Use of Coal:

Coal has many important uses worldwide. The most important use is to generate electric power, steel production, cement manufacturing and other industrial processes and liquid fuels. In addition, coal is also an important ingredient in the manufacture of certain products such as activated carbon ( used in water filters and air cleaners and washing machines blood) , carbon fiber ( reinforcement material is very strong but light used in construction) , and silicon metal ( used to produce silicones and silanes, which are used to make lubricants, water repellents, and resins) . The byproduct of coal can also be used to produce some chemical products such as creosote oil, naphthalene, phenol, and benzene.

Coal quality:

The higher the quality of coal, the carbon content increases, while the hydrogen and oxygen will be reduced. Low-grade coal, such as lignite and sub  -bituminous, have high levels of humidity ( moisture) high and a low carbon content, so that the energy is too low. The higher the quality of the coal, generally the more hard and compact, and the color will be black shiny. Additionally, moisture will decrease while the carbon content increases, which is also the greater energy content.