Abstract: An aqueous zinc nitrite solution contains as impurities 10 ppm or less of sodium (Na) and 100 ppm or less of sulfate ions (SO4) when the aqueous solution has a concentration of zinc nitrite [Zn(NO2)2] of 10% by weight in terms of NO2. Also, disclosed is a method for preparing an aqueous zinc nitrite solution, including a first step of reacting zinc sulfate with calcium nitrite to form an aqueous zinc nitrite solution and a second step of purifying the aqueous zinc nitrite solution.

Abstract: A method of resisting corrosion in concrete containing metal elements is provided. It includes introducing into fresh concrete, containing metal elements, at least one compound capable of sequestering chloride ions. The method may also involve employing a compound which is capable of establishing a corrosion resistant oxide layer on the metal reinforcing elements. The invention also includes certain compounds which may be employed in the method as well as concrete structures containing the compounds. In another embodiment of the invention, concrete structures may be rehabilitated by providing an overlay containing a compound of the type which will contribute to corrosion resistance either through chloride ion sequestering or creating barriers around metal structural elements with the overlay being provided in situ or as a preformed member and with possible use of a slurry in combination with an overlay segment.

Abstract: A method of resisting corrosion in concrete containing metal elements is provided. It includes introducing into fresh concrete, containing metal elements, at least one compound capable of sequestering chloride ions. The method may also involve employing a compound which is capable of establishing a corrosion resistant oxide layer on the metal reinforcing elements. The invention also includes certain compounds which may be employed in the method as well as concrete structures containing the compounds.

Abstract: The invention relates to mixed phase materials for the preparation of catalytic membranes which exhibit ionic and electronic conduction and which exhibit improved mechanical strength compared to single phase ionic and electronic conducting materials. The mixed phase materials are useful for forming gas impermeable membranes either as dense ceramic membranes or as dense thin films coated onto porous substrates. The membranes and materials of this invention are useful in catalytic membrane reactors in a variety of applications including synthesis gas production. One or more crystalline second phases are present in the mixed phase material at a level sufficient to enhance the mechanical strength of the mixture to provide membranes for practical application in CMRs.

Abstract: Methods to at least partially reduce a niobium oxide are described wherein the process includes heat treating the niobium oxide in the presence of a getter material and in an atmosphere which permits the transfer of oxygen atoms from the niobium oxide to the getter material, and for a sufficient time and at a sufficient temperature to form an oxygen reduced niobium oxide. Niobium oxides and/or suboxides are also described as well as capacitors containing anodes made from the niobium oxides and suboxides.

Abstract: An electron-emitting material contains a first metal component selected from Ba, Sr and Ca and a second metal component selected from Ta, Zr, Nb, Ti and Hf and also contains oxynitride perovskite. The electron-emitting material has improved electron emission characteristics, restrained evaporation at elevated temperatures, and minimized consumption by ion sputtering. The electron-emitting material is prepared by firing a metal component-containing raw material disposed in proximity to carbon in a nitrogen gas-containing atmosphere to thereby create oxynitride perovskite.

Abstract: Nitride or oxidenitride based red to yellow pigments, such as tantalum(V) nitride and oxidenitrides containing tantalum may be produced by passing ammonia over nitridable metal compounds, in particular oxide compounds, at 700 to 1250° C. According to the invention, nitriding proceeds in a rotary tube or fluidised bed reactor in the presence of an oxide from the series SiO2, ZrO2, GeO2, SnO2, TiO2 and HfO2 under conditions under which this oxide is substantially not nitrided.

Abstract: An aqueous zinc nitrite solution contains as impurities 10 ppm or less of sodium (Na) and 100 ppm or less of sulfate ions (SO4) when the aqueous solution has a concentration of zinc nitrite [Zn(NO2)2] of 10% by weight in terms of NO2. Also, disclosed is a method for preparing an aqueous zinc nitrite solution, including a first step of reacting zinc sulfate with calcium nitrite to form an aqueous zinc nitrite solution and a second step of purifying the aqueous zinc nitrite solution.

Abstract: The present invention provides a process for recovering a metal nitrite, e.g., sodium nitrite, from a reaction mixture formed from an aromatic displacement reaction such as the synthesis of an aromatic bis(ether phthalimide) in an organic non-polar solvent. The process comprises forming a reaction mixture from the synthesis of an aromatic bis(ether phthalimide) comprising a recoverable amount of metal nitrite; treating the reaction mixture with an amount of water effective to produce an aqueous solution phase of metal nitrite and an organic non-polar phase; and separating the aqueous solution phase of metal nitrite from the organic non-polar phase.

