R. Sarkar et al., Calcination effect on magnesium hydroxide and aluminium hydroxide for the development of magnesium aluminate spinel, CERAM INT, 26(1), 2000, pp. 25-28
Spinellisation and densification of magnesium aluminate spinel was studied.
Magnesium hydroxide and aluminium hydroxide were calcined separately betwe
en 900 and 1600 degrees C. Stoichiometric mixtures of the uncalcined and ca
lcined materials were sintered between 1550 degrees C to 1750 degrees C. Sp
inellisation was found to be reduced with increasing calcination temperatur
e bt sintering at 1750 degrees C produces similar spinellisation for differ
ent batches due to higher diffusivities of the diffusing species. Above 99%
spinellisation was obtained for the uncalcined batch sintered at 1750 degr
ees C. Densification was also found to be greatly dependent on calcination
temperature. Control of reactivity by calcination and slower rate of sinter
ing have reduced the negative effects of the single stage sintering and a m
aximum of 91% densification has been found for the batch, with materials ca
lcined at 1400 degrees C. (C) 1999 Elsevier Science Ltd and Techna S.r.l. A
ll rights reserved.