Patent US1828532A successfully refreshed from Google Patents.
US4157434A
Expired / Lapsed
US
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Process for removing metal-EDTA complex and free EDTA salts from mixed aqueous-organic media
Assignee: General Electric Co
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Filing: 1977-12-30
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Granted: 1979-06-05
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Expires: 1997-12-30
Abstract
Abstract Ethylenediaminetetraacetic acid (EDTA)-complexed heavy metals alone or together with free EDTA salts are removed from solution in a mixture comprising a solvent for a polyphenylene ether resin, an antisolvent for a polyphenylene ether resin and water, by contacting the mixture with alumina for a time at least sufficient to selectively adsorb the metal-EDTA complex and free EDTA salts and recover the mixture of solvent, antisolvent and water substantially free of the metal-EDTA complex and EDTA salts. The alumina can be regenerated to nearly its full original adsorption capacity by contacting with water at a neutral or nearly neutral pH, to give an aqueous solution of the metal-EDTA complex and free EDTA salts.
Inventors
- 👤 Daniel E. Floryan
- 👤 Daniel W. Fox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:22
CPC Classifications
C; C08; C08G; C08G65/00; C08G65/34; C08G65/46
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
112 words
A process for removing a metal-ethylenediamine tetraacetic acid complex alone or together with an unchelated salt of ethylenediamine tetraacetic acid from solution in a mixture comprising a solvent for a polyphenylene ether resin, an antisolvent for said resin and water, the process comprising: (a) contacting said mixture with at least an effective amount of alumina for a time at least sufficient to selectively adsorb substantially all of said metal-ethylenediamine tetraacetic acid complex and unchelated salt of ethylenediamine tetraacetic acid, and (b) recovering a mixture comprising said solvent for said polyphenylene ether resin, said antisolvent and said water substantially free of said metal-ethylenediamine tetraacetic acid complex and unchelated salt of ethylenediamine tetraacetic acid.
Claim 2
Dependent Claim
112 words
A process for removing a metal-ethylenediamine tetraacetic acid complex alone or together with an unchelated salt of ethylenediamine tetraacetic acid from solution in a mixture comprising a solvent for a polyphenylene ether resin, an antisolvent for said resin and water, the process comprising: (a) contacting said mixture with at least an effective amount of alumina for a time at least sufficient to selectively adsorb substantially all of said metal-ethylenediamine tetraacetic acid complex and unchelated salt of ethylenediamine tetraacetic acid, and (b) recovering a mixture comprising said solvent for said polyphenylene ether resin, said antisolvent and said water substantially free of said metal-ethylenediamine tetraacetic acid complex and unchelated salt of ethylenediamine tetraacetic acid.
Claim 3
Dependent Claim
65 words
A process according to claim 1 which includes the additional steps of: (c) contacting the alumina from step (b) with water at a neutral or nearly neutral pH to separate the adsorbed metal-ethylenediamine tetraacetic acid complex and unchelated salt of ethylenediamine tetraacetic acid from said alumina, and (d) recovering an aqueous solution of said metal-ethylenediamine tetraacetic acid complex and unchelated salt of ethylenediamine tetraacetic acid.
Claim 4
Dependent Claim
12 words
A process as defined in claim 1 wherein said metal is copper.
Claim 5
Dependent Claim
12 words
A process as defined in claim 1 wherein said solvent is toluene.
Claim 6
Dependent Claim
12 words
A process as defined in claim 1 wherein said antisolvent is methanol.
Claim 7
Dependent Claim
17 words
A process as defined in claim 1 wherein a disodium salt of ethylenediamine tetraacetic acid is employed.
Claim 8
Dependent Claim
17 words
A process as defined in claim 1 wherein a trisodium salt of ethylenediamine tetraacetic acid is employed.
Claim 9
Dependent Claim
17 words
A process as defined in claim 1 wherein a tetrasodium salt of ethylenediamine tetraacetic acid is employed.
Claim 10
Dependent Claim
19 words
A process as defined in claim 2 wherein the pH of water is from about 6 to about 8.
Claim 11
Dependent Claim
97 words
A process for recovering a copper-ethylenediamine tetraacetic acid complex alone or together with an unchelated sodium salt of ethylenediamine tetraacetic acid from solution in a mixture comprising toluene, methanol and water, the process comprising: (a) contacting said mixture with at least an effective amount of alumina for a time at least sufficient to selectively adsorb substantially all of said copper-ethylenediamine tetraacetic acid complex and unchelated sodium salt of ethylenediamine tetraacetic acid, and (b) recovering a mixture comprising toluene, methanol and water substantially free of said copper-ethylenediamine tetraacetic acid complex and unchelated sodium salt of ethylenediamine tetraacetic acid.
Claim 12
Dependent Claim
97 words
A process for recovering a copper-ethylenediamine tetraacetic acid complex alone or together with an unchelated sodium salt of ethylenediamine tetraacetic acid from solution in a mixture comprising toluene, methanol and water, the process comprising: (a) contacting said mixture with at least an effective amount of alumina for a time at least sufficient to selectively adsorb substantially all of said copper-ethylenediamine tetraacetic acid complex and unchelated sodium salt of ethylenediamine tetraacetic acid, and (b) recovering a mixture comprising toluene, methanol and water substantially free of said copper-ethylenediamine tetraacetic acid complex and unchelated sodium salt of ethylenediamine tetraacetic acid.
Claim 13
Dependent Claim
70 words
A process as defined in claim 10 which comprises the additional steps of: (c) contacting the alumina from step (b) with water at a pH of from about 6 to about 8 to separate the adsorbed copper-ethylenediamine tetraacetic acid complex and unchelated sodium salt of ethylenediamine tetraacetic acid from said alumina, and (d) recovering an aqueous solution of said copper-ethylenediamine tetraacetic acid complex and unchelated salt of ethylenediamine tetraacetic acid.
References Cited (Backward Citations)
US3951917A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-06-04 | 1982-12-04 | 1983-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-06-04 | 1986-12-04 | 1987-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-06-04 | 1990-12-04 | 1991-06-05 | $7700.00 | Window Closed / Lapsed |