Abstract: A process is disclosed for purifying gibbsitic alumina-rich ore of high silica content including admixing the ore with an aqueous digestion solution high in silica concentration. In one aspect the digestion is performed with high alumina and soda concentration at low temperature, e.g., such as by atmospheric digestion.

Abstract: Morphologically improved cerium oxide particulates having low sulfur content, useful, e.g., as catalysts/catalyst supports, and having a B.E.T. specific surface of at least 85.+-.5 m.sup.2 /g, measured at a temperature ranging from 350.degree. C. to 500.degree. C., are prepared by reacting an aqueous solution of cerium (IV) salt with an aqueous solution of sulfate ions to precipitate a basic ceric sulfate, filtering the precipitate which results, washing and optionally drying said precipitate, and then calcining same.

Abstract: A process for preparing a fibrous alkali metal titanate which comprises baking a mixture of rutile and an oxygen-containing alkali metal compound, rutile being finely pulverized to a particle size such that an average particle passes through a 200-mesh sieve, and pulverizing the resulting agglomerate.

Abstract: A chemical vapor purification process for the preparation of high purity metal fluorides using the thermodynamic separation of cations by formation of a gaseous-metal-containing compound, vapor transport, and fluorination is disclosed.

Abstract: Process for the low-temperature treatment according to the Bayer cycle of gibbsite-bearing bauxite of low reative silica content, involving desilication of the said bauxite before leaching, by a liquor of low caustic soda concentration and characterized in that this sodium liquor consists of one or more washing waters originating from the Bayer cycle, mixed or otherwise with leaching liquor, wherein the weighted reactive silica content is preferably lower than 5% of the alumina content of the bauxite and the concentration of the sodium liquor used for desilication ranges from 50 to 120 g/liter of Na.sub.2 O caustic.

Abstract: The invention relates to a process for the preparation of bismuth germanate of formula Bi.sub.4 Ge.sub.3 O.sub.12.According to this process, into an aqueous solution is introduced a bismuth compound such as Bi(NO.sub.3).sub.3, 5H.sub.2 O and a germanium compound such as GeO.sub.2, which are respectively able to release into the solution soluble bismuth complexes and soluble germanium complexes. The pH and temperature of the solution in the stability range of the Bi.sub.4 Ge.sub.3 O.sub.12 phase are then brought to value such that there is a simultaneous release of soluble bismuth and germanium complexes and they are reacted to form a precipitate of Bi.sub.4 Ge.sub.3 O.sub.12. The pH is generally approximately 0.5 to 5 and the temperature is below 120.degree. C.

Abstract: This invention relates to a novel process for recovering catalyst components and, more particularly, to a method for recovering both iodine and noble metal components such as rhodium from tars formed during the preparation of acetic anhydride by the iodine and noble metal catalyzed carbonylation of methyl acetate.

Abstract: At least one rare earth value is selectively separated from at least one other rare earth value, by selectively liquid/liquid extracting an aqueous phase comprising the nitrates of said rare earth values with an organic phase which comprises an organic extractant, said organic extractant comprising at least one organophosphinic compound having one of the formulae (I) or (I'): ##STR1## wherein R.sub.1 and R.sub.2, which may be identical or different, are each substituted or unsubstituted alkyl, cycloalkyl, alkoxyalkyl or alkylcycloalkyl radicals, and X is either hydrogen or a cation.

Abstract: A process for preparing a metamorphosed metal oxide, which comprises heating, under a non-oxidative (and not hydrogenous) atmosphere, a mixture of at least one metal oxide, said metal being selected from the group consisting of elements of Groups III, IV, V and II b and transition elements in Periodic Table, and a carbide represented by the formula:C(M).sub.zwherein M is an element except carbon selected from the group consisting of elements of Groups III, IV and V in Periodic Table, and Z is an integer corresponding to the valency of M, is disclosed. The process is simple and safe and the metamorphosed metal oxide obtained is modified in color tint and provided with electroconductivity.

Abstract: A process for the continuous production of alumina by means of the Bayer process by alkaline attack in reactors on bauxites which primarily consist of aluminum monohydrates and contain silica in a free state or combined in the form of aluminum silicate, the essential aim of which is to delay scaling of the reactors by deposits of sodium silico-aluminate on the reactor walls. The process comprises the following steps: (1) the bauxite is put into suspension by crushing in a sodic liquor (aqueous solution of caustic soda); (2) the suspension is raised to a temperature of from 90.degree. to 108.degree. C. and held at that temperature for a period of time sufficient to convert at least 75% of the aluminum silicate contained in the bauxite into insoluble sodium silico-aluminate; (3) The suspension is then subjected to steam heating by passing through a tube-type heat exchanger under pressure at a temperature which is at least equal to 160.degree. C. and preferably is from 160.degree. to 230.degree. C.

