because in the structure of energy use, coal is considered as the traditional and basic energy source. Coal is widely used in production and life. In the past, coal was used as a fuel in steam engines and locomotives; Then, coal is used as fuel in thermal power plants, coke coal is used as fuel for the metallurgy industry. Recently, thanks to the development of the chemical industry, coal has been used as a raw material to produce a variety of pharmaceuticals, plastics, and plastic fibers.
