Abstract: This invention provides a three dimensional inorganic oxide structure comprising a myriad of cavities interconnected by holes having a narrow pore size distribution, in which the diameters of the cavities is in the range from 1 to 50 .mu.m and that of the holes in the range 1 to 10 .mu.m and in which the pore volume in the range 1 to 10 .mu.m is at least 2 cc/g and in which the inorganic oxide is selected from alumina, silica, titania, zirconia and mixtures thereof and a process for the preparation of such structures.

Abstract: Alumina powder having a .theta.-alumina content of at least 70% by weight and an average primary particle size at least 0.1 .mu.m and containing a tungsten compound in an amount of 0.1 to 5% by weight in terms of tungsten oxide based on alumina can be used as an abrasive for a magnetic recording medium having good properties.

Abstract: Disclosed are spherical corundum particles consisting essentially of single particles having an average particle size of 5 to 35 .mu.m and a shape not including cutting edges. The particles are prepared by adding one or more members selected from halogen compounds, boron compounds, and alumina hydrates to pulverized alumina having a specific particle size, heat-treating the mixture at a temperature of at least 1000.degree. C., and disintegrating the heat-treated product. A rubber or plastic composition having a high thermal conductivity is formed by incorporating such particles into a rubber or plastic, and this composition is valuable as a sealing material for a semiconductor, etc..

Abstract: In a process utilizing steam, the method of producing at least a portion of said steam includes heating a solid substance so as to generate steam, followed by capturing the generated steam at a pressure greater than one atmosphere gage pressure for use in the process at a pressure greater than one atmosphere gage pressure. Suitable solid substances are aluminum hydrate or aluminum fluoride. New hydrated aluminum containing products and uses for those products are obtained by the use of the process.

Abstract: A new transition alumina is made by heating substantially pure diaspore in a vacuum to an elevated temperature of about 300-1000.degree. C. The new transition alumina has increased surface area compared with alpha-alumina formed by heating diaspore in air.

Abstract: A process for producing mixed oxides containing an alumina species in which a mixture of a hydrated alumina having a specified surface area (average crystal size), a fluid medium and a compound having the formula M.sub.x A.sub.y wherein M is selected from the group consisting of metals, silicon, boron, arsenic and tellurium, A is selected from the group consisting of oxygen and anions, x is from 1 to 4 and y has a value satisfying said formula depending on the valence of M, is formed into a uniform sol, the sol is recovered from the liquid medium and dehydrated, and the dehydrated product is de-agglomerated to produce a mixed oxide having an average particle size of about 1 micron or less.

Abstract: The invention concerns the production of aluminum trihydrate crystal by the Bayer process, by digesting ground bauxite, filtering off the red mud, cooling the filtrate, and crystallizing out the dissolved aluminum hydroxide as gibbsite. Before and/or during the crystallization, polyglycerines of the general formula H--(OCH.sub.2 CHOH--CH.sub.2).sub.n --OH, where n is an integer equal to or greater than 3, are added.

Abstract: Fine flaky boehmite particles which have an orthorhombic crystal form and a specified crystal face grown in the form of a flat plate, and a process for the preparation of fine flaky boehmite particles which comprises subjecting aluminum hydroxide or hydrated alumina having a particle size adjusted to the order of submicron to hydrothermal treatment in water or an aqueous alkali solution at a temperature of 150.degree. C. or above and under a pressure of 100 atm or below. The fine flaky boehmite particles are useful as a starting material for the preparation of fine flaky alumina particles or as a filler suitable for a pigment for coating materials, a filler for rubbers and plastics and a coating material for paper making.

Abstract: Alumina hydrate particles have a high surface area and low dispersity and may have a low soluble soda content. They may be made by milling a liquid suspension of alumina hydrate, subjecting the milled suspension to classification into coarse and fine fractions, recycling the coarse fraction to the mill and recycling the fine fraction to the classification stage. A narrow particle size distribution is obtained.

Abstract: An aqueous slurry of about 100-1000 centipoises viscosity suspending about 200-2000 g/l of aluminum hydroxide particles smaller than 5 .mu.m is spray-dried, and the dried powders are calcined to obtain alumina powders. The alumina powders have a sharp particle size distribution, being suitable for electronic, abrasive and refractory applications.

