Abstract: Ammonium orthophosphate products are prepared by reacting ammonia and phosphoric acid together at high speed under vigorous mixing conditions by spraying the reactants through a two-phase, dual coaxial mixer/sprayer and separately controlling the supply and axial outflow rate of the phosphoric acid at 1 to 10 m/sec. and the outflow rate of ammonia at 200 to 1000 m/sec. (N.T.P.). Thorough mixing and a homogeneous product is obtained by directing the outflow spray into a coaxial cylindrical reaction chamber of a specified size with respect to the diameter of the outermost duct of the sprayer/mixer. The product may be granulated on a moving bed of granules and adjusted in respect of the NH.sub.3 to H.sub.3 PO.sub.4 content by changing the concentration of the phosphoric acid and/or supplying additional ammonia to the granulation bed.

Abstract: A process is disclosed for the absorption of gaseous or liquid ammonia in acid solutions or slurries, including an ammonia absorption zone separated from a water vapor generation zone disposed at a higher level. A pressure difference is created between the two zones, so that the ammonia absorption takes place completely in the neighborhood of the point of inflow of the ammonia, with a temperature increase localized only near to said inflow point, and thus without giving rise to the generation of water vapor which therefore takes place in a liquid-vapor separation zone located at a higher level with respect to the ammonia absorption zone. The acid solutions or slurries to be neutralized may consist essentially of solutions of phosphoric acid, sulphuric acid, nitric acid, solutions resulting from the nitric acid attack on phosphorites, acid slurries resulting from nitric acid attack or sulphonitric acid attack on phosphorites, or mixtures thereof.

Abstract: A process which comprises reacting ammonia with phosphoric acid in a reaction vessel to form a reaction mixture comprising ammonium phosphate characterized in that the reaction mixture is allowed to foam whereby there is formed a foaming reaction mixture comprising steam and ammonium phosphate; and in that steam and ammonium phosphate are discharged from the reaction vessel through a common outlet. Preferably the ammoniation is carried out under pressure and the foam reaction mixture is discharged via a spray nozzle into a zone of lower pressure where water is evolved spontaneously, e.g. by flash evaporation as the product is sprayed, to give a solid particulate product.

Abstract: Process and apparatus are described for an improved treatment of gases effluent from an ammonia phosphoric acid reactor in the manufacture of fertilizers. Ammonia is scrubbed from the gases with aqueous acid, preferably concentrated phosphoric acid, and particulates are captured and removed by contact with solid target particulates, preferably alkaline nephaline syenite. Pond water scrubbing is reduced or eliminated with improved costs and recoveries, secondary pollution is minimized, and land is conserved.

Abstract: A process for preparing crystalline ammonium dihydrogen phosphate, comprises the steps of (a) adding a sequestering agent into ammonium hydrogen phosphate aqueous solution, the sequestering agent reacting with metallic ions contained in the aqueous solution to form water soluble compounds, (b) heat-treating the aqueous solution at a temperature of 70.degree. C. or more after addition of the sequestering agent, and (c) crystallizing ammonium dihydrogen phosphate out of the aqueous solution after the heat-treating, so that crystalline ammonium dihydrogen phosphate can be obtained in high whiteness and in the form of columnar crystals.

Abstract: A method of purifying filter-grade wet-process phosphoric acid, then converting the purified phosphoric acid directly to ammonium phosphate without first concentrating the phosphoric acid. The wet-process phosphoric acid is treated with a mixture of ammonia or an ammonium salt and acetone near or at the boiling point of the mixture. Solids are separated from the phosphoric acid liquid phase. The solids are a mixture of metal phosphates, gypsum, and fluosilicates. Adhering phosphoric acid is washed free of the solids with fresh acetone. Wash liquor is combined with purified phosphoric acid. Gaseous ammonia is added to the phosphoric acid-acetone extract in the ratio necessary to produce either monoammonium phosphate (MAP) or diammonium phosphate (DAP). Ammonium phosphate is filtered from the acetone-water mother liquor, then, depending on the level of ammonium phosphate left in the mother liquor and the type of ammonium phosphate produced (MAP or DAP), the mother liquor is treated in one of several ways.

