Abstract: A method is disclosed for purifying molybdenum which involves adding to an ammoniacal ammonium molybdate solution containing the impurities of phosphorus and arsenic with the phosphorus concentration being from about 0.01 to about 0.12 g/l, a soluble magnesium salt to form a precipitate comprising magnesium ammonium salts of the phosphorus and arsenic, and to form a purified ammonium molybdate solution. The amount of the magnesium salt is sufficient to result in a concentration of from about 0.005 to about 0.04 moles/l in the ammoniacal ammonium molybdate solution. The resulting purified ammonium molybdate contains no greater than about 0.01 g P/l. The precipitate is separated from the purified solution which is then contacted with a chelating cation exchange resin supplying a sufficient amount of a cation to result in removal of the major portion of the magnesium ions from the purified solution and form a further purified ammonium molybdate solution.

Abstract: The invention is a method of making ultrapure silicon yttrium oxynitride by using the steps of (a) in an argon stream, heating hydrated yttrium nitrate to a substantially dehydrated point; (b) adding to such heated hydrated yttrium nitrate an amount of silicon diimide to form a suspension and continuing to heat the mixture to melting so as to react the water of hydration of said nitrate with said silicon diimide and thereby form stoichiometric amounts of silica and yttrium/nitrogen/oxygen complex; and (c) heating said silica and nitrate in an inert atmosphere to an elevated temperature and for a period of time to chemically form ultrapure silicon yttrium oxynitride. The temperature of heating the hydrated yttrium nitride can be to a range of 340.degree.-360.degree. C. which is 85-92% of the dehydration point of yttrium nitrate. The temperature to which the mass of step (c) is heated can be in the range of 1450.degree.-1600.degree. C. and the time period can be in the range of 5-6 hours.

Abstract: A whisker of molybdenum oxide in the form of a filament, rod or flake. Molybdenum oxide whiskers are produced by firing metallic molybdenum at a temperature of at least 400.degree. C., preferably at least 800.degree. C., in an atmosphere containing oxygen, or by firing an organic molybdenum compound in an atmosphere containing oxygen at a temperature which is at least equal to its thermal decomposition temperature. They are very strong crystals which are expected to be useful as a filler for plastics and for a variety of other applications.

Abstract: A method of preparing a fibrous alkali metal titanate which comprises drying a slurry of a titanium-containing compound and an oxygen-containing alkali metal compound, baking the dried mixture and pulverizing the resulting agglomerate.

Abstract: A process is disclosed for producing high purity silicon nitride. The process involves contacting an organic compound which can be decomposed into silicon dioxide with essentially anhydrous ammonia at ambient temperature to form a two phase system consisting essentially of ammonia gas and the vapor of the organic compound and heating the two phase system at a sufficient temperature for a sufficient time to form the high purity silicon nitride.

Abstract: A method for obtaining high-purity tantalum pentoxide is disclosed, which comprises the following steps:dissolving a crude tantalum-containing compound in an acid containing hydrofluoric acid;mixing and bringing the resulting acidic aqueous solution of the crude tantalum-containing compound into contact with an organic solution composed of a water-insoluble quaternary ammonium compound and a water-insoluble organic solvent, to extract the tantalum from said acidic aqueous solution into said organic solution;mixing said organic solution with an aqueous solution containing at least one compound selected from the group consisting of an inorganic acid and an ammonium salt, to remove any of the impurities that have partly been extracted into said organic solution together with tantalum from said organic solution;converting the tantalum in said organic solution to tantalum hydroxide by treatment with an alkali containing ammonium hydroxide; andprecipitating said tantalum hydroxide and separating it, followed by cal

Abstract: Process for the manufacture of hydrated lead oxides in the bivalent state characterized by the step of (1) reacting metallic lead with acetic acid (e.g. ammonium acetate, 5%-30% solution) at a temperature up to 200.degree. C. (e.g. 50.degree.-200.degree. C.) under an atmosphere of an oxygen containing gas (e.g. oxygen) of between 1 and 10 atmospheres absolute pressure to form lead acetate, then (2) reacting the lead acetate with a source of ammonium ion (e.g. ammonia) under an absolute pressure between 1 and 5 atmospheres at a temperature up to 100.degree. C. (e.g. 60.degree.-90.degree. C.) to precipitate lead oxides and, optionally, to produce tri- and tetra- basic lead sulphates, by (3) adding to the lead oxides so precipitated sulphuric acid in the stoichliometric amount to produce tri- or tetra- basic lead sulphate, then (4) separating and drying the tri- or tetra- basic lead sulphate so formed.

Abstract: A titanium acylate solution is produced by adding glacial acetic acid to tetra-isopropyl titanate. Distilled water is then added until the solution clears, and a high grade alkaline-earth metal carbonate, such as BaCO.sub.3, SrCO.sub.3 or CaCO.sub.3, or a combination thereof, is added and agitated until the earth-metal dissolves and the solution again becomes clear. An alkaline hydroxide, such as NaOH, is added until the pH of the solution reaches 13 or 10 above, and causes crystals of an earth-metal titanate to form in the solution. The solution is thereafter filtered to produce an alkaline-earth metal titanate filter cake which is then dried and washed to produce the desired powder. At no time during the process is it necessary to apply any external heat to the solution. The heat of reaction is sufficient.

Abstract: The invention is drawn to a continuous process for the recovery of alumina from ores by mixing with an alkali bisulfate, calcining below 450.degree. C. to form the corresponding double salt, washing with water, and separating the insoluble residue from the solubilized aluminum, precipitating impure aluminum, resolubilizing aluminum with sodium hydroxide to form soluble sodium aluminate and separating it from the insoluble impurities, treating the resulting solution to form aluminum precipitate, separating the aluminum and calcining it to form alumina.

