Patent US3258308A successfully refreshed from Google Patents.
US3258308A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the treatment of waste gases
Assignee: Hooker Chemical Corp
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Filing: 1965-08-02
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Granted: 1966-06-28
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Expires: 1985-08-02
Abstract
No abstract record available.
Inventors
- 👤 John A Peterson
- 👤 Theodore H Dexter
- 👤 Rufus G Hartig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:56
CPC Classifications
C; C01; C01B; C01B7/00; C01B7/19; C01B7/191
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
149 words
A METHOD OF RECOVERING AS SODIUM BIFLUORIDE, HYDROGEN FLUORIDE FROM WASTE GASES OBTAINED IN PHOSPHATE ROCK ACIDULATION AND CALCINATION PROCESSES, WHICH GASES CONTAIN SUSPENDED SOLIDS, INCLUDING DUST, AND FLUORINE VALUES, INCLUDING HYDROGEN FLUORIDE AND SILICON TETRAFLUORIDE, COMPRISING SEPARATING SUBSTANTIALLY ALL OF THE SUSPENDED SOLID IMPURITIES INCLUDING THE DUST FROM THE WASTE GAS, CONTACTING SAID WASTE GAS MIXTURE WITH AN AQUEOUS SOLUTION OF FLUOSILICIC ACID SATURATED WITH HYDROGEN FLUORIDE, THEREBY PREFERENTIALLY REMOVING THE SILICON TETRAFLUORIDE CONSTITUENTS BY ABSORBING SAID SILICON TETRAFLUORIDE CONSTITUENTS IN SAID FLUOSILICIC ACID SOLUTION AND SUBSEQUENTLY CONTACTING AND WASTE GAS CONTAINING HYDROGEN FLUORIDE FROM WHICH SAID SILICON TETRAFLUORIDE CONSTITUENTS WERE REMOVED BY ABSORPTION IN THE FLUOSILICIC ACID SOLUTION, WITH AN AQUEOUS SODIUM FLUORIDE-SODIUM BIFLUORIDE SLURRY, THEREBY REMOVING HYDROGEN FLUORIDE FROM SAID WASTE GAS BY ABSORBING AND REACTING SAID HYDROGEN FLUORIDE IN SAID AQUEOUS SODIUM FLUORIDE-SODIUM BIFLUORIDE SLURRY TO PRECIPITATE HYDROGEN FLUORIDE AS SODIUM BIFLUORIDE IN SAID SLURRY.
Claim 2
Independent Claim
149 words
A METHOD OF RECOVERING AS SODIUM BIFLUORIDE, HYDROGEN FLUORIDE FROM WASTE GASES OBTAINED IN PHOSPHATE ROCK ACIDULATION AND CALCINATION PROCESSES, WHICH GASES CONTAIN SUSPENDED SOLIDS, INCLUDING DUST, AND FLUORINE VALUES, INCLUDING HYDROGEN FLUORIDE AND SILICON TETRAFLUORIDE, COMPRISING SEPARATING SUBSTANTIALLY ALL OF THE SUSPENDED SOLID IMPURITIES INCLUDING THE DUST FROM THE WASTE GAS, CONTACTING SAID WASTE GAS MIXTURE WITH AN AQUEOUS SOLUTION OF FLUOSILICIC ACID SATURATED WITH HYDROGEN FLUORIDE, THEREBY PREFERENTIALLY REMOVING THE SILICON TETRAFLUORIDE CONSTITUENTS BY ABSORBING SAID SILICON TETRAFLUORIDE CONSTITUENTS IN SAID FLUOSILICIC ACID SOLUTION AND SUBSEQUENTLY CONTACTING AND WASTE GAS CONTAINING HYDROGEN FLUORIDE FROM WHICH SAID SILICON TETRAFLUORIDE CONSTITUENTS WERE REMOVED BY ABSORPTION IN THE FLUOSILICIC ACID SOLUTION, WITH AN AQUEOUS SODIUM FLUORIDE-SODIUM BIFLUORIDE SLURRY, THEREBY REMOVING HYDROGEN FLUORIDE FROM SAID WASTE GAS BY ABSORBING AND REACTING SAID HYDROGEN FLUORIDE IN SAID AQUEOUS SODIUM FLUORIDE-SODIUM BIFLUORIDE SLURRY TO PRECIPITATE HYDROGEN FLUORIDE AS SODIUM BIFLUORIDE IN SAID SLURRY.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-06-27 | 1969-12-27 | 1970-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-06-27 | 1973-12-27 | 1974-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $7700.00 | Window Closed / Lapsed |