Abstract: Process for the production of solid ammonium polyphosphate in which ammonium phosphate melt is prepared in a pipe reactor and is solidified by controlled cooling to form crystals of a size and in quantity suitable to yield a hard, nontacky, and friable solid. Wet-process phosphoric acid is ammoniated in a pipe reactor to an NH.sub.3 :H.sub.3 PO.sub.4 mole ratio of about 1.0, and the resulting melt is agitated and simultaneously partially cooled by application of recycled pulverized product or air or a water jacket. The partially cooled melt is then solidified continuously into nontacky sheets on a water-cooled metal surface using warm water to slowly remove sensible heat and heat of crystallization. Up to about 55 percent or higher of the P.sub.2 O.sub.5 in the product may be polyphosphate. Without controlled cooling, a supersaturated solution or a microcrystalline texture results and the product is rather like a gel.

Abstract: A mixture of disodium and monosodium orthophosphate in a 2:1 mole ratio is prepared by sequentially reacting phosphoric acid with monohydrate process soda ash and caustic soda in a semi-solid reaction medium.Milled monohydrate process soda ash is contacted in less than stoichiometric proportions with phosphoric acid and the resultant orthophosphate containing reaction mixture is brought to a sodium to phosphorus mole ratio of about 1.67:1 by subsequent reaction with caustic soda. The final reaction product of mixed disodium and monosodium orthophosphate is suitable feedstock for conversion to sodium tripolyphosphate.

Abstract: Crystalline urea phosphate is pyrolyzed in one stage to give molten urea ammonium polyphosphates that contains up to 95 percent of the phosphate as polyphosphate. These are then processed into high-analysis solid or liquid fertilizers. Addition of urea to the process to maintain a urea:biuret ratio of at least 16 prevents precipitation of biuret in the liquid fertilizers.

Abstract: A process for preparing detergent grade sodium tripolyphosphate from wet process phosphoric acid comprising neutralizing said acid to a pH at which the Na:P ratio is about 5:3, contacting the resultant mixture of mono- and disodium orthophosphates with an oxidizing agent selected from the group consisting of ozone, hydrogen peroxide and mixtures thereof, in amounts sufficient to oxidize color causing impurities, and drying and heating said orthophosphates to effect the change to sodium tripolyphosphate.

Abstract: A method for manufacturing potassium polyphosphate from ammonium bisulfate, sulfuric acid, phosphate rock and water, wherein the phosphate rock decomposition is passed through a gypsum filter, muriated potash and/or potassium sulfate is added to the basic filtrate, potassium fluosilicate is filtered off to market or alternate process, muriated potash is again added and the combination heated to the polymerization point to drive off (vaporize) ammonium chloride, muriatic acid and water, whereby potassium polyphosphate is produced. Concentrated sulfuric acid is added to the vapor phase and the product is scrubbed with the ammonium bisulfate and sulfuric acid being returned to process input.

Abstract: Aluminum polyphosphate is made. To this end, solid aluminum hydroxide and polyphosphoric acid which are used in proportions corresponding to an Al:P molar ratio of 1:2.5 to 1:3.5, are introduced separately from, but concurrently with, one another into a reaction zone kept at 150.degree. to 200.degree. C. A moist friable consistency of the starting materials is maintained in the reaction zone by continuously mixing, kneading and comminuting them over substantially the entire period during which they are introduced into the reaction zone. The reaction is continued until a dry sandy powder is formed; and the powder is annealed at 400.degree. to 600.degree. C. over a period sufficient to yield a product undergoing a 0.5 to 1% weight loss on ignition.

Abstract: The purity grade of sodium tripolyphosphate obtained by neutralization with sodium hydroxide of aqueous phosphoric acid obtained by the wet method, removal of the precipitate formed, evaporation to dryness of the resulting solution and calcination of the evaporation residue, is improved by carrying out the neutralization at a temperature not exceeding 85.degree. C., maturing the neutralization product at 70.degree.-85.degree. C. for at least one hour before separating the precipitate, concentrating the sodium phosphate solution, if necessary, to a sodium phosphate content of at least 40 wt.%, and heat treating the solution at 100.degree.-200.degree. C. and at boiling point or under to precipitate the magnesium compounds, prior to the evaporation step.

Abstract: Potassium polyphosphate polymers having ratios of P.sub.2 O.sub.5 to K.sub.2 O which make them suitable as fertilizer products are prepared by reacting potassium fluosilicate also known as potassium silicofluoride with phosphoric acid and sulfuric acid at temperatures of about 250-500.degree. C.