Abstract: A process for producing agglomerates from dust (especially electrostatic precipitator dust) collected from a process involving the thermal conversion of a material containing gibbsite to sub-alpha alumina and alpha alumina, and the agglomerates so formed. The process involves binding the dust particles together using water and undercalcined alumina taken from an intermediate stage of the same thermal conversion that originally produces the dust. The added undercalcined alumina is ground, in order to create fresh surfaces, to a median particle size of less than 30 microns and a specific surface area of about 130 to 300 m.sup.2 /g. About 1-4 parts by weight of the dust are mixed with every part by weight of the ground undercalcined alumina. A special procedure is employed for mixing the solids and water which makes use of intensive mixing.

Abstract: Saltcake generated by the aluminum industry is completely recycled through a process that simultaneously liberates the contained aluminum metal and dissolves the soluble salt fluxes to recover aluminum metal, aluminum oxide and salt fluxes by temperature controlled wet milling, rapid solids-brine separation and solar pond evaporation of the resulting clear brine. The temperature of the feedwater is 70.degree. F. or less to retard the exothermic reaction of aluminum metal with water, thereby minimizing the loss of metal to oxidation and the evolution of undesirable gases. Low temperature is maintained by using process water at or below the desired temperature, by forcibly cooling the mill with ambient air, and by controlling transit time through the mill to avoid excessive grinding of the aluminum metal. Minimizing the production of fine aluminum particles reduces the total surface area of aluminum metal available for exothermic reacton with the water.

Abstract: Needlelike single crystal particles of .alpha.- alumina, .theta.-alumina, mullite, sillimanite, etc. are produced by adding a silicon-containing substance to needlelike alumina precursor particles and heating the resultant product of addition.

Abstract: A process for producing alumina is described in which the efficiency of calcination is greatly improved by utilizing a total heat exchange system in which alumina hydrate is heated stepwise in a plurality of heat exchange stages to sequentially higher temperatures approaching calcining temperatures and is then fed to a calciner for final conversion to alumina, and the calcined alumina is cooled in a plurality of heat exchange stages, with sensible heat being transferred from the calcined alumina cooling stages to the alumina hydrate heating stages at a temperature in each stage only slightly higher than the temperature of a heating stage or at which the heat is consumed in that stage. Further efficiency in the system may be obtained by predrying the alumina hydrate to remove superficial moisture using air from the system. Furthermore, exhaust gases from the calciner may be used to preheat combustion and fluidizing air for the calciner.

Abstract: Aluminum oxide powders having a high .alpha. proportion, crystallite sizes of approximately 0.1 .mu.m and narrow particle size distribution are prepared from customary Bayer aluminum hydroxide (gibbsite) or from aluminum oxide calcined at a low temperature. The starting material is wet-disagglomerated, mixed with .alpha.-aluminum oxide nuclei, dried and calcined. The calcination produces agglomerates which already have the crystallite size required, and which only need to be disagglomerated to the particle size required. The .alpha.-aluminum oxide powders prepared by such process are particularly suitable as a starting material for the production of high-performance ceramics, for example, of blanking dies.

Abstract: A fluid jet orifice and method of making same. The fluid jet orifice comprises an orifice made of sapphire, the sapphire being annealed in a high temperature oxygen atmosphere. Preferably, the high temperature is in a range of approximately 1200.degree. C. to 1700.degree. C., the pressure of the oxygen atmosphere is atmospheric or above, and the annealing time is from approximately 4 to 40 hours.

Abstract: A novel platey alumina with essentially no aggregates, fines or fragments has been obtained. This product proves very advantageous in lapping substrate wafers for microelectronic applications. A process for making such products is also described.

Abstract: Ceramic oxide powders and a method for their preparation. Ceramic oxide powders are obtained using a flame process whereby two or more precursors of ceramic oxides are introduced into a counterflow diffusion flame burner wherein said precursors are converted into ceramic oxide powders. The morphology, particle size, and crystalline form of the ceramic oxide powders are determined by process conditions.

