Abstract: A method of making high T.sub.c 1-2-3 superconductors having perovskite structure using solution techniques is disclosed. The process uses two solvent system to form a resinous pre-ceramic material having a controlled viscosity for facilitating its formation into superconducting articles such as fibers, wires, ribbons, films and the like. The process yields a pre-ceramic which is flexible and which has sufficient structural integrity to withstand normal handling.

Abstract: A two-stage process for producing acetylene and calcium chloride from calcium carbide and water has two successive reaction steps. In step Number 1, calcium carbide is charged into an entrained flow-type reactor vessel containing water. The reaction which follows proceeds to about 60-90% completion. The entrained reaction products and the unreacted feed material are carried over to a secondary reactor to complete the reaction, and the acetylene gas is drawn off. Calcium hydroxide product is removed from the reactor and reacted with hydrogen chloride to form calcium chloride. Heat generated by the exothermic reactions of water with calcium carbide and HCl with calcium hydroxide is used to dry the calcium chloride product and improve its value. In the presence of excess water, the calcium carbide-water reaction is effectively a first order, irreversible reaction.

Abstract: Layered divalent metal pentavalent metallate, M(HAO.sub.4).sub.x (RAO.sub.3).sub.y (Z).sub.z wherein M is divalent metal, A is a pentavalent metal, e.g. phosphorus, R is a substituent group other than H or OH, e.g., phenyl, covalently bonded to A, x+y=1, y is greater than 0, z ranges from 0 to 2, inclusive, and Z is an intercalated moiety is prepared by contacting a source of divalent metal with a substituted phosphonic acid-type compound under hydrothermal conditions.

Abstract: A process for the production of a magnesium oxide having high hydrolysis resistance and high fluidity, which comprises:(A) a step of reacting a water-soluble magnesium salt with an alkaline substance in such an amount that is not more than 0.95 equivalent weight based on 1 equivalent weight of the water-soluble magnesium salt, at a temperature of not more than 40.degree. C.,(B) a step of heating the resultant reaction product and its reaction mother liquor at about 50.degree. to 120.degree. C. to form a magnesium hydroxide,(C) a step of forming particles having an average secondary particle diameter of about 5 to 500 .mu.m by using a spray drier,(D) a step of firing the particles at about 1,100.degree. to 1,600.degree. C., and(E) a step of pulverizing the resultant fired product under conditions which do not substantially destroy the average secondary particle diameter obtained in the above step (C).

Abstract: Metal oxide powders, which are chemically uniform and free-flowing, can be formed by dissolving a metal alkoxide in a non-polar organic solvent, adding water to the resulting composition and then emulsifying the blend of water and solvent containing the alkoxide to cause hydrolysis of the alkoxide. The hydrolysis reaction forms the desired metal oxide as a precipitate which can be recovered by a simple filtration process.

Abstract: The specification discloses forming ceramic films, and especially high temperature superconductor films, by dissolving ceramic precursor metal iodides in organic solvents, applying them to a substrate, evaporating the solvent and pyrolyzing and annealing the resulting ceramic precursor metal iodide films.

Abstract: Refractory oxide crystals suitable for use in tunable lasers and a method for preparing the same are provided. The crystals are characterized by high quantum efficiency, high thermal stability, good crystal transparency, and a high percentage of useful luminescence. The method for preparation of the crystals involves removing substantially all the hydrogen, thermochemically reducing the crystal's oxygen content to produce oxygen (anion) vacancy defects, and subsequently irradiating the crystal with electrons to inactivate trace H.sup.- ions so that an increased amount of short lived F.sup.+ luminescence is produced when the crystal is optically excited.

Abstract: Layered divalent metal pentavalent metallate, M(HAO.sub.4).sub.x (RAO.sub.3).sub.y (Z).sub.z wherein M is divalent metal, A is a pentavalent metal, e.g. phosphorus, R is a substituent group other than H or OH, e.g., phenyl, covalently bonded to A, x+y=1, y is greater than O, z ranges from 0 to 2, inclusive, and Z is an intercalated moiety is prepared by contacting a source of divalent metal with a substituted phosphonic acid-type compound under hydrothermal conditions.

