Abstract: A refractory composition for use in contact with molten aluminum alloys containing a refractory aggregate, a binder and an additive for imparting aluminum resistance to the refractory composition, the additive comprising synthetic calcium fluoride containing aluminum borate aggregate consisting essentially of 10 to 50% by weight boron oxide, 10-50% by weight of aluminum oxide, and 25-75% by weight calcium flouride. The synthetic aggregate may be prepared by blending boric acid, aluminum oxide, and fluorspor and firing the resultant blend at a temperature above 800.degree. C. to form a synthetic aluminum borate having calcium fluoride contained in its insoluble structure.

Abstract: Seeding of beta type alumina compositions in which the alumina in the raw batch is microcrystalline boehmite results in significant increase in hardness, density and strength, as compared to unseeded beta alumina, when fired under similar conditions.

Abstract: Provided is a sintering air suitable for use in forming aluminum borate into a ceramic product, the sintering aid comprised of an aluminum borate compound having a melting point lower than the sintering temperature of aluminum borate.

Abstract: A refractory composition capable, when mixed with water, of forming a hydraulic-setting castable refractory resistant to aluminum penetration and adhesion and with good load bearing properties consisting essentially of a refractory aggregate, a binder for said refractory aggregate, and an aluminum anti-adhesive agent; said agent consisting of a fine powder barium sulfate and a powdered zinc borosilicate frit in a weight ratio of 1.5:1 to 5:1.

Abstract: Refractory compositions which can be gun-applied, or refractory, unfired shapes containing sintered magnesite and/or sintered dolomite as the principal refractory component, 0.5 to 5% by weight of bentonite, 1 to 5% by weight of aluminum sulfate and 0.5 to 5% by weight of an alkaline earth compound, characterized by the fact that they contain magnesium hydroxide and/or caustic-calcined MgO as the alkaline earth compound. The compositions and shapes of the invention have the advantage that they do not exhibit binder migration, and no damping-reduction cracks or chipping occurs therein.

Abstract: An improved process for fabricating barium calcium aluminum impregnants for dispenser cathodes is described. The resulting cathodes have improved lifetimes and reliability through the use of organometallic starting materials in the impregnant process.

Abstract: A ceramic consisting essentially of from 1 to 15 percent of glass and 99 to 85 percent of a mixture of particulate Al.sub.2 O.sub.3 and particulate ZrO.sub.2 is disclosed. ZrO.sub.2 is present in a sufficient amount, usually from 1/4 to 6 percent based on the weight of the ZrO.sub.2 and Al.sub.2 O.sub.3, to strengthen the ceramic significantly, by comparison with an otherwise identical ceramic where the particulate ZrO.sub.2 is replaced either by the glass or by particulate Al.sub.2 O.sub.3. The glass constitutes a vitreous phase bonding the particulates into a dense, gas impervious structure, and can be a calcium magnesium silicate glass containing from 45 to 80 percent of SiO.sub.2, from 8 to 55 percent of CaO and MgO, and not more than 15 percent of Al.sub.2 O.sub.3.

Abstract: Disclosed are an aluminum nitride sintered body comprising aluminum nitride, rare earth element-aluminum compounds and alkaline earth metal-aluminum compounds, and a process for producing an aluminum nitride sintered body, which comprises adding to aluminum nitride powder:(a) powder of at least one compound selected from the group consisting of rare earth element oxides, rare earth element fluorides and compounds capable of being converted into these oxides or fluorides by calcination, and(b) powder of at least one compound selected from the group consisting of alkaline earth metal oxides, alkali earth metal fluorides and compounds capable of being converted into these oxides or fluorides by calcination, in a total amount of 0.01 to 20 wt % as calculated on the weight of the oxides or the fluorides, and then molding and sintering the resultant mixture.

Abstract: A process for producing an artificial light-weight aggregate comprising SiO.sub.2, Al.sub.2 O.sub.3, Fe.sub.2 O.sub.3 and at least one oxide selected from the group consisting of MgO and CaO which has an absolute dry specific gravity of not higher than 1.5, a crushing strength of not less than 55 kfg/cm.sup.2 and a 24 hour water-absorption ratio of not greater than 2.4%. The process comprises granulating a raw powder material comprising SiO.sub.2, Al.sub.2 O.sub.3, Fe.sub.2 O.sub.3 and at least one oxide selected from the group consisting of MgO and CaO, in which the total amount of SiO.sub.2 and Al.sub.2 O.sub.3 is from 75 to 92 wt. %, the weight ratio of Al.sub.2 O.sub.3 /SiO.sub.2 is from 0.25 to 0.70, and the total amount of Fe.sub.2 O.sub.3 and MgO and/or CaO is from 6-20 wt. % and containing at least 80% by weight of a coal ash having a Blaine specific surface area of 2,000 to 9,000 cm.sup.2 /g to give granules having an average apparent specific gravity of 1.1 to 1.8 and a crushing strength of 0.