Abstract: A method of treating high vanadium solid petroleum residues which tend to become environmental pollutants when disposed of in landfills in which the residue is fused with sodium carbonate, sodium sulfate and/or sodium chloride and the resulting melt material is treated with an aqueous phase which can contain sodium carbonate to form a vanadate solution from which ammonium polyvanadate, sodium ammonium vanadate or ammonium metavanadate can be precipitated.

Abstract: A process is disclosed for removing potassium from relatively impure molybdenum trioxide. The process involves contacting the impure molybdenum trioxide containing greater than about 600 weight parts potassium per million with a first acid leach which consists essentially of nitric acid and ammonium nitrate at a temperature of at least about 50.degree. C. for a sufficient time and at above a 2 molar concentration of said nitric acid and an ammonium nitrate concentration of from about 1.5 to about 2 molar in said first acid leach to solubilize the major portion of the potassium and form a once leached molybdenum trioxide containing the remaining portion of the potassium which is separated from the resulting potassium containing acid leach and contacted with a second leach solution substantially similar to the first acid leach followed by separating the resulting twice leached molybdenum trioxide from the resulting potassium containing second leach.

Abstract: In a method for processing contaminated sodium oxalate which becomes available in a separating stage succeeding the digestion of bauxite in accordance with the Bayer process, chemicals used in the digesting process are recovered in that the moist sodium oxalate which has been separated is dried with the hot exhaust gases from a fluidized bed, particularly a circulating fluidized bed, jointly with aluminum hydroxide or aluminum oxide hydrate and/or reactive alumina at a mole ratio of aluminum to sodium of at least 0.8 and the dried product is decomposed in said fluidized bed at a temperature of 780.degree. to 1000.degree. C. to form sodium aluminate. Suitably drying is effected by spray drying in direct contact with the exhaust gases of the fluidized bed and decomposition is effected at a temperature in the range from 850.degree. to 950.degree. C. and with an Al:Na mole ratio not in excess of 1.2.

Abstract: A process is provided for the recovery of vanadium values from vanadium-bearing residues, such as fly ash, boiler ash and scrubber residues from the combustion of crude oil fractions. The process employs a combination of alkaline metal bases, such as sodium carbonate and sodium hydroxide.

Abstract: A method is disclosed of making yttrium silicon oxy compounds, comprising: (a) mixing powdered hydrated metal nitrate with silica in molar equivalent amounts to yield upon heating a desired duo metal oxy compound; (b) agitatingly heating said mixture to melt and decomposition temperatures for the nitrate (e.g., 340.degree.-370.degree. C.), the melt encapsulating the silica particles; and (c) heating the sludge to a temperature (1300.degree.-1550.degree. C.) for a period of time (2-5 hours) effective to stimulate chemical reaction between the decomposed nitrate and silica to form yttrium silicon oxide.

Abstract: The present invention provides for the recovery of gallium from aluminum smelting dust. Aluminum smelting dust is leached with mineral acid, such as sulfuric acid, hydrochloric acid, or nitric acid. Gallium is extracted from the obtained leach liquor with an organic solution containing a liquid cation exchange agent. The resulting loaded organic solution is treated with mineral acid in aqueous solution, either after or before scrubbing with a higher concentration of acid in aqueous solution, to strip gallium. Gallium is extracted from this solution with another organic solution containing an ion-pair extracting type extracting agent. Finally, purified gallium is recovered by stripping the latter loaded organic solution with water or dilute acid in aqueous solution.

Abstract: A process for making a fully or a partially stabilized zirconia is disclosed. The process comprises making an aqueous solution of zirconium sulfate in admixture with an inorganic or organic water soluble salt of one or more metals selected from the group consisting of Be, Mg, Ca, Sr, Ba, Ra, Sc, Y, La, Ac, Ce, Hf, Th and Al. The aqueous solution is atomized into a solvent at least partially miscible with water with the solvent being agitated during the addition of the solution. The coprecipitated metal salt formed is separated from the solvent, washed with inert solvent or solvents, dried, and calcined.

Abstract: Amorphous phases are prepared by heat treatment of intermetallic compounds of Zr-Al alloys in hydrogen-containing gas.

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: Amorphization of intermetallic compounds of Zr-Al alloys is accelerated by arranging previously and artificially the lattice defects at given positions in the crystals.