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As a fossil fuel burned for heat, coal supplies about a quarter of the world's primary energy and two-fifths of its electricity. [4] The largest consumer and importer of coal is China. China mines almost half the world's coal, followed by India with about a tenth. Australia accounts for about a third of world coal exports, followed by Indonesia ...
Lignite (derived from Latin lignum meaning 'wood'), often referred to as brown coal, [1] is a soft, brown, combustible sedimentary rock formed from naturally compressed peat.It has a carbon content around 25–35% [1] [2] and is considered the lowest rank of coal due to its relatively low heat content.
This is a list of countries by coal production ranking countries with coal production larger than 5 million tonnes as of 2023. Coal production (million tonnes) Country
It has the highest carbon content, the fewest impurities, and the highest energy density of all types of coal and is the highest ranking of coals. The Coal Region of Northeastern Pennsylvania in the United States has the largest known deposits of anthracite coal in the world with an estimated reserve of seven billion short tons . [ 2 ]
The rank of coal is correlated with its geologic history, as described in Hilt's law. In the ASTM system, any coal with more than 69% fixed carbon is classified by its content of carbon and volatiles. Coal with less than 69% fixed carbon is classified by its heating value. Volatiles and carbon are on a dry mineral free base; heating value is ...
A coalfield is an area of certain uniform characteristics where coal is mined. The criteria for determining the approximate boundary of a coalfield are geographical and cultural, in addition to geological. A coalfield often groups the seams of coal, railroad companies, cultural groups, and watersheds and other geographical considerations.
Renewable resources are available each year, unlike non-renewable resources, which are eventually depleted. A simple comparison is a coal mine and a forest. While the forest could be depleted, if it is managed it represents a continuous supply of energy, vs. the coal mine, which once has been exhausted is gone.
The maximum number of coal seams found in some of the drill holes is 20. The cumulative thickness of the coal beds range from 0.2 to 36 metres. Claystone invariably forms the roof and the floor rock of the coal beds. The coal is brownish black, black and grayish black in colour. It is poorly to well cleared and compact.