Abstract: Aqueous phosphoric acid, e.g., a slurry of the acid produced by the "wet" process, is contacted with steam under organic volatile-removing conditions to remove volatile organic material. A "wet process" aspect of the process involves contacting crude phosphoric acid produced by the wet process at a temperature, preferably not greater than 100.degree. C., while binding bindable solid impurities present and controlling the density of the acid to avoid deleterously affecting the processing character of the acid. In a first facet of this aspect, humic-extracting extractants are employed to remove humics, and in a second facet, heavy metal-extracting extractants are employed to recover heavy metals, from the acid.

Abstract: Ammonium imidodisulfate and ammonium sulfamate may be converted to sulfur dioxide and ammonia by heating them with a reducing agent or a catalyst in a bath of molten ammonium sulfate and ammonium bisulfate. The reducing agent is sulfur or a sulfur compound and the catalyst is selected from Mo, W, Cu, Fe, Co, Cr, Mn and Ni.

Abstract: An ammonia production process comprising synthesis gas generation and ammonia synthesis with heat recovery in the generation section by steam raising and steam superheating and heat recovery in the synthesis section by steam raising or boiler feed water heating is made more controllable by effecting part of the superheating in the synthesis section, so that a shut-down of the synthesis section results not only in a decrease in steam flow through the superheaters, but also in a decrease in the temperature of the steam fed to them. Thus overheating of the superheaters, a defect of some earlier processes, is avoided. The process is operated with a synthesis pressure under 150, preferably 40-80 bar abs. and preferably synthesis gas generation is based on primary hydrocarbon steam reforming at such a pressure that synthesis gas compression is by under 50%.

Abstract: The invention provides stabilized pulverulent red phosphorus comprising a homogeneous blend of red phosphorus particles with a size of at most about 2 mm, aluminum hydroxide and a further metal hydroxide as oxidation stabilizers, wherein the metal hydroxide is lead hydroxide. The homogeneous blend contains aluminum hydroxide and lead hydroxide in a total proportion of about 0.1 to 6 weight %, based on the quantity of red phosphorus, the aluminum hydroxide and lead hydroxide, calculated as Al.sub.2 O.sub.3 to PbO, being used in a quantitative ratio of about 0.5 to 2.0.

Abstract: Wet process phosphoric acid prepared by treating phosphate rock with sulfuric acid is purified by extracting said wet process phosphoric acid with an organic solvent containing an equilibrium concentration of phosphoric acid in a first extraction section such that substantial extraction of phosphoric acid from said wet process phosphoric acid is prevented while the organic impurities in said wet process phosphoric acid are substantially extracted and under conditions which prohibit significant extraction of iron impurities into said solvent extractant, extracting the extracted wet process phosphoric acid of reduced organic impurity content with an organic solvent in a second extraction section, returning a portion of the solvent from the second extraction section to the solvent extraction phase of the first section, removing the organic impurities from the solvent phase which is obtained from the first extraction section, and returning at least a portion of the solvent from which the organic impurities have b

Abstract: The process comprises passing a hydrocarbon stream under reforming conditions through each of the reactors of the unit; when the catalyst in all of the reactors in the unit except the lead reactor has become deactivated to such an extent that the catalyst in all of the reactors other than the lead reactor must be regenerated, discontinuing the flow of the hydrocarbon stream through all of the reactors in said unit other than the lead reactor while continuing to pass the hydrocarbon stream through the lead reactor; regenerating the beds of catalyst in each of the reactors of said unit other than the lead reactor to remove the carbonaceous deposits from the catalyst in such beds and to restore at least partially the activity of the catalyst while continuing to pass the hydrocarbon stream through the lead reactor under reforming conditions; resuming the flow of the hydrocarbon stream through all of the reactors in the unit; and repeating all of the aforesaid steps until the catalyst in the lead reactor has becom

Abstract: The direct reaction of elemental phosphorus acid catalyzed by hydroiodic acid produces orthophosphorus acid free of orthophosphoric acid and phosphine free of diphosphine.

Abstract: A method for producing a pure phosphoric acid from a phosphoric acid obtained through a wet process, in a high purity comparable to that from the dry process phosphoric acid, in a simpler manner, at a cheaper cost and more effectively, is provided, which method resides, in one main aspect, in concentrating a phosphoric acid obtained through the wet process, up to a P.sub.2 O.sub.

Abstract: A process for treating water vapor generated in concentrating an aqueous urea solution wherein a urea synthesis effluent containing urea, unreacted ammonium carbamate and water from a urea synthesis zone is subjected to a plurality of decomposition stages, the pressures of which stages are stepwise reduced to decompose and separate substantially all of the unreacted ammonium carbamate from the aqueous urea solution. The aqueous urea solution which still contains small amounts of ammonia and carbon dioxide is concentrated to obtain crystalline urea or molten urea substantially free of water. The water vapor generated in concentrating said aqueous urea solution which contains small amounts of ammonia and carbon dioxide is cooled for condensation thereby forming a dilute aqueous ammonium carbamate solution which is subjected to rectification under a gauge pressure below 25 kg/cm.sup.

Abstract: Alcoholic phosphoric acid solutions are produced from acid phosphates or phosphate mixtures in the presence of water and a strong mineral acid by extraction with water. To this end, an aqueous phosphate solution or suspension is contacted countercurrently and thereby mixed with a mixture of at least one alcohol having from 3 to 8 carbon atoms and a strong mineral acid, the alcohol or alcohol mixture and the phosphate solution or suspension being used in a ratio by volume of 2:1 to 20:1, and the mineral acid being used in the quantity just necessary to transform the phosphates approximately quantitatively to phosphoric acid. The alcohol or alcohol mixture, mineral acid and phosphate solution or suspension contain the quantity of water necessary to ensure the formation of a mixture consisting of an alcoholic phase and a separate flowable salt phase, which is separated from the alcoholic phase.

