Transactions of the INDIAN CERAMIC SOCIETY Vol. 83 2024
Effect of Flash Calcined Powders on the Properties of
Spherical Alumina Granules
Maryam Safaei*
Pages : 42-47
DOI : 10.1080/0371750X.2024.2308313
Abstract
Three types of flash calcined powders with different specific surfaces and phases
were selected to make alumina granules. The granulation was performed in a pan
granulator as the spherical form. The hydrothermal and calcination conditions were
applied to the granules. Physical, chemical and microstructural studies were applied
to the hydrated and calcined granules. This study focussed on the thermal historical
effects of the initial powders derived from bauxite on the granules. The least physical
changes and the highest specific surface area were obtained for the granules prepared
with flash calcined powder at 650oC. The hydrated granules can have boehmite, gamma
and bayerite phases with rod, porous and plate morphologies, respectively. The
presence of rod boehmite phase increases the strength of hydrated granules and
plays an important role in the final strength. In the calcination stage, the phases
transformed into the transition alumina and gamma phases with the growth of
nanometer-sized crystals.