Abstract: A refractory composition characterized by relatively high abrasion resistance, good flowability and long working time, comprised of 0.5 to 5 weight percent volatilized silica, 3.0 to 15 weight percent -65 mesh alumina, 20-40 weight percent cement, and the balance a refractory aggregate. Better results are obtained with a composition comprised of from 30-40 weight percent cement.

Abstract: A refractory composition characterized by abrasion resistance and low thermal conductivity comprising about 40 to about 96 weight percent amorphous silica, about 2 to about 50 weight percent -65 mesh calcined refractory aggregate having a density of at least about 140 lb/ft.sup.3 and about 2 to about 40 weight percent calcium aluminate cement.

Abstract: Low temperature fired ceramics produced by firing at a low temperature a mixture consisting of, in weight percentages:(a) 50 to 65% of powder glass consisting of 10 to 55% of CaO, 45 to 70% of SiO.sub.2, 0 to 30% of Al.sub.2 O.sub.3 and up to 10% of impurities; and(b) 50 to 35% of powder Al.sub.2 O.sub.3 containing up to 10% of impurities. The glass component (a) may further contains B.sub.2 O.sub.3 up to 20% based on the total weight of the former glass-forming components. The ceramics exhibit excellent thermal conductivity, high mechanical strength, low thermal expansion and small dielectric constant and such advantageous combination of properties make them useful in many applications, more especially highly suited to the use as substrate of various electronic parts, components or multilayer integrated circuits. Also, since the ceramics can be prepared at lower firing temperatures and a higher heating rate, the production cost and time can be advantageously saved.

Abstract: A dry blend capable of forming a fast-setting cement when reacted with an aqueous component. The blend comprises: a solid phosphorus pentoxide (P.sub.2 O.sub.5) containing component; a solid component comprising a magnesium containing compound; and an optional aggregate.The solid P.sub.2 O.sub.5 containing component is preferably spent solid phosphoric acid catalyst.The dry blend remains a free flowing powder until contacted with the aqueous component, preferably water, then a reaction occurs forming a fast-setting cement.

Abstract: A fired ceramics compact for use in casting of a super alloy material consisting of a solid solution of BaO and Al.sub.2 O.sub.3 wherein the composition of the solid solution lies on or between a first and a second eutectic composition, the first and the second eutectic compositions being adjacent and occurring to either respective side of stoichiometric BaO.Al.sub.2 O.sub.3 in a phase diagram of the solid solution.

Abstract: An improved process for the production of alkaline earth, aluminum-containing spinel compositions, preferably magnesium, aluminum-containing spinel compositions and preferably further comprising at least one additional metal component, comprises combining at least one alkaline earth metal component; at least one organic compound having inherent basicity, and at least one aluminum component at selected pH conditions to form a precipitate and calcining the precipitate to form a spinel composition. The product spinel composition, prepared in the presence of such an organic template and preferably with included additional metal components, is particularly suited for use to reduce the amount of sulfur oxides emitted from a catalyst regeneration zone, e.g., a catalytic cracking unit regeneration zone.

Abstract: An improved process for the production of alkaline earth, aluminum-containing spinel compositions, preferably magnesium, aluminum-containing spinel compositions and preferably further comprising at least one additional metal component, comprises combining at least one alkaline earth metal component; at least one solid organic material acting to alter at least one property of the spinel composition and being capable of being at least partially combusted during the calcination step described hereinafter, and at least one aluminum component at selected pH conditions to form a precipitate and calcining the precipitate to form a spinel composition. The product spinel composition, prepared in the presence of a solid organic material and preferably with included additional metal components, is particularly suited for use to reduce the amount of sulfur oxides emitted from a catalyst regeneration zone, e.g., a catalytic cracking unit regeneration zone.

