Abstract: This invention relates to synthetic chalcoalumite-type compounds represented by formula (1) below:M.sup.2+.sub.a-x/2 Li.sub.x.sup.1+ Al.sub.4.sup.3+ (OH).sub.b (A.sup.n-).sub.c.mH.sub.2 O (1)(whereinM.sup.2+ represents at least one of the following divalent metal ions: Zn.sup.2+, Cu.sup.2+, Ni.sup.2+ and Mg.sup.2+,a is 0.6<a<1.2,x is 0<x<1.4,b is 11<b<13,A.sup.n- is at least one member of the group consisting of SO.sub.4.sup.2-, HPO.sub.4.sup.2-, CO.sub.3.sup.2-, SiO.sub.3.sup.2-, SO.sub.3.sup.2-, HPO.sub.3.sup.2-, H.sub.2 PO.sub.4.sup.-, NO.sub.3.sup.- and OH.sup.-,c is 0.5<c<1.2, andm represents a number of 1 to 4)and processes for their preparation. The synthetic chalcoalumite-type compounds of the present invention are conveniently used for adsorbing agents of acidic substances, anion exchangers, infrared absorption agents for agricultural films, deodorants and recording media for ink jet, etc.

Abstract: Apparatus and a process are provided for converting and/or removing harmful constituents from solid hazardous or other undesirable waste material by heating the waste in a reactor in the presence of a continuous flow of oxygen and waste metals, wherein the waste material becomes a molten metal oxide bath which when solidified, has a spinel structure to chemically bond harmful constituents within the spinel structure by crystal chemical substitution. The resulting metal oxides are environmentally acceptable. A substantially gaseous effluent which may contain particulate material is also generated. The effluent is conducted through a high temperature zone to destroy organic and other harmful constituents influenced by temperature and dwell time. The effluent is further processed through an emissions treatment system to achieve acceptable environmental quality.

Abstract: The present method is to produce an active material powder formed of a spinel oxide containing lithium or a layer-structured oxide containing lithium for a lithium secondary battery which is uniform in composition, fine in particle size and free of oxygen defects, and which is unlikely to cause capacity deterioration resulted from repetitive charge/discharge cycles at a high current density.A suspension 1 prepared by suspending an ingredient of the active material powder in a combustible liquid or an emulsion prepared by emulsifying a solution of the ingredient in the combustible liquid is sprayed in a droplet state 15 together with an oxygenic gas 2. The combustible liquid contained in the droplet 15 is burned to have the ingredient therein reacted and to evaporate the solvent. As a result, active material powder 4 formed of the spinel oxide containing lithium is obtained.

Abstract: There is provided a flash activated hydrotalcite which, when extruded to sizes of about 1/16 inch or more, has a crush load strength of at least about 7 pounds. The process for making this extrudate includes: (a) providing a hydrotalcite compound; (b) heating said compound for less than two seconds to one or more temperatures above about 482.degree. C. (900.degree. F.); (c) cooling said heated compound; (d) collecting said cooled compound; (e) forming said compound into an extrudate; and (f) reactivating said extrudate by heating to one or more temperatures above about 400.degree. C. (752.degree. F.) for about 20 minutes or more. Further strength improvements are achieved by exposing these extrudates to steam for at least about 8 hours prior to step (f).

Abstract: An oxygen scavenging agent and compositions capable of providing good oxygen absorption capabilities which contain said agent, wherein the agent is a modified anionic hydrotalcite particulate material.

Abstract: A direct, simplified and relatively salt-free process is described for making anionic, hydrotalcite-type pillared clay compositions which contain nickel, and their heat-treated derivatives. Compositions of the invention are manufactured from ractants which contain a relatively minor amount of metal salts or, preferably, contain essentially no metal salts. Preferred compositions made by the process form a number of new nickel-containing catalytic materials which are unusually resistant to deactivation, for example resistant to coke formation when used to catalyze chemical conversions of a hydrocarbyl compound with an oxygen-containing gas at elevated temperatures to form synthesis gas.