Abstract: A process for preparing compound metal oxides, superconductive compound oxides, is disclosed. The process comprises preparing an aqueous solution containing a predetermined content ratio of chloride, nitrate or acetate of a rare earth metal, an alkaline earth metal and copper, said content ration corresponding to the composition of the object compound metal oxide, adjusting the pH of the solution to 1.5-2.0, adding oxalic acid in an amount such that the concentration of the residual oxalic acid becomes 0.05 M/l-0.1 M/l, collecting the thus formed precipitate and firing it.

Abstract: Magnesia pellets are formed from finely-divided, highly reactive, lightburned magnesia (MgO) particles by granulating such powders in conventional equipment using either an organic liquid or an organic liquid-binder mixture. The organic liquid may be an alcohol or a ketone the alkyl groups of which, independently, can have from 1 to 4 carbon atoms. Magnesium chloride and water are among disclosed binders which may be used in combination with said organic liquid. The organic liquid should be more than about 80% of any admixtures with water.

Abstract: A superconducting oxide is melted in an oxygen-rich environment, rapidly solidified and annealed in an oxygen atmosphere. The resulting material has a fine grain structure, is chemically homogeneous, and has enhanced resistance to environmental degradation. The materials have well-defined superconducting characteristics as measured through the temperature dependence of their resistivities and diamagnetic susceptibilities.

Abstract: A lightweight magnesia clinker containing magnesium oxide in an amount of more than 85 wt. % and having an apparent porosity of more than 40 vol. % and a bulk specific gravity of less than 2.0 g/cm.sup.3 is disclosed. In the lightweight magnesia clinker, the amount of magnesia clinker particles having a particle diameter of smaller than 3 mm is more than 90 wt. % of the amount of all magnesia clinker particles, and the amount of pores formed in the magnesia clicker particles having a pore size of smaller than 50 .mu.m is more than 90 vol. % of the amount of all pores. A process for the preparation of said lightweight magnesia clinker is also disclosed.

Abstract: Superconducting compositions of the general formula A.sub.n Q.sub.m Cu.sub.3 O.sub.y are prepared by wet mixing a combination organic acid salts, inorganic acid salts and oxides of A, Q and Cu, wherein at least one salt is an organic acid salt, drying the mixed salts, and then heating the resultant mixed salts to a temperature between 500.degree. and 950.degree. C. The temperature is maintained for a time sufficient to form a substantially orthorhombic superconducting composition. The method achieves good results with only one heating step. The presence of at least one organic salt causes carbonate and nitrate salts of A, Q and Cu to convert to oxides at temperatures between 300.degree. and 400.degree. C. With lower processing temperatures, semiconductor materials and superconducting materials can be processed together.

Abstract: A process for adjusting at least one of the structural and surface characteristics of an oxide material, e.g. SiO.sub.2 or Al.sub.2 O.sub.3, by dehydration of a water-containing oxide gel under supercritical conditions by extracting the water with an extraction agent such as CO.sub.2 at a pressure above the critical pressure of the extraction agent.

Abstract: A method of converting fine particle size alkaline earth metal carbonate, e.g., barium or strontium carbonate, into a free-flowing granular form with relatively high bulk density, without sintering, grinding, or briquetting, is disclosed. It involves the following steps:(a) forming a suspension of the carbonate in water with enough deflocculating agent, e.g., sodium polyacrylate or sodium hexametaphosphate, to substantially completely deflocculate the carbonate;(b) drying the resultant suspension at a temperature that is elevated, but without heating the carbonate to its sintering point, for example by spray drying in a spray drier operating at an inlet temperature in the range of about 400.degree. to 600.degree. C., to obtain a granular material primarily passing 10 mesh and held on a 150 mesh screen (Tyler); and(c) heating the granular material to about 600.degree. to 700.degree. C., which causes it to shrink, thereby increasing its bulk density by at least about 5%, preferably at least 10 or 20 percent.