Abstract: A hydrogenation catalyst is prepared by reduction of platinum in an oxidation state of not less than two using a reducing agent in an aqueous medium in the presence of a carbon-containing support after partial poisoning, where use is made of a compound of the general formula I ##STR1## where X, Y and Z can be identical or different and are hydrogen, C.sub.1 -C.sub.18 -alkyl, C.sub.5 -C.sub.10 -cycloalkyl, halogen, hydroxyl, C.sub.1 -C.sub.6 -alkoxy and --NR'R", where R, R' and R" can be identical or different and can be hydrogen, C.sub.1 -C.sub.18 -alkyl or C.sub.5 -C.sub.10 -cycloalkyl. Such a hydrogenation catalyst can be used for preparing hydroxylammonium salts and the process for preparing the above catalysts can also be used for regenerating hydrogenation catalysts based on platinum.

Abstract: The present invention provides a process for abating emissions from a manufacturing stream comprising the steps of:(a) from the manufacturing stream, feeding the emissions comprising NO.sub.x to a scrubbing reactor;(b) to the emissions in the scrubbing reactor, adding alkali solution and NO.sub.2 in an amount sufficient so that a substantial amount of the NO.sub.x forms ammonium nitrite or ammonium nitrate while maintaining the pH of the formed ammonium nitrite solution at greater than about 7.5 and vent gas comprising mist exits from the scrubbing reactor;(c) maintaining the temperature of the vent gas at less than about 40.degree. C.; and(d) removing the mist from the vent gas.

Abstract: The invention relates to a method of preparing dinitramidic acid HN(NO.sub.2).sub.2 and salts thereof having the formula M.sup.+n (.sup.- N(NO.sub.2).sub.2).sub.n, wherein M is a metal cation or a nitrogen-containing cation and n=1-3. The dinitramide salt can be used as oxidiser in solid propellants. Dinitramidic acid is prepared by nitration of a compound selected from a group consisting of NH.sub.2 NO.sub.2, NH.sub.4 NH.sub.2 CO.sub.2 ; NH.sub.2 SO.sub.3 H, NH(SO.sub.3 H).sub.2, N(SO.sub.3 H).sub.3, and its salts with metal cations or organic cations, e.g. NH(SO.sub.3 NH.sub.4).sub.2, and other products formed when ammonia is reacted with sulphuric trioxide, with a common nitrating acid such as nitric acid/sulphuric acid or nitric acid/acetic anhydride. The invention also relates to a method of preparing dinitramide salt, comprising neutralisation of dinitramidic acid with a neutralising agent, e.g. ammonia, and recovery of the dinitramide salt from a mixture of salts formed in the neutralisation.

Abstract: This invention comprises a method and apparatus for obtaining from air an oxygen enriched gas mixture containing at least 40 mole % nitrogen. The apparatus comprises a gas turbine, an oxygen separation unit which is in fluid communication with the turbine air compressor and means for maintaining a proper mass balance tolerance between the turbine compressor/unit and the turbine energy production unit.This invention comprises a method and apparatus for recovering large quantities of an oxygen enriched gas from the volume of a compressed air stream produced by a gas turbine by compensation of the mass loss to the energy production unit section thereof by providing means for maintaining the turbine in proper mass and thermal balance as the turbine is utilized to provide the duty/power requirements of a process which utilizes the oxygen enriched gas stream as a reactant.

Abstract: The thermal stability of an N,N-dinitramide salt of the formula M.sup.+ ?N(NO.sub.2).sub.2 !.sup.- where M.sup.+ is a nitrogen-containing cation, is improved by mixing with the N,N-dinitramide salt a compound of the formula ##STR1## where R, R' and R" are the same or different and are aryl or alkyl. A new composition of matter is formed by mixing the N,N-dinitramide salt and the prophosphatrane compound.

