different grades of coal

  • Coal in a Nutshell

    May 25, 2019 · Coal comes in three main types or grades. First, the swampy peat is squeezed and heated to form a brown, soft coal called lignite. In the process, the material releases hydrocarbons, which migrate away and eventually become petroleum. With more heat and pressure lignite releases more hydrocarbons and becomes the higher-grade bituminous coal ...

  • What is the difference between coking coal and thermal ...

    Thermal coal, also known as steam coal, is used for power and heat generation. In electricity generation, thermal coal is ground to a powder and fired into a boiler to produce heat, which in turn converts water into steam. the steam is used to mov...

  • What is the difference between grade of coal and rank of ...

    Dec 03, 2017 · Hi, I would say that rank refers to the degree of coalification.Plant matter buried under high pressure and temperature undergoes transformation-it becomes more dry,hard and more carbon rich gradually. Based on which they are divided into anthraci...

  • Coal Grades | Ministry of Coal, Government of India

    17 rows · Coal Grades. The gradation of non-coking coal is based on Gross Calorific Value (GCV), .