Abstract: A porous lithium aluminate carrier for catalyst has a spinel structure which has a mean pore diameter in the range of 40 to 1,000 angstroms and a total pore volume in the range of 0.2 to 1.5 mL/g. The porous lithium aluminate carrier can be used for supporting a catalyst compound containing a platinum group metal. The catalyst on the carrier can be favorably employed for promoting catalytic reaction of a nitrite ester and carbon monoxide to prepare a carbonate diester such as dimethyl carbonate.

Abstract: A method for making an essentially unsaturated synthetic meixnerite with high CO.sub.2 adsorption abilities. The method comprises activating hydrotalcite, then cooling and rehydrating such activated material in a carbon dioxide-free environment. The resultant material can absorb more than 10 milliliters of CO.sub.2 per gram.

Abstract: The present invention relates to a process for the preparation of basic polyaluminium chlorosulphates. This process consists, after basification, in carrying out cooking at a temperature between 60.degree. C. and 95.degree. C. such that the cooking time is proportionately shorter than the higher cooking temperature. The polychlorosulphates obtained according to the process of the invention can be used for the treatment of drinking water, effluents and in the paper industry.

Abstract: A synthetic chalcoalumite compound represented by the formula (1)(Zn.sub.a-x.sup.2+ M.sub.x.sup.2+)Al.sub.4.sup.3+ (OH).sub.b (A.sup.n-).sub.c.mH.sub.2 O (1)whereinM.sup.2+ represents at least one of Cu, Ni, Co and Mg;a represents 0.3<a<2.0;x represents 0.ltoreq.x<1.0;b represents 10<b<14;A.sup.n- represents one or two selected from SO.sub.4.sup.2-, HPO.sub.4.sup.2-, CO.sub.3.sup.2-, CrO.sub.4.sup.2-, SiO.sub.3.sup.2-, NO.sub.3.sup.2-, OH.sup.- and Cl.sup.- ;c represents 0.4<c<2.0 andm represents a number of 1 to 4,and a process for the production thereof.

Abstract: A method for preparing an oxide (P), which includes the steps of (i) forming a solid phase compound (O) based on an oxide containing molecular entities (1) chosen from optionally substituted ammonium, diammonium, diazan-ium or diazandium, the entities being distributed within the solid matrix, and (ii) eliminating the entities (1) from the solid phase compound (O) by reacting the solid phase compound (O) with a gaseous stream containing a break-down reactant for the entities (1), and isolating the resulting solid material (P).

Abstract: A method for producing a double metal oxide of the general formula: XMO.sub.3 in which X is Li, Na, K, Pb, Ba, Mg, Ca, Sr, La, Y or Bi, and M is Al, Mn, Ti, Zr, Sn, Mg, Zn, Fe, Co, Ni, Nb, Ta or W, which has a narrow particle size distribution and contains few agglomerates, by calcining a mixture of a simple oxide of metal X and a simple oxide of metal M; amorphous double metal oxide particles comprising X and M or their mixture; or metal oxide precursors which are converted to said simple metal oxides or said double metal oxide, in the presence of iodine or hydrogen iodide.

Abstract: A method for producing a metal oxide powder which comprises heating a metal or metals in an atmosphere gas comprising a halogen gas, a hydrogen halide gas or a mixture of these gases in a concentration of from 0.5% by volume or more to 99.5% by volume or less; and oxygen, water vapor or a mixture of these gases in a concentration of from 0.5% by volume or more to 99.5% by volume or less.

Abstract: There is incorporated as a stabilizer into a halogen-containing resin a complex hydroxide salt represented by the formula?Al.sub.2 (Li.sub.(1-x).M.sub.x)(OH).sub.6 !.sub.n (A.sup.-n).sub.1+x.mH.sub.2 Owherein A is an inorganic or organic anion, M is Mg and/or Zn, n is a valence number of anion A, m is 0 or positive number, and x satisfies the expression of 0.01.ltoreq.x<1.This complex hydroxide salt causes almost no occurrence of initial coloration when incorporated in halogen-containing resins because a part of lithium ion to enter a vacant site of aluminum hydroxide octahedron layer of the gibbsite structure in the lithium aluminum complex hydroxide salt is substituted for the metal ions of Mg and/or Zn. By substitution of a part of lithium ion for the divalent metal ions, the amount of charge-supplying anion is increased and the thermally stabilizing ability is superior to that of the lithium aluminum complex hydroxide salts.

