Patent US3607029A successfully refreshed from Google Patents.
US3607029A
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Continuous process for solvent purification of phosphoric acid
Assignee: UCB SA
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Filing: 1968-05-09
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Granted: 1971-09-21
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Expires: 1988-05-09
Abstract
Abstract The process for extraction and purification of phosphoric acid from impure solutions of phosphoric acid derived by acid attack of phosphate rock wherein the impure solution is first passed in countercurrent flow with an alkyl derivative of phosphoric acid for removal of phosphoric acid from the impure solution and then passing the alkyl phosphoric acid derivative containing the removed phosphoric acid in countercurrent flow with an aqueous medium whereby the latter removes purified phosphoric acid from the solution.
Inventors
- 👤 Jean R Goret
- 👤 Louis M Winand
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:15
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/18; C01B25/234
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
37 words
The process as claimed in claim 1 which includes the step of recycling the solvent issuing from the second extraction zone to the first extraction for passage in countercurrent flow with the impure solution of phosphoric acid.
Claim 2
Dependent Claim
25 words
The process as claimed in claim 1 in which the strong acid added at an intermediate stage of the first extraction zone is sulfuric acid.
Claim 3
Dependent Claim
27 words
The process as claimed in claim 1 which includes the step of treating the product from the third extraction zone with activated carbon to decolorize the product.
Claim 4
Dependent Claim
28 words
The process as claimed in claim 1 which includes the step of treating the product from the third extraction zone with long chain amines to remove anionic impurities.
Claim 5
Dependent Claim
28 words
The process as claimed in claim 1 which includes the step of extracting the depleted solution from the first extraction zone solvents to recover rare earths and yttrium.
Claim 6
Dependent Claim
53 words
A process as defined in claim 1 which includes the step of subdividing the aqueous phosphoric acid from the third extraction zone into one increment as a product and another increment as a wash, and passing the wash increment to the second extraction zone for countercurrent contact with the phosphoric acid-containing solvent extract.
References Cited (Backward Citations)
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US3259472A
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US3388967A
Cited
US3375068A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |