A comparative study of the effects of decomposition rate control and mechanical grinding on the thermal decomposition of aluminum hydroxide

Two different processes of the thermal decomposition of synthetic bayerite, i.e., the non-isothermal decomposition of mechanically ground sample in flowing N-2 and the controlled rate thermal decomposition of crystalline bayerite under vacuum, were investigated comparatively. In comparison with the conventional non-isothermal decomposition of crystalline bayerite in flowing N-2, the reaction temperature of the thermal decomposition was lowered by the individual effects of mechanical grinding of the sample and the reaction rate control. These decomposition processes indicated similar behavior characterized by the restricted changes of the specific surface area during the course of decomposition reaction and the formation of an amorphous alumina as the decomposition product. Different thermal behaviors were observed for those amorphous Al2O3 produced by the respective decomposition processes.