Porous silicon oxynitride refractory shapes
AssigneeNorton Company
InventorMalcolm E. Washburn
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Abstract
A porous refractory body is formed by bonding Si.sub.2 ON.sub.2 grain or other suitable refractory grain with fine crystals of Si.sub.2 ON.sub.2 formed in situ by firing a shaped body under nitridation conditions. The body has an open pore structure, is resistant to the constituents of an aluminum chloride electrolysis cell and has good structural strength.
Claims9
A permeable refractory body consisting of a refractory grain having a mesh size of from 4 to 90, and a silicon oxynitride bond therefor, said body having a porosity, as represented by the ratio of flow rate "F" to pressure drop "P" of F/P of at least about 0.3, where F is measured in cubic feet per hour per inch.sup.2, and P is measured in inches of water per inch of thickness of said body, the pores of said body being essentially free of silicon nitride whiskers.
A porous refractory body consisting essentially of Si.sub.2 ON.sub.2, said body having a porosity, as represented by the ratio of flow rate "F" to pressure drop "P" of F/P, of greater than 6, where F is measured in cubic feet per hour per in..sup.2 and P is measured (at about 0.1 inch water pressure) in inches of water per inch of thickness, the pores of said body being essentially free of Si.sub.3 N.sub.4 whiskers.
A permeable silicon oxynitride product having a bulk density less than 1.8 g/cc, at least 14 volume percent of the volume consisting of continuous channels of pores with pore diameters between 20 and 1000 microns.
Dependencies are inferred from the claim text.