Abstract: Finely divided sodium tripolyphosphate (STPP) particles are sprayed with water in an amount from about 36% to about 130% in excess of the amount stoichiometrically required for formation of sodium tripolyphosphate hexahydrate to form an agglomerated product which is then calcined to a temperature within the range of from about 320.degree. C to about 550.degree. C to produce a granular sodium tripolyphosphate product of low bulk density and low frangibility.

Abstract: A process for thermally treating fine-grained solids with high-oxygen gases at temperatures at which the solids can form molten and gaseous reaction products comprises carrying out the thermal treatment at least in part in a cyclone chamber. The solids, high-oxygen gases and, if desired, an energy carrier (usually a carbon-containing solid, liquid or gas) are mixed to form a suspension at a temperature below the reaction temperature. The suspension is fed to a vertical combustion path (tube) and reacts therein to form another suspension of primarily molten particles which is admitted to the cyclone chamber. Reactants are added to the gas phase within a core-flow region of the cyclone chamber and/or immediately after the discharge of gas therefrom to a cooling chamber.

Abstract: Ammonium polyphosphate is manufactured on a continuous basis by reacting gaseous ammonia and aqueous phosphoric acid at elevated temperatures in a one or multiple stage falling film reaction zone in the presence of a diluting gas if desired, using wet phosphoric acid, preferably containing 28-32%, by weight P.sub.2 O.sub.5 and an excess of ammonia. The phosphoric acid and the gaseous ammonia are preferably carried in counterflow and the temperature in the falling film reaction zone is adjusted using heat transfer fluids to within the range of 120.degree. - 260.degree. C.

Abstract: Wet-process phosphoric acid is partially purified by extraction with an organic solvent followed by scrubbing with a portion of the aqueous phosphoric acid from a water-stripping unit, then water-stripping and base-stripping. At the water-stripping stage, all the remaining impurities and approximately two-thirds of the P.sub.2 O.sub.5 are transferred from the organic to the aqueous phase, which renders the other one-third P.sub.2 O.sub.5, subsequently recovered by base-stripping, essentially free of impurities. The bulk of the aqueous phosphoric acid from the water-stripping is purified further by precipitating the impurities with an alkali metal hydroxide or carbonate. The precipitate is filtered off and the filtrate used for base-stripping. The resulting aqueous solution from base-stripping is adjusted to a desired alkali metal-to-phosphate ratio and used for manufacture of high purity alkali metal phosphate in general and particularly sodium tripolyphosphate.

Abstract: Ammonium polyphosphates are prepared by a process which comprises heating melamine orthophosphate prepared from impure wet-process phosphoric acid in a stream of gaseous ammonia at a temperature between 150.degree. C and 210.degree. C to produce a mixture of melamine and relatively pure short-chain ammonium polyphosphates. The solid product is extracted with water to remove the ammonium polyphosphates and free the insoluble, crystalline melamine for recycle. Thus, the only starting materials consumed in the process are phosphoric acid and ammonia.

Abstract: A process for the production of hydrogen fluoride, phosphoric anhydride, calcium polyphosphates and nitric acid, is disclosed, characterized in that natural phosphate is heated by a plasma stream of working gas in the presence of water vapors to form hydrogen fluoride which is recovered as a commercial product. Then the thus defluorinated phosphate is further heated by an air plasma stream having a bulk temperature of at least 3,500.degree. K. and containing nitrogen oxides. Under such conditions, the defluorinated phosphate decomposes to form phosphoric anhydride and calcium oxide.The gas stream carrying the phosphoric anhydride, the calcium oxide and the nitrogen oxides is cooled down to yield, as commercial products, either phosphoric anhydride and nitric acid, or calcium polyphosphates containing up to 70% P.sub.2 O.sub.5 and nitric acid, or else all of the three products, depending on the cooling conditions.

Abstract: Disclosed is a granulated fertilizer composition comprising mineral phosphates calcined with alkali and between about 0.5 and 15% by weight of tetrapotassium pyrophosphate as an adjuvant. Also disclosed is a process for preparing the subject compositions.

Abstract: A process for the joint production of titanium dioxide and sodium tripolyphosphate from ores of titanium and phosphorus, and from sulphuric acid, in which the titanium dioxide is produced by the "sulphate process" and the impure dilute aqueous solution of sulphuric acid resulting therefrom is concentrated and used in the initial attack of phosphatic ones to provide a solution containing vanadium and chromium which can be removed without requiring any preventive conversion. The resulting sodium phosphate is then converted to sodium tripolyphosphate in a known way.

