The rotary kilns are widely used in many manufacturing industries such as building materials, metallurgy, chemical , and environmental protection . The rotary kiln can be divided into cement kiln , metallurgy chemical kiln and lime kiln according to different materials . Cement kilns for calcining cement clinker, the sub - dry production of cement kilns and wet process cement kilns two categories . Non-ferrous and ferrous metallurgy such as  iron, aluminum, copper , zinc , tin , nickel, tungsten , chromium , filing and other metal rotary kiln smelting equipment, sintering, roasting of ores, concentrates, intermediate .