US4543169A
Expired / Lapsed
US
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Gold recovery process
Assignee: Rai Research Corp
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Filing: 1983-08-31
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Granted: 1985-09-24
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Expires: 2003-08-31
Abstract
Abstract A method is described for precious metal recovery from acidic precious metal-cyanide solutions by means of a weakly-basic anion-exchange material comprising a polymeric felt incorporating radiation-grafted pyridinyl functional groups.
Inventors
- 👤 Vincent F. D'Agostino
- 👤 Joseph Y. Lee
- 👤 Stephen Zapisek
- 👤 George Schore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:03
CPC Classifications
C; C25; C25C; C25C1/00; C01; C01G; C01G11/00; C01G11/003; C01G15/00; C01G15/003; C01G3/00; C01G3/003; C01G5/00; C01G5/003; C01G55/00; C01G55/001; C01G7/00; C01G7/003; C22; C22B; C22B3/00; C22B3/20; C22B3/42; C25C1/20; Y; Y02; Y02P; Y02P10/00; Y02P10/20; Y10; Y10S; Y10S423/00; Y10S423/09; Y10S423/14
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
62 words
A method of metal recovery comprising; (a) forming a weakly-basic anion-exchange material by radiation-grafting monomers comprising pyridinyl functional groups to a polymeric felt substrate to the extent of 10-1500%; and (b) contacting the anion-exchange material with an acidic aqueous solution comprising metal-cyanide anions so as to form a complex between the anions and the pyridinyl groups, thereby removing the anions from solution.
Claim 2
Independent Claim
62 words
A method of metal recovery comprising; (a) forming a weakly-basic anion-exchange material by radiation-grafting monomers comprising pyridinyl functional groups to a polymeric felt substrate to the extent of 10-1500%; and (b) contacting the anion-exchange material with an acidic aqueous solution comprising metal-cyanide anions so as to form a complex between the anions and the pyridinyl groups, thereby removing the anions from solution.
Claim 3
Dependent Claim
33 words
The method of claim 1 further comprising: (a) decomplexing said metal cyanide anions by contacting the ion-exchange material with an aqueous base; and (b) recovering the metal from the aqueous base by electrodeposition.
Claim 4
Independent Claim
24 words
The method of claims 1 or 2 wherein the metal is selected from the group consisting of gold, silver, copper, palladium, cadmium and indium.
Claim 5
Dependent Claim
19 words
The method of claim 3 wherein the metal is gold and the precious metal-cyanide anions comprise gold dicyanide anions.
Claim 6
Independent Claim
25 words
The method of claims 1 or 2 wherein the monomer comprises 2-vinyl pyridine or 4-vinyl pyridine and the polymeric felt comprises a nonwoven polypropylene felt.
Claim 7
Dependent Claim
15 words
The method of claim 2 wherein the aqueous base comprises sodium hydroxide or potassium hydroxide.
Claim 8
Independent Claim
64 words
A method of gold recovery comprising: (a) forming a weakly-basic anion-exchange material by radiation-grafting 2-vinyl pyridine or 4-vinyl pyridine to a polymeric felt substrate to the extent of 100-1000%; and (b) contacting the resin with an acidic aqueous solution comprising potassium gold dicyanide so as to form a complex between the pyridine groups and the gold dicyanide anions, thereby removing the anions from solution.
Claim 9
Independent Claim
64 words
A method of gold recovery comprising: (a) forming a weakly-basic anion-exchange material by radiation-grafting 2-vinyl pyridine or 4-vinyl pyridine to a polymeric felt substrate to the extent of 100-1000%; and (b) contacting the resin with an acidic aqueous solution comprising potassium gold dicyanide so as to form a complex between the pyridine groups and the gold dicyanide anions, thereby removing the anions from solution.
Claim 10
Dependent Claim
37 words
The method of claim 7 further comprising: (a) decomplexing the anion complex by contacting the ion-exchange material with an aqueous solution of potassium or sodium hydroxide; and (b) removing the gold from the aqueous base by electrodeposition.
Claim 11
Independent Claim
16 words
The method of claims 7 or 8 wherein the polymeric felt comprises a nonwoven polypropylene felt.
Claim 12
Dependent Claim
28 words
The method of claim 8 wherein the aqueous solution of potassium or sodium hydroxide is heated to about 100°-180° F. prior to being contacted with the ion-exchange material.
Claim 13
Independent Claim
62 words
A method of precious metal recovery comprising: contacting a weakly basic anionic exchange material with an acidic aqueous solution comprising metal-cyanide anions so as to form a complex between the anions and the material, thereby removing the anions from the solution; said material comprising a polymeric felt substrate radiation-grafted to the extent of 10-1500% with a monomer comprising a pyridinyl functional group.
Claim 14
Independent Claim
62 words
A method of precious metal recovery comprising: contacting a weakly basic anionic exchange material with an acidic aqueous solution comprising metal-cyanide anions so as to form a complex between the anions and the material, thereby removing the anions from the solution; said material comprising a polymeric felt substrate radiation-grafted to the extent of 10-1500% with a monomer comprising a pyridinyl functional group.
Claim 15
Dependent Claim
31 words
The method of claim 11 further comprising: (a) decomplexing the complex by contacting the anion-exchange material with an aqueous base; and (b) recovering the metal from the aqueous base by electrodepositon.
Claim 16
Independent Claim
21 words
The method of claims 11 or 12 wherein the metal is gold and the precious metal-cyanide anions comprise gold dicyanide anions.
Claim 17
Independent Claim
25 words
The method of claims 11 or 12 wherein the monomer comprises 2-vinyl pyridine or 4-vinyl pyridine and the polymeric felt comprises a nonwoven polypropylene felt.
Claim 18
Dependent Claim
15 words
The method of claim 12 wherein the aqueous base comprises sodium hydroxide or potassium hydroxide.
Claim 19
Independent Claim
26 words
The method of claims 11 or 12 wherein the felt substrate comprises a polymer selected from the group consisting of polypropylene, nylon, polyethylene, polytetrafluoroethylene and cellulosics.
References Cited (Backward Citations)
US4230549A
Cited
US4321145A
Cited
US4267159A
Cited
US4339473A
Cited
US4372830A
Cited
US4500396A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-23 | 1989-03-25 | 1989-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-23 | 1993-03-25 | 1993-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-23 | 1997-03-25 | 1997-09-24 | $7700.00 | Window Closed / Lapsed |