Abstract: This invention relates to new crystalline organic compositions having unique combinations of framework-confined uniform mesopores and textural mesopores and to a method for their preparation. The compositions typically possess a framework wall thickness of at least about 17 .ANG., small elementary particle size of less than about 400 .ANG., and ratio of textural to framework-confined mesoporosity of greater than about 0.2. The formation of the mesoporous structure is accomplished by a novel self-assembly mechanism involving hydrogen bonding between neutral amine surfactant (S.degree.) and neutral inorganic oxide precursor (I.degree.). This S.degree.I.degree. templating approach allows for facile and environmentally benign recycling of the cost-intensive template by simple solvent extraction methods.

Abstract: A method for flocculation of red mud in Bayer Process streams utilizing a fatty acid or fatty acid ester free latex polymer flocculant. Preferred fatty acid free emulsifiers useful for the preparation of such flocculants are obtained by reacting ethylene and/or propylene oxide with a reagent selected from the group consisting of ethylene diamine, ethanol and ethylene glycol.

Abstract: A molten carbonate fuel cell comprises a fuel electrode, an oxidizing agent electrode, and an electrolyte body prepared by impregnating a porous body including a retaining material and a reinforcing material with an electrolyte containing an alkali carbonate. The retaining material consists essentially of .alpha.-lithium aluminate (.alpha.-LiAlO.sub.2) having at most 0.60.degree. of a half value width of (104) peak in an X-ray powder diffractometry.

Abstract: A precursor, in gel form, of an oxide having the formula (I), BaO.n(Al.sub.2x Cr.sub.2y O.sub.3), where 1.ltoreq.n.ltoreq.6.6, (x+y)=1, and 0.ltoreq.y.ltoreq.0.5, said oxide being derivable from the precursor gel by the application of heat, is prepared by mixing a solution of a barium salt with a solution of an aluminium salt or a solution of an aluminium salt and a solution of a chromium salt, and polymerising the mixture to produce said precursor gel. A mixture suitable for firing to an oxide of the formula (II), BaO.m(Al.sub.2x Cr.sub.2y O.sub.3), where 4.6.ltoreq.m.ltoreq.6.6; (x+y)=1; and 0.ltoreq.y.ltoreq.0.5, comprises at least one of:(a) barium oxide;(b) a clean thermal precursor of barium oxide; and(c) barium mono-aluminate, BaO.Al.sub.2 O.sub.3 ; with at least one of:(A) alumina, Al.sub.2 O.sub.3 ;(B) hydrated forms of alumina, such as boehmite, Al.sub.2 O.sub.3.H.sub.2 O; and(C) a clean thermal precursor of aluminium oxide; and, where y is not zero, with at least one of(D) chromium(III) oxide, Cr.

Abstract: A technique to synthesize complex oxide ceramic powders which offers advantages of both the coprecipitation and sol-gel routes while doing away with the disadvantages is disclosed. Namely, the ability to achieve chemical homogeneity and crystallite size on the namometer length scale at a nonprohibitive cost is provided by the disclosed method.

Abstract: There is provided a method for making a monovalent inorganic anion-intercalated hydrotalcite-like material by first reacting a magnesium-containing powder and a transition alumina powder in a carboxylic acid-free, aqueous suspension to form a meixnerite intermediate. This intermediate is then contacted with a monovalent inorganic anion, in its acid or soluble salt form, to make a hydrotalcite-like material. The latter is then separated from the suspension. Representative materials include a bromide-, chloride-, nitrate- or vanadate-intercalated, hydrotalcite-like material.

Abstract: A method and nickel-containing catalyst are disclosed for preparing synthesis gas by the reforming of a hydrocarbyl compound using an oxygen-containing compound.

Abstract: Disclosed are ultraviolet light protective agents having the general formula:(Zn.sub.y M.sup.2+.sub.z).sub.1-x M.sup.3+.sub.x O.sub.1+x/2wherein M.sup.2+ is at least one metal selected from the group consisting of Mg, Ca, Ni and Cu; and M.sup.3+ is at least one metal selected from the group consisting of Al and Fe; as well as a sterilizer and a deodorizer which contain the compound of the above formula (I) as an effective component. They are additives to plastics, rubber, cosmetic materials, and paint and also useful as sterilizer or deodorizer, composition components.

