Abstract: The method of making refractory ceramic products in which a slurry is formed of water, powdered alumina, and amorphous fibers containing AL.sub.2 O.sub.3 and SiO.sub.2, the volume of water in the slurry being sufficient to permit the slurry to flow under vibration but insufficient to permit the slurry to flow without vibration, the fibers having a molecular ratio of Al.sub.2 O.sub.3 to SiO.sub.2 substantially less than 3 to 2 and the molecular ratio of Al.sub.2 O.sub.3 to SiO.sub.2 in the combined slurry being at least 3 to 2, thereater placing the slurry in a liquid absorbing mold and vibrating the slurry to fill the mold, then permitting the mold to absorb a portion of the water from the slurry to form a body, then removing the body from the mold and drying the body, and thereafter heating the body to combine silica and alumina from the fibers and powdered alumina to recrystalize the fibers in the from of mullite.

Abstract: The method of molding a ceramic product by forming a mixture of ceramic fibers with lengths less than one-fourth inch, water and a deflouculent, the mixture having a consistency which will not flow, placing the mixture in a water-absorbing mold, vibrating the mold to cause the mixture to flow into contact with the mold and eliminate voids in the mixture, allowing a portion of the water of the mixture to be absorbed by the mold leaving a hardened remnant in the mold, removing the hardened remnant from the mold, and heating the hardened remnant to sinter the fibers therein to each other. In one example, granular alumina is mixed with the mass of fibers, water and the deflouculent to form the mixture.