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7736526 |
Method of filtering phosphate utilizing a rotary table filter or horizontal table filter
The present disclosure is directed to a filter support having a surface with a plurality of perforations therein. At least one spray bar may be substantially fixed adjacent to the surface of the...
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7678354 |
Integrated lime kiln process
A process and system for recovering waste heat from a kiln used for lime or cement production. The system unifies the kiln, a waste heat recovery and power generation circuit and a dry scrubber for...
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7172742 |
Method of preparing wet process phosphoric acid
The present invention relates to a method of preparing wet process phosphoric acid, which comprises: dividing raw materials which contain phosphate rock slurry and sulfuric acid into two parts, and...
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6544489 |
Defoaming compositions for high acid strength media
A defoaming composition useful in high strength acid media includes an ester condensate of a C12-C20 fatty acid and a at least one alcohol derivative selected from the group consisting of C1-C4...
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6365117 |
Method for preparing phosphoric acid
A method for preparing phosphoric acid from calcium phosphate ores, particularly ores highly contaminated with organic compounds, by decomposing the ore with sulphuric acid, wherein according to...
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6251351 |
Wet-process technique for refining phosphoric acid
A process for purification by multistage countercurrent extraction of wet-process phosphoric acid includes the steps of (a) preparing an aqueous phosphoric acid by decomposition of crude phosphates...
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6235257 |
Process waters in phosphate manufacturing
Modification of phosphoric acid manufacturing provides improved process waters: decontaminated water pH-adjusted to be only slightly acidic, scrubber process water, gypsum stack water, and a...
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5679315 |
Method of production of high purity silica
The present invention provides a basic method for producing high purity silica and ammonium fluoride from silicon tetrafluoride-containing gas, particularly the gas generated by acidulation. The...
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5395603 |
Automatic control system for a chemical process, especially a wet process phosphoric acid plant
Maximum throughput of a wet process phosphoric acid plant at a fixed recovery can be obtained by controlling the filter feed to give a desired specific gravity of the filtrate from the last washing...
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5366640 |
Conversion of phosphoric acid waters
Converting wet-process phosphoric acid operations, to minimize and nearly eliminate discharge of contaminants to the environment, by generation, use, and treatment of new and unique process waters....
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5318707 |
Method of clarifying phosphoric acid
A method for clarifying phosphoric acid by flocculation or coagulation of solids wherein an effective amount of a carboxylic-type polymer having a portion of sulfonic functionality is used as the...
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5316748 |
Phosphoric acid manufacturing with converted waters
Generation, use, and treatment of new and unique process waters in or for wet-process phosphoric acid manufacturing to substantially eliminate discharge of contaminants to the environment. Acid...
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5236679 |
Removal of aluminum contamination during production of phosphoric acid
This invention provides a method for removing aluminum contamination from phosphoric acid during the acidulation of phosphate rock with sulfuric acid in the presence of recycled phosphoric acid....
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5211735 |
Process for preparing phosphated or nitrophosphated fertilizers through solubilization of phosphate rock
The invention aims at a process for preparing phosphated or nitrophosphated fertilizers through reaction of phosphate rock in aqueous pulp, with sulfuric and/or phosphoric acids, with addition, or...
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5211928 |
Method of improving gypsum slurry filtration in the production of phosphoric acid
A method for improving gypsum slurry filtration in the production of wet process phosphoric acid wherein an effective amount of carboxylic-type polymer having a portion of sulfonic functionality is...
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5188812 |
Automatic control system for a phosacid attack tank and filter
A method for controlling the phosphoric acid product concentration in a continuous phosphoric acid recovery process comprising supplying a constant feed stream of phosphate ore to an attack tank...
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5185135 |
Method of dewatering a wet process phosphoric acid slurry
A digested slurry from a wet process phosphoric acid production process is dewatered by gravity-assisted vacuum filtration using as a filtration aid an aqueous solution of a polymeric filtraton aid...