Abstract: Disclosed is a high yield method for the production of gaseous germane of high purity comprising the steps of: forming an aqueous, alkaline first solution of GeO.sub.2 in alkali metal hydroxide wherein the GeO.sub.2 is present at a molar concentration of less than 0.2 and the ratio of GeO.sub.2 to alkali metal hydroxide is less than 1 to 2; adding an alkalai metal borohydride to the first solution at a mole ratio of BH.sub.4 to GeO.sub.2 of greater than 4:1; reacting the second solution with 1.5 to 3.0 M H.sub.2 SO.sub.4 whereby to form a gaseous product containing GeH.sub.4 ; and recovering GeH.sub.4 from the gaseous product.

Abstract: The present invention is directed to a method for removing organic substances from aluminate liquors of the Bayer process. The method comprises the steps of contacting the liquor with an oxygen containing gas under elevated pressure in the presence of metallic ions acting as a catalyst to oxidize the organic substances, precipitating the metallic ions jointly with aluminum hydroxide, separating the precipitate from the oxidized liquor and recycling the precipitated aluminum hydroxide containing the metallic ions into the oxidation step as a catalyst carrier.

Abstract: This invention relates to a process for preparing a titanium oxide powder comprising heating titanium dioxide powder in an atmosphere of ammonia gas at a temperature of about 500.degree. C. to about 950.degree. C. The product powder is very fine, highly uniform in particle size and useful as an electrically conductive material. The powder is colored blue to black depending upon the process conditions and therefore is useful as a pigment, too.

Abstract: A process for the fluid-fluid extraction of gallium, germanium or indium from acid or base hydrous solutions, in which a mixture of at least two hydroxyquinolines in various quantities is employed, is described.

Abstract: The invention concerns a method and apparatus for decomposing a sodium aluminate liquor supersaturated with alumina, obtained from alkaline action on bauxite by the Bayer process, decomposition being initiated by introduction of alumina trihydrate seed to trigger the decomposition, thereby forming a suspension. In this process the suspension is fed in at the top of a non-agitated reactor described as a "decomposer", and removed from the bottom of the decomposer; the speed at which the suspension moves downwardly is regulated at 1.5 to 10 meters per hour. The apparatus comprises a cylindrical-conical reactor which is fitted with an arrangement for feeding in the suspension at the top, and with an arrangement for taking out the suspension at the bottom. In one embodiment of the apparatus the suspension is taken from the base of the decomposer through an internal tube, with air injected into the bottom of it, is raised to the level of the top of the decomposer and is then sent downstream.

Abstract: For the removal of sulfur compounds, especially H.sub.2 S, from gases that contain hydrocarbons, and/or CO.sub.2, the gases are scrubbed with a physical solvent, which is to be regenerated and reused. To obtain sulfur free of hydrocarbons, as well as a practically sulfur-free LPG fraction and optionally a C.sub.5+ fraction, an oxidizing agent is added to the solvent for reacting the sulfur compounds to elemental sulfur, and the sulfur is separated. The concomitantly absorbed hydrocarbons and/or CO.sub.2 can then be desorbed from the separated solvent by physical regeneration and can be recovered.

Abstract: A method for the production of micronized zirconia by the addition of an alkali to an aqueous solution of a zirconium salt or to a mixed aqueous solution of said zirconium salt and a stabilizer such as yttrium, calcium, and magnesium compounds, which method comprises carrying out the reaction for formation of a hydroxide by the addition of the alkali continuously in a flow type reaction system while keeping the pH of said reaction system at a fixed level, separating the hydroxide produced consequently by the reaction, and drying and calcining the separated hydroxide, and a zirconia-containing micronized particle which contains such stabilizer and has an average particle diameter of not more than 0.02 .mu.m.

Abstract: In the preparation of titanium dioxide comprising autothermically digestion a titanium-containing raw material with sulphuric acid to form a solid relatively easily soluble digestion cake containing titanyl sulphate, extracting metal sulphates from this cake by water or dilute sulphuric acid, separating the undissolved residues and, optionally after crystallization of iron sulphate heptahydrate, hydrolyzing the titanyl sulphate to produce titanium oxide hydrate, and calcining the titanium oxide hydrate to titanium dioxide, the improvement which comprises adding to the raw material a metal sulphate and effecting the autothermic decomposition with sulphuric acid of about 80 to 88% concentration. Advantageously the acid is obtained by mixing dilute acid with concentrated sulphuric acid or oleum, some of the dilute acid and metal sulphate coming from a by-product filter cake produced in the course of the process.

Abstract: In a method of 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 moist sodium oxalate which has been separated is dried with the hot exhaust gases from a rotary kiln 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 rotary kiln 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 rotary kiln and decomposition is effected at a temperature in the range from 850.degree. to 950.degree. C. and with an Al:Na ratio not in excess of 1.2.

Abstract: High molecular weight organic compounds, such as humic acid derivatives, are removed from Bayer process caustic liquors by oxidation of these compounds. The process involves addition of oxygen to the caustic liquor in quantities in the range established by the solubility of the oxygen in the liquor under the oxidation conditions.

Abstract: Morphologically improved cerium oxide particulates 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 450.degree. C., are prepared by hydrolyzing an aqueous solution of a cerium (IV) salt in an acidic medium, filtering the precipitate of hydrolysis which results, washing and optionally drying said precipitate, and then calcining same.