operation flash calcined alumina powder a 300 manufactured by uop des plaines ill was fed into a 4 feet rotating tub at a rate of 0 8 lbs min while a pump and nozzle assembly continuously supplied at a rate of 0 51 lbs min a sodium silicate solution the solution consisted of 1 part grade 40 sodium silicate and about 8 parts water small amount of 30 u00d7 40 mesh alumina seed was charged first into the nodulizer in order to initiate forming of larger alumina particulates the operation continued until about 50 lbs of material were accumulated the particle size fraction 8 u00d7 14 mesh was separated and subjected to curing in a closed container subsequently about 4 5 lbs of the sample was charged into a one feet pot sprayed with about 120 cc water and activated as described in example 1 the silica content of this sample is about 2 2 mass as calculated on a volatile free alumina basis this sample is referred to as alsiw spherical particulates were prepared and cured as described in example 3 instead of water the particulates were sprayed with a colloidal silica solution and activated as described in example 2 this sample is referred to as alsisi in order to show that si is used in both forming and final spraying stage of material preparation the samples were.