Abstract: A process includes a step of melting aluminium alkoxide in hexylene glycol (2-methyl 2,4-pentonediol). Then, the solution is subject hydrolysis. During this, hydrolysis and dehydrating condensation of hexylene glycol is controlled by alkoxide. This is found effective for obtaining alumina having uniform porous structure with high specific surface area.

Abstract: Transparent, monolithic metal oxide aerogels of varying densities are produced using a method in which a metal alkoxide solution and a catalyst solution are prepared separately and reacted. The resulting hydrolyzed-condensed colloidal solution is gelled, and the wet gel is contained within a sealed, but gas permeable, containment vessel during supercritical extraction of the solvent. The present invention is especially advantageous for making metal oxides other than silica that are prone to forming opaque, cracked aerogels.

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 method of modifying crystal structure of alumina trihydrate crystallizing from saturated Bayer liquors, which method includes the treatment of the saturated Bayer liquors with a crystal modifying amount of a polysaccharide, preferably a dextran.

Abstract: A process for treating an alkali metal hydrosulfite solution which comprises contacting the alkali metal hydrosulfite solution with aluminum in a reaction mixture, and admixing carbon dioxide gas with the reaction mixture to remove dissolved aluminum as an aluminum-containing precipitate, the alkali metal hydrosulfite solution having a residual alkalinity of from about 0.1 to about 20 grams per liter of hydroxide ion.

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: Ceramic structures having high strength at temperatures above 1000.degree. C. after sintering are made by mixing ceramic powders with binder deflocculants such as guanidine salts of polymeric acids, guanidine salts of aliphatic organic caboxylic acids or guanidine alkylsulfates with the foregoing guanidine salts.

Abstract: A novel process is described for the preparation of monodisperse ceramic ders wherein particulate oxides or hydroxides are obtained by reaction of hydrolysable compounds with water. The reaction is carried out in the presence of a complexing agent and, optionally, a stabilizer.

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: Mixed oxides of alumina and zirconia having a controlled granulometric distribution, consisting essentially of spherical, submicronic particles, wherein zirconia is distributed uniformly in alumina and may reach 38% by weight, said zirconia being in the stabilized form at room temperature in the tetragonal phase, after having subjected the amorphous hydrated composite oxides to thermal treatments, wherein occurs the transition of zirconia to the tetragonal phase.

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: Continuous production of aluminum hydroxycarbonate gel by continuous reaction of aluminum salt solution with mixed alkaline carbonate and bicarbonate solution under homogeneous conditions in a relatively small reaction vessel, and continuing the reaction in a subsequent reaction vessel under controlled pH. The product gel is separated from the non-aluminum cation containing reaction mixture within less than about 6 hours, whereby formation of poorly soluble addition reaction products such as dihydroxy aluminium sodium carbonate, which contribute undesired non-aluminum cations to the gel product, is reduced. The aluminum salt solution is adjusted in pH by adding to it a portion of the mixed carbonate and bicarbonate solution to obtain a clear solution of pH 3.5 to 4.0. This results in a smooth, creamy gel with less objectionable chalky mouth feel.

Abstract: Disclosed is a method for producing hydrotalcite in high yield including reacting activated magnesia with an aqueous solution containing aluminate, carbonate, and hydroxyl ions. The method further includes a first step of heating magnesium carbonate or magnesium hydroxide to a temperature between about 500.degree.-900.degree. C. to form activated magnesia or magnesium oxide. The method is suited to producing synthetic hydrotalcite from industrial Bayer liquor.

Abstract: A process is disclosed for the control of the particle form of aluminum hydroxide crystals precipitated from an alkali metal aluminate solution which comprises either the use of certain monohydric and polyhydric alcohols or controlling the caustic concentration of the sodium aluminate solution or a combination whereby particles shapes may be produced principally comprising acicular form or principally comprising lamellar form, depending upon the caustic concentration of the alkali metal hydroxide and the vol. % of the alcohol.

Abstract: Process for the manufacture of vitreous metal oxides in which a metal alcoholate derived from an alcohol, the pka of which is less than 15.74, is hydrolysed with an aqueous medium, the pH of which is greater than 1.5. The process is applied especially to the manufacture of vitreous zirconium oxide.

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: A process for treating dry, particulate alumina for use in preparing alumina slurries which are resistant to gellation in which the particulate alumina is contacted with a carbon dioxide rich gaseous medium for a suitable time.