Abstract: A glass manufacturing process using a granular, free-flowing form of alkaline earth metal carbonate, e.g., barium or strontium carbonate, is disclosed. The alkaline earth metal carbonate has a relatively high bulk density and is made without sintering, grinding, or briquetting. The carbonate is prepared from a fine particle size material by the following steps:(a) forming a suspension of the carbonate in water with enough deflocculating agent, e.g., sodium polyacrylate or sodium hexametaphosphate, to substantially completely deflocculate the carbonate;(b) drying the resulting suspension, at a temperature that is elevated, but without heating the carbonate to its sintering point, for example, by spray drying in a spray drier operating at an inlet temperature in the range of about 400.degree. to 600.degree. C., to obtain a granular material primarily passing 10 mesh and held on a 150 mesh screen (Tyler); and(c) heating the granular material to about 600.degree. to 700.degree. C.

Abstract: A process for preparing compound metal oxides, a superconductive compound oxides for instance, is disclosed. The process comprises preparing an aqueous solution containing a predetermined content ratio of chloride, nitrate or acetate of a rare earth metal, an alkaline earth metal and copper, slightly basifying the solution to form hydroxides of the rare earth metal and copper and then introducing carbon dioxide to form carbonate of the alkaline earth metal, collecting the thus formed mixed precipitate of hydroxides and carbonate and firing it.

Abstract: A process for producing barium titanates which comprises admixing a titanium alkoxide with a barium salt of a lower carboxylic acid in the presence of an organic solvent containing at least ethylene glycol monomethyl ether to provide a uniform mixture, bringing the mixture in contact with water to form a gelated product and drying and calcining the gelated product.

Abstract: A method for producing a magnesia powder for use as an electrical insulating material. A magnesia clinker powder is washed with an aqueous solution of an acid. The acid radical content of the powder is subsequently reduced to 0.015% by weight or less by washing the powder with water or by subjecting the powder to a heat treatment.

Abstract: A process for the preparation of copper oxide superconductors which comprises (1) mixing and grinding yttrium nitrate hydrate, copper nitride, and an oxidizing agent such as barium peroxide in a suitable solvent; (2) forming a paste thereof; (3) applying the paste to a substrate; (4) heating the substrate with the paste thereon; and (5) therafter cooling. The process yields copper oxide superconducting compounds in a purity of at least 80 percent.

Abstract: A process for the preparation of copper oxide superconductors which comprises (1) mixing copper nitride, an oxidizing agent such as barium peroxide, and yttrium oxide; (2) forming pellets of the aforementioned mixture; (3) heating the pellets; and (4) thereafter cooling the pellets. The process yields copper oxide superconducting compounds in a purity of from about 60 to over 95 percent.

Abstract: An improved process for the manufacture of a metal oxide is disclosed. In the process wherein a hydrolyzable organometallic compound is hydrolyzed by an alkaline hydrolyzing agent in an alkaline organic solvent, and thereafter, the metal oxide is formed by a condensation reaction of a metal hydroxide resulting from the hydrolysis of the organometallic compound, the improvement comprises feeding the organometallic compound and the hydrolyzing agent into the organic solvent so that a concentration of the hydrolyzed compound is initially above a critical level of supersaturation, and thereafter, is maintained in a range from above an upper limit of solubility to the critical level of super-saturation. According to the above process, the metal oxide can be obtained in the form of a powder material with a uniform particle size distribution.

Abstract: A class of melt-produced, high temperature suerpconductors and processes of making same are provided. The superconductor has a preferred composition of R-Ba-Cu-O wherein R is chosen from the group of rare earth metals excluding: Praseodyium; Cerium; and Terbium. The process is carried out at a relatively low temperature of about 950.degree. C., and the process allows fabrication of melt-produced high temperature superconductors of arbitrary shape. The process is based on the reaction between molten barium-copper oxides and solid rare earth oxides, rare earth barium oxides, rare earth copper oxides, or rare earth barium-copper oxides. In an embodiment, the method comprises the steps of: mixing and grinding BaCO.sub.3 and CuO with other nominal compositions; pressing the resultant mixture into a pellet, if necessary; placing the pellet or powder on a pellet or powder that can include rare earth copper oxides; heating the pellet and/or powders to a temperature of approximately 950.degree. C.

