Patent US4438076A successfully refreshed from Google Patents.
US4438076A
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Method of extracting gold and silver from an ore
Assignee: GEA Group AG
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Filing: 1983-08-12
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Granted: 1984-03-20
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Expires: 2003-08-12
Abstract
Abstract Gold and/or silver is leached from comminuted ore with an alkaline cyanide lixiviant at a superatmospheric pressure of at least 25 bar and with high purity oxygen (at least 90% pure) to reduce the residence time at high yield.
Inventors
- 👤 Hartmut Pietsch
- 👤 Wolfgang Turke
- 👤 Ernst Bareuther
- 👤 Fritz Kampf
- 👤 Hubert Bings
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:03
CPC Classifications
C; C22; C22B; C22B11/00; C22B11/08; Y; Y10; Y10S; Y10S204/00; Y10S204/13
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
118 words
A method of recovering at least one element selected from the group which consists of gold and silver from an ore containing same, comprising the steps of: forming a slurry of the ore in an aqueous alkali cyanide solution; and maintaining said slurry in a turbulent state at a pressure of 25 to 130 bar by passing it through a tube reactor in continuous unidirectional flow, while injecting oxygen of a purity of at least 90% into said slurry in said tube reactor at said pressure so that the CN/O 2 molar ratio is at most 0.7 at 25 bar and 0.7 g/l NaCN and is lower at higher pressures whereby said element is leached from said ore.
Claim 2
Independent Claim
118 words
A method of recovering at least one element selected from the group which consists of gold and silver from an ore containing same, comprising the steps of: forming a slurry of the ore in an aqueous alkali cyanide solution; and maintaining said slurry in a turbulent state at a pressure of 25 to 130 bar by passing it through a tube reactor in continuous unidirectional flow, while injecting oxygen of a purity of at least 90% into said slurry in said tube reactor at said pressure so that the CN/O 2 molar ratio is at most 0.7 at 25 bar and 0.7 g/l NaCN and is lower at higher pressures whereby said element is leached from said ore.
Claim 3
Dependent Claim
26 words
The method defined in claim 1 wherein the slurry is maintained in said tubular reactor at a temperature of at most 70° C. during the leaching.
Claim 4
Dependent Claim
23 words
The method defined in claim 2 wherein the flow velocity of the slurry in said reactor is 0.8 to 3 meters per second.
Claim 5
Dependent Claim
17 words
The method defined in claim 3 wherein said flow velocity is 1.5 to 2.5 meters per second.
Claim 6
Dependent Claim
23 words
The method defined in claim 3 wherein said slurry is provided to have a solids content of 300 to 1200 grams per meter.
Claim 7
Dependent Claim
17 words
The method defined in claim 5 wherein said solids content is 700 to 1000 grams per liter.
Claim 8
Dependent Claim
24 words
The method defined in claim 6 wherein the temperature of said slurry in said reactor is maintained at at least 20° C. room temperature.
Claim 9
Dependent Claim
21 words
The method defined in claim 6 wherein said oxygen is introduced into said slurry with a purity of at least 99.8%.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-20 | 1987-09-19 | 1988-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-20 | 1991-09-19 | 1992-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-20 | 1995-09-19 | 1996-03-20 | $7700.00 | Window Closed / Lapsed |