Abstract: The process allows essentially all of the nitrogen and P.sub.2 O.sub.5 values in the treated black ammonium polyphosphate liquid to be recovered in the form of valuable clarified product. In the process, a heel of black liquid fertilizer is first clarified by a prior-art procedure using flocculants. The improvement over the prior art picks up with the byproduct tops which is then diluted with the water of formulation required to dissolve additional amounts of ammonium polyphosphate melt. This diluted liquid is filtered, the filter cake containing upwards of 99 percent of the undesirable black carbonaceous material is discarded, and the clear filtrate, which contains essentially all of the nitrogen and P.sub.2 O.sub.5 originally in the tops, is then used in lieu of the prior-art water of formulation to dissolve additional ammonium polyphosphate melt to produce more black ammonium polyphosphate liquid.

Abstract: Black carbonaceous floc in wet-process phosphoric acid is removed by contact with an oxidizing agent during the neutralization step with ammonia. In an embodiment the black floc is removed in liquid fertilizers derived from wet-process phosphoric acid by reaction with an oxidizing agent at high temperatures.The oxidizing agent is preferably nitric acid.

Abstract: A process for inhibiting the growth of insoluble magnesium-containing solids in liquid fertilizer compositions, prepared from the ammoniation of wet process phosphoric acids, comprises the addition of surfactant compounds to the fertilizer.

Abstract: A process and product of waste recovery at phosphorus furnaces is disclosed wherein small sized discrete particles of carbonaceous material or beneficiated phosphate ore are mixed with a mineral axis, an alkaline fluid and water, and the reacted mixture is tumbled in a horizontal cylinder at a temperature below that at which the carbonaceous material oxidizes to form agglomerates which are then indurated to discrete particulate size as desired for a charge component; the agglomerates are fed to a phosphorus smelting furnace together with other materials needed to make elemental phosphorus, furnace gases are cooled with recirculating water, a side stream of the water is taken off, treated, and used as feedstock in fluid fertilizers. The side stream of water contains elemental phosphorus, and the side stream is used as make-up water in fertilizer processes. Apparatus is disclosed for agglomerating coke and phosphate and, further, for measuring the abrasion and shatter resistance of agglomerates.

Abstract: An improved process for the production of concentrated, high-grade, nitrogen-phosphate (N--P.sub.2 O.sub.5) base suspension fertilizer from wet-process or other phosphoric acids and ammonia. The process involves addition of small proportions of fluosilicic acid during preparation of the suspension to cause modification of monoammonium phosphate crystals to shapes and sizes that do not settle during vibration such as occurs during shipment.

Abstract: A body of liquid, such as an aqueous fertilizer mixture, in a tank is stirred and mixed by apparatus which produces a pattern of recirculating flow including a zone of rapid streamline flow in the tank, preferably an upwardly diverging conical pattern and preferably at an eccentric point in the tank. An addition component in fluid state, such as anhydrous liquid ammonia, is injected into the rapidly flowing liquid in a plurality of fine streams from a stationary injection manifold so as to produce an intimate dispersion of finely divided addition fluid at spaced points in the mixture which is immediately carried away from the injection area and widely dispersed in the liquid mixture. When anhydrous ammonia is thus dispersed in a fertilizer mixture containing a suitable reactant, such as phosphoric acid (H.sub.3 PO.sub.

Abstract: A homogeneous, zinc-containing liquid fertilizer concentrate is prepared by mixing, in aqueous solution, ammonium thiosulfate and zinc oxide. This zinc-containing concentrate is suitable for mixing with a liquid fertilizer preparation such as aqueous ammonium polyphosphate to prepare a complete zinc-containing fertilizer solution. The nutrient value of the concentrate and the fertilizer can be enhanced by the addition of a potassium salt or nitrogen solution. The long-term stability of the fertilizer solution can be improved by the addition of attapulgus clay.

