Rotary kiln is a pyroprocessing device, which is mainly used to raise materials to a high temperature in a continuous process, as the common saying – calcinations. It is usually used with the material as follows: cement, lime, refractories, metakaolin, titanium dioxide, alumina, vermiculite, iron ore pellets，etc.

According to different material, the rotary kiln can be divided into three types, cement kiln, metallurgy kiln and limestone kiln. The cement kiln is mainly used for calcimine of cement clinker; usually, it has two types -- wet and dry. The metallurgy kiln is used in metallurgy industry and ironworks, such as lean iron ore, chromium ore and ferronickel ore calcimine. The lime kiln, also named active lime kiln, is used for roasting the active lime which is used in steel works and ferroalloy works, and calcined dolomite. 

The basic components of a rotary kiln are the shell, the refractory lining, support tyres and rollers, drive gear and internal heat exchangers. The kiln is made from rolled mild steel plate, usually between 15 and 30mm thick. The refractory lining consists of refractory bricks or cast refractory concrete, aiming at insulating the steel shell from the high temperatures. The support tyres usually consist of a single annular steel casting, machined to a smooth cylindrical surface. And the rollers must support the kiln, allow rotation that is as nearly frictionless as possible. The drive gear is connected through a gear train to a variable-speed electric motor， and have a high starting torque in order to start the kiln with a large eccentric load. The heat exchange in a rotary kiln may be by conduction, convection and radiation, in descending order of efficiency. 

That’s the brief introduction about the rotary kiln. Hope this information is useful for you!