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 catalytic converter utilizing a resilient, flexible shot-free ceramic fiber containing mounting mat for mounting a monolith within a metallic casing is disclosed. The mounting mat may be comprised of shot-free ceramic fibers alone or preferably is comprised of a composite of shot-free ceramic fibers in combination with an intumescent sheet material.

Abstract: A process for the production of large boehmite crystal aggregates, useful for soft polishing applications is provided herein. A caustic aluminate liquor is contacted with an oxygen-containing gas at elevated temperatures and pressures in the presence of about 1-50 mg/L of copper ions. The liquor is oxidized until a molar ratio of Na.sub.2 O.sub.free to Al.sub.2 O.sub.3 of less than or equal to 1 is achieved, and the oxidized liquor is cooled under quiescent conditions of little or no agitation which causes the crystallization and precipitation or novel large boehmite particles.

Abstract: The present invention provides a process for the production of fine, tabular boehmite crystals substantially within the size range of 0.2-0.8 microns. The crystals are particularly suitable for use as a pigment/filler in paper, paint and ink applications.

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 process for preparing hydrated alumina consisting essentially of spherical particles having a narrow granulometric distribution (polydispersion index dw/dn.ltoreq.2) starting from aqueous solution of aluminum sulphate, the molar ratio SO.sub.4.sup.= /Al.sup.3+ being greater than 1, by homogeneous precipitation in the presence of cationic polyelectrolytes, which are soluble under the reaction conditions and have a mean molecular weight higher than one million and an ionicity, deriving from the cationic groups present in the polyelectrolyte, of at least 3 milliequivalents/gram.

Abstract: A process for adjusting at least one of the structural and surface characteristics of an oxide material, e.g. SiO.sub.2 or Al.sub.2 O.sub.3, by dehydration of a water-containing oxide gel under supercritical conditions by extracting the water with an extraction agent such as CO.sub.2 at a pressure above the critical pressure of the extraction agent.

Abstract: A process for producing calcium carbonate from calcium hydroxide derived from, for example, limestone, comprises injecting a gas containing carbon dioxide into a recirculating stream flowing in a recycle piping system in communication with a reaction vessel. The carbon dioxide containing gas is injected at a turbulent area located in the recycle piping system. By controlling reaction parameters including pH and temperature, novel calcium carbonate products are formed by the process.

Abstract: Here is provided an adsorbent for adsorbing and removing an arsenic compound which becomes a catalyst poison in a selective contact reduction process for removing nitrogen oxides (NOx) from a combustion exhaust gas by the use of an ammonia as a reducing agent and a denitrating catalyst.The adsorbent of the present invention comprises a material in which the total volume of pores is 0.2 to 0.7 cc/g and the volume of the pores having a pore diameter of 300 .ANG. or more is 10% or more with respect to the total pore volume, and the material is a specific element, its oxide, an ion-exchanged zeolite or the like.In addition, the present invention is directed to a method for removing the arsenic compound from the combustion exhaust gas by injecting the adsorbent into the flow of the gas on the upstream side of the denitrating catalyst.

Abstract: A process for making alpha alumina particles wherein a Bayer process caustic aluminate solution is treated with both alumina hydrate seed material and alpha alumina promoter particles to precipitate alumina hydrate particles. The precipitated particles are separated from the solution and then dried and calcined to produced alpha alumina particles. Addition of promoter particles in the precipitation step lowers the calcination temperture necessary to produce alpha alumina and results in smaller sized crystallites in the product.

Abstract: Procedure for making Al.sub.2 O.sub.3 spheroids, 600 micrometers in diameter or less, utilizes an AlOOH sol containing 0.25% weight percent MgO (in the form of Mg(NO.sub.3).sub.2 .multidot.6H.sub.2 O) and HNO.sub.3. The sol is dispersed into droplets in a particle forming fluid (e.g., 2-ethylhexanol) where gelling occurs. The gelled spheroids are collected, dried and pre-fired in air at temperatures less than 1,200.degree. C. for up to about 12 hours. The dried and prefired beads are fired in a 2-step process at temperatures of about 1,850-1,950.degree. C. in the following sequence:a first dry oxygen firing for about ten minutes, followed by a wet hydrogen firing for up to 350 minutes. Reasonably transparent microspheres having crystallites in the range of 5-100 micrometers are obtained with little intergranular porosity, and their density is estimated to be near theoretical.