Abstract: A process for the manufacture of substantially spherical particles of at least one metal compound of Group II of the Periodic Table, comprising dissolving such compound in a solvent therefor to form a solution and introducing the solution into a non-solvent medium; said non-solvent medium consisting essentially of at least two liquids that are non-solvents for said compound, at least one of said non-solvents being immiscible with the solvent solution and at least one of said non-solvents being miscible with said solvent solution.

Abstract: In synthetic, substantially spherical crystal aggregates of xonotlite having a particle size of more than 20 microns, and preferably up to 150 microns, up to 30% of the silicon atoms can be replaced by titanium or zirconium atoms, and inert particles can be incorporated in the crystal aggregates.

Abstract: A method of preparing a superconducting oxide by combining the metallic elements of the oxide to form an alloy, followed by oxidation of the alloy to form the oxide. Superconducting oxide-metal composites are prepared in which a noble metal phase intimately mixed with the oxide phase results in improved mechanical properties. The superconducting oxides and oxide-metal composites are provided in a variety of useful forms.

Abstract: A method of growing large, up to 1 mm size single crystals of superconducting YBa.sub.2 Cu.sub.3 O.sub.x, wherein x equals from 6.5 to 7.2.

Abstract: A strontium or barium carbonate product that is better suited for use as a glass ingredient is obtained by sintering the powdered carbonate in a kiln lined with fused amorphous silica. The carbonate picks up fewer harmful contaminants from the amorphous silica lining than it does from, say, a refractory silica-alumina brick lining or a kiln having a metallic inner surface.

Abstract: High purity magnesium oxide fine particles are produced by introducing a flow of a magnesium vapor-containing gas and a flow of an inert gas separately into a mixing region to provide a flow of a mixture gas; by introducing the flow of the mixture gas into an oxidizing region while a flow of a molecular oxygen-containing gas is introduced into the oxidizing region concurrently with the flow of the mixture gas; to provide a flow of a reaction mixture in which the magnesium vapor is oxidized, by introducing the flow of the reaction mixture containing the resultant magnesium oxide fine particles into a collecting region; and, by collecting the magnesium oxide particles from the reaction mixture by, for example, a filter located in the collecting region.

Abstract: A process for the preparation of at least one porous oxide or hydroxide body comprises:(i) adding at least one body comprising a sol of the oxide or hydroxide to a fluid freezing medium; and(ii) raising the temperature of the solid, quenched sol so that solvent nucleation occurs, resulting in the formation of crystals of the dispersion medium, and the dispersion medium melts thereby leaving one or more porous oxide or hydroxide bodies.

Abstract: Water soluble precursors of ceramic compounds are emulsified in an organic fluid containing an organic surfactant. The emulsion is subsequently mildly heated at a pressure of about 0.05 atmospheres to remove the free water from the emulsion droplets. The resulting sludge consists of particles deriving from the dehydrated emulsion droplets. These particles may only be bound by the surfactant, all or most of the original organic fluid having been boiling off under low pressure. This sludge is then heated in a standard air atmosphere to char the surfactant, which char is to maintain the separation between the dried droplet-derived particles to prevent forming sintered or fused agglomerates thereof. With continued heating the transient char is subsequently burned off and the particles are calcined to controllably and simply produce a fine ceramic powder of spherical particles having a narrow size distribution and an average size in the particularly useful range of 0.1 micron to 1.0 micron.

Abstract: The present invention disclosed a magnesia clinker excellent in corrosion resistance, which is useful for a magnesia carbon refractory and also for a refractory for steel manufacturing furnace, and the magnesia clinker is characterized by:(a) having a purity of MgO of 97 wt. % or higher;(b) containing 2.0 wt. % or less of CaO;(c) containing 0.01 wt. % or more of B.sub.2 O.sub.3 ;(d) containing 0.3 wt. % or less of SiO.sub.2 ;(e) containing impurities other than MgO, CaO, B.sub.2 O.sub.3 and SiO.sub.2 of 2 wt. % or less;(f) having a bulk density of 3.35 (g/cc) or higher and an apparent porosity of 3.0 (vol. %) or less; and(g) having a mean crystal size of magnesia of 100 .mu.m or larger.