Abstract: Colored pigments are provided from the green-yellow to red spectrum based on oxide-nitrides with two or three different cations Q, R and S in the crystal lattice, wherein the nitrogen to oxygen atomic ratio is determinative for the color. These pigments crystallise in the pyrochlore, spinel or elpasolite structure. Pigments in the perovskite are as provided with increased color brilliance. The color of the pigments can be adjusted in a wide range of the color spectrum during their preparation within a substance class with the cations Q, R and S and while retaining the crystal structure, by increasing or lowering the atomic ratio N to O in the oxide-nitride and bringing about the required charge balancing by replacing an equivalent quantity of the cation Q with the valency q by a cation R with the valency q+1.

Abstract: Gamma-aluminum oxynitride ground powders, white in color and well suited for conversion into optically transparent ceramic shaped articles, 100% of the particles of which being less than 10 .mu.m in size and exhibiting a transmittance of at least 8%, are prepared by grinding particulate gamma-aluminum oxynitride agglomerates having a porosity of greater than 75%, such agglomerates themselves being produced by interreacting dry powdery admixture of aluminum nitride, alpha-alumina, and an alumina of high specific surface area or precursor thereof.

Abstract: A synthetic method for ammonium dinitramide comprising a process for the formation of urea nitrate by reacting urea with diluted nitric acid; a process for the formation of nitrourea by reacting the urea nitrate with sulfuric acid; a process of reacting the nitrourea with a nitration reagent such as nitronium tetrafluoroborate, and then adding ammonia gas to the reaction mixture; and a process of filtering off the resultant by-product of crystals, concentrating its filtrate, adding ethyl acetate to this concentrated filtrate, filtering off the precipitate, concentrating again its filtrate under vacuum, and finally separating ADN as crystals by adding chloroform to the concentrated filtrate.Effects:ADN can be synthesized with the following features: urea as starting material is readily available and is cheaper in price, the process is uncomplicated and more simplified, the operation is safe, and the final product gives a high yield.

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: There is provided a method for the preparation of tetramethylammonium aluminosilicate from tetramethylammonium hydroxide, a solid source of silica and a hydrolyzable aluminum compound. Tetramethylammonium aluminosilicate prepared by the above method is useful for the synthesis of M41S.

Abstract: A process of use of hydrogenation catalyst, obtainable by carrying out essentially the following steps:(a) treatment of a platinum metal salt with finely divided sulfur followed by(b) reduction of the platinum metal salt to metallic platinum metal.

Abstract: Bimetallic oxynitrides and nitrides which have catalytic properties comprise two transition metals selected from Groups IIIB to VIII of the Periodic Table of the Elements. Preferably, one metal is either molybdenum or tungsten. The other can be tungsten or molybdenum, respectively, or another transition metal, such as vanadium, niobium, chromium, manganese, cobalt, or nickel. They have a face centered cubic (fcc) arrangement of the metal atoms and have a surface area of no less than about 40 m.sup.2 /gm.

Abstract: Oxonitrides with a perovskite of the general formula LnTaON.sub.2, where Ln is a rare-earth element, and which exhibit an enhanced brightness, are produced by annealing a powder mixture consisting of a Ta (V) compound and a Ln compound in a reducing atmosphere that contains ammonia. Added to the powder mixture being annealed is a mineralizing agent from the series of alkali metal or alkaline earth halides, Na.sub.3 AlF.sub.6, Na.sub.2 SiF.sub.6, AlF.sub.3 or of the ammonia salts of carbonic acid or a mono- or dicarboxylic acid with 1 to 4 C atoms in a quantity of 0.1 to 10 parts by weight, relative to 1 part by weight of the mixture of the Ta and Ln compounds. Such oxonitrides can be used as pigments that are yellow-orange to reddish brown in color.

Abstract: A method is disclosed for forming an ionically bonded dinitramide salt or acid useful as a stable oxidizer for solid fuel rocket propellant or explosive formulations is disclosed. The dinitramide salt is formed by the reaction of an N(alkoxycarbonyl)N-nitroamide and a nitronium-containing compound, at a temperature of from about +60.degree. C. to about -120.degree. C., followed by contacting the reaction mass with a base to form the dinitramide salt, or an alcohol to form the corresponding dinitramidic acid. The N(alkoxycarbonyl)N-nitroamide may be formed by first mixing the corresponding alkylcarbamate with an anhydride of one or more 1-20 carbon organic acids, then adding nitric acid to the reaction mixture. If the salt of the N(alkoxycarbonyl)N-nitroamide is to be formed, a base is then added until the pH reaches about 7-10. The nitronium-containing reactant may be a covalently bonded compound containing a NO.sub.2 -- group; a nitryl halide; or a nitronium salt having the formula (NO.sub.2.sup.+).sub.q X.