Abstract: Alumina particles having average particle size of about 1-20 microns are converted to alpha alumina in a steam-fluidized bed maintained at about 380.degree.-600.degree. C. and a pressure greater than about 1000 psig. Acidifying the steam reduces average crystallite size of the product and lowers content of some impurities. A preferred product is alpha alumina having an average crystallite size of less than about 0.2 micron.

Abstract: A product suitable as a ceramic comprises substantially nonaggregated alumina particles with 95% by number having an aspect ratio (i.e., the ratio of the longest dimension to the shortest dimension for any single particle) not greater than 1.1 and more than 80% having an aspect ratio not greater than 1.05 and having a geometric mean size of from 0.02 to 0.5 microns. Usually the product contains no more than 3% by weight as aggregates and preferably the product is as small as can conveniently be manufactured.

Abstract: The process for the manufacture of special aluminas from the powder produced in the calcination of alumina hydrate, as proposed by the invention, achieves the recovery of this by-product, treating it separatedly from the rest of the alumina, in order to convert it into special alumina of high calcination degree, or alpha alumina, being adequate for uses other than aluminum production. The process is carried out by submitting the by-product to a water-washing stage that reduces its sodium content, solid and liquid separation, filtering and drying. A drying operation is finally carried out with a calcination at a high temperature wherein the alumina of high calcination degree is transformed into alpha alumina.

Abstract: Microcrystalline boehmite suitable for conversion to anhydrous alumina products is produced by hydrothermal treatment of precursor alumina raw material at controlled pH and in the presence of microcrystalline boehmite seed material. Reaction mix may include submicron seed material for seedling for later conversion of the microcrystalline boehmite to alpha alumina. Removal of metal cations by ion exchange is employed when high purity product is required. Other materials may be added to reaction mix. Production of alumina products, catalysts, and ceramic bodies is disclosed.

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 are obtained.

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.

Abstract: This invention relates to a process for disproportionation of hydrocarbon olefins by contacting said hydrocarbon at disproportionation conditions with a catalyst prepared by incorporating a metals solution containing cobalt and an element selected from the group consisting of molybdenum and tungsten into an alumina hydrogel. The final calcined catalysts have surface areas greater than about 300 m.sup.2 /g and more than about 40% of their pore volume in pores having diameters less than about 50 .ANG..

Abstract: A process for the preparation of at least one porous oxide or hydroxide body comprises:(i) adding at least one body comprising a sol of the oxide or hydroxide to a fluid freezing medium; and(ii) raising the temperature of the solid, quenched sol so that solvent nucleation occurs, resulting in the formation of crystals of the dispersion medium, and the dispersion medium melts thereby leaving one or more porous oxide or hydroxide bodies.

Abstract: An alumina comprising particles which are aggregates or agglomerates of primary particles in which the internal porosity is provided by micropores of predetermined average width within the range 4 to 20 Angstroms and in which the pore width over the majority of the pores is within 1 Angstrom of the predetermined value, and a method for producing such an alumina by heating a particulate hydrous alumina to dehydrate it under an atmosphere in which the partial pressure of water vapor is maintained essentially constant at a predetermined value.

Abstract: This invention relates to a process for preparing wide port-containing catalysts prepared by incorporating a metals solution containing an element selected from the group consisting of molybdenum, tungsten and mixtures thereof, and an element selected from the group consisting of nickel, cobalt and mixtures thereof, into a phosphated alumina hydrogel support. The final calcined catalysts have surface areas greater than about 300 m.sup.2 /g, crush strengths greater than about 9 lbs and more than about 20% of their pores greater than 150 .ANG..

Abstract: This invention relates to a process for preparing highly active hydrotreating catalysts prepared by incorporating a metals solution containing cobalt and an element selected from the group consisting of molybdenum, tungsten and mixtures thereof, into a phosphated alumina hydrogel support. The final calcined catalysts have surface areas greater than about 300 m.sup.2 /g, flat plate crush strengths greater than about 16 lbs and more than about 80% of their pore volume in pores having diameters less than about 70 .ANG..

Abstract: This invention relates to a process for preparing highly active hydrotreating catalysts prepared by incorporating a metals solution containing nickel, an element selected from the group consisting of molybdenum, tungsten and mixtures thereof, and a stabilizing amount of phosphorus into a phosphated alumina hydrogel support. The final calcined catalysts have surface areas greater than about 300 m.sup.2 /g, crush strengths greater than about 18 lbs and more than about 80% of their pore volume in pores having diameters less than about 70 .ANG..