Abstract: Hydrodesulfurization and demetallalization of hydrocarbon charge is effected by hydrogenation in the presence of, as catalyst, a Group VI A metal and a non-noble Group VIII metal on a trimodal alumina support. The alumina support is formed by mixing at least two different finely divided charge aluminas each of which has a different pore mode.

Abstract: The present invention includes metal oxide foam particles and a method of making the same. A decomposable metal salt feed solution is injected into a hot atomizing gas. The mixture of hot atomizing gas and feed solution is maintained in the reactor until the feed solution converts to metal oxide foam particles. The metal oxide foam particles have a high specific surface area.

Abstract: A method for the production of aluminum hydroxide, including reacting water in the liquid phase and aluminum at a pH above about 12.4. In this pH range, aluminum hydroxide is produced at acceptable rates both for aluminum surface areas above 75,000 mm.sup.2 /g and for aluminum surface area of less than about 50,000 mm.sup.2 per gram, and even down to 20 mm.sup.2 per gram. According to an alternative view of the invention, it is characterized by the production of aluminum hydroxide by reacting aluminum with liquid water containing choline. Aluminum hydroxide particles having unique morphologies are obtained.

Abstract: A ceramic sintered body and a method for manufacturing the same in which the body includes a first material having at least one of a precursor and a metastable material of the final sintered body and a second material morphologically related to the first material and added to the first material to affect transformation of said first material into the desired crystalline form of the ceramic sintered body, in which method transformation of a metal oxide compound from one phase to another, where the compound has a high activation energy and is confronted with a high nucleation energy barrier to the transformation, produces the body and includes the steps of making a mixture by bringing a multiplicity of particles of the compound into intimate contact with the multiplicity of nucleation particles having crystallographically related structure to act as nuclei for the transformation and sintering the resulting mixture to transform the compound from one phase to another by nucleation and growth, independently of gro

Abstract: Disclosed is a basic aluminum material having enhanced antiperspirant activity, the material having the empirical formula Al.sub.2 (OH).sub.6-a X.sub.a, where 0.5.ltoreq.a.ltoreq.5.0 and X is a univalent complex oxoanion of nitrogen, chlorine and other halogens, which forms salts with Al.sup.3+ in aqueous solution so that these salts are essentially completely dissociated, which is readily soluble in water with metallic ions in the solution, and which forms conjugate acids that are strong acids; and wherein the material is characterized by:(a) size exclusion high performance liquid chromatography peaks corresponding to peak 3 and peak 4 of size exclusion chromatograms formed by HPLC technique;(b) a peak 4 relative area of at least 25%, a peak 3 relative area of less than 60%, the sum of the relative peak 3 and peak 4 areas being at least 50%; and(c) less than 10% chromatographic peaks eluting at shorter retention times than peak 3, corresponding to peaks 1 and 2.

Abstract: A method of manufacture including bringing seed and aluminum hydroxide together in an aqueous medium and hydrothermally digesting for producing boehmite at the expense of the aluminum hydroxide.

Abstract: A boehmite or boehmite precursor can be improved in its dispersibility by subjecting it to a hydrothermal treatment at a pH of less than 3.5 and at elevated temperature and pressure.

Abstract: In a process for precipitating alumina hydrate from a stream of Bayer process liquor, wherein the stream is first divided into a major portion and a minor portion, the minor portion fed to an agglomeration stage and seeded with fine seed to induce precipitation and formation of a slurry, and the major portion cooled and charged with coarse seed and directed to a growth stage to induce formation of alumina hydrate product, the steps of: separating solids from the minor portion after formation of the slurry; cooling, to a temperature of between about 45.degree. C. and about 60.degree. C., the liquid remaining after separating solids from the slurry formed in the agglomeration stage; adding an amount of coarse seed to the remaining liquid to generate a slurry of fresh hydrate nuclei; and recombining the slurry of fresh hydrate nuclei with the major portion of the stream.