Abstract: Disclosed is a basic aluminum material having enhanced antiperspirant activity, the material having the empirical formula Al.sub.2 (OH).sub.6-a X.sub.a, where 0.5.ltoreq.a.ltoreq.5.0, and X is a univalent complex oxoanion of nitrogen, chlorine and other halogens, which forms salts with Al.sup.3+ in aqueous solution so that these salts are essentially completely dissociated, which is readily soluble in water with metallic ions in the solution, and which forms conjugate acids that are strong acids; and wherein the material is characterized by:(a) size exclusion high performance liquid chromatography peaks corresponding to peak 3 and peak 4 of size exclusion chromatograms formed by HPLC technique;(b) a peak 4 relative area of at least 25%, a peak 3 relative area of less than 60%, the sum of the relative peak 3 and peak 4 areas being at least 50%; and(c) less than 10% chromatographic peaks eluting at shorter retention times than peak 3, corresponding to peaks 1 and 2.

Abstract: A method for forming an ionically bonded ammonium dinitramide salt having the formula NH.sub.4.sup.30 N(NO.sub.2).sub.2 - useful as a stable oxidizer for solid fuel rocket propellant or explosive formulations is disclosed. The ammonium dinitramide salt is formed by the reaction of ammonia and a nitronium-containing compound, such as a nitronium salt or a covalently bonded compound containing a NO.sub.2 - group, at a temperature of from about - 20.degree. C. to about 120.degree. C. The nitronium-containing compound may be either a covalently bonded compound containing a NO.sub.2 - group or a nitronium salt having the formula (NO.sub.2.sup.+).sub.n X.sup.-n, where X is the anion of the nitronium salt and n= 1-2.

Abstract: A N,N-dinitramide salt is disclosed having the formula MN(NO.sub.2).sub.2 where M is a cation selected from the class consisting of a metal ion and a nitrogen-containing ion. The dinitramide salt exhibits high temperature stability, high energy density, and an absence of smoke generating halogens, rendering it useful as an oxidizer in rocket fuels. The dinitramide salts are meltable and pumpable oxidizers which may be used in start-stop rocket engines instead of other less stable oxidizers.

Abstract: This invention comprises a method and apparatus for obtaining from air an oxygen enriched gas mixture containing at least 40 mole % nitrogen. The apparatus comprises a gas turbine, an oxygen separation unit which is in fluid communication with the turbine air compressor and means for maintaining a proper mass balance tolerance between the turbine compressor/unit and the turbine energy production unit.This invention comprises a method and apparatus for recovering large quantities of an oxygen enriched gas from the volume of a compressed air stream produced by a gas turbine by compensation of the mass loss to the energy production unit section thereof by providing means for maintaining the turbine in proper mass and thermal balance as the turbine is utilized to provide the duty/power requirements of a process which utilizes the oxygen enriched gas stream as a reactant.

Abstract: A method is disclosed for forming a N,N-dinitramide salt having the formula MN(NO.sub.2).sub.2 where M is a cation selected form the class consisting of a metal ion and a nitrogen-containing ion, which comprises contacting a carbamate with a nitrating agent to form an acidic dinitramide intermediate reaction product, and neutralizing the acidic dinitramide with a compound selected from the class consisting of ammonia (NH.sub.3), hydrazine (N.sub.2 H.sub.4), a primary amine having the formula RNH.sub.2, a secondary amine having the formula RR'NH, and a salt having the formula AX; where R and R' are the same or different 1-6 carbon alkyls, A is a metal ion or a nitrogen-containing ion, and X is an anion selected from the class consisting of fluoride, chloride, hydroxyl, carbonate, alkoxide, and carboxyl anion, to form the corresponding dinitramide salt.

Abstract: Aluminum oxynitride is prepared by the pyrolysis of an organosiloxydihaloalane such as trimethylsiloxydichloroalane in the presence of a nitrogen-containing atmosphere. The organosiloxydihaloalane may conveniently be prepared by reacting together an aluminum halide and at least one disiloxane.

