US3758566A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Removal of iron impurities
Assignee: Celanese Corp
•
Filing: 1971-04-21
•
Granted: 1973-09-11
•
Expires: 1991-04-21
Abstract
Abstract Iron impurities are removed from an aqueous nitric acid solution containing copper and vanadium catalyst ions by solvent extraction with an organic solution of an organo-phosphate prior to passing the aqueous nitric acid solution through an ion exchange zone for recovery of the copper and vanadium.
Inventors
- 👤 G Organ
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:03
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/42; C07C51/48; C01; C01B; C01B21/00; C01B21/20; C01B21/38; C01B21/46
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
49 words
The process of claim 1 wherein the amount of said organic solution contacted with said aqueous nitric acid solution is sufficient to provide at least 25 parts by weight of said organic ester of orthophosphoric acid per part by weight of iron present in said aqueous nitric acid solution.
Claim 2
Dependent Claim
14 words
The process of claim 1 wherein said organic solvent is normally liquid hydrocarbon solvent.
Claim 3
Dependent Claim
20 words
The process of Claim 1 wherein said organic solvent is a water-immiscible, monohydric alkanol of five to 10 carbon atoms.
Claim 4
Dependent Claim
79 words
The process of claim 1 wherein said aqueous nitric acid solution contains by weight from about 10 to 35 percent nitric acid, 10 to 25 percent lower alkyl dicarboxylic acids, 0.1 to 1.0 percent copper and 0.01 to 0.1 percent vanadium, and is derived from a process wherein adipic acid is recovered by crystallization from the product obtained by the nitric acid oxidation of cyclohexanone, cyclohexanol or mixtures thereof in the presence of a catalyst containing copper and vanadium.
Claim 5
Dependent Claim
46 words
The process of claim 5 wherein said organic solvent is a monohydric alkanol of five to 10 carbon atoms, a dialkyl ether of six to 15 carbon atoms, a normally liquid hydrocarbon or an alkanone of six to 15 carbon atoms having a single carbonyl group.
Claim 6
Dependent Claim
87 words
The process of claim 6 wherein the intimate contact of said aqueous nitric acid solution and said immiscible organic solution is accomplished at a temperature within the range of 20* C. to 60* C., a pressure sufficient to prevent boiling, and wherein the amount of said immiscible organic solution contacted with said aqueous nitric acid solution is sufficient to provide from 50 to 500 parts by weight of said organic ester of orthophosphoric acid per part by weight of iron present in said aqueous nitric acid solution.
Claim 7
Dependent Claim
21 words
The process of claim 7 wherein said organic solvent is a water immiscible, monohydric alkanol of five to 10 carbon atoms.
Claim 8
Dependent Claim
14 words
The process of claim 7 wherein said organic solvent is a normally liquid hydrocarbon.
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) | 1976-09-10 | 1977-03-12 | 1977-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-10 | 1981-03-12 | 1981-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-10 | 1985-03-12 | 1985-09-11 | $7700.00 | Window Closed / Lapsed |