Synthesis of beta-alumina powders by microwave heating from solution-derived precipitates

The synthesis of beta-alumina powder by microwave heating of the precipitate obtained through solution-precipitate techniques was described. A homogeneous mixture of Al-2(SO4)(3)(.)18H(2)O and Na(2)SO(4)(.)10H(2)O was precipitated by dropping the mixed solution of kaolin-derived aluminum sulfate and sodium hydroxide into ethanol with agitation by stirring. The precipitates were calcined at various temperatures for 1 h under conventional and microwave heating process for obtaining the beta-alumina powder with the structure consisting of beta- and beta"-alumina phases with a larger amount of beta"-alumina phase. The amount of beta"-alumina phase in the microwave-calcined samples was larger than that in the conventionally calcined samples. (C) 2004 Elsevier Ltd and Techna Group S.r.l. All rights reserved.