Abstract: Spray-coating materials having a high heat-resistance and thermal conductivity for the surface protection of materials. The spray-coating material consists of 8-35 wt. % magnesium oxide MgO or calcium oxide CaO, 2-10 wt. % of beryllium oxide BeO and 55-90 wt. % of aluminum oxide Al.sub.2 O.sub.3, zirconium dioxide ZrO.sub.2, silicon dioxide SiO.sub.2, chromic oxide Cr.sub.2 O.sub.3 and titanium dioxide TiO.sub.2. The spray-coating material of the invention can be employed to advantage, for example, in the chemical industry and in metallurgy.

Abstract: There is disclosed a material for hot or plasma spraying, especially a material based on oxide ceramics, and a process for the production thereof. The composition of the invention is a mixture of powdered oxides containing at least two fundamental oxides with high melting point, and at least one glass-forming oxide the melting point of which is lower. The invention also includes a process for the production of such composition by the melting and agglomeration of individual components in the oxidizing medium of a plasma stream, including the special treatment of the starting components.

Abstract: To produce a dolomite sinter with a low porosity and a good hydration stability made of difficult-to-sinter raw dolomite, the dolomite is milled and caustic burnt dolomite, dolomite hydrate or semi-burnt dolomite in quantities between 3 and 20% by weight relative to the total mixture is added to the raw dolomite powder and is calculated as oxide, as well as foreign oxide, such as Fe.sub.2 O.sub.3, Al.sub.2 O.sub.3 or SiO.sub.2, in such quantities that the total content of the foreign oxide mixture is 1 to 3% by weight.

Abstract: Provided by this invention is a slaking-resistant calcia refractory comprising, as a fired mixture, (a) 2% by weight or less of silicon dioxide, (b) aluminum oxide (Al.sub.2 O.sub.3) and magnesium oxide (MgO) of the amount defined in the graph of FIG. 5 as within the region enclosed by the lines connecting point A (2.5 wt % Al.sub.2 O.sub.3 and 0 wt % MgO), point B (1.5 wt % Al.sub.2 O.sub.3 and 1.5 wt % MgO), point C (1.5 wt % Al.sub.2 O.sub.3 and 8.5 wt % MgO) and point D (10 wt % Al.sub.2 O.sub.3 and 0 wt % MgO), (c) 0.9% by weight or less of iron oxide, and (d) a predominant amount of calcium oxide.

Abstract: A highly reinforced refractory is disclosed. In accordance with the invention higher reinforcement of refractory shapes such as plunging bells or injection lances is achieved by infiltrating a bed of metal fibers in a mold with an aqueous slurry of a refractory material containing a superplasticizer. Refractory Concrete comprises e.g. calcium aluminate cement, alumina aggregate of 35 mesh or less maximum particle size, sulfonated naphthalene formaldhyde as superplasticizer and greater than 4 volume % metal (steel) fibers.

Abstract: A calcia clinker having an excellent resistance to slaking and an enhanced modulus of rupture at elevated temperatures is produced by a process comprising the steps of: (1) calcining a lime material at a temperature of 800.degree. to 1300.degree. C. to prepare a calcia; (2) providing an admixture, in the form of fine particles having a specific surface area of 5000 cm.sup.2 /g or more, of the calcia with an additive comprising (A) 0.5 to 3%, in terms of oxide and based on the weight of CaO in the calcia, of at least one inorganic compound of an element selected from the group consisting of titanium, aluminum and silicon and (B) 0.5 to 2.0%, based on the weight of CaO in the calcia, of calcium fluoride; and sintering the above-mentioned compound (A), and; (3) sintering the admixture at a temperature of 1200.degree. to 1650.degree. C.

Abstract: In a high temperature gas measuring device consisting of a zirconia oxide solid electrolyte cell bonded to a support member, a sealant exhibiting a thermal coefficient of expansion comparable to zirconia and a melting point in excess of 1000.degree. C. is used to seal the cell to the support member. The preferred sealants which meet these requirements include:(1) 3 MgO.sup.. Al.sub.2 O.sub.3.sup.. 6 SiO.sub.2(2) 52% Nd.sub.4 (SiO.sub.4).sub.3, 48% Ca.sub.2 SiO.sub.4(3) 57% La.sub.4 (SiO.sub.4).sub.3, 43% Ca.sub.2 SiO.sub.4(4) 50% Y.sub.4 (SiO.sub.4).sub.3, 50% Ca.sub.2 SiO.sub.4(5) (a) La.sub.2 O.sub.3.sup.. Al.sub.2 O.sub.3 : 50 mol % of each (b) 40% La.sub.2 O.sub.3.sup.. 60% Al.sub.2 O.sub.3.