Abstract: A process for producing ultra-fine barium titanate particles. In the first step of this process, a ceramic precursor material containing a metal cation, a nitrogen-containing material, a solvent, and an anion capable of participating in an anionic oxidation-reduction reaction with the nitrogen-containing material, is provided; the nitrogen-containing material contains at least three nitrogen atoms, at least one oxygen atom, and at least one carbon atom. In the second step of the process, droplets of such ceramic precursor material are formed. In the third step of the process, the droplets are dried until particles which contain less than about 15 weight percent of solvent are produced. In the fourth step of this process, such particles are ignited in an atmosphere which contains substantially less than about 60 weight percent of the solvent's saturation value in such atmosphere.

Abstract: The invention relates to a process for the production of metallic titanium, characterized in that the process comprises reducing a titanium-fluorine compound selected from titanium tetrafluoride and any hexafluorotitanate soluble in a molten fluoroaluminate, with metallic aluminum in a molten fluoroaluminate. A process for the production of intermediates useful in the processing ilmenite and related minerals is also described.

Abstract: Aluminum can be removed from tetrahedral framework sites of zeolite frameworks and substituted with elements such as silicon, gallium, titanium or zirconium. The process involves three steps:(a) forming a mixture of the ammonium or alkaline metal form of the zeolite in the hydrated state and a crystalline ammonium fluoro-halo-metallate salt;(b) heating the mixture at elevated temperatures to remove the aluminum from the zeolite and to introduce the metal from the salt into the structure of the zeolitic component by solid-state reaction while forming a fluoro-halo-aluminate complex salt; and(c) removing the formed fluoro-halo-aluminate complex salt.

Abstract: A powdered admixture of a boron, carbon, nitrogen or silicon derivative of a first metal is combined with a source of a second metal and, optionally, a source of a third metal or an iron-group metal, subjected to densification conditions (heat and pressure), partially reacted and converted to a hard, wear resistant material. The wear resistant material contains an amount of the first metal derivative as well as a material of varying stoichiometry which is the partial reaction product of components of the powdered admixture. The material may also contain residual, unreacted portions of components other than the first metal derivative. Articles formed from this material can be useful as, for example, nozzles in abrasive or nonabrasive waterjet cutting machines and various parts of wire drawing apparatus.

Abstract: A powdered admixture of a boron, carbon, nitrogen or silicon derivative of a first metal is combined with a source of a second metal and, optionally, a source of a third metal or an iron-group metal, subjected to densification conditions (heat and pressure), partially reacted and converted to a hard, wear resistant material. The wear resistant material contains an amount of the first metal derivative as well as a material of varying stoichiometry which is the partial reaction product of components of the powdered admixture. The material may also contain residual, unreacted portions of components other than the first metal derivative. Articles formed from this material can be useful as, for example, nozzles in abrasive or nonabrasive waterjet cutting machines and various parts of wire drawing apparatus.

Abstract: A powdered admixture of a boron, carbon, nitrogen or silicon derivative of a first metal is combined with a source of a second metal and, optionally, a source of a third metal or an iron-group metal, subjected to densification conditions (heat and pressure), partially reacted and converted to a hard, wear resistant material. The wear resistant material contains an amount of the first metal derivative as well as a material of varying stoichiometry which is the partial reaction product of components of the powdered admixture The material may also contain residual, unreacted portions of components other than the first metal derivative. Articles formed from this material can be useful as, for example, nozzles in abrasive or nonabrasive waterjet cutting machines and various parts of wire drawing apparatus.

Abstract: Process for the manufacture of a powder of mixed metal oxides by cohydrolysis of metal alcoholates in the presence of an acidic organic compound and mixed metal oxide powders in which the molar relationships R1 and R2 of a metal oxide to the sum of the metal oxides in the powder and in a particle of the powder are such that ##EQU1## The process applies especially well to powders of zirconia doped with yttrium oxide or other oxides.

Abstract: A process for the preparation of improved zirconium oxides comprising A) providing a zirconium oxide which has been produced by thermal decomposition of zircon followed by chemical digestion of the resultant silicate phases, B) reacting the zirconium oxide at high temperature with an alkali metal hydroxide or carbonate so as to form an alkali metal zirconate, C) hydrolyzing the resultant alkali metal zirconate so as to produce a suspension of zirconium oxide hydrate in a concentrated solution of alkali metal hydroxide, D) separating the zirconium oxide hydrate from the concentrated solution and washing the zirconium oxide hydrate which has been isolated, and E) drying the zirconium oxide hydrate at a temperature in the range of from 110.degree. to 570.degree. C.

