APPARATUS AND PROCESS FOR CONTINUOUS CALCINATION OF ALUMINIUM HYDROXIDE

摘要

A method and apparatus for calcining an aluminum hydroxide source to an aluminum oxide in which the amount of the alpha -modification can be controlled from very low to very high values. In accordance with the present invention, the calcination of the source material takes place in two stages, in the first of which the material is preheated with air and then passed to a fluidized bed calciner after which it is delivered to a holding cyclone. In the second stage, the previously calcined material which may contain up to about 80% of the alpha -modification is calcined further in a rotary tubular kiln which is followed downsteam by a cooler.