Abstract: An energy efficient process and apparatus is described that allows production of concentrated polyphosphate containing ammonium phosphate suspension fertilizers that can be stored and handled at temperatures well below 0.degree. F. Ammoniation of the merchant-grade wet-process phosphoric acid provides all of the heat required by the process. Use of a unique enlarged dual pipe-type reactor system allows operation for extended periods without clogging. To obtain the high concentration and excellent low temperature storage and handling properties, the ammonium phosphate must be produced within closely specified and previously undisclosed N:P.sub.2 O.sub.5 and solution concentration ranges. Operation outside the specified composition range will reduce the maximum plant food concentration and may cause some of the ammonium phosphate salts to crystallize and foul the heat-transfer surfaces.

Abstract: Phosphoric acid and ammonia are reacted together with additions of water when necessary in a reaction vessel to form a molten entrained stream reaction mixture to which a water quench is added to produce an ammonium polyphosphate liquid fertilizer.

Abstract: A one vessel process for manufacturing stable ammonium phosphate fertilizer utilizes a spray reactor in which phosphoric acid is reacted with ammonia to form ammonium phosphate. The ammoniation is conducted under conditions which form sufficient ammonium polyphosphate to stabilize the solution in the liquid condition. The liquid may be stored and transported without substantial solidification or crystalization so that the product may be subsequently used as an ammonium phosphate fertilizer.

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: This invention concerns polymers of the general formula: ##STR1## wherein R is a multivalent hydrocarbon radical and Het is a 5 to 8 membered heterocyclic system having a nitrogen, oxygen or sulfur hetero atom. The polymers are useful for making articles of manufacture and as coating for delivering beneficial agents such as fertilizers.

Abstract: A method for the treatment of phosphoric acid containing one or more impurities comprising the ions of at least one of the metals from the group magnesium, iron and aluminium, including the step of heating the acid under such conditions of temperature, pressure, time and concentration as to cause at least some of these impurities, (and in the case where magnesium is the major constituent among such impurities, more than 60% (mass/mass) of such magnesium) to precipitate as a pyrophosphate of the relevant metal ion.

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: A process is described for the production of ammonium polyphosphate employing a novel reactor configuration and reaction technique to convert wet-process phosphoric acid having a low polyphosphate content and anhydrous ammonia into an ammonium polyphosphate product having a high proportion of the total P.sub.2 O.sub.5 in the polyphosphate form while minimizing operational problems such as scale build up on the reactor walls and subsequent conversion of the polyphosphate formed to orthophosphate.

Abstract: Liquid ammonia, a reactant with superphosphoric acid in the process for fertilizer production, is passed through an annular jacket surrounding a tubular reaction zone where reaction occurs to maintain the interior surface of the tubular reactor at a temperature sufficiently low to prevent the formation of scale on interior reactor surfaces.

Abstract: Langbeinite (2MgSO.sub.4,K.sub.2 SO.sub.4) is reacted with diammonium phosphate (NH.sub.4).sub.2 HPO.sub.4 to yield a dry farm field fertilizer of grade 21-12-7+1.22 Mg.The chemical process is also adjusted for a dry farm field "double cropping" fertilizer.The cost of the basic liquid fertilizer containing Magnesium has been likewise reduced.These fertilizers contain magnesium in the presence of phosphorus.The micronutrients, Zn, Cu, Fe, Mn and B may be added in rates proportional to the deficiency shown by soil tests.

Abstract: The method comprises processing slime and off-gases resulting from the production of phosphorus with an aqueous solution of copper sulphate having a concentration of from 15 to 50% at a temperature within the range of from 20.degree. to 80.degree. C. As a result, two products are obtained, i.e. a liquid product and a solid one.The solid product containing mainly copper phosphide as well as fluorides and chlorides of alkali metals and silicon, and silicates of calcium and aluminum, is used as a modifying and refining agent for hypereutectic silumines and for the manufacture of a copper-phosphorus alloy.The liquid product containing phosphoric acid, sulphuric acid and copper sulphate is used as starting product for the preparation of a copper-containing fertilizer.The method according to the present invention makes it possible to modify the production of phosphorus so as to eliminate the formation of secondary wastes and improve the environmental control.

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: 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: A process for the production of a potassium polyphosphate liquid fertilizer in which potassium chloride is reacted with phosphoric acid or polyphosphoric acid in a specific molar ratio, steam, air or other inert gas being blown through the reaction mixture to facilitate removal of hydrochloric acid. The reaction product is dissolved in water or a weak solution, of a liquid ferilizer, the pH adjusted and the resulting solution or slurry is suitable for direct use as a solution fertilizer.

