US4353740A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chlorine extraction of gold
Assignee: Individual
•
Filing: 1981-09-11
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Granted: 1982-10-12
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Expires: 2001-09-11
Abstract
Abstract A process for treating a particulated gold bearing ore to recover the gold therein is disclosed. The process includes roasting the ore to remove sulfides as sulfur dioxide followed by chlorination of the ore at a temperature of about 350° C. in the presence of iron to form a mixture of volatile gold chlorides and volatile gold-iron chlorides in the chlorine off gases followed by condensing the gold compounds by passing the mixture through a salt such as sodium chloride to form a salt melt and separating the gold from the melt.
Inventors
- 👤 Wendell E. Dunn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:45
CPC Classifications
C; C22; C22B; C22B11/00; C22B11/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
150 words
A process for recovering gold from a gold-containing ore comprising the steps of: (a) grinding the ore, (b) oxidative roasting of the ore in the presence of a gas selected from the group consisting of air or oxygen to remove sulfides in the ore, at an elevated temperature; (c) chlorinating the ore by contacting the ore with chlorine at a temperature of 300° to 400° C., in the presence of at least one mole or iron per mole of gold present in the ore to convert gold in the ore into volatile gold chloride and gold chloride-iron chloride complex and producing spent ore, (d) passing volatiles from the chlorination step through a halide salt selected from the group consisting of a alkali and alkaline metal chloride, bromide and iodide to separate volatilized gold values to form a halide salt-gold chloride mixture, and (e) separating metallic gold from the halide salt.
Claim 2
Dependent Claim
150 words
A process for recovering gold from a gold-containing ore comprising the steps of: (a) grinding the ore, (b) oxidative roasting of the ore in the presence of a gas selected from the group consisting of air or oxygen to remove sulfides in the ore, at an elevated temperature; (c) chlorinating the ore by contacting the ore with chlorine at a temperature of 300° to 400° C., in the presence of at least one mole or iron per mole of gold present in the ore to convert gold in the ore into volatile gold chloride and gold chloride-iron chloride complex and producing spent ore, (d) passing volatiles from the chlorination step through a halide salt selected from the group consisting of a alkali and alkaline metal chloride, bromide and iodide to separate volatilized gold values to form a halide salt-gold chloride mixture, and (e) separating metallic gold from the halide salt.
Claim 3
Dependent Claim
82 words
The process of claim 1 comprising grinding the ore to a particle size of 20 to 200 mesh, the roasting step (b) is conducted at a temperature of 400° to 550° C., the roasted ore is subjected to a vacuum to degas the roasted ore, the chlorination step (c) is conducted at a temperature of 350° C. in the presence of 1 to 3 moles of iron, ferric chloride, and ferrous chloride per mole of gold in the ore subjected to chlorination.
Claim 4
Dependent Claim
23 words
The process of claim 2 wherein roasting and chlorination of the ore is concluded as a pressure of 1 to 2 atmospheres, absolute.
Claim 5
Dependent Claim
21 words
The process of claims 2 or 3 wherein the spent ore is leached to separate from the spent ore silver chloride.
Claim 6
Dependent Claim
15 words
The process of claim 4 wherein the spent ore is leached with an ammonical solution.
Claim 7
Dependent Claim
41 words
The process of claim 1 wherein metallic gold is separated by dissolving the halide salt-gold chloride mixture in water followed by contacting the solution formed thereby with a metal selected from the group consisting of iron, tin, zinc, aluminum and copper.
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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) | 1985-10-11 | 1986-04-12 | 1986-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-11 | 1990-04-12 | 1990-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-11 | 1994-04-12 | 1994-10-12 | $7700.00 | Window Closed / Lapsed |