Abstract: A method for making a synthetic mixed metal oxide or meixnerite which, when activated, has a high B.E.T. surface area, typically about 290 m.sup.2 /g or greater. The method comprises activating hydrotalcite, then cooling and hydrating such activated material with a metal salt solution in a carbon dioxide-free environment. Such hydration can produce a material that absorbs more than 100% of its weight in water. Following hydration, this material is activated a second time in a virtually carbon dioxide-free environment. Such reactivation decomposes the salt and leaves a supported metal oxide readily available to be used for catalyst reactions.

Abstract: A technique to synthesize complex oxide ceramic powders which offers advantages of both the coprecipitation and sol-gel routes while doing away with the disadvantages is disclosed. Namely, the ability to achieve chemical homogeneity and crystallite size on the namometer length scale at a nonprohibitive cost is provided by the disclosed method.

Abstract: There is provided a method for making a polyvalent inorganic anion-intercalated hydrotalcite-like material by first reacting a magnesium-containing powder and a transition alumina powder in a carboxylic acid-free, aqueous suspension to form a meixnerite intermediate. This intermediate is then contacted with a polyvalent inorganic anion, in its acid, acid salt or ammonium salt form, to make a hydrotalcite-like material. The latter is then separated from the suspension. Representative materials include a borate- metatungstate- and paramolybdate-intercalated hydrotalcite-like material.

Abstract: There is provided an improved method for making synthetic hydrotalcite by first reacting a divalent metal compound with a trivalent metal oxide powder in a carboxylic acid-free, aqueous solution or suspension to form an intermediate. This intermediate is then contacted with an anion source such as carbon dioxide; a carbonate-containing compound; an acid or an ammonium salt to form a layered double hydroxide having the formula:A.sub.1-x B.sub.x (OH).sub.2 C.sub.z.mH.sub.2 O, where A represents a divalent metal cation, B represents a trivalent metal cation, C represents a mono- to polyvalent anion, and x, z and m satisfy the following conditions: 0.09<x<0.67; z=x/n, where n=the charge on the anion; and 2>m>0.5. Said layered double hydroxide is typically separated from the suspension by filtering, centrifugation, vacuum dehydration or other known means.

Abstract: There is provided a method for making a divalent inorganic anion-intercalated hydrotalcite-like material by first reacting a magnesium-containing powder and a transition alumina powder in a carboxylic acid-free aqueous suspension to form a meixnerite intermediate. This intermediate is then contacted with a divalent inorganic anion, in its acid, acid salt or ammonium salt form, to make a hydrotalcite-like material. The latter is then separated from the suspension. Representative materials include a sulfate- and metavanadate-intercalated hydrotalcite-like material.

Abstract: There is provided an improved method for making synthetic hydrotalcite by first reacting powdered magnesium oxide with a high surface area, transition alumina in a solution or suspension to form a meixnerite-like intermediate. This intermediate is then contacted with an anion source such as an acid, and most preferably carbon dioxide, to form the layered double hydroxide which is separated from the suspension by filtering, centrifugation, vacuum dehydration or other known means. On a preferred basis, the transition alumina combined with activated magnesia consists essentially of an rehydratable alumina powder having a surface area of 100 m.sup.2 /g or greater. To make related double hydroxide compounds, still other reactants such as bromides, chlorides, boric acids, or salts thereof, may be substituted for the carbon dioxide gas fed into this suspension.

Abstract: There is provided a method for making monovalent organic anion-intercalated hydrotalcite-like materials by first reacting a magnesium-containing powder and a transition alumina powder in a carboxylic acid-free, aqueous suspension to form a meixnerite intermediate. This intermediate is then contacted with a monovalent organic anion to form a hydrotalcite-like material. The latter is then separated from the suspension. Representative materials include a stearate-, acetate- or benzoate-intercalated hydrotalcite-like material.

Abstract: The processing of aluminium dross containing Al and Al.sub.2 O.sub.3 originating from aluminium production, comprises the steps of separating aluminium from the dross to produce a dross residue and reacting the dross residue at a temperature above 1360.degree. C. with a calcium-oxygen compound to form calcium aluminate as an at least partially melted material. To obtain a product specially suitable for use in steel-making, the calcium aluminate is rapidly cooled to form a glassy solid product. The two steps may be performed in the same vessel, which has a suitable refractory lining.

