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: Production of substantially water-insoluble linear ammonium polyphosphates of the general formula (NH.sub.4 PO.sub.3).sub.n, in which n is a number between 10 and 1000. To this end, substantially equimolecular proportions of ammonium orthophosphate and phosphorus pentoxide are reacted by heating them to temperatures within the range 170.degree. and 350.degree.C in the presence of gaseous ammonia. The reaction is effected while continuously and simultaneously mixing, kneading and comminuting the reaction material in a reactor. The reactor is closed, provided with means for the supply of solid feed material, a gas inlet and a gas outlet, a discharge opening for the removal of final product, and with mixing, kneading and comminuting implements which are rotatably secured to the inside of the reactor.

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

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: 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: Potassium phosphates useful as fertilizer materials, are produced by the reaction of phosphate rock or a solubilized form thereof, concentrated sulfuric acid and potassium hydrogen sulfate wherein the potassium hydrogen sulfate is added in a controlled manner and preferably in admixture with at least a portion of the sulfuric acid, the precipitated calcium sulfate precipitate is removed and the filtrate processed for recovery of the potassium phosphates. In further embodiments, high-sulfate containing filtrates are treated to lower the sulfate ion content of the products and effect partial neutralization by any of several methods such as by treatment thereof with fresh phosphate rock or source of calcium ion such as calcium oxide, alternatively or successively, and the resulting solution is used as a fertilizer, or liquids are removed and the solids are dried and/or dehydrated for recovery of the potassium phosphate compounds. Also methods are provided for the addition of nitrogen values.

Abstract: A process for the production of fertilizers from phosphoric and sulfuric acids, liquid anhydrous ammonia, and water. The ammonia is premixed with a small quantity of water in a common pipe; the resulting mixture is subsequently mixed downstream of said common pipe with the acids introduced to the pipe through a pipe cross. The acids and aqua ammonia react in the pipe cross and extension of the pipe beyond the cross. Overall length of the pipe reactor is 7 feet and it is cooled by a water jacket. In another variation of the process, the cooling water jacket is not used and the reaction tube is made of either Hastelloy C metal or Teflon-lined mild steel pipe. Slurry from the reactor is granulated with recycle fines, additional phosphoric and sulfuric acids, and ammonia in a rotary drum. Product from the granulator is cooled and screened for product size removal. Equipment is uncomplicated, easy to operate, and inexpensive.

Abstract: An improved method for the continuous production of stable aqueous ammonium polyphosphate compositions which are useful as fertilizers and fire retardants. Wet-process superphosphoric acid which is primarily in the orthophosphate form and anhydrous ammonia vapor are combined in a pipe reactor wherein the exothermic ammoniation of the acid and the conversion of a portion of the orthophosphate to polyphosphate caused by the heat liberated in the exothermic ammoniation reaction occur. A stream of the acid is introduced into the interior of a stream of ammonia vapor in the pipe reactor in order to avoid corrosion of the pipe reactor.Water is added to the reaction mixture to quench the conversion reaction and to provide the amount of water that is required in the desired final composition. The resulting stream is combined with a cooler stream of the desired final stable aqueous ammonium polyphosphate wherein the polyphosphate is cooled and the ammoniation is completed rapidly.

Abstract: There is disclosed a method and apparatus for the production of ammonium polyphosphate solutions of high concentrations from phosphoric acid and ammonia. The process is ideally suited for the production of such solutions from wet-process phosphoric acid which has a P.sub.2 O.sub.5 content of from 56 to about 70 weight percent, impurity-free basis, and which, preferably, contains from 5 to about 50 percent of its phosphorus present as polyphosphoric acid. The method comprises introducing the phosphoric acid into a reactor bearing a Teflon liner and reacting it therein with vapors of ammonia while controlling the amount of ammonia from 0.2 to about 0.3 pound ammonia per pound of P.sub.2 O.sub.5 in the feed acid, sufficient to achieve a peak reaction temperature in the reactor between about 525.degree. and 775.degree.F., the absolute value of which is dependent on the bulk water content of the feed acid.

Abstract: Improved stable suspension liquid fertilizers based on ammonia and phosphoric acid obtained by the wet method, and combining both a high content of fertilizing elements and a long storage life are prepared by ammoniating the phosphoric acid with gaseous ammonia in two steps at a temperature of from 90.degree.C to 120.degree.C until a pH of between 6 and 8 is attained, rapidly cooling the resulting ammonium phosphate suspension to a temperature of from 0.degree.C to 35.degree.C, and during the cooling adding a suspending agent to the suspension while maintaining the suspension under stirring.

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.