Abstract: Ammonium polyphosphate fertilizer solutions contaminated with carbon and carbonaceous residues are decarbonized by a sequential treatment to produce a light-colored solution/slurry of fertilizer solution containing essentially no visible carbon. In the first step, a mixture of an organic amine with a quaternary ammonium salt is dispersed in the contaminated fertilizer solution. In the second step a water immiscible hydrocarbon of low polarity is incorporated into the fertilizer solution by low shear agitation. In the third step a very slow agitation of the mixed system provides for the rising and coalescence of the low density hydrocarbon droplets containing the carbonaceous particles into a layer above the fertilizer solution.

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: Process for making magnesium potassium ammonium phosphate, using ammonia, urea, potassium hydroxide, magnesium hydroxide, and phosphoric acid with specified maxima of iron, alumina, and sulfate.

Abstract: A simplified, commercially feasible, split-addition method of producing a liquid, sprayable fertilizer composition which contains ammonium phosphates is disclosed which yields a fertilizer with improved storage properties over prior compositions of this type and capable of being sprayed using existing equipment with a minimum of clogging problems. The method includes initially admixing a fractional portion of a total quantity of monoammonium phosphate (MAP) to be employed with water and adding ammonia thereto so as to induce an essentially instantaneous ammoniation reaction; the remainder of the MAP is then added to yield the final fertilizer composition. The addition of a suspending agent is usually desirable. This split addition of MAP (most preferably a 70% - 30% split) unexpectedly serves to minimize formation of large ammonium phosphate crystals in the fertilizer, so that the storage properties are improved and the composition can be sprayed without fear of frequent clogging of the spraying equipment.

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: A process of manufacturing liquid fertilizer from ortho phosphoric acid is described herein. Specifically, the process involves extracting ortho phosphoric acid from phosphate rock using sulfuric acid in the usual manner. The ortho phosphoric acid is then concentrated to a P.sub.2 O.sub.5 content of 30-58% by weight. The wet process ortho phosphoric acid is then ammoniated at a carefully controlled pH in a range of about 3.0 to 5.5. Water and commercial clays are added to the ammoniated phosphoric acid during ammoniation or after ammoniation. A stable non-gelling suspension fertilizer results.

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: High analysis fertilizer formulations of a low bulk density powdered ureaform having soluble and insoluble components combined with soluble monopotassium phosphate in which the resulting mixtures are dry homogeneous blends that are free of fillers and binding agents and may be carried in liquid for application to surface or subsurface areas by conventional liquid fertilizer applying equipment.

Abstract: Described are encapsulated slow release fertilizers prepared by providing a fertilizer substrate, spraying molten sulfur thereon; encapsulating the sulfur-coated fertilizer by solvent deposition of bitumen and then powder coating the bitumen- and sulfur-coated fertilizer with a finely ground, dry, mineral powder which reduces the tackiness of the combined coating.

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: A process for preparing concentrated, high-grade, nitrogen-phosphate (N--P.sub.2 O.sub.5) base suspension fertilizer from wet-process or other impure orthophosphoric acids. The process involves a new procedure for the direct ammoniation of orthophosphoric acid in stages for production of fluid, high-analysis, N--P.sub.2 O.sub.5 suspension fertilizer with good physical properties. The new process contains a novel method for prevention of settling of crystals in the suspension during vibration, such as that which occurs during shipment. Settling is avoided by producing small, thin crystals of diammonium phosphate through control of the N:P.sub.2 O.sub.5 ratio and temperature in the second and third ammoniation stages.

Abstract: Precipitate settling in ammonium polyphosphate liquid fertilizer solutions containing magnesium, iron, aluminum compound impurities, prepared by concentrating and ammoniating wet process orthophosphoric acid, is impeded by addition to the ammonium polyphosphate, prior to precipitate formation, a source of Cl.sup.- in amounts sufficient to alter the morphology of the precipitate crystals such that the length-to-width ratio of the crystals formed is increased by at least 200%, as compared to the ratio for crystals formed in the absence of Cl.sup.- addition. Since there is little propensity for the longer and thinner crystals to settle out of solution, the crystals remain innocuously suspended in the solution.

