At present, due to the raw materials, most of the production processes of alumina in China use the sintering method and the combined method. Rotary kiln is mostly used in the drying and calcination of bauxite and the roasting of aluminum hydroxide. In recent years, the introduction of fluidized roasting equipment has been widely used, but in some old factories, rotary kiln still accounts for a large proportion.

The rotary kiln is a sintering kiln of alumina clinker. In the preparation of alumina, the bauxite and soda ash and lime are proportioned into the rotary kiln, calcined at 1200 ~ 1300 ° C, and then discharged into the kiln, and then processed to prepare aluminum hydroxide and mother liquor to prepare aluminum hydroxide. It can be produced by calcining at a high temperature of 1200 ° C in a rotary kiln. The calcination process in the rotary kiln is a high temperature flame and the heated material is reversely moved in the furnace. Alkali lime bauxite raw slurry (40% water) or aluminum hydroxide (12%-18% water) is added from the kiln tail, dehydrated by low temperature drying, heating, high temperature calcination, discharging from the kiln head, and the high temperature gas is The kiln head flows to the kiln tail. Therefore, the kiln is divided into pre-tropical and high-temperature calcined zones. In order to prevent the slurry from bonding to the kiln lining during the heating and calcining process and strengthening the heat transfer process, a chain is arranged between the refractory masonry, and the kiln lining is continuously struck during the rotary motion of the kiln body. The service life has a certain impact.

The rotary kiln body for alumina production is a simplified steel plate welded with refractory material. Refractory materials work in harsh conditions and harsh conditions. It should have the following characteristics: strong resistance to alkali corrosion, long-term operation at high temperature of 1200 ~ 1300 °C, without damage; can withstand the impact of dynamic load; can resist the erosion of the charge; can withstand the erosion of high temperature airflow. The refractory materials used in the rotary kiln are mainly high-aluminum bricks and magnesia-chrome bricks, while the low-temperature drying kiln is lined with clay bricks.

At present, the amorphous refractory material has been widely used in the aluminum industry. Due to the high temperature wear and thermal shock stress of the material in the kiln mouth of the rotary kiln, the kiln mouth is easily deformed and damaged in the transition zone of the alumina clinker kiln. The ambient temperature is 400-1000 ° C, which is severely damaged by alkali and mechanical damage (vibration, distortion), and the liner often falls off.