EFFECT OF CALCINATION PARAMETERS OF ALUMINA HYDRATE ON THE PROPERTIESOF ALUMINA

In the present investigation, the variation of properties of alumina h ydrate and alumina during calcination with respect to different parame ters like temperature, retention time, grain size and soda content to evaluate the change of BET surface area have been studied. The effect of mineralisers like AlF3 and NH4F, for transformation of alpha phase of alumina has also been studied on a laboratory scale. Conversion to about 96% of alpha alumina was achieved by using 1% of mineraliser at 1100-degrees-C. While the BET surface area reduced with temperature an d finer size of alumina hydrate, the alpha formation showed an increas ing trend. The change of properties like density, porosity, humidity a nd compressibility with respect to temperature has also been reported.