Abstract: Solid plant food formulations are disclosed which can be embedded in the soil adjacent but spaced from the plant roots for the release of primary plant nutrients and fertilizing components each time the plant is watered. The solid compositions contain fertilizer constituents, gel-forming materials and reactants therefore which, in the presence of water, combine to form a semi-permeable surface membrane or layer through which the plant nutrients migrate. Beneficial trace elements are also included. Sequestering agents are incorporated to enhance and insure the migration of the nutrients, particularly the trace elements, into the soil and preventing the formation of water-soluble products through metathetic reactions or reactions with the ingredients in the soil. The amount of nutrients released is proportionate to the volume of water applied.

Abstract: The invention relates to a process for the production of phosphoric acid containing calcium phosphates, i.e. Ca-containing phosphoric acid, by evaporating Ca-containing mother liquor from Odda process, whereby practically all the remaining nitrate and fluorine are removed in the form of HNO.sub.3, HF and SiF.sub.4, in which process the Ca-containing mother liquor is given a Ca/P weight ratio which is lower than 0.45 and is evaporated while recycling Ca-containing phosphoric acid, the recirculation being so controlled that the liquor has a phosphorus concentration during evaporation which is always adequate to prevent the liquor from forming a paste-like mass. Thus, it was discovered that the undesirable paste-like consistency experienced when calcium is present during evaporation can be avoided by controlling the phosphorus content.

Abstract: This invention relates to novel fertilizer particles having an inner core and an outer water permeable sulfur coating; to a method of preparing these fertilizer particles by contacting a particulate core material in a fluidized bed, or other suitable coating apparatus, with molten sulfur which solidifies upon the core material; the process preferably being conducted in a fluidized bed having an inert atmosphere in the material contacting zone. This invention is particularly useful in preparing triple superphosphate fertilizers with a water permeable coating of elemental sulfur.

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: Fertilizers containing the elements nitrogen, phosphorus and potassium, and organic compounds acting as growth activators for plants. These organic compounds comprise compounds of high molecular weight, which result from the polycondensation of naphthoquinone and maleic anhydride and which are added to the fertilizers at a rate of from 0.5 to 10% by weight of the total fertilizer. Incorporation can occur at the stage of providing the raw materials or at the stage of granulation, the fertilizer thus activated being applied in known manner.

Abstract: Granular products for the treatment of soil are described which comprises a central solid nucleus containing fertilizer, herbicide, or a mixture of fertilizer and herbicide, all soluble in water without decomposition, as well as, about each product a coating consisting of solid materials at least 40% of which are soluble in water without decomposition, and at least 15% of which consist of active material different from that of the nucleus, and a polymeric resin the amount of which does not exceed 10% of the total weight of the coating. Comparative tests are described which show that these novel granular products can be as readily dissolved in the soil as uncoated fertilizer granules.

Abstract: This invention relates to a fertilizer stick composed of water soluble thermoplastic material and dispersed therein about 10 to about 80% of fertilizer material. The fertilizer stick gradually dissolves when placed in a potting medium or soil to supply plant growth nutrients to the roots of a plant.

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 process for preparing concentrated, high-grade, nitrogen-phosphate (N--P.sub.2 O.sub.5) base suspension fertilizer from wet-process or other impure orthophosphoric acids. The process involves a new procedure for the direct ammoniation of orthophosphoric acid in stages for production of fluid, high-analysis, N--P.sub.2 O.sub.5 suspension fertilizer with good physical properties. The new process contains a novel method for prevention of settling of crystals in the suspension during vibration, such as that which occurs during shipment. Settling is avoided by producing small, thin crystals of diammonium phosphate through control of the N:P.sub.2 O.sub.5 ratio and temperature in the second and third ammoniation stages.

