Rotary kiln belongs to building material equipment, which can be divided into cement kiln, metallurgy chemical kiln and lime kiln according to different materials. Rotary kiln is used for making of cement clinker and there are dry and wet methods to make activated carbon. Metallurgy chemical kiln is used in metallurgy industry and ironworks for iron ore, chromium ore and ferronickel ore calcimine. Rotary kiln is used for calcimine of high aluminum vandal ochre in refractory material industry; for calcimine of calotte and aluminum hydroxide in aluminum manufacturer; for claiming of chrome sand ore and chrome powder ore in chemical plant.