Abstract: A beta-alumina solid electrolyte for use in a sodium-sulfur battery is composed of beta-alumina crystals having a degree of orientation toward the C axis thereof, of 0.2-0.4 and an aspect ratio of 4.0 or less. The beta-alumina solid electrolyte is composed of the beta-alumina crystals having a degree of orientation toward the C axis thereof, of 0.2-0.4 and has such a particle diameter distribution that the average particle diameter is 3 .mu.m or less, the proportion of the particles having a particle diameter of 5 .mu.m or less is 90% or more, and the maximum particle diameter is 300 .mu.m or less. A process for producing a beta-alumina solid electrolyte using an alumina source material, a magnesium source material and a sodium source material, uses a magnesium-aluminum spinel as the magnesium source material and subjects all materials to mixing, granulation, molding and firing to obtain a beta-alumina solid electrolyte without subjecting the materials to calcination.

Abstract: A complex metal oxide powder having at least two metal elements, which contains polyhedral particles each having at least 6 planes, a number average particle size of from 0.1 to 500 .mu.m, and a D.sub.90 /D.sub.10 ratio of 10 or less in which D.sub.10 and D.sub.90 are particle sizes at 10% and 90% accumulation, respectively from the smallest particle size side in a cumulative particle size curve of the particles, and an yttrium-aluminum garnet powder containing polyhedral particles each having at least 6 planes, and a number average particle size of 20 to 500 .mu.m. These complex metal oxides contain less agglomerated particles, and have a narrow particle size distribution and a uniform particle shape.

Abstract: This invention relates to compositions resulting from the reaction, in aqueous phase, of aluminum hydroxide, of alkali metal cation hydroxide and of calcium or strontium hydroxide. The addition of such a composition to PVC resins or to olefinic resins from Ziegler catalysis prevents the degradation of these resins under the effect of light or of heat, in particular during extrusion.

Abstract: The present invention is a method for producing alumina trihydrate with a low silica content from Gibbsite-containing bauxite of low reactive silica content. The present method involves two desilication steps: one step before extraction of alumina from the bauxite, i.e., a pre-desilication, and an additional desilication step following alumina extraction, i.e., a post-desilication. The present method comprises the steps of:(a) heating a suspension of ground bauxite in an aqueous solution comprising sodium hydroxide at a temperature greater than 80.degree. C.; and(b) increasing the sodium hydroxide concentration of the suspension from (a); and(c) heating the suspension from (b) at a temperature greater than 80.degree. C.; and(d) diluting the suspension from (c) with an aqueous solution; and(e) heating the suspension from (d) at a temperature greater than 80.degree. C., affording a suspension comprising a supersaturated, desilicated sodium aluminate liquor and insoluble solid.

Abstract: A method for making a synthetic meixnerite which, when activated, has a high B.E.T. surface area, typically about 290 m.sup.2 /g or greater. The method comprises activating hydrotalcite, then cooling and hydrating such activated material in a carbon dioxide-free environment. Such hydration can produce a material that absorbs more than 100% of its weight in water. Following hydration, this material is activated a second time in a virtually carbon dioxide-free environment.

Abstract: A method for generation of phase-pure doped and undoped Li.sub.x Mn.sub.y O.sub.z precursors. The method of this invention uses organic solutions instead of aqueous solutions or nonsolution ball milling of dry powders to produce phase-pure precursors. These precursors can be used as cathodes for lithium-polymer electrolyte batteries. Dopants may be homogeneously incorporated to alter the characteristics of the powder.

Abstract: Disclosed are basic aluminum antiperspirant materials having univalent complex oxoanions (e.g., nitrate); methods of making such materials; antiperspirant compositions containing such basic aluminum materials, another antiperspirant active material (e.g., a basic zirconium halide salt), and optionally a neutral amino acid: and methods of making such compositions. Size exclusion high performance liquid chromatography chromatograms of the disclosed basic aluminum materials have a peak 4 relative area of at least 25%, a peak 3 relative area of less than 60%, the sum of the peaks 3 and 4 being at least 50%; and less than 10% of the chromatographic peaks eluting at peaks 1 and 2. The disclosed basic aluminum materials have less than 25% of the aluminum in the form of Al.sup.b polyhydroxyaquoaluminum, and have a .sup.27 Al NMR spectrum in which the area of the 71.5-73.5 ppm resonance line includes more than 50% of the combined areas of the 62.5-63.5 ppm and 71.5-73.

