US3903247A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cleaning of phosphoric acid
Assignee: IMI TAMI Institute for Research and Development
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Filing: 1974-07-05
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Granted: 1975-09-02
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Expires: 1994-07-05
Abstract
Abstract Cleaning of phosphoric acid. An aqueous phosphoric acid starting solution is extracted with a mixture of 75-95% by weight of at least one dialkyl ether in which each alkyl radical has 2-5 carbon atoms and 5-25% by weight of at least one aliphatic alcohol having 3-8 carbon atoms. The extract is heated to cause phase separation and an aqueous phase is withdrawn as product.
Inventors
- 👤 Ruth Blumberg
- 👤 Avraham Matitiahu Baniel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:39
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/18; C01B25/234
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
134 words
A PROCESS FOR EXTRACTING PHOSPHORIC ACID FROM AN AQUEOUS STARTING SOLUTION THEREOF WHICH COMPRISES CONTACTING SAID AQUEOUS STARTING SOLUTION WITH A MIXED SOLVENT CONTAINING 75-95% BY WEIGHT OF AT LEAST ONE EITHER R--O--R1 IN WHICH R AND R1 ARE HE AME OR DIFFERENT ALIPHATIC RAFICALS HAVING 2-5 CARBON ATOMS AND 5-25% BY WEIGHT OF AT LEAST ONE ALIPHATIC ALCHOL HAVING 3-8 CARBON ATOMS, AT A TEMPERATURE LOW ENOUGH TO FORM A CLEAR HOMOGENEOUS EXTRACT PHASE CONTAINING EXTRACTED PHOSPHORIC ACID DISTINCT FROM A RESIDUAL AQUEOUS PHASE , SEPERATING THE EXTRACT PHASE FROM THE AQUEOUS PHASE, RAISING THE TEMPERATURE OF THE EXTRACT PHASE AND ADDING SUFFICIENT WATER SO THAT THE EXTRACT SEPERATES INTO A LOWER AQUEOUS LAYER CONTAINING PHOSPHORIC ACID AND AN UPPER SOLVENT LAYER, AND SEPARATING THE LOWER AQUEOUS LAYER FROM THE UPPER SOLVENT LAYER.
Claim 2
Dependent Claim
134 words
A PROCESS FOR EXTRACTING PHOSPHORIC ACID FROM AN AQUEOUS STARTING SOLUTION THEREOF WHICH COMPRISES CONTACTING SAID AQUEOUS STARTING SOLUTION WITH A MIXED SOLVENT CONTAINING 75-95% BY WEIGHT OF AT LEAST ONE EITHER R--O--R1 IN WHICH R AND R1 ARE HE AME OR DIFFERENT ALIPHATIC RAFICALS HAVING 2-5 CARBON ATOMS AND 5-25% BY WEIGHT OF AT LEAST ONE ALIPHATIC ALCHOL HAVING 3-8 CARBON ATOMS, AT A TEMPERATURE LOW ENOUGH TO FORM A CLEAR HOMOGENEOUS EXTRACT PHASE CONTAINING EXTRACTED PHOSPHORIC ACID DISTINCT FROM A RESIDUAL AQUEOUS PHASE , SEPERATING THE EXTRACT PHASE FROM THE AQUEOUS PHASE, RAISING THE TEMPERATURE OF THE EXTRACT PHASE AND ADDING SUFFICIENT WATER SO THAT THE EXTRACT SEPERATES INTO A LOWER AQUEOUS LAYER CONTAINING PHOSPHORIC ACID AND AN UPPER SOLVENT LAYER, AND SEPARATING THE LOWER AQUEOUS LAYER FROM THE UPPER SOLVENT LAYER.
Claim 3
Dependent Claim
16 words
Process according to claim 1, wherein the extraction temperature is within the range of -5*to 80*C.
Claim 4
Dependent Claim
13 words
Process according to claim 2, wherein the extraction temperature does not exceed 40*C.
Claim 5
Dependent Claim
15 words
A process according to claim 1, wherein said aqueous starting solution is technical-grade phosphoric acid.
Claim 6
Dependent Claim
41 words
A process according to claim 1, wherein said aqueous starting solution is a residual acid solution remaining after extraction of a technical-grade phosphoric acid with an ether R-O-R1 in which R and R1 are aliphatic radicals having 2- 5 carbon atoms.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-01 | 1979-03-03 | 1979-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-01 | 1983-03-03 | 1983-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-01 | 1987-03-03 | 1987-09-02 | $7700.00 | Window Closed / Lapsed |