coal wikipedia - EAS

25 kết quả
  1. Coal - Wikipedia

    https://en.wikipedia.org/wiki/Coal

    Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams.Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years.

  2. Coal mining - Wikipedia

    https://en.wikipedia.org/wiki/Coal_mining

    Coal mining is the process of extracting coal from the ground. Coal is valued for its energy content and since the 1880s has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron from iron ore and for cement production. In the United Kingdom and South Africa, a coal mine and its structures are a colliery, a coal mine is …



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