Patent US3933635A successfully refreshed from Google Patents.
US3933635A
Expired / Lapsed
US
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Method for removing soluble selenium from acidic waste water
Assignee: United States Department of the Interior
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Filing: 1975-07-15
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Granted: 1976-01-20
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Expires: 1995-07-15
Abstract
Abstract Selenium is removed from solution in acidic waste water by treatment of the water with a metallic reducing agent. The invention is particularly effective for removal of selenium from zinc smelter effluent by reaction of the effluent with powdered zinc.
Inventors
- 👤 Wayne N. Marchant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:43
CPC Classifications
C; C22; C22B; C22B19/00; C22B19/20; C22B19/26; C02; C02F; C02F1/00; C02F1/70; C02F1/705; C22B15/00; C22B15/0063; C22B15/0084; C22B15/0089; C22B15/0091; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
44 words
A method for removing selenium from zinc smelter effluent comprising reacting the effluent with a metallic reducing agent at a temperature of about 25° to 85° C for a time sufficient to reduce a substantial portion of the soluble selenium to insoluble metallic selenium.
Claim 2
Independent Claim
44 words
A method for removing selenium from zinc smelter effluent comprising reacting the effluent with a metallic reducing agent at a temperature of about 25° to 85° C for a time sufficient to reduce a substantial portion of the soluble selenium to insoluble metallic selenium.
Claim 3
Dependent Claim
15 words
The method of claim 1 which the reaction temperature is about 50° to 70° C.
Claim 4
Dependent Claim
12 words
The method of claim 1 in which the reducing agent is zinc.
Claim 5
Dependent Claim
13 words
The method of claim 3 in which the zinc is in powder form.
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) | 1979-01-19 | 1979-07-21 | 1980-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-19 | 1983-07-21 | 1984-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-19 | 1987-07-21 | 1988-01-20 | $7700.00 | Window Closed / Lapsed |