Abstract: Biammonium phosphate is obtained by the neutralization of phosphoric acid with ammonia in a saturator operating at atmospheric pressure. Unreacted gaseous ammonia is washed in a tower with a "rain" of phosphoric acid for ammonia recovery without any saline deposit, scaling or clogging. A second tower collects the overflow of washing acid.

Abstract: The present invention relates to a process for reacting ammonia and wet process phosphoric acid to produce ammonium phosphates, which process comprises feeding the reagents to a vessel comprising two tubular members in fluid flow communication with one another and with a gas disengagement vessel, at least one of said tubular members being generally upright, the ammonia being fed to the basal portion of the upright member, the phosphoric acid being fed to the other tubular member; allowing the resultant reaction mixture to circulate spontaneously up the upright member, through the gas disengagement vessel and through the other member to the upright member; and recovering the ammonium phosphate reaction products from the reaction system.

Abstract: A process for granulating ammonium phosphate containing composition for use as a fertilizer which comprises feeding a slurry or melt of ammonium phosphate, wherein said slurry or melt is capable of further reaction with ammonia, into a kneading mill, feeding recycled particles from the subsequent classification and crushing procedure into said kneading mill, wherein the said slurry or melt added to the mill is from 5 to 95% wt.

Abstract: An improved process for the purification of wet-process phosphoric acid (WPPA) with acetone and ammonia. The main product is the purified acid and a byproduct is the impure acid fraction in a liquid form containing most of the impurities including the added ammonia. The WPPA is mixed with acetone and the specified amount of ammonia to form two liquid phases that separate rapidly. The top layer contains about 75 percent of the phosphoric acid, nearly all the acetone, and a small fraction of the impurities. The bottom liquid layer has a viscosity usually in the range of 40 to 2500 centipoises, depending on the acid concentration and the amount of ammonia used. The acetone is distilled from the two liquid phases for recycle to the process.

Abstract: A process for producing ammonium phosphate that is substantially free of arsenic which comprises:(a) reacting crude phosphoric acid containing dissolved arsenic having a +5 valence state with ammonia and arsenic-reducing agent in sufficient proportions to form an ammonium phosphate solution and to reduce the arsenic from the +5 valence state;(b) forming ammonium phosphate crystals from said solution, leaving a mother liquor that contains substantially all of said arsenic; and(c) recovering said ammonium phosphate crystals that are substantially free of arsenic from said mother liquor.

Abstract: When crude wet process phosphoric acid is solvent extracted, an aqueous raffinate containing phosphoric acid and a small amount of solvent is produced as a by-product. Certain materials are added to the raffinate, in order to produce two phases, one aqueous and the other of solvent. The phases are separated, the solvent recycled for reuse in a solvent extraction process and the aqueous phase treated with ammonia or alkali or alkaline earth metal compounds to form a fertilizer or other phosphate salt.

Abstract: Process for the preparation of a purified solution of phosphoric acid, which may be partially neutralized, from wet process phosphoric acid, by liquid-liquid extraction by means of a substantially water-immiscible organic solvent. The phosphoric acid is treated in the selected solvent, preferably isobutyl alcohol, in the presence of sulphuric acid, by means of an aqueous solution containing phosphate ions and calcium ions in solution, the sulphate ions are precipitated in the form of calcium sulphate, and suspended in said aqueous solution which is separated from the phosphoric solution. The process is advantageously employed for the continuous preparation of concentrated solutions of monosodium phosphate.

