Commonly known as the rotary kiln, the rotary calcining kiln is also called the rotary dryer, belonging to construction equipment. Depending on the materials, the rotary kiln falls into three types: clinker rotary kiln, limestone rotary kiln and cement rotary kiln.

 

The cement rotary kiln is mainly used for calcining cement clinker, divided into the dry method production equipment and the wet type production equipment. Clinker rotary kiln is widely used in steel works in the metallurgy industry for magnetizing roasting of poor iron ore ; oxidizing roasting of chromium and nickel iron ore; roasting high aluminum vanadium and soil ore pellets in refractory plants; roasting clinker and aluminum hydroxide in aluminum manufacturers and roasting chrome ore and powder in chemical plants . The limestone rotary kiln (i.e. the active lime kiln) is used for roasting active lime in steel works and ferroalloy plants and light roasting dolomite.

 

The shell of the kiln is made of mild steel plate. Mild steel is the only viable material for the purpose, but presents the problem that the maximum temperature of the feed inside the kiln is over 1400°C, while the gas temperatures reach 1900°C. The melting point of mild steel is around 1300°C, and it starts to weaken at 480°C, so considerable effort is required to protect the shell from overheating.