Investigation of the Effect of high Alumina Cement on the Properties of Foamed Alumina Insulation Bricks

The purpose of this study was to investigate the effect of high alumina cement and Sintering temperature on microstructure, physical and mechanical properties of foamed alumina insulation bricks. The Slurry samples  were prepared containing 75wt% of alumina and 25% wt of deionised water containing 1%, 3%, 5%, 7% wt% high Alumina cement and 2% wt% foam. Then samples were poured into metal molds. After drying the samples, they were sintered at 1510° C for 3 h. The Samples containing 7% wt cement were also sintered at 1600,1650° C for 3. The results showed that alumina slurry containing 2% foam and 7% high alumina cement additives at 1s-1 shear velocity had a viscosity equal to 3 Pa.s, which decreased with increasing shear velocity to 100 s-1and its decreased to 0.3 Pa.s. The samples showed a total density between 63.6 and 87.6  g/cm3, a total porosity between 59 and75%, a flexural strength between 6.6 and 6.8 Mpa and the average size of the spherical porosity between 8.5 and 11µm depending on the amount of cement and the baking temperature. phase investigations show that the peaks formed at the temperature of 1510° C correspond to the corundum and calcium aluminate phase)CaO.6Al2O3).