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5173280 |
Method of clarifying phosphoric acid using high charge sulfonic-type polymers
A method for clarifying phosphoric acid by flocculation or coagulation of solids wherein an effective amount of a polymer having a predominantly sulfonic functionality is used as the clarification...
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5120519 |
Scale control in phosphoric acid manufacture
High molecular weight copolymers of acrylamide which contain between 5-100 mole % of acrylic acid and have a molecular weight of at least 1,000,000 prevent scale adhering to surfaces in contact...
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5084261 |
Recovery and utilization of gypstack leachate in hemihydrate phosphoric acid process
Disclosed is a process for treating a waste stream containing calcium sulfate by depositing said waste stream on a gypstack, collecting the leachate from the gypstack, and recovering the P2 O5...
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5009873 |
Crystal modification in wet process phosphoric acid production
A wet process production of phosphoric acid in which phosphate rock is digested, whereby phosphoric acid is released and calcium sulfate crystals are formed, employs a polymeric crystal modifier in...
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5002744 |
Method for defluorinating wet process phosphoric acid
A method for defluorinating wet process phosphoric acid. Phosphatic waste clay from phosphate rock beneficiation is mixed with the wet process phosphoric acid. The mixture is heated for a time...
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4994248 |
P2 O5 recovery and phosphoric acid purification
Disclosed is an improved process for purifying phosphoric acid where a calcium sulfate hemihydrate slurry is first filtered to produce a first filtrate and a filter cake which comprises calcium...
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4853201 |
Recovery of P2 O5 values from phosphoric acid hemihydrate crystals
P2 O5 values occluded in the crystals which are precipitated during the hemihydrate process for manufacturing phosphoric acid are recovered by dissolving and recrystallizing the hemihydrate...
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4834787 |
Phosphate rock utilization
A process providing solubilization of phosphate rock by contacting the rock with sulfurous acid in the presence of an oxidizing agent selected from the group consisting of hydrogen peroxide and...
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4828811 |
Method for producing phosphoric acid from phosphate ore
A process and apparatus for producing phosphoric acid by the recovery of P2 O5 from a phosphate ore is disclosed. A slurry of a phosphate ore in an aqueous phosphoric acid solution is formed in...
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4822582 |
Process for the removal of heavy metals from acid, phosphate-containing, aqueous media
A process for the removal of heavy metals from an acid phosphate containing, liquid medium in which process a precipitate containing heavy metals is formed and is subsequently separated and wherein...
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4800071 |
Filtration aids for removal of calcium solids from aqueous phosphoric acid
Separation of gypsum from phosphoric acid liquor produced during the production of phosphoric acid from finely ground phosphate rock. These aids are characterized as containing sulfonate and...
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4797265 |
Process for the production of highly concentrated phosphoric acid
A process for the production of highly concentrated phosphoric acid, comprises improvements in digesting phosphate rock with a mixed acid consisting essentially of sulfuric acid and phosphoric acid...
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4780294 |
Process for making crude phosphoric acid
Crude phosphoric acid is made by subjecting crude phosphate ore containing sulfide to processing treatment with a mineral acid in a closed system comprised of a processing reactor, a filtering zone...
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4777027 |
Continuous process for preparing phosphoric acid and calcium sulphate
There is described a process which comprises adjusting on the one hand the flow rates of a circulating mixture relative to a base flow rate according to very specific specifications, and on the...
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4762698 |
Method for increasing fluosilicic acid recovered from wet process phosphoric acid production
A method is disclosed for increasing the fluosilicic acid (FSA) recovered from a wet process phosphoric acid manufacturing process. The filtrate obtained by washing a filter cake is pumped to a...
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4734272 |
Phospho-gypsum recovery process
This disclosure involves a process for treating wet phospho-gypsum, a by-product from wet phosphoric acid manufacture, to remove fluorine values so as to make the sulfur values in the...
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4714600 |
Process for production of phosphoric acid from dry matrix by SO3 treatment and extraction
Phosphoric acid is produced from dry phosphate ore, matrix by acidulation with sulfur trioxide in the presence of sulfuric acid catalyst to form polyphosphoric acid, treatment with sufficient water...