Abstract: A process for the manufacture of alkali metal polyphosphates having a predetermined crystalline form, in which a mixture of alkali metal orthophosphates having a molar ratio of alkali metal oxide to phosphoric anhydride between 1 and 2 is first granulated, the resulting granules are dried and then are subjected to thermal treatment in the presence of aqueous vapor.

Abstract: Stable sludge-free ammonium polyphosphate fertilizer solution is prepared by introducing ammonia and a blend of impure wet process phosphoric acid having a P.sub.2 O.sub.5 content of 58 to 68% and solvent extracted wet process phosphoric acid of reduced Fe.sub.2 O.sub.3, Al.sub.2 O.sub.3, MgO and free H.sub.2 O content into a reactor wherein the mixed reactants are retained for at least about 0.10 second after which the reaction product is immediately quenched and the resulting solution aged to effect precipitation and nucleation of suspended insoluble metallic phosphates and insoluble organic matter, and filtered.

Abstract: The present invention relates to a method for producing an alkali metal pyrophosphate useful, for example, as a plant food. Broadly, the method comprises reacting an alkali metal nitrate and aqueous phosphoric acid in the presence of catalytic amount of a metal oxide at a temperature of at least about 700.degree.C to produce a substantially pure alkali metal pyrophosphate and gaseous reaction products.

Abstract: A continuous process for preparing crystalline, water-insoluble ammonium polyphosphates of controlled pH utilizing a continuous reaction arena, is disclosed.

Abstract: A method for manufacturing bromine-polyphosphate and bromine-iodine-polyphosphate complex compounds having detergent and disinfecting properties is described.These compounds disinfectant a wide range of application as efficient disinfectants and disinfectants detergents in such fields as medicine, veterinary medicine, agriculture, dairy and meat industries.

Abstract: Modified ammonium polyphosphates which are water-soluble and contain at least one radical selected from the group consisting of borate, sulphate, sulphite, and phosphite produced by admixing component (i) an organic ammoniating and condensing agent, component (ii) a phosphoric acid, the molar proportion of said component (i) to said component (ii) based on the P.sub.2 O.sub.5 content in said component (ii), being from 1.3:1 to 3:1, and component (iii) a compound selected from sulphuric acid, boric acid, boric oxide, phosphorous acid, sulphurous acid and the sodium potassium, calcium, urea and ammonium salts of said compound, the proportion of said component (iii) being from 2 to 1/10 moles per mole of P.sub.2 O.sub.5 in the admixture; and heating until a self-sustaining exothermic reaction occurs whereby said three components react and form said water-soluble modified ammonium polyphosphates. The process of preparing said polyphosphates is also claimed.

Abstract: Finely divided sodium tripolyphosphate (STPP) particles are sprayed with a solution of sodium orthophosphate to prepare an agglomerated feed material which is then calcined at 300.degree. to 600.degree.C to produce granular STPP of medium range bulk density.

Abstract: Ammonium phosphate solutions free of precipitates are prepared from wet-process phosphoric acid containing incidental metallic impurities such as iron, aluminum and magnesium by concentration of the phosphoric acid to an anhydrous state and the formation of acyclic polyphosphoric acids therein which prevent the precipitation of the metallic impurities upon neutralization. The acid is heated to a temperature greater than 120.degree. C. at atmospheric or subatmospheric pressures while removing the volatile impurities and thereafter is neutralized with ammonia. The neutralization step can be performed at elevated temperatures with anhydrous ammonia or the acid can be cooled and neutralized at ambient temperatures. The resulting ammonium phosphate is diluted with water to obtain an ammonium phosphate solution which is clear and free of precipitates.

Abstract: A batch process is disclosed for the production of relatively pure urea ammonium polyphosphate liquid fertilizers from crystalline urea phosphate made from wet-process acid and urea. Initially, crystalline urea phosphate is fed to a tank where it is combined with previously produced liquid product; the latter is added to provide fluidity for agitation. The mixture is then ammoniated batchwise in one stage to pyrolyze the urea phosphate to condense orthophosphate to polyphosphate and form molten urea-ammonium polyphosphates. Pyrolysis takes place at relatively low temperatures of 220.degree. F. to 300.degree. F. and heat from ammoniation of the urea phosphate crystals provides all the heat to effect the condensation. The molten pyrolyzate which contains mixtures of urea, ammonium orthophosphate, and ammonium polyphosphate is dissolved in an ammonia-water mixture to yield high-analysis liquid fertilizer that contains 10 to 15 percent nitrogen and 16 to 30 percent P.sub.2 O.sub.