US4267069A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Regeneration of activated carbon to increase its gold adsorption capacity
Assignee: Individual
•
Filing: 1979-09-28
•
Granted: 1981-05-12
•
Expires: 1999-09-28
Abstract
Abstract A method of regenerating an activated carbon which has had its collecting capacity for gold adsorption reduced through use which includes the step of contacting the carbon with an aqueous copper salt solution having a pH of less than 6. The regeneration is improved if the solution contains carbonic acid or if the copper salt solution treatment is followed by treatment with a carbonate or bicarbonate solution.
Inventors
- 👤 Raymond J. Davidson
- 👤 Vittorio Veronese
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:05
CPC Classifications
C; C01; C01G; C01G7/00; C01G7/003; C01B; C01B32/00; C01B32/30; C01B32/354; C01B32/36; C22; C22B; C22B3/00; C22B3/20; C22B3/22; C22B3/24; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
39 words
A method of regenerating an activated carbon which has had its collecting capacity for gold adsorption reduced through use, includes the step of contacting the carbon with an aqueous copper salt solution having a pH of less than 6.
Claim 2
Independent Claim
39 words
A method of regenerating an activated carbon which has had its collecting capacity for gold adsorption reduced through use, includes the step of contacting the carbon with an aqueous copper salt solution having a pH of less than 6.
Claim 3
Dependent Claim
18 words
A method of claim 1 wherein the copper salt solution is a copper chloride or copper nitrate solution.
Claim 4
Dependent Claim
15 words
A method of claim 1 wherein the copper salt solution is a copper sulphate solution.
Claim 5
Dependent Claim
21 words
A method of claim 1 wherein the copper salt solution contains up to 5 percent by weight of the copper salt.
Claim 6
Dependent Claim
14 words
A method of claim 1 wherein the copper salt solution also contains carbonic acid.
Claim 7
Dependent Claim
20 words
A method of claim 5 wherein the carbonic acid is produced in situ by bubbling carbon dioxide through the solution.
Claim 8
Dependent Claim
13 words
A method of claim 6 wherein the solution is saturated with carbon dioxide.
Claim 9
Dependent Claim
24 words
A method of claim 5 wherein the carbonic acid is produced in situ by adding a suitable carbonate or bicarbonate salt to the solution.
Claim 10
Dependent Claim
24 words
A method of claim 8 wherein the carbonate salt is added in an amount of up to five percent by weight of the solution.
Claim 11
Independent Claim
48 words
A method of regenerating an activated carbon which has had its collecting capacity for gold adsorption reduced through use, includes the step of contacting the carbon with an aqueous copper salt solution containing up to 5 percent by weight of the copper salt and also containing carbonic acid.
Claim 12
Independent Claim
48 words
A method of regenerating an activated carbon which has had its collecting capacity for gold adsorption reduced through use, includes the step of contacting the carbon with an aqueous copper salt solution containing up to 5 percent by weight of the copper salt and also containing carbonic acid.
Claim 13
Dependent Claim
21 words
A method of claim 10 wherein the solution is saturated with carbonic acid produced by bubbling carbon dioxide through the solution.
Claim 14
Dependent Claim
15 words
A method of claim 11 wherein the copper salt solution is a copper sulphate solution.
Claim 15
Dependent Claim
28 words
A method of claim 1 wherein contact between the copper salt solution and the carbon is followed by contacting the carbon with a suitable carbonate or bicarbonate solution.
Claim 16
Dependent Claim
11 words
A method of claim 13 wherein the carbonate is ammonium carbonate.
Claim 17
Dependent Claim
23 words
A method of claim 13 wherein the carbonate or bicarbonate solution contains up to five percent by weight of the carbonate or bicarbonate.
Claim 18
Dependent Claim
26 words
A method of claim 13 wherein contact between the carbon and the solution or solutions is achieved by agitating the carbon in the solution or solutions.
Claim 19
Dependent Claim
33 words
A method of claim 13 wherein contact between the carbon and the solution or solutions is achieved by placing the carbon in a column and passing the solution or solutions through the column.
References Cited (Backward Citations)
DE2009120A1
Cited
US3970737A
Cited
FR2252113B1
Cited
US3920403A
Cited
US3935006A
Cited
US4208378A
Cited
US4155983A
Cited
US4094668A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-11 | 1984-11-10 | 1985-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-11 | 1988-11-10 | 1989-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-11 | 1992-11-10 | 1993-05-12 | $7700.00 | Window Closed / Lapsed |