Abstract: A method of producing a .beta.-sialon fine powder which comprises using a silane compound represented by the general formula of SiH.sub.x Cl.sub.4-x (0.ltoreq.x.ltoreq.4) as a Si source, aluminum chloride as an Al source and an ether represented by the general formula of ROR' (R,R'=C.sub.y H.sub.2y+1, 1.ltoreq.y.ltoreq.5) as an oxygen source respectively, dissolving them in an organic solvent capable of dissolving them to obtain a solution, introducing ammonia gas into the solution to produce a precipitates, and burning the precipitates in a nonoxidative atmosphere. In the .beta.-sialon fine powder obtained by the method of the invention, respective elements of Si, Al, O and N are uniformly distributed in a chemical viewpoint. A high density high strength sintered body can be produced even at a relatively low temperature by using the .beta.-sialon fine powder.

Abstract: The present invention relates to new conductive perovskites containing oxygen and nitrogen, their preparation and their use particularly as electrode material.The conductive perovskites containing oxygen and nitrogen according to the invention correspond to the general formula IAB(O,N).sub.3 (I)in the cationic lattice of which:A denotes a metal chosen from the metals of groups IA and IIA, yttrium and the lanthanides,B denotes a metal chosen from the transition metals of groups IVA to IB,on the express condition that at least one of the metals A and B is present in an oxidation state other than its normal maximum oxidation state.

Abstract: A process for complete removal of nitrites and nitrates from an aqueous solution (1) by means of electrolysis, wherein the aqueous solution (1) is fed to the cathode space (4) of an electrolysis cell (2) and an aqueous solution (10), still containing only non-participating residual salts, is discharged from the anode space (6), whereas the gas (7) formed at the cathode is fed to a catalyst bed (8). In the latter, the gases H.sub.2, NH.sub.3, NO and N.sub.2 O collected in the cathode space (4) are converted to the non-toxic substances N.sub.2 and H.sub.2 O. In addition, partial combustion of H.sub.2 by O.sub.2 from the anode space (6) for maintaining the temperature of the catalyst bed (8).

Abstract: Nitrogen oxide is removed from flue gases of combustion plants or reaction gases by a process wherein the nitrogen oxide contained in the stream of gas is converted into a stochiometric composition of N.sub.2 O.sub.3 and removed from the gas stream.

Abstract: This invention relates to a method for catalyzing the reactionsQZ+H.sub.2 X.fwdarw.QZX (1) psandQZX.fwdarw.QZ+H.sub.2 X (2)wherein Q=C or N;Z=O or S;X=O, S, NH or NR;R=C.sub.1 to C.sub.8 alkyl which may be linear, branched or cyclized,which comprises:contacting at least one polydentate nitrogen-containing chelating agent complexed with a metal atom with the reactants of one of said reactions, wherein said contacting takes place in the presence of a means for oxidizing when reaction (1) is catalyzed and in the presence of a means for reducing when reaction (2) is catalyzed.

Abstract: The present invention relates to new nitrogen or oxynitrogen compounds of perovskite structure, corresponding to the general formula I:ABO.sub.3-n N.sub.n (I)in which:the cationic lattice consists of:a metal cation A chosen from the group comprising: Li.sup.+, Na.sup.+, K.sup.+, Rb.sup.+, Cs.sup.+, Ag.sup.+, Tl.sup.+, Ca.sup.2+, Ba.sup.2+, Sr.sup.2+, Pb.sup.2+, Cd.sup.2+, Ln.sup.3+, Bi.sup.3+, Y.sup.3+, Th.sup.4+, U.sup.4+, trans-U.sup.4+ ; anda metal cation B chosen from the group comprising: W.sup.6+, Re.sup.6+, Mo.sup.6+, Ta.sup.5+, Nb.sup.5+, Mo.sup.5+, W.sup.5+, Ti.sup.4+, Zr.sup.4+, Sn.sup.4+, Ge.sup.4+, Nb.sup.4+, Ta.sup.4+, Al.sup.3+, Ga.sup.3+, In.sup.3+, Tl.sup.3+, Fe.sup.3+, Cr.sup.3+ ;n=1, 2, or 3, andthe cationic charges a of the metal A and b of the metal B satisfy the equations:a+b=6+na.gtoreq.n,and the solid solutions of these compounds.