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: There is provided a method for pillaring a layered silicate, such as kenyaite, with polymeric oxide by using a single step treatment with a mixture of swelling agent and pillar precursor. The swelling agent may be an organic cation, such as a cetyltrimethylammonium cation, and the pillar precursor may be a compound which is capable of hydrolyzing to form a polymeric oxide. Tetraethylorthosilicate is an example of such a pillar precursor.

Abstract: An improved method for producing aluminum titanate powder material for making aluminum titanate ceramics.

Abstract: The disclosure concerns the fabrication, by chemical process, of a ceramic material belonging to the system:Ba.sub.x Sr.sub.1-x (Ti.sub.u Zr.sub.v Hf.sub.w)O.sub.3The fabrication method comprises the following steps:preparation of an alcohol solution containing at least one titanium, zirconium or hafnium alcoholate,preparation of a determined quantity of hydrated barium hydroxide and/or hydrated strontium hydroxide in solid state;under violent shaking, dissolving of the hydroxide or hydroxides in the alcohol solution, and continuing of the reaction until a paste is obtained,drying of the paste obtained.

Abstract: A method of producing powder of lithium zirconate is disclosed, in which a gel-like zirconium compound obtained by hydrolyzing or neutralizing an aqueous solution of a zirconium salt is mixed with an aqueous solution of a lithium salt and the mixture is dehydrated, temporarily burned and pulverized.

Abstract: An elastic bar member is coupled to an orbiting mass oscillator and the entire assembly is suspended from a cable or the like such that the bar member has freedom of lateral motion and is nakedly immersed in a slurry having particulate material contained therein such as a mineral ore reject from which metal has been extracted. The rotor of the orbiting mass oscillator is driven at a speed such as to generate cycloidal sonic energy in the bar preferably at a frequency such as to set up resonant standing wave vibration of the bar in a cycloidal quadrature pattern. The cycloidal vibrational energy tends to set the surrounding fluid material into a whirling rotation or rotary traveling wave which facilitates the agglomeration or coagulation of the particles in the material and enhances the settling operation to make for more complete separation of the particles from the liquid.

Abstract: An elastic bar member is clamped to an orbiting mass oscillator and the entire assembly is suspended from a cable or the like such that the bar member has freedom of lateral motion and is nakedly immersed in a leachant having a material contained therein such as a mineral ore from which metal is to be extracted. The rotor of the orbiting mass oscillator is driven at a speed such as to generate cycloidal sonic energy in the bar preferably at a frequency such as to set up resonant standing wave vibration of the bar in a cycloidal nutating pattern. The cycloidal vibrational energy tends to set the surrounding fluid material into a whirling rotation or rotary traveling wave which facilitates the mixing of the ore and leachant and enhances the leaching operation to make for more complete separation of the mineral from the ore.

Abstract: Methods of producing ABO.sub.3 compounds in which A represents a first metal ion and B represents a second metal ion from mixed metal coordination complexes are disclosed. The methods involve reacting compounds serving as a source of the B metal ion with a substituted aromatic compound, in solution, and thereafter reacting the metal coordination complex formed with a compound serving as a source of the A metal, in solution. An example is the reaction of titanium tetraisopropoxide with catechol to form a titanium catecholate coordination complex which is thereafter reacted with barium hydroxide octahydrate to form a pentamethanol barium triscatecholatotitanate mixed metal coordination complex which can be calcined at elevated temperatures to produce the ABO.sub.3 compound, barium titanate (BaTiO.sub.3), which is known to have outstanding dielectric, ferroelectric and piezoelectric properties. Portions of the A and/or B ions can be substituted with other metals.

Abstract: The present invention involves a method for producing a variety of barium titanate based powder products consisting of submicron, dispersible primary particles having narrow size distributions. The method, in its broadest aspects, involves heating an aqueous slurry of PbO, or Pb(OH).sub.2, and Ca(OH).sub.2 with a stoichiometric excess of the hydrous oxides of Ti(IV), Sn(IV), Zr(IV) and Hf(IV) to a temperature not exceeding 200.degree. C. Thereafter, the resulting slurry temperature is adjusted to between 50.degree. and 200.degree. C. and a solution of Ba(OH).sub.2 and Sr(OH).sub.2, having a temperature of 70.degree. to 100.degree. C. is added within a period of five minutes or less to the slurry. About 10 minutes after the addition of the Ba(OH).sub.2 and Sr(OH).sub.2 solution is completed, the slurry is heated to a temperature not exceeding 225.degree. C. to ensure formation of a stoichiometric perovskite product. Thereafter, the slurry is cooled and the solid product is recovered.

