Patent US2835558A successfully refreshed from Google Patents.
US2835558A
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Recovery of selenium
Assignee: Diamond Shamrock Corp
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Filing: 1955-08-09
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Granted: 1958-05-20
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Expires: 1975-08-09
Abstract
No abstract record available.
Inventors
- 👤 Luther E Vaaler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:58
CPC Classifications
C; C01; C01B; C01B19/00; C01P; C01P2006/00; C01P2006/80
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
91 words
THE METHOD OF SEPARATING SELENIUM FROM A SELENIUMCONTAINING SOURCE MATERIAL, SAID METHOD COMPRISING THE SUCCESSIVE STEPS OF CONTACTING SAID SOURCE MATERIAL WITH AN ALKALI METAL HYDROXIDE THEREBY TO EXTRACT SELENIUM FROM SAID SOURCE MATERIAL AS A SOLUBLE SELENATE, FROMING THEREFROM BY THE ADDITION OF A COMPOUND SELECTED FROM THE GROUP OF WATER SOLUBLE COMPOUNDS OF BARIUM, STRONTIUM, AND RADIUM, AND INSOLUBLE SELENATE BY SOLUBLE IMPURITIES, REDUCING THE INSOLUBLE SELENATE BY THE ADDITION OF A SOLUTION CONTAINING AN OXIDIZABLE ION AND PRECIPITATING SUBSTANTIALLY PURE SELENIUM THEREFROM BY THE ADDITION OF SULFUR DIOXIDE.
Claim 2
Independent Claim
91 words
THE METHOD OF SEPARATING SELENIUM FROM A SELENIUMCONTAINING SOURCE MATERIAL, SAID METHOD COMPRISING THE SUCCESSIVE STEPS OF CONTACTING SAID SOURCE MATERIAL WITH AN ALKALI METAL HYDROXIDE THEREBY TO EXTRACT SELENIUM FROM SAID SOURCE MATERIAL AS A SOLUBLE SELENATE, FROMING THEREFROM BY THE ADDITION OF A COMPOUND SELECTED FROM THE GROUP OF WATER SOLUBLE COMPOUNDS OF BARIUM, STRONTIUM, AND RADIUM, AND INSOLUBLE SELENATE BY SOLUBLE IMPURITIES, REDUCING THE INSOLUBLE SELENATE BY THE ADDITION OF A SOLUTION CONTAINING AN OXIDIZABLE ION AND PRECIPITATING SUBSTANTIALLY PURE SELENIUM THEREFROM BY THE ADDITION OF SULFUR DIOXIDE.
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) | 1961-05-19 | 1961-11-18 | 1962-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-05-19 | 1965-11-18 | 1966-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-05-19 | 1969-11-18 | 1970-05-20 | $7700.00 | Window Closed / Lapsed |