Patent US4632701A successfully refreshed from Google Patents.
US4632701A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the recovery of silver from a residue essentially free of elemental sulphur
Assignee: 698638 Alberta Ltd
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Filing: 1985-03-04
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Granted: 1986-12-30
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Expires: 2005-03-04
Abstract
Abstract A process for the recovery of silver from a residue essentially free of elemental sulphur obtained by acidic pressure oxidation leaching or iron-containing sulphidic material which comprises forming a slurry of the residue with lime at a temperature of at least about 80° C. to raise the pH of the slurry to at least about 9. The slurry is maintained at this temperature for from about 0.5 to about 4 hours, and the resultant slurry is subjected to silver recovery treatment.
Inventors
- 👤 Roman M. Genik-Sas-Berezowsky
- 👤 Donald R. Weir
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:04
CPC Classifications
C; C22; C22B; C22B11/00; C22B11/04; C22B7/00; C22B7/006; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
98 words
A process for the recovery of silver from a residue essentially free of elemental sulphur obtained by acidic pressure oxidation leaching of iron-containing sulphidic material, said residue containing less than about 10% by weight of elemental sulphur compared to the sulphur in the sulphidic material, comprising forming a slurry of the residue with lime at a temperature of at least about 80° C. to raise the pH of the slurry to at least about 9, maintaining the slurry at said temperature for from about 0.5 to about 4 hours, and subjecting the resultant slurry to silver recovery treatment.
Claim 2
Dependent Claim
98 words
A process for the recovery of silver from a residue essentially free of elemental sulphur obtained by acidic pressure oxidation leaching of iron-containing sulphidic material, said residue containing less than about 10% by weight of elemental sulphur compared to the sulphur in the sulphidic material, comprising forming a slurry of the residue with lime at a temperature of at least about 80° C. to raise the pH of the slurry to at least about 9, maintaining the slurry at said temperature for from about 0.5 to about 4 hours, and subjecting the resultant slurry to silver recovery treatment.
Claim 3
Dependent Claim
31 words
A process according to claim 1 wherein the residue is silver and gold containing residue essentially free of elemental sulphur obtained by acidic pressure oxidation of refractory auriferous iron-containing sulphidic material.
Claim 4
Dependent Claim
14 words
A process according to claim 1 wherein the silver recovery treatment comprises cyanidation treatment.
Claim 5
Dependent Claim
109 words
A process for the recovery of silver from a residue essentially free of elemental sulphur obtained by acidic pressure oxidation leaching of iron-containing sulphidic material, said residue containing less than about 10% by weight of elemental sulphur compared to the sulphur in the sulphidic material, comprising forming a slurry of the residue at a temperature of at least about 80° C. with lime to raise the pH to at least about 9 and with an alkali carbonate to raise the pH to at least about 10, maintaining the slurry at said temperature for from about 0.5 to about 4 hours, and subjecting the resultant slurry to silver recovery treatment.
Claim 6
Dependent Claim
109 words
A process for the recovery of silver from a residue essentially free of elemental sulphur obtained by acidic pressure oxidation leaching of iron-containing sulphidic material, said residue containing less than about 10% by weight of elemental sulphur compared to the sulphur in the sulphidic material, comprising forming a slurry of the residue at a temperature of at least about 80° C. with lime to raise the pH to at least about 9 and with an alkali carbonate to raise the pH to at least about 10, maintaining the slurry at said temperature for from about 0.5 to about 4 hours, and subjecting the resultant slurry to silver recovery treatment.
Claim 7
Dependent Claim
31 words
A process according to claim 4 wherein the residue is silver and gold containing residue essentially free of elemental sulphur obtained by acidic pressure oxidation of refractory auriferous iron-containing sulphidic material.
Claim 8
Dependent Claim
13 words
A process according to claim 4 wherein the alkali carbonate comprises sodium carbonate.
Claim 9
Dependent Claim
14 words
A process according to claim 4 wherein the silver recovery treatment comprises cyanidation treatment.
Claim 10
Dependent Claim
19 words
A process according to claim 1 wherein the resultant slurry is subjected to silver recovery treatment without liquid-solids separation.
Claim 11
Dependent Claim
38 words
A process according to claim 1 wherein the residue obtained from the iron-containing sulphidic material contains less than about 0.5% by weight of elemental sulphur compared to the sulphur in the material subjected to acidic pressure oxidation leaching.
Claim 12
Dependent Claim
20 words
A process according to claim 2 wherein the residue is subjected to a gold recovery step before said lime step.
Claim 13
Dependent Claim
19 words
A process according to claim 4 wherein the resulting slurry is subjected to silver recovery treatment without liquid-solids separation.
Claim 14
Dependent Claim
35 words
A process according to claim 4 wherein the essentially elemental sulphur-free residue contains less than about 0.5% by weight of elemental sulphur compared to the sulphur in the material subjected to acidic pressure oxidation leaching.
Claim 15
Dependent Claim
20 words
A process according to claim 5 wherein the residue is subjected to a gold recovery step before said lime step.
Claim 16
Dependent Claim
106 words
A process for the recovery of silver from iron-containing sulphidic material comprising subjecting the material to acidic pressure oxidation leaching to convert sulphur values in the material to sulphate form and produce an essentially sulphur-free residue containing less than about 10% by weight of elemental sulphur compared to the sulphur in the sulphidic material, forming a slurry of the residue with lime at a temperature of at least about 80° C. to raise the pH of the slurry to at least about 9, maintaining the slurry at said temperature for from about 0.5 to about 4 hours and subjecting the resultant slurry to silver recovery treatment.
Claim 17
Dependent Claim
106 words
A process for the recovery of silver from iron-containing sulphidic material comprising subjecting the material to acidic pressure oxidation leaching to convert sulphur values in the material to sulphate form and produce an essentially sulphur-free residue containing less than about 10% by weight of elemental sulphur compared to the sulphur in the sulphidic material, forming a slurry of the residue with lime at a temperature of at least about 80° C. to raise the pH of the slurry to at least about 9, maintaining the slurry at said temperature for from about 0.5 to about 4 hours and subjecting the resultant slurry to silver recovery treatment.
Claim 18
Dependent Claim
47 words
A process according to claim 14 comprising forming a slurry of the residue at a temperature of at least about 80° C. with lime to raise the pH to at least about 9 and with an alkali carbonate to raise the pH to at least about 10.
Claim 19
Dependent Claim
31 words
A process according to claim 14 wherein the residue is silver and gold containing residue essentially free of elemental sulphur obtained by acidic pressure oxidation of refractory auriferous iron-containing sulphidic material.
Claim 20
Dependent Claim
19 words
A process according to claim 14 wherein the resultant slurry is subjected to silver recovery treatment without liquid-solids separation.
Claim 21
Dependent Claim
20 words
A process according to claim 16 wherein the residue is subjected to a gold recovery step before said lime step.
Claim 22
Dependent Claim
30 words
A process according to claim 14 wherein said essentially elemental sulphur-free residue contains less than about 0.5% by weight of elemental sulphur compared to the sulphur in the sulphidic material.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-29 | 1990-06-30 | 1990-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-29 | 1994-06-30 | 1994-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-29 | 1998-06-30 | 1998-12-30 | $7700.00 | Window Closed / Lapsed |