Abstract: Very small and uniform metal oxide particles are produced by a process including the steps of ejecting a metal vapor-containing gas into a metal-oxidizing region through a nozzle and ejecting a molecular oxygen-containing gas into the metal-oxidizing region through another nozzle in such a manner that the streams of the metal vapor-containing gas and the molecular oxygen-containing gas are smashed into each other to produce a turbulent flow diffusing flame in which the metal vapor is oxidized into very small and uniform metal oxide particles.

Abstract: A process for producing ultra-fine ceramic particles with the particle size of less than 1000 .ANG., which comprises the steps of forming powdered dust cloud of metal powder such as Si constituting a portion of aimed ceramic particles in a reaction gas containing the other portion of said aimed ceramic particles, igniting said powdered dust cloud to cause explosive burning and synthesizing said aimed ceramic particles and gathering said resulting ceramic particles. By the process, ceramic particles such as Al.sub.2 O.sub.3, MgO, SiO.sub.2, TiO.sub.2, TiN having particle size of 10-100 nm can be produced.

Abstract: Magnesium hydroxide of a substantially spherical particle form having an average particle size of from 5 to 500 .mu.m and a specific surface area of from 25 to 1 m.sup.2 /g.

Abstract: Magnesium hydroxide of a fine plate-like particle form having an average particle size (d) of from 0.2 to 0.8 .mu.m as measured by a light transmission type liquid phase sedimentation method, wherein the proportion of particles having a particle size of d+0.5 .mu.m or larger is not higher than 50% by weight based on the weight of the total particles, and the particle thickness distribution is such that the proportion of particles having a thickness of 0.05 .mu.m or less is not higher than 5% by number and the proportion of particles having a thickness of 0.2 .mu.m or more is not higher than 20% by number.

Abstract: A process for producing highly pure magnesium hydroxide, which comprises reacting magnesium hydroxide starting material containing impurities, with an aqueous solution containing a water-soluble calcium salt and carbon dioxide to form an aqueous solution containing a magnesium salt and calcium carbonate precipitates whereby said impurities are transferred to the precipitates, filtering off the precipitates, then reacting the aqueous solution containing the magnesium salt, with ammonia to form a slurry comprising magnesium hydroxide solid and an aqueous solution containing an ammonium salt, and filtering the slurry to obtain highly pure magnesium hydroxide solid and an aqueous solution containing the ammonium salt.

Abstract: A process for producing a low-sulfur content hot reducing gas stream comprising (a) contacting a sulfur bearing hot reducing gas stream with a desulfurizing agent comprising a desulfurizing fixed bed of solid particles comprising calcium oxide to thereby produce a low-sulfur content hot reducing gas stream and a calcium sulfide composition, then (b) contacting said calcium sulfide composition with an oxidizing gas composed of CO.sub.2, H.sub.2 O and O.sub.

Abstract: A magnesia-calcia clinker having a high density, said clinker containing MgO, CaO and Fe.sub.2 O.sub.3 as oxides, having the following chemical composition in percent by weightMgO, CaO and Fe.sub.2 O.sub.3 : at least 99% in totalMgO: at least 10%Fe.sub.2 O.sub.3 : 0.2-5%and having a density corresponding to at least 97.5% of the theoretical density. The above magnesia-calcia clinker can be produced by adding a water-soluble iron compound to sea water, bittern or brine, simultaneously with, or after, the addition of the water-soluble iron compound, adding a calcined product of dolomite, lime or a hydrate thereof to form a precipitate composed mainly of magnesium hydroxide, mixing the resulting magnesium hydroxide with a calcium compound, and dead-burning the resulting mixture.

Abstract: A process for the preparation of finely divided acicular hexagonal ferrites which have a high coercive force and are of the general formula MFe.sub.12 O.sub.19, where M is barium or strontium, and their use for the production of magnetic recording media and plastoferrites.

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: A method for making ultra-fine ceramic particles, in which metal powder constituting a portion of the ultra-fine ceramic particles intended for production is injected at a rate of not less than 70 grams per minute into a plasma jet so that the metal powder is vaporized. The vaporized metal powder is then mixed with a reactive gas, which includes an element consituting the other portion of the ultra-fine ceramic particles, filled in the surrounding area of the plasma jet, and thereby the vaporized metal powder and the reactive gas produce a synthetic reaction. The ultra-fine ceramic particles are produced continuously because of the reaction flame.

