Anthracite minimum carbon content of 95%. They also differ in usage from standard grade anthracite (used mainly for power generation), being employed mainly in metallurgy as a cost-efficient substitute for coke in processes such as sintering and pelletising, as well as pulverised coal injection (PCI) and direct injection into blast furnaces. They can also be used in water purification and domestically as a smokeless fuel. HG and UHG anthracite account for a small percentage of the total anthracite market. The major producing countries are Russia, Ukraine, Vietnam, South Africa and the US. The primary sizes used in the United States for
Anthracite times been futile, and several such combustion areas exist today. The existence of an underground combustion site can sometimes be identified in the winter where fallen snow is seen to be melted by the warmth conducted from below. Proposals for harnessing this heat as geothermal energy have not been successful. A vein of anthracite that caught fire in Centralia, Pennsylvania in 1962 has been burning ever since, turning the once-thriving borough into a ghost town. Among current producers, Russia, China and Ukraine have the largest estimated recoverable reserves of anthracite. Other countries with substantial reserves include Vietnam and North Korea.