Abstract: An improved process for precipitating alumina from Bayer process liquors is disclosed. The process involves dividing an incoming pregnant liquor stream into a minor portion of about 10 to about 25% by volume of the total incoming pregnant liquor stream, and directing that stream into a series of small tanks where the minor stream is permitted to agglomerate. Fine aluminum hydroxide seed having a median particle size of between about 30 and about 60 microns is added to this stream. The slurry resulting from the agglomeration stage is then directed to a set of larger vessels in which the growth stage will take place. At this point, the remaining portion of the pregnant liquor is combined with the slurry resulting from the agglomeration stage. A coarse seed charge of about 150 to about 600 grams/liter of seed having a median particle size of between about 80 and about 100 microns is charged into the second set of vessels.

Abstract: The present invention relates to a novel method of manufacturing a composite body, such as a ZrB.sub.2 -ZrC-Zr composite body, by utilizing a post-treatment technique which may improve the oxidation resistance of the composite body. Moreover, the invention relates to novel products made according to the process. The novel process modifies at least a portion of a composite body by exposing said body to a source of second metal.

Abstract: A low temperature process is described for forming a coating or powder comprising one or more metals or metal compounds by first reacting one or more metal reactants with a halide-containing reactant to form one or more reactive intermediates capable of reacting, disproportionating, or decomposing to form a coating or powder comprising the one or more metal reactants. When one or more metal compounds are formed, either as powders or as coatings, a third reactant may be injected into a second reaction zone in the reactor to contact the one or more reactive intermediates formed in the first reaction zone to thereby form one or more metal compounds such as metal nitrides, carbides, oxides, borides, or mixtures of same.

Abstract: A process for producing alpha alumina particles includes steps of precipitating alumina hydrate from an aqueous sodium aluminate solution by treatment with alumina hydrate seed material and alpha alumina promoter particles; and calcining the precipitated alumina hydrate in the presence of a mineralizer. A preferred mineralizer is aluminum fluoride. The process produces alpha alumina particles having a plate-like shape and an average size of less than about 1.5 microns.

Abstract: The present invention relates to alumina oxide particles having an internal foam structure and a method of making the same. The method first creates foam particles of aluminum sulfate and, subsequently, converts the aluminum sulfate to aluminum oxide particles with the same internal foam structure. The aluminum oxide foam particles made by this method have large specific surface areas and pore volumes.

Abstract: In a process utilizing steam, the method of producing at least a portion of said steam, including heating a water-containing, solid substance for generating steam and capturing the generated steam for said process. A suitable solid substance is Al(OH).sub.3 . New alumina products and uses therefor are obtained.

Abstract: A method for the production of inorganic oxide particles by a procedure comprising the steps of dispersing inorganic oxide particles as seed particles in a water-containing alcohol solution thereby preparing a suspension of said seed particles and adding a hydrolyzable and condensable organic metal compound to said suspension thereby effecting growth of said seed particles, which method further comprises causing the presence in said water-containing alcohol solution of an alkylene glycol having 2-8 carbon atoms, in an amount in the range of 1 to 50% by weight, based on the amount of said water-containing alcohol solution.

Abstract: Production of composite ceramic articles by infiltration of a particulate, permeable bed or permeable preform with a polycrystalline matrix produced as a metal-oxidant reaction product, wherein the bed or preform is comprised of dross.

Abstract: The present invention provides a method for preparing metal oxide powder. A first solution, which is substantially organic, is prepared. A second solution, which is an aqueous solution substantially immiscible in the first solution, is prepared and delivered as drops to the first solution. The drops of the second solution are atomized by a pulsed electric field forming micro-drops of the second solution. Reagents in the first solution diffuse into and react with reactants in the micro-drops of the second solution forming metal hydroxide or oxalate particles. The metal hydroxide or metal oxalate particles are then recovered and dried to produce the metal oxide powder. An apparatus for preparing a metal oxide powder is also disclosed.