Abstract: Materials of oxygen ion conductors comprising CeO.sub.2 -CaO type oxides wherein 5-60 mol % of CaO is mixed with CeO.sub.2 having a fluorite structure, and composite oxides wherein CeO.sub.2 of said CeO.sub.2 -CaO type oxides is replaced by oxide of magnesium or aluminum by 5-10 mol %.

Abstract: Refractory oxide crystals having high-quantum efficiency and high thermal stability for use as broadly tunable laser host materials. The crystals are formed by removing hydrogen from a single crystal of the oxide material to a level below about 10.sup.12 protons per cm.sup.3 and subsequently thermochemically reducing the oxygen content of the crystal to form sufficient oxygen anion vacancies so that short-lived F.sup.+ luminescence is produced when the crystal is optically excited.

Abstract: A method of manufacturing fine powder of BaZrO.sub.3 is described, in which a zirconium compound is first hydrolyzed. The hydrolyzed zirconium compound is then reacted with a water-soluble barium compound in a strongly alkaline solution having a pH not lower than 13.6.

Abstract: This invention provides a process for production of a microcrystalline metal oxide having an average particle size less than about 1000 angstroms.An important feature of the invention process involves the application of ultrasonic wave energy during the stage that a solution of metalorganic compounds is being treated to form a gelled solution. The ultrasonic energy input during the gelling stage enhances the production of a high purity metal oxide powder having fine grain particles of uniform microspheric dimensions.

Abstract: High density magnesia clinker characterized by having a chemical composition, as oxides in weight %, ofMgO: 97.5% or moreCaO: 0.8-2.0%SiO.sub.2 : 0.12-1.0%Fe.sub.2 O.sub.3 : 0.3% or lessAl.sub.2 O.sub.3 : 0.15% or lessB.sub.2 O.sub.3 : 0.03% or lesswith a bulk density of at least 3.48 g/cm.sup.3. The said high density magnesia clinker can be produced by forming magnesium oxide by calcination of naturally occurring magnesite having a composition, based on ignition in weight %,MgO: 97.5% or moreCaO: 0.8-2.0%SiO.sub.2 : traces to 0.15%Fe.sub.2 O.sub.3 : 0.3% or lessAl.sub.2 O.sub.3 : 0.15% or lessB.sub.2 O.sub.3 : 0.1% or less,grinding the same after, or with, addition of amorphous silica, silica gel or a silicon compound capable of forming SiO.sub.2 by dead-burning in such a manner as to have the SiO.sub.2 content of 0.12-1.0% after dead-burning and dead-burning.

Abstract: The present invention relates to a method for the production of refractory oxide powders by pyrolyzing with laser energy a metal- and oxygen-containing organic chemical species characterized by the following properties: (a) some or all of the organic fragments (ligands) are bound to the metal by one or more metal-oxygen bonds, (b) the chemical species is able to absorb laser energy, preferably from a CO.sub.2 laser, in a vibrational mode, (c) the chemical species can be obtained in a gas state, at a temperature below the decomposition temperature.

Abstract: A high density magnesia fine powder having an improved sintering property is produced in such a manner that magnesium is vaporized at 700.degree. C. or more in a magnesium-vaporizing refractory tube while an inert gas flows through the magnesium-vaporizing tube; the flow of the vaporized magnesium-containing inert gas is introduced into a magnesium-oxidizing tube; a molecular oxygen-containing gas is introduced into the magnesium-oxidizing tube in a concurrent relationship to the flow of the vaporized magnesium-containing inert gas to provide a reaction mixture, while the temperature of the magnesium-oxidizing region is adjusted to 800.degree. C. to 1600.degree. C. and the partial pressures of the vaporized magnesium and oxygen in the magnesium-oxidizing region are regulated to 0.

Abstract: Molten alkaline earth metal halides are used to convert highly stable oxides into the corresponding anhydrous halides. Usually a third reactant, such as silica, is added in order to bind the basic oxide thus formed. The solid oxide compounds (e.g. silicates) which result are wellknown ceramic phases of a high degree of purity.