Abstract: A more efficient and economical phosphorus furnace process with much improved and safer working conditions is described. The process is carried out without an electrostatic precipitator, while ensuring that the furnace exit gases are at consistently low temperatures, and at a slight positive pressure in the duct from the furnace to the precipitator and that partial condensation of phosphorus prior to the condensers takes place substantially dry.

Abstract: Sulfur and sulfur compounds contained in a gas are oxidized in contact with a catalyst comprising vanadium oxide, iron oxide and alumina, said catalyst having a surface higher than 30 m.sup.2 /g and being obtained by impregnation of aluminum with soluble vanadium and iron compounds.

Abstract: This is a continuous process for producing ammonia synthesis gas and includes the partial oxidation of particles of solid carboniferous fuels entrained in nitrogen. In the process, air is separated into high pressure nitrogen and substantially pure oxygen. A first stream of said nitrogen is used as a safe pneumatic vehicle in a grinding and transport operation which introduces ground, finely divided solid carbonaceous fuel into a venturi injector where the particles of solid fuel are dispersed in a second stream of said nitrogen. The solid fuel-nitrogen gaseous dispersion is then reacted with a free-oxygen containing gas preferably in the absence of supplemental H.sub.2 O, other than any moisture normally found in the reactants, in a freeflow partial oxidation synthesis gas generator. The nitrogen stream serves as a carrier for the particles of solid carbonaceous fuel and as a temperature moderator in the gas generator. After cleaning, shifting, and purifying the raw synthesis gas, a gaseous mixture of N.sub.

Abstract: Calcium hypochlorite compositions useful as bleaching agents and disinfectants are produced by the reaction of solid granular hydrated lime and a solid granular alkali metal hydroxide with chlorine gas. The process takes place in the absence of a solvent and produces dry, free-blowing Ca(OCl).sub.2 compositions.

Abstract: Contaminated phosphoric acid, particularly wet-processed phosphoric acid, is purified by extracting it from its aqueous solution by means of an organic solvent, which is immiscible or partially miscible with water and in which phosphoric acid is soluble, separating the phosphoric acid being dissolved in the organic solvent from extraction residue, and recovering the phosphoric acid from the organic solution.The aqueous phosphoric acid is more particularly mixed in a reaction zone, in a ratio by volume within the range 1:0.3 to 1:30, with a solvent having a boiling point higher than that of water or higher than that of the resulting water solvent-azeotrope, the phosphoric acid/solvent-mixture is heated to temperatures between the boiling point of water or of the said azeotrope and that of the solvent until distillation of substantially all uncombined water originally present in the mixture, and residue and resulting anhydrous phosphoric acid solution in the organic solvent are separated.

Abstract: A process is disclosed for recovering recoverable chlorine from chemical plant waste streams.An aqueous stream containing recoverable chlorine is reacted with an alkali metal hydroxide, such as sodium hydroxide, to form a slurry of solid particles of alkaline earth metal hydroxide, such as calcium hydroxide, suspended in a liquid. The calcium hydroxide is filtered or otherwise separated from the liquid. The liquid is admixed with an organic alcohol to form an organic-aqueous solution. A halogenating agent, such as chlorine, is reacted with the organic-aqueous solution to form a solution of organic hypochlorite in an organic phase and an aqueous phase.The solution of organic hypochlorite is phase separated to form aqueous and organic phases. The aqueous phase containing sodium chloride may be recycled for use as a reactant in a chlor-alkali electrolytic cell.

Abstract: Substantially fluoride-free phosphoric acid is produced by the acidulation of phosphate rock with sulfuric acid wherein the acidulation reaction is conducted in the presence of added potassium as K.sub.2 O bearing compounds, e.g. KHSO.sub.4, K.sub.2 SO.sub.4, KH.sub.2 PO.sub.4 or KOH, and additional silica, to precipitate fluorides and silica as potassium silicofluoride and then removed on separation of the gypsum formed. Optionally, additional silica may be added to the phosphoric acid solution recovered after precipitation and removal of the gypsum, to precipitate additional fluoride as potassium silicofluoride to further purify the phosphoric acid. In a further embodiment sufficient potassium may be added along with additional silica in the acidulation step to produce potassium dihydrogen phosphate and phosphoric acid as additional products.

Abstract: This invention relates to a process for preparing hydrophobic silicon dioxide which comprises treating silicon dioxide having a surface area of at least 50 m.sup.2 /g with an organosilicon compound containing from 2 to 4 silicon atoms per molecule, in which at least 2 hydrocarbon radicals are bonded to each silicon atom, and any silicon valences which are not satisfied by hydrocarbon radicals are satisfied by siloxane oxygen atoms and at least one tin compound containing Sn-bonded halogen and/or organic radicals.

Abstract: A method for handling the problem of crud formation in the solvent extraction of wet-process phosphoric acid is described. Crud is the name ordinarily given to the thick interfacial layer of semi-floatable material which tends to form and accumulate, and which interferes with many of the extraction processes and, in particular, with the solvent extraction of wet-process phosphoric acid. The method described provides for the operation of the solvent extraction stages in a manner that allows the formation and temporary accumulation of crud in those stages whereupon the solvent and the crud are then removed from the extraction stages and treated in a series of operations which include a clarification step, an acid removal step, a water wash step and a caustic treatment step, which steps effectively separate the solvent from the crud, and remove the crud components from the system and regenerate otherwise unusable solvent.

Abstract: Impure "wet process" phosphoric acid is purified by solvent extraction in an improved process which uses a solvent composition which comprises an aliphatic nitrile.