Abstract: An article of manufacture is provided comprising a polycrystalline cubic aluminum oxynitride having a density of at least 98% of theoretical density, and being transparent to electromagnetic radiation in the wavelength range from 0.3 to 5 micrometers with an in-line transmission of at least 20% in this range.A method of preparing the optically transparent aluminum oxynitride is also provided comprising the steps of forming a green body of substantially homogeneous aluminum oxynitride powder and pressureless sintering said green body in a nitrogen atmosphere and in the presence of predetermined additives which enhance the sintering process. Preferred additives are boron and yttrium in elemental or compound form.

Abstract: A method of preparing substantially homogeneous aluminum oxynitride powder is provided comprising the steps of reacting gamma aluminum oxide with carbon in the presence of nitrogen, and breaking down the resulting powder into particles in a predetermined size range. A method of preparing a durable optically transparent body from this powder is also provided comprising the steps of forming a green body of substantially homogeneous cubic aluminum oxynitride powder and sintering said green body in a nitrogen atmosphere and in the presence of predetermined additives which enhance the sintering process. Preferred additives are boron, in elemental or compound form, and at least one additional element selected from the group of yttrium and lanthanum or compounds thereof. The sintered polycrystalline cubic aluminum oxynitride has a density greater than 99% of theoretical density, an in-line transmission of at least 50% in the 0.3-5 micron range, and a resolving angle of 1 mrad or less.

Abstract: An aluminum oxynitride refractory of a sufficiently high nitrogen content is produced efficiently and inexpensively by a method which comprises mixing alumina of Bayer Process with aluminum dross and electrically fusing the resultant mixture in an electric furnace.

Abstract: The present invention relates to a process for stabilizing a mixture of molten alkali metal nitrates and alkali metal nitrites usable particularly as a heat transfer fluid and to the stabilized mixture thus obtained.The process comprises adding to the mixture a quantity of alkali metal hydroxide such that the value of the logarithm of the ratio P(H.sub.2 O)/.vertline.OH.sup.- .vertline..sup.2 (where P(H.sub.2 O) denotes the partial pressure of water vapor expressed in atmospheres and .vertline.OH.sup.- .vertline. the hydroxide ion concentration expressed in moles/kg) is between a value b corresponding to the disproportionation of the nitrites into nitrate and nitric oxide and a value a corresponding to the appearance of peroxides, the values a and b being determined for a given nitrate/nitrite ratio, a given temperature and given partial pressures of the gases blanketing the mixture.

Abstract: New compositions of matter which are halogenated derivatives of borates are disclosed which are catalytically active in the polymerization of halogenated phosphazene trimers and other oligomers are disclosed.

Abstract: An article of manufacture is provided comprising a polycrystalline cubic aluminum oxynitride having a density of at least 98% of theoretical density, and being transparent to electromagnetic radiation in the wavelength range from 0.3 to 5 micrometers with an in-line transmission of at least 20% in this range.A method of preparing the optically transparent aluminum oxynitride is also provided comprising the steps of forming a green body of substantially homogeneous aluminum oxynitride powder and pressureless sintering said green body in a nitrogen atmosphere and in the presence of predetermined additives which enhance the sintering process. Preferred additives are boron and yttrium in elemental or compound form.

Abstract: A method of preparing substantially homogeneous aluminum oxynitride powder is provided comprising the steps of reacting gamma aluminum oxide with carbon in the presence of nitrogen, and breaking down the resulting powder into particles in a predetermined size range.A method of preparing a durable optically transparent body from this powder is also provided comprising the steps of forming a green body of substantially homogeneous cubic aluminum oxynitride powder and sintering said green body in a nitrogen atmosphere and in the presence of predetermined additives which enhance the sintering process. Preferred additives are boron, in elemental or compound form, and at least one additional element selected from the group of yttrium and lanthanum or compounds thereof. The sintered polycrystalline cubic aluminum oxynitride has a density greater than 99% of theoretical density, an in-line transmission of at least 50% in the 0.3-5 micron range, and a resolving angle of 1 mrad or less.

Abstract: A pigment for a color-changing heat indicator comprising a product obtained by interaction of an aqueous solution containing ions of copper and mercury with an aqueous solution of a nitrogen-containing organic compound: an amide of carbonic acid, an amide of thiocarbonic acid, a tertiary amine to give a reaction mixture which is reacted with an aqueous solution containing ions of iodine at an atomic ratio of copper:mercury:iodine equal to 2:1.5:3-5 and an amount of the nitrogen-containing organic compound equal to 0.8-8% of the total content of copper and mercury; the pigment has its critical temperature of from 38.degree. to 70.degree. C. and a heat-resistance of from 160.degree. to 180.degree. C.

