Abstract: Substantially spherical mono-sized particles of zirconia can be prepared by the forced hydrolysis of an aqueous solution of zirconyl chloride. A zirconyl chloride solution having a molarity up to about 0.4 is heated for at least 72 hours at a temperature of at least 95.degree. C. to generate suspended particles of hydrated zirconium oxide, which are recovered and calcined to provide the mono-sized zirconia powders. In preferred embodiments, mono-sized powders of a mixture of zirconia with one or more of its stabilizing metal oxides is prepared by precipitating the metal in the form of its hydroxide onto pre-formed zirconium-containing particles.

Abstract: A monolithic refractory honeycomb filter of zircon or zircon plus an oxide additive is useful to remove impurities from molten metal, particularly from molten steel. The filter has a frontal contact surface containing the openings of a plurality of through-and-through cells for passage of the molten metal. Impurities adhere to the frontal contact surface of the filter and to the cell walls themselves.

Abstract: High surface area agglomerates of a porous oxide for the support of catalysts are provided. The agglomerates, in coarse particulate form, are incorporated into a sinterable ceramic structure as a discrete discontinuous phase. The agglomerates provide the high surface area necessary for effective catalyst support within the ceramic structure, which is sintered to provide appreciable density and strength.

Abstract: A method of preparing a monolithic catalyst support having an integrated high surface area phase is provided. A plasticized batch of ceramic matrix material intimately mixed with high surface area powder is formed into the desired shape for the monolith and then heated to sinter the ceramic. The resulting monolith has a strong substrate of the ceramic matrix material and a high surface area phase provided by the high surface area powder extruded with the batch.

Abstract: A method of forming a monolithic ceramic catalyst support having a high surface area phase of porous oxide embedded within the monolith structure is provided. The porous oxide phase is incorporated into a sinterable ceramic structure as a discrete discontinuous phase. The high surface area necessary for effective catalyst support is thereby provided within the ceramic structure, which is sintered to provide appreciable density and strength.

Abstract: Monolithic catalyst support structures in which a support phase of high surface area oxide material is disposed on or within a sintered ceramic material are improved by using a mixture of alumina and silica as the high surface area oxide support phase. The mixtures of alumina and silica retain higher surface area, after firing or exposure to elevated service temperatures, than does either component individually, and thereby impart higher overall surface area to the monolithic support structures.

Abstract: A catalyst support having both substantial high strength and high surface area can be produced by heating a shaped mixture of a porous oxide having a surface area of at least 20 m.sup.2 /g and the precursor of an inorganic binder for the porous oxide. The binders are precursors of alumina, silica, or titania, and are capable of imparting substantial strength to the support at relatively low firing temperatures.