US4038361A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recovery of nitric acid soluble transition metals from sulfur and iron containing ores of the same
Assignee: INTERTECH SYSTEMS Inc A CORP OF
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Filing: 1976-03-17
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Granted: 1977-07-26
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Expires: 1996-03-17
Abstract
Abstract The ore is subjected to nitric acid leaching and the leach solution is heated to a temperature at which one of the additional sulfur and iron values is selectively insolubilized with respect to the solution, while the other is maintained in solution for subsequent separation from the liquor after the insolubles have been removed and the liquor has been neutralized. In addition, in one embodiment of the invention the heating and acid neutralization steps are controlled within certain prescribed limits to make it possible to remove the metals from the liquor by solvent extraction without the problem of lasting precipitates forming in the liquor and fouling the extraction process. Where there is a sizable amount of dissolved iron in the liquor, the liquor may be subjected to autoclaving at a temperature above about 149° C (300° F) to precipitate the iron as the oxide thereof. This effect is possible even where the liquor is high in sulfate concentration.
Inventors
- 👤 John G. Posel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:01
CPC Classifications
C; C22; C22B; C22B3/00; C22B3/04; C22B3/06; C22B3/065; C01; C01B; C01B17/00; C01B17/02; C01B17/06; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
127 words
A method of recovering one or more metal values of the group consisting of copper, silver, nickel, cobalt and zinc from a sulfur and iron containing ore of the metal or metals, comprising intermixing the ore and at least a stoichiometric amount of nitric acid of about 30-50% by volume concentration to form an aqueous acid leach solution of the same, heating the solution to a temperature at or above the melting point of sulfur while the solution is contained under pressure in a relatively inert atmosphere, controlling the temperature of the solution to substantially precipitate the iron values from the solution, relatively separating the iron precipitate from the acid soluble phase of the solution, and recovering the metal value or values from the acid soluble phase.
Claim 2
Independent Claim
127 words
A method of recovering one or more metal values of the group consisting of copper, silver, nickel, cobalt and zinc from a sulfur and iron containing ore of the metal or metals, comprising intermixing the ore and at least a stoichiometric amount of nitric acid of about 30-50% by volume concentration to form an aqueous acid leach solution of the same, heating the solution to a temperature at or above the melting point of sulfur while the solution is contained under pressure in a relatively inert atmosphere, controlling the temperature of the solution to substantially precipitate the iron values from the solution, relatively separating the iron precipitate from the acid soluble phase of the solution, and recovering the metal value or values from the acid soluble phase.
Claim 3
Dependent Claim
33 words
The process according to claim 1 wherein after the iron values are precipitated, the solution is flashed to precipitate any insolubilized sulfur therefrom and the sulfur precipitate is separated with the iron precipitate.
Claim 4
Dependent Claim
36 words
The process according to claim 1 wherein the acid insolubles are separated from the acid soluble phase before the metal values are removed therefrom, and the iron precipitate is separated concurrently with the other acid insolubles.
Claim 5
Dependent Claim
35 words
The process according to claim 3 wherein after the iron values are precipitated, the solution is flashed to precipitate any insolubilized sulfur therefrom and the sulfur precipitate is separated concurrently with the other acid insolubles.
Claim 6
Dependent Claim
32 words
The process according to claim 1 wherein the sulfur is crystallized as a salt thereof and relatively separated from the acid soluble phase after the metal value or values are removed therefrom.
Claim 7
Dependent Claim
35 words
The process according to claim 1 wherein the temperature of the leach solution is controlled to precipitate the iron as a salt thereof and then the salt is relatively separated from the acid soluble phase.
Claim 8
Dependent Claim
30 words
The process according to claim 6 wherein the relatively iron-free acid soluble phase is evaporated to crystallize and relatively separate the sulfur therefrom in the form of a sulfate salt.
Claim 9
Dependent Claim
37 words
The process according to claim 7 wherein the iron-precipitation step is carried out during the leaching stage and the sulfate-salt-crystallization step is carried out after the metal value or values are removed from the acid soluble phase.
Claim 10
Dependent Claim
27 words
The process according to claim 1 wherein the metal value or values are solvent extracted from the acid soluble phase and then recovered from the extractant liquid.
Claim 11
Dependent Claim
32 words
The process according to claim 1 wherein the leach solution is heated to a temperature of above about 125° C. during the leaching stage to precipitate the iron as a salt thereof.
Claim 12
Dependent Claim
18 words
The process according to claim 1 wherein the leach solution is subjected to agitation during the leaching stage.
Claim 13
Dependent Claim
33 words
The process according to claim 1 wherein an aqueous suspension of the ore is formed and then added to the acid while the acid is under agitation and pressurization in the leach container.
Claim 14
Dependent Claim
35 words
The process according to claim 1 wherein the reaction gases generated in the container are collected externally of the container, oxidized to the higher oxides of nitrogen, and intermixed with water to regenerate nitric acid.
Claim 15
Dependent Claim
16 words
The process according to claim 13 wherein the regenerated nitric acid is returned to the container.
Claim 16
Dependent Claim
51 words
The process according to claim 1 wherein the acid soluble phase is subjected to autoclaving at a temperature of above about 300° F. to precipitate dissolved iron as the oxide thereof, and the oxide is relatively separated from the acid soluble phase before the metal value or values are recovered therefrom.
Claim 17
Dependent Claim
23 words
The process according to claim 15 wherein the acid soluble phase is subjected to autoclaving after the acid insolubles are relatively separated therefrom.
References Cited (Backward Citations)
US1119473A
Cited
US2344004A
Cited
US2643204A
Cited
US3034864A
Cited
US2898196A
Cited
US2762703A
Cited
US2916357A
Cited
US3637371A
Cited
US3656937A
Cited
US3793429A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-25 | 1981-01-24 | 1981-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-25 | 1985-01-24 | 1985-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-25 | 1989-01-24 | 1989-07-26 | $7700.00 | Window Closed / Lapsed |