Development of magnesium aluminate spinel by solid oxide reaction

An attempt has been made to develop magnesium aluminate spinel of stoichiometric composition from sea water magnesia and purer variety of alumina. The effect of surface area on spinellisation and densification was studied at temperatures from 1500 degrees C to 1600 degrees C. Rate of firing was found to be an important parameter in the study 99% densification of the spinel with respect to the theoretical density has been achieved at 1550 degrees C with relatively slower rate of firing. The quality of sea water magnesia with respect to the B2O3 content can be assessed from the hot modulus of rupture strength values. Thermal shock resistance test of spinel has shown no strength degradation upto 3rd cycle and a 75% loss of strength occurred after 10 cycles of experiment at 1000 degrees C