Abstract: Vapor mixtures containing ammonia, acid gases and water are contacted with aqueous ammonium phosphate solution to separate the ammonia from the acid gases and to permit recovery of the acid gases. This treatment may be performed on vapor mixtures obtained by steam stripping liquids containing ammonia and acid gases.

Abstract: A method and apparatus for stripping ammonia from an alkaline regenerant solution used for the regeneration of a zeolite ion exchange bed. The regenerant passes through a stripping column. An acidic working solution is circulated from a holding tank through a vacuum creating means and then back into the holding tank. The ammonia is stripped from the regenerant under a vacuum created in the stripping column by the vacuum creating means so as to cause the stripped ammonia to chemically react with working solution to form an ammonium salt solution. Carbon dioxide free air is passed upward through the column countercurrent to the flow of regenerant.

Abstract: A method for removing nitrogen monoxide effectively from a nitrogen monoxide-containing gas which comprises contacting a nitrogen monoxide-containing gas with an aqueous solution containing a ferrous ion complex formed from a ferrous ion and an organic compound of 2 to 24 carbon atoms having in the molecule at least one atomic group selected from mercapto, amino, imino and nitrilo groups. When a sulfite or sulfide is present in the above aqueous solution, the nitrogen monoxide-absorbing capacity of the aqueous solution can be enhanced and nitrogen monoxide absorbed in the aqueous solution is reduced to non-toxic nitrogen. According to this method, nitrogen monoxide can be removed effectively, even if the gas to be treated contains an oxidizing substance such as oxygen.

Abstract: A process for producing urea from CO.sub.2 and NH.sub.3 in which the CO.sub.2 and NH.sub.3 are reacted in a reactor, the reaction product is passed into a first stage decomposer maintained at the same pressure as the reactor, the reaction product is contacted in the first stage decomposer with NH.sub.3 to form a urea solution substantially free of CO.sub.2, said urea solution substantially free of CO.sub.2 is passed from the first stage decomposer to a second stage decomposer also maintained at the same pressure as the reactor and is contacted in said second stage decomposer with a stream of inert gas and an aqueous solution of substantially pure urea is withdrawn from the second reactor.

Abstract: Carbide addition agents comprising (a) from about 20 to about 60 atomic percent of carbon, (b) from about 25 to about 60 atomic percent of at least one metal selected from the group consisting of vanadium and columbium, and (c) from about 10 to about 40 atomic percent of at least one metal selected from the group consisting of iron and manganese, are useful alloy addition agents for steel.

Abstract: The reduction of nitrogen oxides is effected by passing stack offgases containing nitrogen oxides over a heavy metal sulfide catalyst in an atmosphere where ammonia is present.

Abstract: Pure phosphoric acid is prepared from crude wet process phosphoric acid which contains pentavalent vanadium compounds by first extracting the crude acid with an alcohol of limited water solubility and then washing the extracted phosphoric acid solution with aqueous phosphoric acid, in the presence of an agent for reducing the pentavalent vanadium compounds.

Abstract: Triazanium perchlorate monohydrate is disclosed as a new composition of matter, together with a method of snythesizing such salts by amination of hydrazines by hydroxylamine-O-methylsulfonate.

Abstract: Our invention relates to an improved process for the partial purification of wet-process phosphoric acid with co-production of impure phosphoric acid or solid fertilizer materials containing most of the impurities originally present in the crude acid. The crude acid is treated with methanol and ammonia to precipitate most of the metallic and fluorine impurities as solid ammonium metallic phosphates and fluorine compounds that filter and settle rapidly. The solids are separated from the reaction mixture and methanol is distilled from the resulting clarified solution to form concentrated partially purified acid. The solid ammonium metallic phosphates are fertilizer materials. Alternately, the reaction slurry is separated into a clarified liquid fraction and a settled slurry fraction. Methanol is distilled from the settled fraction which causes most of the impurities to redissolve yielding an impure phosphoric acid.

Abstract: Desensitized free-flowing red phosphorus. The phosphorus is comprised of a homogeneous blend consisting of between about 80 and 98 weight% of red phosphorus having a particle size of up to about 2 mm, and of between about 2 and 20 weight% of an organic or organo-silicon compound desensitizer. The desensitizer is liquid, inactive with respect to red phosphorus and has a minor vapor pressure at room temperature at atmospheric pressure.

Abstract: The anti-scaling effect of additives added to control the formation of scale during the washing of calcium sulphate anhydrite or hemihydrate crystals is increased when the additives are added as soon as possible after the wash liquors leave the crystals. The invention is of especial use in the washing of calcium sulphate hemihydrate produced during the production of phosphoric acid and is carried out by adding the additives via the central valve of the rotating pan filter on which the hemihydrate crystals are washed.

