Abstract: Porous, granular particulates of titanium, zirconium or cerium oxide, preferably essentially spherical in shape, and having a specific volume of at least 0.1 cm.sup.3 /g and an apparent packed density of at least 0.2, are prepared by (a) intimately admixing a suspension or sol of titanium, zirconium or cerium oxide, at least one hydrophobic agent, and at least one organic solvent which is immiscible or only slightly miscible with water, thus producing a liquid phase essentially devoid of oxide values and granular solids based on titanium, zirconium or cerium oxide, (b) separating the liquid phase from the granular solids, and, optionally, (c) washing, drying and calcining the granular solids.

Abstract: Hydrophobic, essentially spheroidal precipitated silica particulates, well adapted as a reinforcing filler material for silicone elastomers, have a density of at least 0.15, a water wettability of at least 20% and a maximum water uptake of 5%.