Abstract: An improvement in the process for extracting alumina from gibbsitic bauxites, wherein the basic, known process comprises mixing the bauxites with a sodium hydroxide-sodium aluminate digestion liquor, digesting the bauxites at a temperature in the range of 100.degree.-180.degree. C., diluting the resulting slurry, separating the red mud therefrom, precipitating alumina hydrate by cooling and agitation of the sodium aluminate liquor, and calcining the alumina hydrate precipitate to obtain alumina, wherein the improvement is characterized by so controlling the process that, in the liquid phase of the slurry leaving the digestion reactor, the reactive hydroxide ion concentration is maintained below 6 g/l, and preferably between 0 and 2 g/l, where the reactive hydroxide ion concentration is defined by the following formula: ##EQU1## where: C.sub.Al.sbsb.2 O.sub.3,gi.sup.eq is the equilibrium solubility of Al.sub.2 O.sub.3 for gibbsite, in g/l.C.sub.Al.sbsb.2 O.sub.3 is the actual concentration of Al.sub.2 O.sub.

Abstract: This invention is directed to the formation of homogeneous, aqueous precursor mixtures of at least one substantially soluble metal salt and a substantially soluble, combustible co-reactant compound, typically an amino acid. This produces, upon evaporation, a substantially homogeneous intermediate material having a total solids level which would support combustion. The homogeneous intermediate material essentially comprises highly dispersed or solvated metal constituents and the co-reactant compound. The intermediate material is quite flammable. A metal oxide powder results on ignition of the intermediate product which combusts same to produce the product powder.

Abstract: A white colored deodorizer comprising zinc oxide and at least one oxide selected from the group consisting of aluminium oxide and silicon oxide and a method for preparation of it are disclosed.

Abstract: A process for preparing finely-divided oxides of metals of metalloids of the elements of main groups III and IV and sub-groups III, IV, V and VI of the Periodic System of Elements, comprising reacting compounds of these elements with a polymerizable hydrocarbon compound or mixture to form a polymer product, which is then thermally treated to yield the oxide product.

Abstract: A process is disclosed for producing aluminum hydroxide in the form of gibbsite in particular shapes, suitable for use as a filler, flame retardant and/or fibrous reinforcement. The process includes the steps of crystallizing gibbsite from a Bayer process sodium aluminate liquor, in the presence of an additive comprising either a hydroxycarboxilic acid for producing needle shaped, rod-like hydrargillite or in the presence of a polyalcohol, fatty acid or lithium compound for producing platy or tabular gibbsite.

Abstract: This invention relates generally to a novel method of preparing self-supporting bodies and to the novel products made thereby. In its more specific aspects, this invention relates to a method of producing self-supporting bodies having controlled porosity and graded properties and comprising one or more boron-containing compounds, e.g., a boride or a boride and a carbide. The method comprises, in one embodiment, reacting a powdered parent metal, in molten form, with a bed or mass comprising a boron carbide material and, optionally, one or more inert fillers, to form the body. In another embodiment, both of a powdered parent metal and a body or pool of molten parent metal are induced to react with a bed or mass comprising a boron carbide material and, optionally, one or more inert fillers. in addition, combustible additives (e.g., gelatin, corn starch, wax, etc.) can be mixed with the bed or mass comprising a boron carbide material to aid in the porisity producing process.

Abstract: Zirconium-doped pseudoboehmite with the following properties: zirconium content of 0.5 to 10 mol % relative to Al water content of 20 to 35 weight percent total of the anionic impurities less than 0.5 weight percent. It is synthesized by a process wherein zirconium salt is added in calculated quantity to an aqueous aluminum sulfate solution, the resulting mixture is fed simultaneously with a sodium aluminate liquor into a water pool having a temperature of 50.degree. to 100.degree. C., thereby precipitating zirconium-doped alumina gel while a pH of 3.5 to 8 is maintained, the pH of the suspension is adjusted after addition of the aluminum sulfate solution to 8.5 to 10.5 by further addition of sodium aluminate liquor, the suspension is digested if necessary at the pH of 8.5 to 10.5 and the temperature of 50.degree. to 100.degree. C. for a period of up to 24 hours, the formed pseudoboehmite crystals are filtered off, the filter cake is redispersed with water and the suspension is sprayed-dried.

Abstract: A process for producing a dawsonite with a short-prismatic, isometric crystal habit. The dawsonite can be produced without occupational medicine concerns and can be used as, among other things, a flame-retardant additive in plastics.

