Patent US2110990A successfully refreshed from Google Patents.
US3920403A
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Method of desorbing gold from activated carbon
Assignee: United States Department of the Interior
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Filing: 1974-02-01
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Granted: 1975-11-18
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Expires: 1994-02-01
Abstract
Abstract Gold in the form of its cyanide complex is desorbed from activated carbon by contacting the carbon with a stripping liquid at temperatures above that 130*C but below the decomposition temperature of the gold cyanide complex. The stripping liquid may comprise water, dilute caustic or dilute caustic cyanide.
Inventors
- 👤 J Richard Ross
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:14
CPC Classifications
C; C22; C22B; C22B11/00; C22B11/04; C01; C01G; C01G7/00; C22B3/00; C22B3/20; C22B3/22; C22B3/24; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
72 words
A METHOD FOR RECOVERING GOLD ADSORBED ON ACTIVATED CARBON IN THE FORM OF A GOLD CYANIDE COMPLEX WHICH COMPRISES: CONTACTING THE GOLD-LOADED CARBON WITH A LIQUID SELECTED FROM THE GROUP CONSISTING OF WATER, DILUTE CAUSTIC, AND DILUTE CAUSTIC CYANIDE AT A TEMPERATURE IN THE RANGE OF 150* TO 165*C WHEREBY ADSORBED GOLD CYANIDE IS DESORBED FROM THE CARBON AND GOES INTO SOLUTION IN THE LIQUID, AND RECOVERING DISSOLVED GOLD FROM THE LIQUID.
Claim 2
Independent Claim
72 words
A METHOD FOR RECOVERING GOLD ADSORBED ON ACTIVATED CARBON IN THE FORM OF A GOLD CYANIDE COMPLEX WHICH COMPRISES: CONTACTING THE GOLD-LOADED CARBON WITH A LIQUID SELECTED FROM THE GROUP CONSISTING OF WATER, DILUTE CAUSTIC, AND DILUTE CAUSTIC CYANIDE AT A TEMPERATURE IN THE RANGE OF 150* TO 165*C WHEREBY ADSORBED GOLD CYANIDE IS DESORBED FROM THE CARBON AND GOES INTO SOLUTION IN THE LIQUID, AND RECOVERING DISSOLVED GOLD FROM THE LIQUID.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein said liquid is passed in counterflow relationship to the gold-loaded carbon in a pressure vessel.
Claim 4
Dependent Claim
27 words
The method of claim 2 wherein dissolved gold is recovered from the liquid by electrolytic means and wherein the gold-depleted liquid is recycled to the desorption step.
Claim 5
Dependent Claim
12 words
The method of claim 3 wherein the liquid is a dilute caustic.
Claim 6
Dependent Claim
13 words
The method of claim 3 wherein the liquid is a dilute caustic cyanide.
Claim 7
Dependent Claim
29 words
The method of claim 3 wherein the gold content of said gold-loaded carbon is in the range of 250 to 1000 troy ounces of gold per ton of carbon.
Claim 8
Dependent Claim
17 words
The method of claim 4 wherein said dilute caustic contains from about 0.1 to 1.0% sodium hydroxide.
References Cited (Backward Citations)
US981451A
Cited
US2493396A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |