Coal is a readily combustible black or brownish-black sedimentary rock normally occurring in rock strata in layers or veins called coal beds. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure. Coal is composed primarily of carbon along with variable quantities of other elements, chiefly sulfur, hydrogen, oxygen and nitrogen.

Coal, a fossil fuel, is the largest source of energy for the generation of electricity worldwide, as well as one of the largest worldwide anthropogenic sources of carbon dioxide emissions. Gross carbon dioxide emissions from coal usage are slightly more than those from petroleum and about double the amount from natural gas. Coal is extracted from the ground by mining, either underground or in open pits.

Shanghai Yongxian Machinery Manufacturing Co., Ltd. is a group company with nearly twenty years experience in machinery and equipment manufacturing. Yongxian is a key enterprise specializing in researching and manufacturing drying equipment and crushing equipment, and we are also a manufacture and export base of rotary dryers, rotary kilns and flour-making, sand-making and stone-crushing equipment.