Abstract: Highly pure sodium ammonium hydrogenphosphate and ammonium chloride are prepared from wet process phosphoric acid. A mixture of phosphoric acid, ammonia and/or sodium chloride is added to a circulating mother liquor, to which is additionally added ammonia until the pH of the liquor reaches 5.5 to 9.0. The liquor is then cooled to cause sodium ammonium hydrogenphosphate to crystallize at 30.degree. to 60.degree. C. The resulting filtrate is added with an acidic compound to adjust its pH to 5.6 to 6.4 whereby the solubility of the hydrogenphosphate is increased while that of ammonium chloride is reduced to a minimum. The filtrate is cooled to 5.degree. to 50.degree. C to precipitate ammonium chloride as crystals without involving co-precipitation of the hydrogenphosphate. The filtrate from which the ammonium chloride crystals have been removed is recycled for use as a circulating mother liquor.

Abstract: Phosphate values can be recovered from an organic extract which is formed by contact of wet process phosphoric acid and a water immiscible solvent, in a process in which the extract is treated with an inorganic base or a dihydrogen phosphate salt to give an acid free solvent and an aqueous solution of phosphoric acid and phosphate salt with a cation to P usually in the 0.1 - 0.5 : 1 region. The aqueous solution represents a concentrated soluble phosphate source for subsequent neutralization and conversion to e.g. tripolyphosphates.

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: An improved, stable, aqueous suspension fertilizer composition is provided containing from about 8 to about 75 weight percent monoammonium phosphate, from about 1 to about 6 weight percent ammonia, and from about 1 to about 3 weight percent clay. The composition has a total equivalent water content in the range of about 25 to about 60 weight percent. When desired, additional ingredients such as an aqueous urea-ammonium nitrate solution, having a nitrogen content of about 28 to about 32 percent, and potash can be employed. The composition is further characterized in that the mole ratio of ammonia to phosphoric acid equivalent is maintained in the range of from about 1.2:1 to about 1.8:1. The composition is produced by admixing the ingredients in an agitator-equipped mixing vessel for an effective period of time and under suitable agitation conditions to form a suspension.

Abstract: Crude phosphate is leached with nitric acid to produce an acid slurry, which is thereafter neutralized with ammonia in two successive stages while simultaneously cooling it and adding acid, part of the crude phosphate phosphorus being replaced with phosphoric acid added to the slurry to be neutralized, and in such a manner that at maximum 40% of the phosphoric acid is fed to the first neutralization stage and the rest is fed to the second neutralization stage, whereby the acidity of the slurry is adjusted to pH 2.5 - 4.5 during the first and to pH 5.0 - 6.0 during the second neutralization stage.

Abstract: Stable aqueous ammonium phosphate containing a higher proportion of polyphosphates is obtained by reacting phosphoric acid with ammonia in the presence of sulfuric, nitric or hydrochloric acids under conditions sufficient to produce a partially neutralized melt containing polymeric phosphates at a temperature between 400.degree. and about 750.degree. F. by the autogenous heat of neutralization, quenching and further neutralizing the melt.

Abstract: The invention relates to a process for the manufacture of solid monammonium phosphate with good granulation properties suitable for use in compound fertiliser manufacture. An improvement in product quality is obtained when between 20% and 80% of an aqueous slurry of ammonium phosphate, formed by the ammoniation of wet-process phosphoric acid, is mixed with a second acid prior to entry into a moisture disengagement unit. This treatment precipitates some monammonium phosphate crystals which provide nuclei for further crystal growth. After a short time delay to allow crystals to form, the remainder of the slurry is then added separately to the moisture disengagement unit.

Abstract: Ammonium phosphates are produced from wet-process phosphoric acids containing silicon and fluorine compounds by preconcentrating the acid and evolving some of the water, silicon and fluorine compounds as a vapor phase, maintaining it at a temperature above about 50.degree. C., neutralizing the liquid acid concentrate with ammonia, and absorbing the isolated vapor phase from the evaporation zone in a relatively cool, neutralized ammonium phosphate solution at a pH of at least about 5.5.

