Occidental Petroleum

Leathers Chemical Company, Limited

Occidental Research Corporation

Occidental Chemical Company

Occidental Research and Engineering Ltd.

John D Ellis

Fernando N Ore

James H Moore

George Crichton

George C Morris

Millard C Godwin

Allen S Adams

Fredrick M Gragg

Aqueous ammonium phosphate solutions can be produced using an apparatus comprising: a fluid reactor having a plurality of inlets at one end thereof suitable for the admission of phosphoric acid, ammonia and water, the inlets being so positioned as to provide for rapid ammoniation of the phosphoric acid with the evolution of heat, to produce a reaction product mixture containing a liquid portion and steam, the fluid reactor having an exit for the expulsion of the reaction products mixture at the other end thereof, by steam generated by the heat liberated in the ammoniation process; a columnar vessel having an outlet at one end and, at the other end, enclosing the exit of the fluid reactor, a plurality of barriers obturating the columnar vessel in a spaced-apart relationship, and having a plurality of apertures therein for the passage of reaction products mixture therethrough; an inlet quench device connected to the columnar vessel for introduction therein of a liquid aqueous quenching fluid; and, a device in communication with the exit of the fluid reactor, for separating steam from the liquid portion of the reaction mixture and removing the separated steam from the apparatus.

Phosphoric acid ammoniation apparatus

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.

Phosphoric acid ammoniation process to produce liquid fertilizers

Phosphoric acid is prepared from phosphate rock and sulfuric acid by using a reaction train comprising a dissolving slurry and a crystallization slurry maintained at different sulfate levels. Both inter and intra vessel circulation are used at high rates to minimize reagent concentration gradients and temperature gradients and provide a suitable crystallization environment. Preferably, the intra vessel circulation is substantially in plug flow, as through a draft tube.

Phosphoric acid process with high circulation rates

The invention comprises a multi-vessel reaction apparatus useful for reacting phosphate rock and sulfuric acid in which the reaction slurry undergoes intra- and inter- vessel circulation (preferably through a draft tube). The solution portion of the slurry in a first vessel or set of vessels (the 'dissolver') is preferably maintained at at lower sulfate ion concentration and the solution portion of the slurry in the second vessel or system of vessels (the 'crystallizer') is preferably maintained at a positive sulfate ion concentration. Also preferred are means for maintaining the second vessel or set of vessels at a reduced pressure. Most preferred is that means be included in at least one said vessel for incorporating a crystal modifier (e.g. a sulfonic acid, a sulfonic acid salt, tall oil fatty acids or alkoxylated or esterified tall oil fatty acids) in the crystallizer. The system can be used in the anhydrite, hemihydrate or gypsum types of processes.

Apparatus useful for wet process phosphoric acid production

A system for the preparation of phosphoric acid from phosphate rock and sulfuric acid, includes in combination a first reaction vessel containing a first slurry comprising calcium sulfate hemihydrate, monocalcium phosphate and phosphoric acid, a second reaction vessel containing a second slurry comprising calcium sulfate hemihydrate, circulation means including a draft tube disposed centrally in each of said vessels and an agitator positioned axially in each of said vessels within said draft tube, a first conduit interconnecting said first and second reaction vessels for conducting said first slurry from said first reaction vessel to said second reaction vessel, a second conduit interconnecting said vessels for conducting said second slurry from said second reaction vessel to said first reaction vessel, an inlet pipe for introducing phosphate rock and phosphoric acid to said first reaction vessel, said inlet pipe connected with the interior of said draft tube in said first vessel and wherein a vent is connected to said inlet pipe to permit escape of gases and, thus, increasing the rate of flow of said phosphate rock and phosphoric acid to said first reaction vessel.

System for phosphoric acid production with decreased foaming

Phosphate rock and sulfuric acid are reacted under conditions which result in the formation of calcium sulfate hemihydrate and phosphoric acid of about 35% to about 55% P.sub.2 O.sub.5. A two vessel reaction system is used in which the reaction slurry undergoes intra- and inter- vessel circulation (preferably through a draft tube). The solution portion of the slurry in the first vessel (the 'dissolver') is preferably maintained at a negative sulfate concentration (i.e. excess Ca.sup.+2) and the solution in the second vessel (the 'crystallizer') is preferably maintained at a positive sulfate ion concentration. Also preferred is that the second vessel be maintained at a reduced pressure, (e.g. to provide evaporation cooling). Better filtration rates can thus be obtained due to the favorable shape, dominant size and size distribution of the hemihydrate crystals. Most preferred is that a crystal modifier (e.g. a sulfonic acid, a sulfonic acid salt, tall oil fatty acids or alkoxylated or esterified tall oil fatty acids) be present in the crystallizer. Surprisingly, the sulfuric acid used in the process can be less (e.g., 0.5-10%) than the stoichiometric amount to convert the calcium in the feed phosphate rock to calcium sulphate.

Hemihydrate type phosphoric acid process

An apparatus for reacting phosphoric acid and ammonia to form a molten reaction mixture, to which water can be added to produce an ammonium polyphosphate product, comprises:

Phosphoric acid ammoniation apparatus with water quench

Phosphate rock and sulfuric acid are reacted under conditions which result in the formation calcium sulfate hemihydrate and phosphoric acid of about 30% to about 55% P.sub.2 O.sub.5. A two vessel reaction system is used in which the reaction slurry undergoes inter- and intra- vessel circulation. This results in excellent dispersion of reactants and minimization of temperature and concentration gradients throughout the slurry.

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Upland, CA, United States of America

John D Ellis