Abstract: A beta-alumina solid electrolyte for use in a sodium-sulfur battery is composed of beta-alumina crystals having a degree of orientation toward the C axis thereof, of 0.2-0.4 and an aspect ratio of 4.0 or less. The beta-alumina solid electrolyte is composed of the beta-alumina crystals having a degree of orientation toward the C axis thereof, of 0.2-0.4 and has such a particle diameter distribution that the average particle diameter is 3 .mu.m or less, the proportion of the particles having a particle diameter of 5 .mu.m or less is 90% or more, and the maximum particle diameter is 300 .mu.m or less. A process for producing a beta-alumina solid electrolyte using an alumina source material, a magnesium source material and a sodium source material, uses a magnesium-aluminum spinel as the magnesium source material and subjects all materials to mixing, granulation, molding and firing to obtain a beta-alumina solid electrolyte without subjecting the materials to calcination.

Abstract: A carbonate fuel cell matrix comprising support particles and crack attenuator particles which are made platelet in shape to increase the resistance of the matrix to through cracking. Also disclosed is a matrix having porous crack attenuator particles and a matrix whose crack attenuator particles have a thermal coefficient of expansion which is significantly different from that of the support particles, and a method of making platelet-shaped crack attenuator particles.

Abstract: There is provided a method for making a divalent or polyvalent organic anion-intercalated hydrotalcite-like materials by first reacting a magnesium-containing powder and a transition alumina powder in an aqueous suspension to form a meixnerite intermediate. This intermediate is then contacted with a dicarboxylate or polycarboxylate anion to form a hydrotalcite-like material. The latter is then separated from the suspension. Representative materials include an oxalate-, succinate- or terephthalate-intercalated hydrotalcite-like material.

Abstract: A quantum splitting oxide phosphor is described for use with VUV radiation. The oxide material has an atomic ratio, comprising: Sr.sub.1-X Pr.sub.X Al.sub.12-X Mg.sub.X O.sub.19 ; where 0<X.ltoreq.0.20. The material is stable and compatible for use as a phosphor with VUV radiation created by Hg vapor discharge.

Abstract: A process for preparing a powdered product with superior homogeneity. A precursor solution is prepared by adding an additive selected from glycerol, glyceryl nitrate, polyglycerols, glycols or polyglycols with a concentration of 0.1-2.0 percent by weight to an aqueous solution of metal nitrate. The precursor solution is atomized into droplets and thereafter heat treated to obtain a powdered product of particles.

Abstract: A process for treating sodium hydroxide waste liquor containing aluminum, comprising the steps of: adding, to aluminum-containing sodium hydroxide waste liquor, at least one of MgO and Mg(OH).sub.2 in an amount of 0.5 to 3 moles with respect to 1 mole of aluminum to cause a reaction at 70.degree. C. or more; and separating and removing a precipitated magnesium-aluminum compound is disclosed. The present invention makes it possible to recover recyclable sodium hydroxide from an aluminum-containing sodium hydroxide waste liquor. Even if the recovering procedure is repeated, no carbonate ions are accumulated. Therefore, it is possible to prevent degradation of the treating solution containing sodium hydroxide. Further, the by-product is a useful compound, and thus, there is no problem in the reprocessing or disposal of the by-product.

Abstract: A method of making a .beta.-alumina compound which is a polyaluminate of the general formula M.sub.y O.multidot.xAl.sub.2 O.sub.3 in which M is a metal selected from monovalent metals and divalent metals, y=2 when M is a monovalent metal, y=1 when M is a divalent metal and x=4-12 comprises forming a green precursor of the 62 -alumina compound by mixing together particulate aluminium metal and a reagent compound comprising an oxide of the metal M or a precursor thereof. The mixture is heated to 800.degree.-1150.degree. C. in an oxidizing environment to cause oxidation of at least part of the aluminium. Further heating then takes place to 1150.degree.-1350.degree. C. in said environment to cause the oxidized aluminium and oxide of the metal M to react to form the .beta.-alumina compound.