Abstract: Phosphoric acids having H.sub.2 0/P.sub.2 O.sub.5 mole ratios of about 4.5 or less are converted to aqueous solutions of ammonium polyphosphates of which at least about 40 percent of the P.sub.2 O.sub.5 is present as acyclic polyphosphates. The reaction is conducted at 500.degree. to about 750.degree. F. sufficient to increase the polymeric P.sub.2 O.sub.5 content at least 10 percent by reacting a highly dispersed, unconfined acid spray with substantially anhydrous ammonia. High conversions to polymeric species are obtained while minimizing both reactor fouling when using impure wet-process acids, and corrosion occurring with either wet-process or "white" acids.

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: Process for the production of granular mixed fertilizer in which ammonium phosphate melt is prepared in a pipe reactor and dispersed through a plurality of apertures in the wall of the pipe to bind small particles of fertilizer materials into granules. Wet-process phosphoric acid is ammoniated to an NH.sub.3 :H.sub.3 PO.sub.4 mole ratio of about 1.0 and the steam formed by the heat of reaction atomizes the ammonium phosphate melt resulting in proper distribution of the melt for granulation. Up to about 30 percent of the P.sub.2 O.sub.5 in the melt may be polyphosphate. The ammonium phosphate is essentially anhydrous and the granules of mixed fertilizers do not require drying. Elimination of drying greatly decreases investment, dust and fume evolution, and fuel requirement.

Abstract: The present invention relates to a two stage process for preparing ammonium phosphates in which ammonia at a comparatively low pressure and recovered from within the process of the invention is reacted with phosphoric acid in the liquid phase to yield an immediate product which is then ammoniated further in the second stage under elevated pressure.

Abstract: The present invention relates to a two stage process for preparing ammonium phosphates in which ammonia at a comparatively low pressure and recovered from other processes is reacted with phosphoric acid in the liquid phase to yield an intermediate product which is then ammoniated further in the second stage under elevated pressure.

Abstract: Ammonium polyphosphates having a major portion of the P.sub.2 O.sub.5 content thereof in the form of condensed phosphates are prepared by reacting wet-process phosphoric acid directly with ammonia under specified conditions. It is demonstrated that exchange and recovery of heat from the hot ammonium polyphosphate reaction mixture is critical to allow production of ammonium polyphosphate solutions from orthophosphoric acid and ammonia with polyphosphate contents high enough for chelating inherent impurities during extended periods of storage. Moreover, the present invention avoids substantial corrosion of the equipment.

Abstract: A process for the production of a granular fertilizer material from sludge materials discharged from scrubbing processes that remove pollutants from boiler flue gases. Waste sludge discharged from flue gas scrubber systems often contain large amounts of calcium and sulfur as well as lesser amounts of other compounds known to have plant nutrient value. The sludge is treated with an acid such as phosphoric, sulfuric or nitric, or a mixture of these, and ammonia. The resulting sludge-ammonia-acid salt mixture is combined with partially dried, previously processed solid material (recycle) in a horizontal rotating vessel. Additional ammonia and/or acid is added to the rotating vessel to cause the sludge-salt mixture to solidify and granulate. Other plant nutrients may be added to the rotating vessel during granulation. The granulated material discharged from the rotary vessel is further processed (dried, cooled, and screened) to obtain desirable moisture content and particle size.

Abstract: Process for production of diammonium phosphate from orthophosphoric acid and ammonia. A specially designed inline reactor, a pipe reactor, is used to produce a homogeneous slurry with a lower moisture content than can be produced and pumped utilizing a preneutralizer as used in many prior-art granular fertilizer processes. Because of the lower moisture content of the slurry, drying requirements are eliminated. This eliminates two items of equipment, to wit, a preneutralizer and a dryer, and greatly simplifies pollution abatement since both items are sources of fumes and dust. The equipment utilized in the present process is inexpensive and simple to operate. The products produced are dust-free and of such particle size distribution that they are well suited for subsequent use in producing bulk blends.