Abstract: A process of production of alumina includes method for controlling specific surface area of alumina. Control of specific surface area is performed by controlling porous structure of alumina. In the process, aluminum alkoxide is subject hydrolysis for forming alumina sol. During hydrolysis process, polyether is used as organic solvent in order to control the porous structure of produced alumina.

Abstract: A polynucleate aluminum hydroxy silicate-sulphate compound (PASS) having the following average composition:Al.sub.A (OH).sub.B (SO.sub.4).sub.C (SiO.sub.X).sub.D (H.sub.2 O).sub.EwhereinA is 1.0;B ranges from 0.75 to 2.0;C ranges from 0.30 to 1.12;D ranges from 0.005 to 0.1;X is greater than 2.0 but less than or equal to 4.0 such that 3=B+2C+2D (X-2);E is larger than 4 when the product is in aqueous form. The compound is useful for water treatment and other applications where an aluminum hydroxide gel system is required. The compound, in aqueous solution, has a long storage life.

Abstract: The present invention provides a process for the production of crystalline boehmite of fine particle size and enhanced specific surface area. Coarse gibbsite particles, obtained from the Bayer Process, are lightly calcined and the non-boehmite-containing material is removed by dissolution in caustic aluminate liquors of appropriate composition.

Abstract: Improved alumina-zirconia composite sintered materials with sufficient high mechanical strength and thermal shock resistance as well as excellent hardwearing resistance are made by mixing, heating and melting zirconia and alumina, then the produced melt was quenched, and the resulting solid was ground and milled while adding thereto at least one compound of ceria and/or titania, to an average grain size of from about 0.5 to about 1.5 .mu.m, and subjected the resulting powder to molding and sintering at a temperature of from 1450.degree. to about 1600.degree. C., said zirconia, ceria and titania being employed in the amount of about 10-20%, about 3-7%, and about 15-25% by weight, respectively, plus the balance of alumina. Said sintered materials are useful for employment in structural materials, refractorial materials, erosion resistance materials, cutting tool materials, grinding and polishing materials, etc.

Abstract: X-ray amorphous, aluminum oxide which exhibits a specific surface area (BET) according to DIN 66 131 of >10 m.sup.2 /g, an average particle size of .gtoreq.0.1 .mu.m and a water content of >10%. The X-ray amorphous aluminum oxide can be produced by reacting water vapor and vaporous aluminum trichloride in a molar ratio of 1.5 to 10:1, preferably 7.+-.1:1=H.sub.2 O:alCl.sub.3 at a temperature of 200.degree. to 1000.degree. C., preferably 600.degree..+-.50.degree. C. and at a dwell time of >1 sec., preferably 3.5.+-.1 sec. and a partial vacuum of 100.+-.10 mm H.sub.2 O column. By means of calcination thereof an aluminum oxide can be obtained which consists of .gtoreq.90% by weight of .alpha.-aluminum oxide and exhibits a specific surface area (BET) according to DIN 66 131 of >5 m.sup.2 /g and an average particle size of .gtoreq.0.1 .mu.m.

Abstract: An alumina-zirconia electrofusing material whose chemical composition consists of about 30-75 wt. % Al.sub.2 O.sub.3 and about 25-70 wt. % ZrO.sub.2 is provided in an amount of about 5-50 wt %, and this electrofusing material is mixed with other materials, and a resultant mixture is press-shaped and fired to produce a slide gate refractory. In order to further improve resistance to corrosion and spalling, particle diameters of the electrofusing material are continuously distributed in a range from about 0.1 mm to about 2.5 mm.

Abstract: A process for the preparation of boehmitic alumina compounds having a purity of, at least, 99.95% Al.sub.2 O.sub.3. The compounds produced according to the invention have a pore radii in the range of 3 to 100 nm. The preparation of such compounds is carried out by, first, obtaining an alumina suspension from a neutral aluminum alkoxide hydrolysis and, then, aging the alumina suspension in an autoclave, preferably, at a steam pressure of 1 to 30 bar, corresponding to a temperature of 100.degree. C. to 235.degree. C., for between 0.5 and 20 hours. The aging step of the invention is preferably carried out with stirring at a peripheral speed of 1 to 6 m/s.