical industry range, not checked against a sourced 2025 figure) | thermal-grade middlings sold to power plants | null (no sourced figure found) |
| Underground longwall mining (Appalachia, Kuzbass, Poland, Shanxi, Bowen underground) | most Chinese and US output; null for a world share | single longwall mines 3-8 Mt a year (indicative; basis: typical industry range, not checked against a sourced 2025 figure) | 60-80% of the panel (indicative; basis: typical industry range, not checked against a sourced 2025 figure) | coal mine methane | null (no sourced figure found) |
| By-product (slot oven) coke making | most world coke output; global coke production was 685 Mt in 2013, 70% of it in China (Smil 2016) | a battery produces about 0.5-2 Mt of coke a year (indicative; basis: typical industry range, not checked against a sourced 2025 figure) | 600-800 kg of coke plus 50-100 kg of breeze per t of coal (Smil 2016) | coke-oven gas, tar, ammonium sulphate, benzol | null |
| Heat-recovery (non-recovery) coke ovens | null | null | null | electricity from waste heat | null |
How each method works
Open-cut mining (Bowen Basin, Elk Valley, Tavan Tolgoi)Draglines and truck-shovel fleets remove overburden to reach multiple seams. Coal goes to a preparation plant on site. Queensland's Bowen Basin is the largest source of premium hard coking coal traded by sea.
Scalable and safer than underground; high strip ratios and weather risk (Queensland floods in 2008 and 2011).
Industry practice (indicative) Underground longwall mining (Appalachia, Kuzbass, Poland, Shanxi, Bowen underground)Longwall shearers mine deeper, often higher-quality low-volatile seams. Poland's JSW and US producers such as Warrior Met Coal work this way. Mines are gassy, so methane drainage is essential.
Reaches premium seams; fires and methane explosions are a serious risk, such as the 2024 Grosvenor and Moranbah North incidents in Queensland.
Industry practice By-product (slot oven) coke makingBatteries of narrow ovens heated through brick walls carbonise blends for 15-18 hours; the gas is collected and cleaned to recover tar, ammonia and benzol, and the cleaned gas fires the ovens and steel plant (Smil 2016).
Recovers valuable gas and chemicals; emissions control is demanding.
Smil (2016) Still the Iron Age Heat-recovery (non-recovery) coke ovensOvens burn the volatile gases inside the oven under negative pressure, so leaks are drawn in rather than out; the hot flue gas raises steam for power instead of being recovered as chemicals. Common for merchant coke plants in India and the US (indicative).
Cleaner and simpler; no chemical by-products.
Industry practice Unit economics are indicative ranges from the sources named; costs vary widely by deposit, region and year.Who does it: global
| Company | Country | Activity | Volume | Year | Source |
|---|---|---|---|---|---|
| BHP (BHP Mitsubishi Alliance) | Australia | largest seaborne hard coking coal producer (Bowen Basin) | 36 Mt metallurgical coal, BMA 100% basis (BHP share 18.0 Mt) | FY2025 | BHP Operational Review for the year ended 30 June 2025 |
| Glencore (Elk Valley Resources) | Switzerland | Canadian steelmaking coal acquired from Teck in July 2024, plus Australian mines | 32.5 Mt steelmaking coal, 100% basis | 2025 | Glencore Full Year 2025 Production Report |
| Shanxi Coking Coal Group Volume not verified in sources checked, so left blank. | China | largest Chinese coking coal producer | not published | 2025 | Not found in sources checked |
| Anglo American Steelmaking Coal Volume not verified in sources checked, so left blank. | UK | Queensland mines (Moranbah North, Grosvenor) being sold | not published | 2025 | Not found in sources checked |
| Whitehaven Coal Volume not verified in sources checked, so left blank. | Australia | bought Daunia and Blackwater from BMA in 2024 | not published | FY2025 | Not found in sources checked |
| Erdenes Tavan Tolgoi Volume not verified in sources checked, so left blank. | Mongolia | state miner supplying China overland | not published | 2025 | Not found in sources checked |
Who does it: India
| Company | Country | Activity | Volume | Year | Source |
|---|---|---|---|---|---|
| Bharat Coking Coal (BCCL) | India | Coal India subsidiary mining the Jharia coalfield | 40.5 Mt coal (coking and non-coking) | FY2025 | Ministry of Coal Annual Report 2025-26, Chapter 9 |
| Central Coalfields (CCL) | India | Coal India subsidiary with coking and non-coking coal in Jharkhand | 87.54 Mt coal (coking and non-coking) | FY2025 | Ministry of Coal Annual Report 2025-26, Chapter 9 |
| Tata Steel Volume not verified in sources checked, so left blank. | India | captive coking coal mines at Jharia and West Bokaro; large importer | not published | FY2025 | Not found in sources checked |
| SAIL Volume not verified in sources checked, so left blank. | India | state steelmaker with captive collieries; largest public-sector importer of coking coal | not published | FY2025 | Not found in sources checked |
| JSW Steel Volume not verified in sources checked, so left blank. | India | largest private steelmaker; imports coking coal and runs coke ovens | not published | FY2025 | Not found in sources checked |
India mined 65.7 Mt of coking coal in 2024 (World Mining Data 2026), but most is high-ash and must be washed and blended, so steelmakers imported 57.6 Mt of coking coal in FY2025 and 39.2 Mt in April-October 2025 (Ministry of Coal), chiefly from Australia, the US and Russia. India was also the largest importer of coke, with 17.4% of world import value in 2024 (UN Comtrade).