Abstract: A method of densifying a fumed metal oxide is disclosed wherein the metal oxide is converted to a flowable sol and then dried to form a fragmented solid which is calcined. The calcined oxide may be wet milled to provide a slip for casting articles such as fused silica crucibles used in melting silicon. The method also permits the production of very refractory fused glass compositions from fumed metal oxides at temperatures substantially below those required where a melting step is employed.

Abstract: An elongated burner for producing a stream of metal oxide soot comprises a burner face having two parallel arrays of orifices for issuing a gas-oxygen mixture to produce two intersecting linear flames. Disposed between the gas-oxygen orifices is an array of orifices for issuing metal halide vapor into the flame. Two parallel arrays of orifices, one on each side of the vapor orifices and closely spaced therewith provide high velocity jets of inner shield gas on opposite sides of the vapor streams. Disposed between the inner shield gas orifices and the gas-oxygen orifices are two elongated slots which are much greater in width than the diameters of the aforementioned orifices. These slots provide a large volume, low pressure dry, nonreactive gas which prevents the flame from "backsplashing" onto the region of the vapor orifices and further prevents the deposition of soot on the burner face.

Abstract: A method is disclosed wherein high purity fused silica is produced from a liquid flowable form of a silica slurry or sol and the refractoriness of the fused silica is enhanced by homogeneously doping the silica with aluminum and/or titanium oxide, preferably in conjunction with elemental silicon.

Abstract: A method of densifying a fumed metal oxide is disclosed wherein the metal oxide is converted to a flowable sol and then dried to form a fragmented solid which is calcined. The calcined oxide may be wet milled to provide a slip for casting articles such as fused silica crucibles used in melting silicon.

Abstract: A method is disclosed wherein high purity fused silica is produced from a liquid flowable form of a silica slurry or sol and the refractoriness of the fused silica is enhanced by homogeneously doping the silica with a selected metal oxide in conjunction with elemental silicon.

Abstract: A basic fused refractory material consisting essentially of, by weight on the oxide basis, 50-67% MgO, 33-50% CaO, and preferably at least 98% MgO + CaO. The method of producing the fused refractory material by melting and solidifying a batch of refractory raw materials, wherein the cooling rate inducing solidification throughout the fused melt is at least 600 Centigrade degrees per hour and sufficient to yield the fused refractory product characterized by a fine microstructure retaining at least 2.0% MgO in solid solution in the lime phase and increased hydration resistance of the fused refractory material.

Abstract: A refractory of fused or dead-burned dolomitic grain bonded with fine magnesite. The dolomitic grain is divided into three coarse and intermediate particle size fractions in the batch, while the magnesite is alone in the fine fraction. The four particle fractions are separated by three discrete gaps in the size distribution of particles resulting in a burned refractory of high hot strength and corrosion resistance to furnace slags in basic oxygen furnaces. The width of each gap is at least equivalent to the gap created by removing, from a ground raw material batch with continuous particle size distribution, the raw material retained on one primary Tyler sieve after screening (sizing) the batch.

Abstract: A refractory of fused or dead-burned dolomitic grain bonded with fine magnesite. The dolomitic grain is divided into one coarse and one intermediate particle size fraction in the batch, while the magnesite is alone in the fine fraction. The fine, intermediate and coarse fractions are separated by large discrete gaps in the size distribution of particles resulting in a burned refractory of high hot strength and corrosion resistance to slags in basic oxygen furnaces. The width of each large gap in the particle size distribution is at least equivalent to the gap created by removing from a ground raw material batch, with a continuous particle size distribution, the particles retained on at least three consecutive primary Tyler sieves after screening (sizing) the batch.

Abstract: Basic refractory batch of coarse and intermediate sized fused or dead-burned dolomitic grain with 20-35% of a fine fraction of dead-burned magnesia and an effective amount of a compound yielding not more than 4% by weight (preferably 0.5-2.5%) zirconia, silica, or mixtures thereof. The dolomitic grain is separated into 2 size fractions (both collectively in the range of -4+65 Tyler mesh) while the magnesite is all -100 Tyler mesh and preferably at least 75% -325 Tyler mesh. The zirconia and silica yielding materials are preferably substantially all -325 Tyler mesh. Formed shape made from the batch and burned at 1600.degree.C is characterized by a modulus of rupture at 1340.degree.C (hot strength) consistently above 1800 psi and occasionally approaching 3000 psi without a significant loss in corrosion resistance to molten basic oxygen furnace slags.