Abstract: A boehmite having an orthorhombic crystal form in which the ratio of the maximum length in the direction of the a-axis of the crystal to the distance between the opposing crystal faces perpendicular to the c-axis of said crystal is at least 10, said maximum length in the direction of the a-axis of the crystal is at least 2500 .ANG. and said distance between the opposing faces perpendicular to the c-axis of said crystal is 250-900 .ANG..

Abstract: Inorganic metal oxides having high surface area and pore volume are prepared by spray drying. The admixture which is spray dried to yield the metal oxides is produced from reactants comprising at least one hydrolyzable metal compound, a sufficient amount of water to at least partially hydrolyze the metal compound and an organic solvent. The admixture is supplied as a plurality of droplets to a reaction zone operated under conditions of temperature and pressure below the critical temperature and pressure of the reactants but sufficient to produce a product comprising metal oxide powders and a gas comprising organic solvent vapors. The powders are separated from the gas in a known fashion and collected. Spray drying of non-aqueous systems unexpectedly produces metal oxides having properties generally intermediate conventionally produced oxides and aerogels.

Abstract: The invention relates to a process for manufacturing highly active, dispersed aluminum hydroxide, of low apparent density. First, unground, very fine grained aluminum tri-hydroxide, of which more than 99% of the grains are at most 3 .mu.m in size, is introduced continuously into a reactor along with a stream of hot dry air, is whirled up and strongly dispersed, heated to 400.degree.-600.degree. C. and shock dehydrated. The low apparent density aluminum oxide flowing out of the reactor in the hot air stream is precipitated out by suitable mechanical means, dispersed in mildly acidic or mildly basic water and rehydrated with the aid of heating. The invention also relates to shaped components of highly active, dispersed low apparent density aluminum oxide having a specific surface area of at least 200 m.sup.2 /g, a pore volume of more than 1.2 cm.sup.3 /g and adequate resistance to fracture and wear.

Abstract: This invention relates to a process for preparing catalyst supports with a narrow pore size distribution by simultaneously titrating an acid aluminum species, a basic aluminum species and a phosphorus oxide. The porous alumina supports have surface areas above about 300 m.sup.2 /g with more than 80% of the pores having diameters less than 50 .ANG..

Abstract: This invention relates to a process for preparing catalyst supports with a wide pore size distribution by simultaneously titrating an acid aluminum species and a basic aluminum species, and interacting the precipitate with a phosphorus-containing oxide during the aging step. The porous resulting alumina supports have surface areas above about 300 m.sup.2 /g with a significant fraction of the pores having diameters greater than 350 .ANG. and a significant fraction of the pores having diameters less than 70 .ANG..

Abstract: Disclosed is a process of preparing an alumina carrier which comprises kneading an amorphous alumina hydrate, whose alumina concentration is in the range of 28-35 wt. % and which has been obtained by neutralizing an aluminum sulfate solution with a sodium aluminate solution at two stages, while endowing said hydrate with sufficient shearing effect and alternate compression and expansion effect; extruding a resulting dough; drying and calcining the extrudates. According to this process, it becomes possible to control the growth of pseudoboehmite grains contained in the alumina hydrate by controlling the time required for kneading, and accordingly it becomes possible to control the pore distribution of the finally obtained alumina carrier.

Abstract: High surface area, wide-pore-containing porous aluminas are prepared by mulling together aluminum nitrate derived hydrogels with sodium aluminate derived hydrogels, extruding, drying and calcining at 500.degree.-700.degree. C.

Abstract: (1) Rehydration bondable alumina of median particle size less than 5 microns, LOI (250.degree. to 1100.degree. C.) about 4 to 12% by weight, and having the ability to yield rehydration bonded objects of lower density and higher strength as compared with objects made of seven micron rehydration bondable alumina, or density less than 0.9 cm.sup.3 /g at strength about equal to or greater than 7 MPa; (2) rehydration bondable alumina having the ability to yield rehydration bonded objects having at least 0.6 cc of pore volume per gram for pores smaller than 300 Angstroms. Also encompassed are materials containing such alumina and originating from e.g. bauxite.

Abstract: High surface area, wide-pore-containing porous alumina are prepared by mulling together alumina hydrogel and alpha alumina monohydrate, extruding, drying and calcining at 500.degree.-700.degree. C.

