What is the difference between thermal coal and metallurgical coal?

Thermal coal, also called steam coal, is burned to generate heat for electricity production. Metallurgical coal, also called coking coal, is heated in the absence of oxygen to produce coke, a carbon material used as a reducing agent in blast furnace steelmaking. The two products have distinct markets, pricing, and end users. Metallurgical coal commands a price premium over thermal coal, and the steel demand cycle is its primary price driver. Australia is the world's largest exporter of high-quality metallurgical coal.

Which countries produce the most coal?

China is the world's largest coal producer by volume, accounting for over half of global output, followed by India, Indonesia, the United States, and Australia. Australia and Indonesia dominate international coal trade, supplying coal to power and steel markets across Asia. Russia and Colombia are significant exporters to European and South American markets. Coal production in Western Europe and North America has declined substantially over recent decades as mines have closed under economic and policy pressure.

What is longwall mining in coal operations?

Longwall mining is the dominant underground coal extraction method globally, used across China, Australia, the United States, and Europe. A longwall shearer cuts along a coal face that can extend hundreds of metres in width, while hydraulic roof supports advance behind it, allowing the worked-out roof to collapse in a controlled manner. The method achieves coal recovery rates of 70 to 85 percent of the seam, making it significantly more efficient than room and pillar methods. Longwall operations require substantial capital investment but deliver high productivity.

How deep are underground coal mines?

Underground coal mine depths vary substantially. Many longwall coal mines operate at depths of 200 to 500 metres, where coal seams are accessible but above the geothermal gradient that makes deep mining prohibitively hot. Some mines, particularly in China and Ukraine, operate at depths exceeding one kilometre, requiring refrigeration and intensive ventilation. Open cut coal mines have no depth constraint but are limited by the economic stripping ratio of waste rock to coal seam.

What happens to coal mines when they close?

Coal mine closures require structured rehabilitation under the regulatory conditions attached to mining permits. Open cut mines require recontouring of disturbed land, revegetation, and long-term monitoring of groundwater quality. Underground mines require sealing of shafts and decline entries, management of subsidence risks, and water treatment if acid mine drainage is a risk. Regulators in Australia, the United States, and Europe require mining companies to maintain financial bonds or closure funds to guarantee rehabilitation obligations, though actual closure costs sometimes exceed these provisions.