Abstract: Gas containing nitrogen oxides is treated in two separate stages. In the first stage, the nitrogen oxides in the gas are reacted with sulfurous acid. The gaseous product of this reaction is reacted with an alkaline solution, typically caustic alkali. As a result of these treatments, the nitrogen oxides are converted into neutral salts.

Abstract: A detergent composition containing an anionic surface active agent and/or a nonionic surface active agent, characterized by containing as a builder 5 to 50% by weight of a salt of imido-bis-sulfuric acid, 0.05 to 30% by weight of a salt of a saturated or unsaturated fatty acid or a mixture thereof and 0.1 to 15% by weight of a salt of a polycarboxylic acid or a mixture thereof.

Abstract: Disclosed herein is a process for preparing aqueous solutions of calcium nitrite by forming a solution of sodium nitrite and calcium nitrate; cooling the solution to precipitate sodium nitrate; admixing calcium hydroxide with the residual aqueous phase and forming a double salt of calcium nitrite/calcium hydroxide; and decomposing the double salt in the presence of water to form a solution of calcium nitrite and insolubilize calcium hydroxide.

Abstract: Calcium nitrate with low nitrate content is prepared by reacting in a series of absorption reactors lime slurry and nitrogen oxide gases. The lime slurry flows serially through the series of absorption reactors with a major portion being recycled to the inlet of a Venturi absorber in each reactor. Nitrogen oxide gases flow cocurrently with the slurry from each reactor to the following Venturi inlet and are contacted by recycle slurry in each Venturi with a molar ratio of calcium hydroxide to nitrogen oxides of at least about 20. Slurry from the last reactor with a calcium nitrite content of below about 22 weight percent and a calcium hydroxide content of at least about 2 weight percent may be freed of unreacted calcium hydroxide, for example by treatment with NO.sub.x gases, and then concentrated to the desired product concentration. The exit gases may be scrubbed with incoming lime slurry after passing through a holdup vessel which increases the ratio of NO.sub.2 to NO.

Abstract: An improved process for nitrite production is based on controlled oxidation of nitric oxide in a mixture of nitrogen oxides and oxygen. Oxidized gas is absorbed into an aqueous solution containing a basically reacting ammonium or alkali metal compound to produce nitrite and unabsorbed exit gas. The mole ratio of nitric oxide (NO) to nitrogen dioxide (NO.sub.2) in the unabsorbed exit gas is maintained within a range between 0.8 and 1.2 by either recycling a selected fraction of oxidized gas through the oxidizer or by selectively splitting the inlet stream to the oxidizer. Increased product yield as well as reduced NO.sub.x emissions are achieved as a result.

Abstract: An aqueous solution of calcium nitrite having high purity and high concentration is obtained by contacting a nitrogen oxides containing gas with an aqueous slurry of calcium hydroxide.It is necessary to use the aqueous slurry having high calcium hydroxide content such as 20 to 40 wt. %, whereby it is necessary to feed the gas having high nitrogen oxides concentration such as 5 to 12 vol. % to give high conversion to calcium nitrite. In order to prevent a formation of a by-product of calcium nitrate, a nitrogen oxides containing gas having 5 to 12 vol. % of a nitrogen oxides concentration and 1.5 to 2.5 of a molar ratio of NO/NO.sub.2 is fed under a high pressure enough to prevent a condensation of said slurry as a first stage and then, the unabsorbed gas is oxidized and the resulting gas having 1 to 5 vol. % of a nitrogen oxides concentration and 1.6 to 2.5 of molar ratio of NO/NO.sub.2 is fed to the aqueous slurry having 2 to 12 wt.

Abstract: The trialkali metal salts of nitrilotriacetate are well known detergent builders. However, when hypochlorite bleach is added to the wash water it can oxidize the soluble uncomplexed nitrilotriacetate with the resultant loss of the beneficial effects of the use of such salts as a builder. Now, a method has been developed of protecting the desirable builder properties of the trialkali metal nitrilotriacetate in an aqueous solution containing active chlorine which comprises adding to the nitrilotriacetate a sufficient amount of trialkali metal imidodisulfate to protect at least some of the nitrilotriacetate from damage by the chlorine.