Abstract: A method of preparing substantially homogeneous aluminum oxynitride powder is provided comprising the steps of reacting gamma aluminum oxide with carbon in the presence of nitrogen, and breaking down the resulting powder into particles in a predetermined size range. A method of preparing a durable optically transparent body from this powder is also provided comprising the steps of forming a green body of substantially homogeneous cubic aluminum oxynitride powder and sintering said green body in a nitrogen atmosphere and in the presence of predetermined additives which enhance the sintering process. Preferred additives are boron, in elemental or compound form, and at least one additional element selected from the group of yttrium and lanthanum or compounds thereof. The sintered polycrystalline cubic aluminum oxynitride has a density greater than 99% of theoretical density, an in-line transmission of at least 50% in the 0.3-5 micron range, and a resolving angle of 1 mrad or less.

Abstract: A process of producing a water dispersible alumina comprising forming an aqueous alumina slurry, acidifying the slurry to a pH range of from about 5 to about 8, aging the acidified slurry at elevated temperatures and for a sufficient amount of time to convert the greater portion of the alumina to a colloidal sol, recovering the sol and drying the sol to produce a highly water dispersible alumina.

Abstract: Sinterable metal-oxygen composition powders are prepared by mixing aqueous solutions of the metal salt and of poly(acrylic acid), or its ammonium salt, to form a precipitate which is dried, ignited to remove the organic composition and calcined to form the metal oxide or metal-oxygen compound powder.

Abstract: A process for the vapor phase production of alumina by introducing steam into the vapor space above a heated, liquid phase aluminum alkoxide in which the aluminum alkoxide is hydrolyzed in a heated reaction zone downstream from the liquid alkoxide and collected as a dry powder without the necessity for utilizing conventional drying processes.

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: 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: Spherical, submicronic, monodispersed, and non-agglomerated particles of metal oxides by reacting with steam a gaseous stream containing an aerosol of liquid particles of a hydrolyzable metal compound. Into a duct, in which an inert gas stream containing vapors of a hydrolyzable metal compound flows, there is fed through a nozzle a cold inert gas stream, the temperatures and flows of the two gaseous streams being such as to establish in the duct a temperature lower than the condensation temperature of the metal compound; the mixed gaseous streams having a turbulent flow in the duct, with a Reynolds number equal to or higher than 1800. At the duct outlet, the aerosol of metal compound liquid particles, which has formed in the duct, is caused to react with steam, wherefore solid particles of hydrated metal oxide form, which are subsequently calcined to the oxide.

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: Processes for the preparation of pure alumina powders or pure non-stoichiometric alumina-magnesia spinel powders starting with ammonium alum-based compositions which are dehydrated, the dehydration being carried out on dehydrated salts having a bulk density less than 0.2 kg/dm.sup.3 and wherein the dehydration is followed by a calcination with a heating schedule containing at least one intermediate stage at 750.degree. to 850.degree. C., the process of the invention permitting the reproducible production of such aluminas or spinels having specific surfaces of from 100 to 200 m.sup.2 /g and characterized by a very high homogeneity which guarantees a rigorously unimodal pore structure, such aluminas and spinels being useful in preparing isotopic enrichment barriers for gaseous diffusion, as well as metal polishes, catalysts, and catalyst supports.

Abstract: This invention relates to aluminium compounds and their preparation.In accordance with the invention a peptizable alumina hydrate is prepared by hydrolyzing an aluminium alkoxide at a water:aluminium ratio at or near the stoichiometric value. One example of an aluminium alkoxide which has been hydrolyzed in accordance with the present invention is aluminium sec-butoxide (Al(OC.sub.4 H.sub.9).sub.3.sup.s); thus alkoxide has been hydrolyzed at water:aluminium ratios of 3:1 and 4:1 to give peptizable alumina hydrates.Cold water (e.g. at 16.degree.-22.degree. C.) and aluminium alkoxide are preferably brought together to effect the hydrolysis.

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: Aluminum hydroxycarbonate gel is precipitated under highly homogeneous conditions by continuously introducing an aluminum salt solution and an alkaline-reacting carbonate and bicarbonate solution into a vigorously agitated reactor vessel and continuously withdrawing the reaction mixture.