Abstract: A method for purifying phosphoric acid obtained with sulfuric acid acting on natural phosphates, comprises extracting the phosphoric acid with a mixed solvent formed essentially by 95% to 50% by volume of an ether containing 5 to 7 carbon atoms, and by 5% to 50% by volume of at least one of the esters resulting from the reaction of the phosphoric acid with alcohols having 3 to 5 carbon atoms.

Abstract: The process involves stripping ammonium nitrogens and organic materials, as gases, which are present in process waste waters to be discharged from plants wherein gases for use in ammonia synthesis are manufactured by reforming hydrocarbons with steam, decomposing the organic materials selectively in the presence of a catalyst at a temperature of about 120.degree. to 400.degree. C., mixing the remaining gases with the flue gases from said plants so as to provide a gaseous mixture having ammonia therein in an amount of about 0.3 to 10 moles per mole of nitrogen oxides present in the flue gases, reacting the gaseous mixture over a catalyst at a temperature of about 150.degree. to 700.degree. C. and oxidizing the unreacted ammonia, if any, in the presence of a catalyst at a temperature of about 150.degree. to 700.degree. C. to render the nocuous substances innocuous.

Abstract: A purification system for producing extremely pure H.sub.2 from H.sub.2 gas streams containing water and small amounts of O.sub.2 comprises a single column with alternating layers of adsorbent and a catalyst for the reaction 2H.sub.2 + O.sub.2 .fwdarw. 2H.sub.2 O. The alternating layers are arranged so that the gas to be purified first meets an adsorbent layer, next a catalyst layer and finally an adsorbent layer. Two such columns can be operated alternatively, one being used to produce purified gas, while the other is backflushed with as little as 2% of the product gas of the operating column. By this technique, H.sub.2 gas can be produced having a purity as high as 99.9999% or higher. The inventive system can also be used to purify O.sub.2 gas streams containing water and small amounts of hydrogen.

Abstract: A method of making a single crystal intermetallic compound semiconductor which includes growing a single crystal in a crucible while maintaining the extent of the melt beyond the growing surface of its single crystal substantially constant during growth.

Abstract: A process for the production of carbon fibers from coal-tar pitch or from other strongly aromatic distillation residues wherein an oxygen-containing polymer is added to the starting material before or during the heat treatment which is followed by the usual stages of spinning, oxidizing and carbonizing.

Abstract: A process for carrying out a catalytic high pressure synthesis using gaseous reactants in the presence of a fused iron oxide catalyst, which comprises passing the gas through one or more layers of a catalyst which consists predominantly or entirely of particles of which the length of one spatial dimension is several times the length of at least one of the two other spatial dimensions perpendicular thereto, and at least one of the smaller spatial dimensions is less than 5 mm long, the catalyst being so arranged in one or more cylindrical catalyst beds, arranged in series in the direction of flow of the gas, that the particles are orientated with their longest spatial dimension substantially parallel to the direction of flow of he gas and a catalyst bed for carrying out the process.

Abstract: A working solution comprising anthraquinone and its derivatives, used for the production of hydrogen peroxide on becoming degraded by formation of non-effective anthraquinone is generated by an auto-oxidation process employing anthraquinone, which comprises:Contacting, at a temperature of below 130.degree.C., and in the presence of a catalyst comprising a metal selected from a platinum group and supported on a carrier, said degraded working solution, which comprises non-effective anthraquinone and tetrahydroanthraquinone with an olefinic compound whose hydrogenation product is gaseous at said contact temperature andSubsequently, contacting the thus treated working solution, at a temperature above 130.degree.C., and in the presence of a catalyst comprising a metal selected from the platinum group and supported on a carrier, with an olefinic compound whose hydrogenation product is gaseous at said contact temperature,Said method being characterized by the fact that at a temperature below 130.degree.C.

Abstract: A method of manufacturing silicon carbide crystals in which a core of silicon dioxide is embedded in a mass of granular silicon carbide, or materials which form silicon carbide on heating this mass being heated to a temperature at which silicon dioxide volatilizes, i.e. above about 1500.degree.C, and the silicon carbide coheres. This leaves a cavity, formerly occupied by the silicon dioxide which is surrounded by silicon carbide. Heating is then continued at a temperature, above about 2500.degree.C, at which silicon carbide crystals are formed on the walls of the cavity.

Abstract: The effectiveness of gas scrubbing process for the removal of sulfur dioxide from a sulfur-dioxide-containing gas is improved by employing an integrated scrubbing process.