US4406752A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrowinning of noble metals
Assignee: General Electric Co
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Filing: 1982-11-29
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Granted: 1983-09-27
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Expires: 2002-11-29
Abstract
Abstract Nobel metals such as silver and gold are removed from solutions containing them in an electrolytic process in which the cathode of an electrolytic cell comprises a carbon fiber mass. Metal ions are plated out on to the carbon fibers which exhibit a large surface area in the highly porous cathode. Recovery of the metal values is obtained through heating the plated fiber mass to a temperature sufficient to burn off the carbon fibers.
Inventors
- 👤 Joseph L. Weininger
- 👤 Bang M. Kim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:23
CPC Classifications
C; C25; C25C; C25C1/00; C25C1/20; C02; C02F; C02F1/00; C02F1/46; C02F1/461; C02F1/467; C02F1/4672; C02F1/4676; C02F1/4678
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
89 words
A method for electrowinning of noble metals comprising: passing a solution containing noble metals through an electrolytic cell having an anode and cathode, the cathode of which comprises a carbon fiber mass; simultaneously applying a direct current voltage between said anode and cathode, the negative polarity of said voltage being applied to said cathode, so as to deposit said dissolved metal on said carbon fiber cathode; removing said fiber mass from said cell; and heating said plated fiber mass to a temperature sufficient to burn off said carbon fibers.
Claim 2
Independent Claim
89 words
A method for electrowinning of noble metals comprising: passing a solution containing noble metals through an electrolytic cell having an anode and cathode, the cathode of which comprises a carbon fiber mass; simultaneously applying a direct current voltage between said anode and cathode, the negative polarity of said voltage being applied to said cathode, so as to deposit said dissolved metal on said carbon fiber cathode; removing said fiber mass from said cell; and heating said plated fiber mass to a temperature sufficient to burn off said carbon fibers.
Claim 3
Dependent Claim
24 words
The method of claim 1 in which said heating step is performed at a temperature of between approximately 250° C. and approximately 400° C.
Claim 4
Dependent Claim
22 words
The method of claim 1 in which said noble metals are selected from the group consisting of silver, gold and combinations thereof.
Claim 5
Dependent Claim
22 words
The method of claim 1 in which said heating step is performed at a temperature sufficient to also melt said metal deposit.
References Cited (Backward Citations)
US4330387A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-09-26 | 1987-03-28 | 1987-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-26 | 1991-03-28 | 1991-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-26 | 1995-03-28 | 1995-09-27 | $7700.00 | Window Closed / Lapsed |