Abstract: Ultrapure and homogeneous boehmites and/or pseudo-boehmites, suitable, whether before or after drying and/or calcination, as, e.g., fillers, binders, thickeners, dispersing agents, and the like, are prepared (i) by admixing an amorphous aluminum hydroxycarbonate, itself advantageously prepared by carbonating an alkali metal aluminate with carbon dioxide and then filtering and washing the precipitate which results, with a solution of an acid, a base, a salt, or mixture thereof, with the pH of the resulting reaction medium being maintained at a value of less than 11, (ii) next heating such reaction medium at a temperature of less than 90.degree. C. for a period of at least 5 minutes, and (iii) then heating the reaction medium resulting from the step (ii) at a temperature ranging from 90.degree. C. to 250.degree. C.

Abstract: A method of preparing substantially homogeneous aluminum oxynitride powder is provided comprising the steps of reacting gamma aluminum oxide with carbon in the presence of nitrogen, and breaking down the resulting powder into particles in a predetermined size range.A method of preparing a durable optically transparent body from this powder is also provided comprising the steps of forming a green body of substantially homogeneous cubic aluminum oxynitride powder and sintering said green body in a nitrogen atmosphere and in the presence of predetermined additives which enhance the sintering process. Preferred additives are boron, in elemental or compound form, and at least one additional element selected from the group of yttrium and lanthanum or compounds thereof. The sintered polycrystalline cubic aluminum oxynitride has a density greater than 99% of theoretical density, an in-line transmission of at least 50% in the 0.3-5 micron range, and a resolving angle of 1 mrad or less.

Abstract: The specification discloses new and improved processes for forming water-free metal or non-metal oxide materials, which may then be melted and formed into optical components in vitreous or crystal form, which are free of the hydrogen-impurity absorption in the near infrared wavelength range. In one process, a water-free oxide is prepared by reacting a chosen nonpolar compound containing the desired metal or non-metal with an aprotic oxygen-containing compound to form the oxide as a precipitate in a chosen aprotic nonaqueous liquid solvent which provides a water-free environment during the formation of the oxide, to prevent the inclusion of water and water-derived impurities in the oxide as formed.

Abstract: The specification discloses new and improved processes for forming water-free metal or non-metal oxide materials, which may then be melted and formed into optical components in vitreous or crystal form, which are free of the hydrogen-impurity absorption in the near infrared wavelength range. In one process a water-free oxide is prepared by reacting a chosen organic compound containing oxygen bonded to an atom of the metal or non-metal, with a chosen organic acid anhydride to form an intermediate product which is then decomposed to form the desired oxide and to simultaneously regenerate the organic acid anhydride. The regenerated organic acid anhydride reacts with and removes traces of water and water-derived impurities during the formation of the desired oxide and prevents the inclusion of these impurities in the oxide as formed.

Abstract: The specification discloses a process for forming a water-free rare earth oxychloride powder by exposing a water-containing rare earth oxide powder to a reactive atmosphere of chlorine and oxygen at 1000.degree. C. for 24 hours to remove water impurities from the oxide powder and to simultaneously convert the oxide powder to the oxychloride powder.

Abstract: A combined process for preparing alumina and alpha-olefins (.alpha.-olefins) is disclosed. The process comprises:(a) reacting tri-(C.sub.2 to C.sub.24) alkylaluminum with ethylene in the presence of nickel catalyst to form triethylaluminum and C.sub.2 to C.sub.24 .alpha.-olefins,(b) adding aluminum tri-(C.sub.4 to C.sub.8) alcoholate to the reaction product of step (a),(c) equilibrating the admixture of step (b) so that substantially all of the triethylaluminum is converted into aluminum ethyl alcoholates, compounds with at least one C.sub.4 to C.sub.8 alcoholate group per molecule,(d) subjecting the equilibrated mixture of step (c) to a fractionation to recover, (1) a C.sub.2 to C.sub.24 .alpha.-olefin fraction, and (2) an aluminum ethyl alcoholate fraction (a mixture of compounds with the general formula Al(C.sub.2 H.sub.6).sub.X (OC.sub.6 H.sub.13).sub.Y (where X is 0 to 2 and Y is 3 to 1) and X+Y=3).(e) adding C.sub.4 to C.sub.8 alcohol to the aluminum ethyl alcoholate fraction to form aluminum tri-(C.

Abstract: A process for the treatment of gasoline boiling range hydrocarbons to increase the octane number thereof comprising contacting same with a gamma alumina catalyst derived from the hydrolysis of aluminum alkoxides.

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: Recovery of fluoride values from carbonaceous waste cathode materials is achieved by reacting the waste materials with oxygen, water, and sulfur dioxide at temperatures between about 600.degree. C. and 1200.degree. C.

