Fluidized-Bed Calcination of Alumina. A New Fuel Saving Process.

Moist, micro-crystalline aluminum hydroxide (Al (OH)//3) that is produced in the Bayer process, is calcined in rotary kilns at a high temperature and converted into alumina. This conventional technique is characterized by a high heat consumption as well as by frequent damages to refractory lining of the kiln. Based on many years of research carried out by the Metallgesellschaft A. G. of Frankfurt, West Germany. A new process based on the fluidization of aluminum hydroxide has been developed. Its flowsheet is shown and operation is described. Advantages in fuel economy are outlined.