Abstract: A method is provided of preparing high-purity mixtures of zirconia and another metal oxide substantially free of sodium oxide impurity. Trioxydizirconium ion and a salt of another metal in an aqueous solution are added to a highly basic solution, resulting in the homogeneous precipitation of the combined hydroxides or hydrous oxides. The precipitate is recovered, washed with the water and then with an organic solvent, and then dried, most preferably employing an azeotropic distillation procedure. The resulting material is then calcined to provide a mixture of zirconia with the other metal oxide. In a preferred embodiment, the zirconia mixtures are in the form of fine powders which can be sintered to form a product having greater than 99% of its theoretical density.

Abstract: A ceramic composition represented by the following general formula:Pb.sub.1-x La.sub.x (Zr.sub.y Ti.sub.1-y).sub.1-x/4 O.sub.3wherein O<x<1, O<y<1) is produced by a method which comprises adding a mixed solution of a titanium alkoxide and a zirconium alkoxide to an aqueous solution containing lead nitrate and/or lead acetate and lanthanum nitrate and/or lanthanum acetate thereby simultaneously effecting hydrolysis of said alkoxides and coprecipitation of lanthanum components, further adding an alkaline substance to the resultant system thereby effecting substantially thorough precipitation of lead and lanthanum components, and heating the produced precipitate.

Abstract: A process for preparing a zirconia-alumina base composite ultra-fine powder is described, including the steps of: mixing an aluminum salt or an alumina hydrate with an aqueous zirconium oxychloride solution, with or without metal salt acting as a stabilizer; mixing urea or a substance capable of generating ammonia by hydrolysis with the resulting mixture; and allowing the mixture to react at a temperature of 140.degree. to 300.degree. C. and a pressure of 4 to 150 kg/cm.sup.2 in a high-temperature and -pressure vessel. The reaction product is further dried, calcined and crushed to obtain an ultra-fine powder.

Abstract: The beneficiation or upgrading of an iron-containing titaniferous ore to a synthetic rutile by subjecting the ore to reduction followed by acid leaching of the reduced ore is improved by forming a mixture of the ore and an aqueous sulfuric acid solution, adding a reducing agent to this mixture and then subjecting this mixture containing the reducing agent to reduction at elevated temperatures. The resulting reduced ore, which is characterized by an increase in the ferrous iron content thereof and an increase in its specific surface area, exhibits an enhanced response to subsequent acid leaching to provide a synthetic rutile of improved purity.

Abstract: A process for preparing pigmentary titanium dioxide by grinding and mixing a titanium-bearing material, such as sorelslag, with an alkali metal compound such as sodium hydroxide, and roasting the mixture. The roasted material is ground followed by washing and filtering. Thereafter, the solid residue is digested with hydrochloric acid. After removing the acid by filtration and washing the solid residue, the residue is calcined to provide a titanium dioxide pigment.

Abstract: Process for the selective separation of uranium in carbonated aqueous solution from soluble impurities including in particular at least one of the elements zirconium and/or hafnium and/or molybdenum, thereby making it possible to produce a uraniferous liquor in a greatly improved state of purity, comprising precipitation of the zirconium and/or hafnium by introducing an alkali metal hydroxide, then separation of the zirconiferous precipitate which possibly contains hafnium and/or molybdenum from the resulting uraniferous solution with its reduced impurities content, which still possibly contains molybdenum, which is characterized in that in order to increase the removal of zirconium and/or hafnium and/or molybdenum, the uraniferous carbonated aqueous solution is treated by means of a dilute alkaline aqueous solution containing at most 17 g/l of at least one alkali metal hydroxide expressed in respect of OH.sup.

Abstract: The present invention relates to a low temperature method of preparing a compound of the formula:ABO.sub.3whereinA=Ba, Sr, Ca and Pb; andB=Ti, Zr and Hf,by(a) reacting a B-alkoxide, with a predetermined amount of aqueous A-hydroxide,(b) heating the reaction mixture to an initial temperature of 100.degree. C.-250.degree. C. at 1-40 atmospheres of pressure;(c) cooling the reaction mixture and thereafter, heating it to a subsequent temperature of approximately 40.degree. C. to 60.degree. C.;(d) dialyzing the cooled reaction product and recovering the tenate.

Abstract: In the recovery of chromium from a residue containing chromate and vanadate, by oxidative decomposition of a chromium and vanadium-containing ore in the presence of an alkali at temperatures of about 600 to 1200.degree. C., and leaching such residue with water, the improvement which comprises adding titanium dioxide to the residue and heating, whereby upon leaching the chromium enters the water while the vanadium is substantially left in the residue.