Abstract: A process for forming uniform distributions of at least one substance in a solid. The process comprises forming a predistribution of the at least one substance in at least one compound, e.g., mixing the at least one substance so that it is distributed throughout the at least one compound, and reacting the at least one compound with water to form a hydroxide, which hydroxide has a larger surface area than the at least one compound. Predistribution must take place before a substantial portion of the compound reacts to form the hydroxide. This process can be used to form a dry powder having at least one substance uniformly distributed therein.

Abstract: Aqueous suspensions of alumina particulates, at least a portion of which comprising ultrafine boehmite, are prepared by maintaining a pH<9 aqueous formulation of poorly crystallized and/or amorphous activated alumina powder for such period of time as to effect the at least partial transformation of such alumina powder into ultrafine boehmite.

Abstract: The process relates to the preparation of a shaped body having at least one dimension less than 100 microns and comprising alumina or an alumina hydrate. An aqueous composition comprising a water-soluble aluminum compound, for example aluminum chloride, sulphate, acetate, formate, propionate, oxalate, phosphate or nitrate and a water-soluble organic polymer is formed into the desired shape. The body so formed is dried, and is subjected to hydrothermal treatment at a temperature of at least 200.degree. C. to decompose the aluminum compound to alumina or an alumina hydrate. The body is optionally further heated subsequent to the hydrothermal treatment.

Abstract: An alumina particle and a method of its manufacture. The alumina particle comprises a spheroidal alumina particle of about 1/16 inch in diameter and a crush strength of from about 13 to about 16 pounds. The method comprises preparing a mixture of an acidic alumina hydrosol and an ammonia percursor at below gelation temperature, dispersing the mixture as droplets in a water-immiscible liquid at a temperature and for a time to effect at least partial gelation of the hydrosol to form hydrogel particles, contacting the hydrogel particles with a liquid having a pH no greater than about 7 and an osmotic pressure sufficient to prevent disintegration of the hydrogel particles, aging the hydrogel particles in an aqueous solution having a pH greater than 7, and thereafter drying and calcining the hydrogel particles.

Abstract: Alumina fibers are prepared by a method comprising(a) forming aluminum methoxide from aluminum alkoxides using methanol;(b) recovering aluminum methoxide as a solid precipitate phase, washing to remove higher alcohols and drying to recover a powder;(c) reacting the recovered powdered aluminum methoxide with dilute hydrochloric acid to form aluminum chlorohydrate; then(d) concentrating the aluminum chlorohydrate solution under vacuum to desired viscosity.

Abstract: The invention relates to a new highly reactive alumina and the method of preparing it. The alumina is characterized by an amorphous structure and a specific surface of greater than 600 m.sup.2 /g. It is prepared by thermal decomposition of the double carbonate of aluminum and ammonium of the formula AlNH.sub.4 CO.sub.3 (OH).sub.2 at a temperature of between about 200.degree. and 500.degree. C.Aluminum hydroxychlorides of the formula Al.sub.2 (OH).sub.x Cl.sub.6-x can be prepared from it.

Abstract: A method of purifying waste water with treated aluminum oxide. The method comprises contacting the waste water with Al.sub.2 O.sub.3 which has been treated with ions which when incorporated in the crystal lattice of the Al.sub.2 O.sub.3 are capable of delaying crystallization of the gamma phase of the Al.sub.2 O.sub.3 or with the salts of said ions.In one embodiment, the Al.sub.2 O.sub.3 is artificially synthesized and the treatment comprises incorporating the ions, which may be either anions or cations, in the course of the synthesis.Alternatively, the Al.sub.2 O.sub.3 may be treated by subjecting the Al.sub.2 O.sub.3 to a surface treatment with ions capable of delaying crystallization of the gamma phase or the salts thereof.In yet another embodiment, the Al.sub.2 O.sub.3 may be doped with CO.sub.2.

Abstract: Disclosed is a method for producing hydrotalcite in high yield including reacting activated magnesia with an aqueous solution containing aluminate, carbonate, and hydroxyl ions. The .[.method further includes a first step of.]. .Iadd.activated magnesia is produced by .Iaddend.heating magnesium carbonate or magnesium hydroxide to a temperature between about 500.degree.-900.degree. C. .[.to form activated magnesia or magnesium oxide..]. The method is suited to producing synthetic hydrotalcite from industrial Bayer liquor.