Abstract: Fertilizer materials, especially potassium dihydrogen phosphate, are produced by the reaction of phosphate rock or a solubilized form thereof, such as mono calcium phosphate, dicalcium phosphate, etc., concentrated sulfuric acid, potassium hydrogen sulfate and, optionally fresh or recycle phosphoric acid, the resulting mixture is filtered to remove the calcium sulfate precipitate and the potassium dihydrogen phosphate is recovered from the filtrate, either by concentration and filtration or by extraction with an organic solvent.

Abstract: process for production of fertilizers from phosphoric and sulfuric acids, anhydrous ammonia, and urea, and for the production of high-analysis granular ammonium phosphates, ammonium phosphate sulfates, and urea-ammonium phosphate sulfates--some with polyphosphate contents of up to 68 percent of the total P.sub.2 O.sub.5. A specially designed pipe-cross reactor is used to produce a homogeneous melt or slurry of low moisture content from the reactants and thus eliminates the need for a preneutralizer as used in many prior-art granular fertilizer processes. Because of the low melt or slurry moisture content, the dryer is eliminated. The elimination of these two items greatly simplifies pollution abatement, since both items are sources of fumes and dust. The equipment used to produce granular monoammonium phosphate, diammonium phosphate, urea-ammonium phosphate sulfate, and ammonium phosphate sulfate fertilizers is inexpensive and simple to operate.

Abstract: a method for improving the storage properties of liquid fertilizers made from wet-process phosphoric acid. The wet-process acid is essentially defluorinated so that when it is processed by ammoniation to make high-analysis ammonium polyphosphate liquid fertilizers, the sometimes almost immediate precipitation of undesirable sludge compounds of magnesium does not occur in the liquid over long periods of storage. The liquids may be produced by dissolving hot ammonium polyphosphate melts directly as it is produced or by dissolving dry granular solid ammonium polyphosphate made from this type acid.Both ammonium polyphosphate and urea-ammonium polyphosphate base solutions made from defluorinated wet-process acid are highly stable and they exhibit increased tolerance for higher magnesium and lower polyphosphate levels.

Abstract: The process allows essentially all of the nitrogen and P.sub.2 O.sub.5 values in the treated black ammonium polyphosphate liquid to be recovered in the form of valuable clarified product. In the process, a heel of black liquid fertilizer is first clarified by a prior-art procedure using flocculants. The improvement over the prior art picks up with the byproduct tops which is then diluted with the water of formulation required to dissolve additional amounts of ammonium polyphosphate melt. This diluted liquid is filtered, the filter cake containing upwards of 99 percent of the undesirable black carbonaceous material is discarded, and the clear filtrate, which contains essentially all of the nitrogen and P.sub.2 O.sub.5 originally in the tops, is then used in lieu of the prior-art water of formulation to dissolve additional ammonium polyphosphate melt to produce more black ammonium polyphosphate liquid.

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.

Abstract: An energy efficient process and apparatus is described that consists of a pipe reactor, melt dissolution tank, acid and ammonia heat exchangers, product cooler, and clay addition facilities in which a concentrated polyphosphate containing ammonium phosphate suspension fertilizers is produced that can be stored and handled at temperatures well below 0.degree. F. The suspension is produced from merchant-grade wet-process phosphoric acid which is ammoniated in a unique enlarged pipe-type reactor sized to have throughputs of 20-100 pounds P.sub.2 O.sub.5 /hr-in.sup.2 and 0.25-2 pounds P.sub.2 O.sub.5 /hr-in.sup.3 of internal reactor area and volume, respectively, and which can be operated for extended periods without clogging. All of the heat required by the process is obtained by transferring a portion of the heat of ammoniation from the hot liquid in the melt dissolution tank to the incoming acid and ammonia streams. The resultant product contains 10 to 40 percent polyphosphate and when produced within an N:P.

Abstract: Method for production of granular ammonium polyphosphate fertilizer in which ammonium polyphosphate melt is prepared in a simple inline reactor and distributed onto a bed of solids in a drum granulator to bind smaller fertilizer particles into granules. The desired polyphosphate content can be obtained in the granular product by adjusting the total heat input of the feed reactants to the reactor by means of energy conservation modifications to the system. Energy losses from the reaction system are controlled by use of a predetermined quantity of insulation so that varying amounts of the maximum theoretical heat input can be utilized to produce products of polyphosphate contents as desired.