Patent US3647261A successfully refreshed from Google Patents.
US3647261A
Expired / Lapsed
US
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Process for solution mining of silver
Assignee: Dow Chemical Co
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Filing: 1970-05-04
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Granted: 1972-03-07
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Expires: 1990-05-04
Abstract
Abstract Disclosed herein is a process for the in situ leaching of noble metal values from ores. The process comprises feeding into a subterranean stratum chlorinated aqueous brine having an oxidation potential of at least about 500 millivolts. Noble metal values are solubilized into the brine which is then recovered from the stratum. The process is relatively efficient and economical and can be performed without complex, time-consuming excavations or the accumulation of processed tailings.
Inventors
- 👤 Vernon A Stenger
- 👤 Walter R Kramer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:02
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/28
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
12 words
A process as in claim 1 wherein the brine comprises sodium chloride.
Claim 2
Dependent Claim
12 words
A process as in claim 1 wherein the brine comprises calcium chloride.
Claim 3
Dependent Claim
26 words
A process as in claim 1 wherein the brine employed is a naturally occurring solution comprising the chlorides of alkaline and alkaline earth elements in water.
Claim 4
Dependent Claim
39 words
A process as in claim 1 wherein the subterranean stratum contains at least 1 ounce of silver values per ton of ore and wherein the ratio by weight of oxidizable iron compounds to silver values does not exceed 400:1.
Claim 5
Dependent Claim
39 words
A process as in claim 1 comprising (a) feeding the brine into the ore stratum by injection through an inlet well penetrating the stratum, and (b) collecting silver chloride containing brine from an outlet well penetrating the same stratum.
Claim 6
Dependent Claim
29 words
A process as in claim 1 and including the subsequent step of contacting the brine with the chloride form of an anion exchange resin containing quaternary ammonium functional groups.
Claim 7
Dependent Claim
22 words
A process as in claim 7 and including the subsequent step of contacting the brine with hydrogen sulfide to precipitate silver values.
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) | 1975-03-07 | 1975-09-06 | 1976-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-07 | 1979-09-06 | 1980-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-07 | 1983-09-06 | 1984-03-07 | $7700.00 | Window Closed / Lapsed |