Solid fuel purposes, such as refining metals. Coal is the largest source of energy for the generation of electricity worldwide, as well as one of the largest worldwide anthropogenic sources of carbon dioxide releases. The extraction of coal, its use in energy production and its byproducts are all associated with environmental and health effects including climate change. Variations such as smokeless coal can be formed naturally in the form of anthracite, a metamorphosed type of coal with a very high carbon content that gives off a smokeless flame when set alight. Coke is a fuel with few impurities and a high carbon
History of the iron and steel industry in the United States when coke from coal started replacing charcoal as the fuel and reducing agent. Coke has a higher crushing strength than charcoal, allowing larger smelting furnaces. Because iron and steel-making at the time consumed more coal than iron ore, the steel mills moved closer to the coal mines to minimize transportation costs. A problem of coke was that it carried impurities such as sulfur, which degraded the quality of the steel. Although coke quickly became the dominant fuel for iron-smelting, in 1884 charcoal was still used to make ten percent of iron and steel in the US. The use of charcoal