what are the different grades of coal

Best answer


The four ranks are:Anthracite: The highest rank of coal. …Bituminous: Bituminous coal is a middle rank coal between subbituminous and anthracite. …Subbituminous: Subbituminous coal is black in color and is mainly dull (not shiny). …Lignite: Lignite coal,aka brown coal,is the lowest grade coal with the least concentration of carbon. …

People also ask


  • How many types of coal are there?

  • There are four major types (or 鈥渞anks鈥? of coal. Rank refers to steps in a slow, natural process called 鈥渃oalification,鈥?during which buried plant matter changes into an ever denser, drier, more carbon-rich, and harder material. The four ranks are: Anthracite: The highest rank of coal.

  • What determines the rank of a coal?

  • The rank of a coal is determined primarily by the depth of burial and temperature to which the coal was subjected over time. With increasing temperature, peat is converted to lignite, a very soft, low-rank coal. With further increases in temperature, lignite is transformed into subbituminous coal and then into bituminous coal.

  • What are the characteristics of coal?

  • All types of coal contain fixed carbon, which provides stored energy and varying amounts of moisture, ash, volatile matter, mercury, and sulfur.

  • What type of coal has the lowest carbon content?

  • Peat exhibits the lowest carbon content (less than 60%) and has an energy density of 15 MJ / kg Figure 2. Lump of lignite or brown coal.

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