US3656893A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ion exchange removal of cyanide values
Assignee: EIDP Inc
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Filing: 1970-07-02
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Granted: 1972-04-18
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Expires: 1990-07-02
Abstract
Abstract A method of removing cyanide values from aqueous solutions containing sodium or potassium cyanide, or the sodium or potassium salts of the complex cyanides of the metals copper, nickel, zinc, silver, gold and cadmium, utilizing a mixed bed of ion exchange resins.
Inventors
- 👤 Walter John Sloan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:07
CPC Classifications
B; B01; B01J; B01J47/00; B01J47/02; B01J47/04; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/903; Y10S210/904
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
43 words
The method of removing cyanide values from an aqueous process solution according to claim 1 wherein said ion exchange bed is a mixture of the hydrogen form of a carboxylic ion exchange resin and the free base form of a weak base resin.
Claim 2
Dependent Claim
43 words
The method of removing cyanide values from an aqueous process solution according to claim 1 wherein said ion exchange bed is a mixture of the hydrogen form of a phosphonic ion exchange resin and the free base form of a weak base resin.
Claim 3
Dependent Claim
35 words
The method of removing cyanide values from an aqueous process solution according to claim 1 in which the cation exchange portion of the mixed bed is composed of a mixture of carboxylic and sulfonic resins.
Claim 4
Dependent Claim
43 words
The method of removing cyanide values from an aqueous process solution according to claim 1 wherein said acids are periodically removed from the weak base resin of step (3) by contacting with sodium or potassium hydroxide to form the salts of said acids.
Claim 5
Dependent Claim
31 words
The method of removing cyanide values from an aqueous process solution according to claim 5 wherein said salts of said acids are returned to said electroplating bath or other desired use.
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) | 1975-04-18 | 1975-10-18 | 1976-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-18 | 1979-10-18 | 1980-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-18 | 1983-10-18 | 1984-04-18 | $7700.00 | Window Closed / Lapsed |