Comparison of alumina granules prepared by spray freeze granulation drying and spray drying

Alumina granules were fabricated by using the spray freeze granulation drying (SFGD) and spray drying (SD) processes, and the granule properties, such as the granule size distribution, packing density, angle of repose, and compression strength, were examined. In addition, powder compacted bodies were made from the SFGD and SD granules, and the corresponding densities and defects were evaluated. Furthermore, the compacted bodies were sintered, and their densities and strength were evaluated. It was found that the properties of SFGD granules were affected by the solid content of the slurry, because the slurry droplets were frozen with water to fabricate these granules. The sintered body fabricated from SFGD granules exhibited a higher strength compared to that from the SD granules, as weak and homogeneous granules were fabricated using SFGD. (C) 2020 The Ceramic Society of Japan. All rights reserved.