Abstract: There is disclosed an improved method for making synthetic meixnerite having reduced carbonate contamination levels and a x-ray diffraction pattern resembling that shown in FIG. 1, the meixnerite is made by combining magnesium oxide and transition alumina, preferably an activated alumina powder having a BET surface area of about 100 m.sup.2 /g or greater, in a substantially carbonate-free environment.

Abstract: A superstoichiometric MgAl.sub.2 0.sub.4 spinel, which can be used, for example, as material for a high temperature crucible, is synthesized by, producing a precursor mixture comprising intimately mixed oxides of the corresponding metals in the spinel. Magnesium is added in a superstoichiometric amount to the precursor mixture. Prior to spinel formation, from one to five percent by weight of a reactive salt containing fluorine and/or boron, based on the metal oxides of the spinel, are added to the precursor mixture, and the doped precursor mixture is mixed for from 0.5 to 3 hours. Finally, the mixed precursor mixture is heated for between 0.5 and 4 hours at a temperature between 1150.degree. C. and 1400.degree. C. to synthesize the Mg.sub.(1+x) Al.sub.2 0.sub.4 spinel which is superstoichiometric with respect to magnesium.

Abstract: The invention provides a method of making an analogue of .beta."-alumina, the analogue having a layered .beta."-alumina spinel-type structure in which ate least some of the Na ions in the layers of Na ions separated by layers of Al and O ions in said .beta."-alumina spinel-type structure are replaced by substitute metal cations. The substitute metal cations are mono-, d- and/or trivalent. The method comprises dispersing in a boehmite having a well developed and highly ordered crystal structure at least one oxide of the substitute metal cations or a precursor thereof to form a starting mixture, and heating the mixture to a conversion temperature at which it is converted to the analogue.

Abstract: A process for production of a fine alpha-alumina powder having a specific surface area of not smaller than 10 m.sup.2 /g and superior polishing characteristics is provided, the process comprising heat-treating a mixture of gamma-alumina powder and silica at a temperature at which gamma-alumina is converted to alpha-alumina in the presence of silica, wherein the mixture contains not more than about 10 wt % of silica, based on the weight of the gamma-alumina.

Abstract: An apparatus provides high temperature and short residence time conditions for the production of nanoscale ceramic powders. The apparatus includes a confinement structure having a multiple inclined surfaces for confining flame located between the surfaces so as to define a flame zone. A burner system employs one or more burners to provide flame to the flame zone. Each burner is located in the flame zone in close proximity to at least one of the inclined surfaces. A delivery system disposed adjacent the flame zone delivers an aerosol, comprising an organic or carbonaceous carrier material and a ceramic precursor, to the flame zone to expose the aerosol to a temperature sufficient to induce combustion of the carrier material and vaporization and nucleation, or diffusion and oxidation, of the ceramic precursor to form pure, crystalline, narrow size distribution, nanophase ceramic particles.

Abstract: A substantially amorphous, aluminum-containing oxide having the composition Al.sub.1-x-y1-y2 Bi.sub.x M.sub.1y1 O.sub.z (wherein x is defined by 0.0001.ltoreq.x.ltoreq.0.10, M.sub.1 is at least one selected from Si, P, B, Sb, Se, Te, Sn, Zn, In, Cr, Nb, Sc, Y, Sr, Ba, Ca, Na, Li, Mg, Mn, W, Ti, Zr, Hf, Be and rare earth metals, M.sub.2 is at least one selected from Fe, Ni, Co, Rh, Ru, Re, Cu and Pb, y1 is defined by 0.ltoreq.y1.ltoreq.0.1, y2 is defined by 0.ltoreq.y2.ltoreq.0.01, z is defined by 1.2.ltoreq.z.ltoreq.1.5, and x, y1, y2 and z are each an atomic ratio); an aluminum-containing metal composition containing the above oxide and Al and/or Bi in a metallic state; a process for producing the above oxide or the above metal composition; and a molded article formed from the above oxide or the above metal composition. The above oxide or the above metal composition is useful as an electronic part, a catalyst, and the like.