Abstract: The sol-gel process for forming dense, alumina-base ceramics, the process comprising1. preparing a dispersion of aluminum oxide monohydrate containing a precursor of a modifying additive in the form of a soluble salt;2. gelling the dispersion;3. drying the gel dispersion to form a solid;4. calcining the solid; and5. sintering the calcined solid,is improved by adding to the dispersion at least about 10 weight percent, based on the oxide equivalent of the soluble salt precursor, of at least one densification aid selected from the group consisting of alcohols, glycols and polyether compounds having a vaporization point in excess of the temperature at which the dispersion is dried. This improved process is particularly useful for manufacturing abrasive grains.

Abstract: An improved method of preparing alumina, including a first stage in which an alumina hydrogel is formed from seed aluminum hydroxide, and a second stage in which the alumina hydrogel is processed for conversion into alumina.

Abstract: An improved process for the preparation of alumina, including forming an alumina hydrogel from aluminum hydroxide, and processing the alumina hydrogel into alumina. The improvement involves the alumina hydrogel forming step which is connected in the presence of sulfate ion and which comprises providing, in a reaction zone, an aqueous slurry containing seed aluminum hydroxide and having a pH of 6-11, and feeding to the reaction zone an aluminum compound and a pH controlling agent for mixing with the aqueous slurry while maintaining the aqueous slurry at a temperature of at least about 50.degree. C. at feed rates so that the pH of the aqueous slurry is maintained within the range of 6-11 and that 0.2-5 mols/hour of aluminum components, in terms of elemental aluminum, are fed to the reaction zone per mole of the seed aluminum hydroxide originally contained in the aqueous slurry, whereby the seed aluminum hydroxide is caused to grow to the aluminum hydrogel.

Abstract: Aqueous alumina coating compositions well adopted for directly impregnating/coating both ceramic and metallic catalyst supports to provide integral, both macroporous and microporous coatings therefor, which coated supports are useful for the fabrication of a wide variety of catalysts for catalyzing a broad spectrum of reactions, including those characterized by highly limited internal diffusion or by progressive catalyst poisoning, e.g.

Abstract: A porous refractory inorganic oxide product is produced by shaping a mixture of carbon black and a refractory inorganic oxide and/or a precursor of refractory inorganic oxide; drying a product; firing it in an oxygen-containing gas flow while burning said carbon black.

Abstract: A process is provided for preparing basic aluminum carbonate gels substantially free from foreign anions at a pH within the range from about 5.5 to about 7.0, according to the reactants used, and then converting such gels to high purity fibrous colloidal alumina monohydrate of the boehmite crystal lattice structure by hydrolysis with weak acids.

Abstract: Process for the preparation of alkali-poor .alpha.-alumina for ceramic purposes. Technical grade aluminum hydroxide is activated and calcinated in the presence of a mineralizing mixture comprising halides and boron compounds. The process further comprises activating aluminum hydroxide at a temperature of 500-600 degrees C., washing the activated product with alkali-free water containing calcium ions and having a conductivity not exceeding 70 .mu.S/cm until the alkali content expressed in Na.sub.2 O becomes lower than 0.15% by weight, adding 0.4-0.7% by weight of a mineralizing mixture to the washed product, and calcinating the same at a temperature of 1200-1350 degrees C.

Abstract: An improved process for the production of a low density formed product of an activated alumina having a large macro-pore volume and an excellent abrasion resistance, which comprises mixing the starting solid material selected from an alumina powder being able to be re-hydrated and a mixture of the alumina and other solid material with water, said starting solid material having an average particle size of 1 micron to 35 micron and a quarter deviation of particle distribution of not more than about 1.5, forming the mixture of a solid material and water into various shapes, re-hydrating the formed product by keeping it under wetted atmosphere or in water, and calcining the resulting re-hydrated product.

Abstract: A method of manufacturing spherical alumina particles which comprises the steps of digesting, at an elevated temperature and an elevated pressure, gibbsite with an aqueous hydrochloric acid solution and then forming an aqueous basic aluminum chloride solution; adding, at an elevated temperature, an aqueous ammonia to said aqueous basic aluminum chloride solution to form an alumina hydrosol containing ammonium chloride; commingling said alumina hydrosol with a gelling agent; thereafter dispersing droplets of said mixture in a suspending medium under conditions effective to transform said droplets into hydrogel particles; ageing said hydrogel particles first in said suspending medium and then in aqueous ammonia; and then washing said hydrogel particles with water, drying and calcining to obtain spherical alumina particles.