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4684512 |
Phosphate recovery from wet phosphoric acid purification process
The invention is a process for recovering phosphorus value from magnesium pyrophosphate containing filter media in the wet superphosphoric acid purification process. The invention comprises...
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4683127 |
Process for making wet-process phosphoric acid
Wet-process phosphoric acid is made by subjecting a phosphate ore to processing treatment with a mineral acid resulting in the formation of a processed suspension. The formation of silicofluorides...
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4643882 |
Process for recovery by a solvent of the uranium present in phosphoric acid
A process for the recovery of the uranium present in phosphoric acid produced by a wet process in (A) by means of a suitable solvent (L9), which is carried out after separation of the gypsum in (B)...
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4637922 |
Method for removing organic materials from a wet process phosphoric acid
A method for removing organic materials from a wet process phosphoric acid obtained by treating an uncalcined phosphate rock with sulfuric acid. The wet process phosphoric acid is contacted with a...
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4636372 |
Aluminum fluorophosphates made from impure phosphoric acids and conversion thereof to alkalimetal phosphates
Alkali metal phosphates and HF can be produced from a substantially calcium-free fluoroaluminum phosphate precipitate (which also contains iron) made by the aging of wet process phosphoric acid...
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4632814 |
Process for stabilizing phosphoric acid
An improved process for stabilizing wet process phosphoric acid is described in which the acid is treated with pressurized carbon dioxide and then is aged so as to enhance the rate of...
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4608238 |
Process for treating phospho-gypsum waste product from wet-acid process of making phosphoric acid
This disclosure concerns an improved phospho-gypsum recovery process in which phospho-gypsum waste product and coke are first heated to remove moisture, some SO2 and other vaporous matter, then...
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4592901 |
Method of removing suspended solids from phosphoric acid
A process for removing impurities from phosphoric acid, especially concentrated wet process phosphoric acid, comprises filtering phosphoric acid through a filter cake (e.g., diatomite) on a porous...
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4588570 |
Method for the preparation of phosphoric acid and calcium sulphate
The present invention provides a continuous method for preparing phosphoric acid and calcium sulphate by reacting calcium phosphate with a mixture of sulphuric acid and phosphoric acid. Our method...
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4581156 |
Control of foam formation in the manufacture of wet process phosphoric acid
Significant improvements in defoaming in a wet-process phosphoric acid reactor are obtained by adding to the reactor during the digestion process both a surfactant defoamer and a polyacrylamide.
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4577804 |
Wet grinding phosphate rock in an acidic slurry
Phosphate rock contained in an acidic slurry is ground by equipment wherein the acidic slurry contacts the metallic surfaces of the equipment. A method for monitoring and controlling grinding ball...
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4559204 |
Treatment of phosphate ore used in preparing phosphate matrix slurries
There is disclosed a method of producing water-based phosphate matrix slurries wherein the as-mined phosphate matrix is dried prior to the formation of the slurry. Drying the matrix decreases the...
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4557915 |
Production of phosphoric acid
Phosphoric acid is produced, with concomitant recovery of solids comprising compounds of fluorine and silica, by (i) acidulating a first amount of phosphate ore with a strong acid to produce a...
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4556545 |
Method for conditioning phosphate ores
There is disclosed an improved process of beneficiating phosphate-containing ores. The process comprises stabilizing a hydrocarbon oil, normally used in a conditioning step to improve separation of...
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4540511 |
Defoamer and processing aid for wet process phosphoric acid
A defoamer composition comprising a mixture of defoaming effective amounts of monocarboxylic acid having from 12 to 26 carbon atoms, a monoalkanolamide, and an alcohol selected from the group...
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4524057 |
Production of concentrated phosphoric acid and hemihydrated calcium sulfate
Concentrated phosphoric acid and calcium sulfate hemihydrate are directly produced by sulfuric acid attack upon calcium phosphate, the improvements comprising (i) continuously conducting the acid...
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