Research in the Area of Preparing Activated Alumina. Part 4. New Technological Approaches for Synthesis of Ultrafine [alpha]-Al.sub.2O.sub.3

Results of new integrated technological approaches to synthesis of ultrafine [alpha]-alumina using commercially available metallurgical alumina as a raw material are presented. The effect of seven different modes for calcination of the initial [gamma]-Al.sub.2O.sub.3 in the temperature range 1200 - 1600°C is studied. It is revealed that experimental regimes determine the size of the primary crystals and milling capacity of firing products. It is established that by varying temperature regimes it is possible to obtain intentionally both monomodal and multimodal powders.