Abstract: Spheroidal alumina particles have a combination of high macroporosity, surface area, crush strength and low attrition loss and bulk density. The particles are prepared by an improved external gelation oil-drop process. In the process a slurry of alumina, preferably a microcrystalline boehmite-pseudoboehmite intermediate, is prepared in an acidic aqueous medium and droplets of the slurry are passed through air into a column containing an upper body of water-immiscible liquid and ammonia and a lower body of aqueous coagulating agent. Catalysts employing the particles as a support and having catalytic agents distributed at controlled depths in the particle have excellent initial and sustained activity and durability, especially for eliminating pollutants in automotive exhaust streams.

Abstract: The invention relates to gels produced by dispersing solid primary particles of an inorganic substance in a liquid to form a sol containing colloidal particles which are aggregates of the primary particles and drying the sol to produce a porous gel.The gels find applications in chromatography. Calcined gels give porous ceramic materials suitable for use as catalyst supports.

Abstract: A high surface area alumina is prepared by heating a solution of an aluminum trialkoxide in a secondary or tertiary alcohol solvent to a sub-critical temperature at which the solvent decomposes to form water, and the water so formed hydrolyzes the aluminum trialkoxide. Solutions include aluminum tri-s-butoxide in s-butanol. The resultant aluminas have surface areas 500 m.sup.2 /g or greater.

Abstract: High purity alpha-alumina bodies useful as catalyst supports are made by peptizing boehmite alumina in an acidic mixture containing fluoride anions, extruding the peptized alumina into shaped bodies and drying and calcining the bodies. The alpha-alumina bodies are characterized by a narrow pore-size distribution, having 85 percent of the total pore volume comprising pores of a diameter of from 10,000 to 200,000 Angstroms and by a surface area of less than one square meter per gram.

Abstract: An alumina composition comprising a microcrystalline boehmite-pseudoboehmite intermediate having from about 70 to about 85 weight percent of the total amount of Al.sub.2 O.sub.3 present in crystalline form. The composition is prepared by adding aluminum sulfate and sodium aluminate solutions to a mixture of water and aluminum sulfate solution to precipitate alumina and adjusting the pH to a pH higher than the precipitation pH. The reactant concentrations, and rates of addition, temperatures, and pH's in the precipitation are specifically controlled to form the boehmite-pseudoboehmite intermediate.

Abstract: An improved Claus catalyst is provided in the form of activated alumina in which sodium oxide concentration, LOI and surface area of the catalyst are carefully controlled to achieve increased sulfur conversion. Sulfur recovery is enhanced by choosing an alumina catalyst having properties which minimize chemisorption of sulfur dioxide on the catalyst at reaction conditions. Sodium oxide may be present in an amount of 0.1 to 2.5 wt % of the catalyst (1100.degree. C. calcined basis). The catalyst desirably has a surface area greater than 100 m.sup.2 /g (BET) and an LOI (hydroxyl content as determined by heating from 400.degree. to 1100.degree. C.) between 2.0 and 6.0 wt %. A method of producing the catalyst and a method of using the catalyst are also provided.

Abstract: A method is provided for forming stable dispersions of boehmite alumina in water containing a peptizing acid by mixing said alumina with dilute aqueous acid solutions and treating the alumina prior to dispersion by heating at temperatures of from about 250.degree. F. to 700.degree. F. and pressures of from about 10 psig to about 2000 psig in the presence of up to 80 weight percent of water based upon the total alumina for a period of time sufficient to stabilize the alumina to the extent necessary. Dispersions can be prepared which will remain fluid up to days longer than will those prepared from the untreated alumina.

Abstract: Catalyst carrier produced by a process of dehydrating alumina hydrate, granulating and roasting at 150.degree..about.850.degree. C. to yield particles; and curing said particles in an aqueous solution of caustic alkali or in an aqueous solution of sodium aluminate or in a mixture of both under a saturated steam pressure of 120.degree.-200.degree. C.; and said manufacturing process.

Abstract: A pseudoboehmite having properties suitable for incorporation into a matrix for a zeolite containing catalyst and the process for producing the same from an aluminum sulfate derived gel.