where is coal found and how is it formed
Coal Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure. Coal is composed primarily of carbon, along with variable quantities of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.[1] Coal is a fossil fuel that forms when dead plant matter is converted into peat, which in turn is converted into lignite, then sub-bituminous coal, after that bituminous coal, and lastly anthracite. This involves biological and geological processes. The geological processes take place over millions of years.[2]
Coal Coal is extracted from the ground by coal mining. Since 1983, the world's top coal producer has been China.[3] In 2015 China produced 3,747 million tonnes of coal â€“ 48% of 7,861 million tonnes world coal production. In 2015 other large producers were United States (813 million tonnes), India (678), European Union (539) and Australia (503).[3] In 2010 the largest exporters were Australia with 328 million tonnes (27% of world coal export) and Indonesia with 316 million tonnes (26%),[4] while the largest importers were Japan with 207 million tonnes (18% of world coal import), China with 195 million tonnes (17%) and South Korea with 126 million tonnes (11%).[5]