Patent US3167391A successfully refreshed from Google Patents.
US3167391A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of anhydrous hydrogen fluoride
Assignee: Harshaw Chemical Co
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Filing: 1963-07-18
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Granted: 1965-01-26
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Expires: 1983-07-18
Abstract
No abstract record available.
Inventors
- 👤 Carl F Swinehart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:41
CPC Classifications
C; C01; C01B; C01B7/00; C01B7/19; C01B7/191
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
158 words
IN A PROCESS FOR THE PURIFICATION OF ANHYDROUS HYDROGEN FLUORIDE FROM THE REACTION BETWEEN SULFURIC ACID AND FLUORSPAR COMPRISING EFFECTING SAID REACTION TO PRODUCE FREE GASEOUS HYDROGEN FLUORIDE, ABSORBING SAID HYDROGEN FLUORIDE GAS IN AN AQUEOUS ACID SOLUTION, HEATING SAID SOLUTION CONTAINING THE ABSORBED HYDROGEN FLUORIDE GAS TO DISTILL SAID GASEOUS HYDROGEN FLUORIDE CONTAINING IMPURITIES COMPRISING WATER VAPOR, PENTAVALENT PHOSPHORUS COMPOUNDS AND HEXAVALENT SULFUR COMPOUNDS AND CONTACTING SAID HYDROGEN FLUORIDE GAS WITH A SCRUBBING LIQUID CONSISTING ESSENTIALLY OF LIQUID HYDROGEN FLUORIDE, THE IMPROVEMENT COMPRISING CONTINUALLY ADDING LIQUID WATER TO SAID SCRUBBING LIQUID TO MAINTAIN THE WATER CONCENTRATION BETWEEN 1 PART BY WEIGHT WATER TO 9 PARTS BY WEIGHT HYDROGEN FLUORIDE AND 1 PART BY WEIGHT WATER TO 500 PARTS BY WEIGHT HYDROGEN FLUORIDE WHEREBY TO RETAIN SAID PHOSPHORUS AND SAID SULFUR IN SAID SCRUBBING LIQUID AND TO REDUCE THE PHOSPHORUS CONTENT AND THE SULFUR CONTENT OF SAID GASEOUS HYDROGEN FLOURIDE AND TO RECOVER SUBSTANTIALLY PURE ANHYDROUS HYDROGEN FLUORIDE.
Claim 2
Dependent Claim
158 words
IN A PROCESS FOR THE PURIFICATION OF ANHYDROUS HYDROGEN FLUORIDE FROM THE REACTION BETWEEN SULFURIC ACID AND FLUORSPAR COMPRISING EFFECTING SAID REACTION TO PRODUCE FREE GASEOUS HYDROGEN FLUORIDE, ABSORBING SAID HYDROGEN FLUORIDE GAS IN AN AQUEOUS ACID SOLUTION, HEATING SAID SOLUTION CONTAINING THE ABSORBED HYDROGEN FLUORIDE GAS TO DISTILL SAID GASEOUS HYDROGEN FLUORIDE CONTAINING IMPURITIES COMPRISING WATER VAPOR, PENTAVALENT PHOSPHORUS COMPOUNDS AND HEXAVALENT SULFUR COMPOUNDS AND CONTACTING SAID HYDROGEN FLUORIDE GAS WITH A SCRUBBING LIQUID CONSISTING ESSENTIALLY OF LIQUID HYDROGEN FLUORIDE, THE IMPROVEMENT COMPRISING CONTINUALLY ADDING LIQUID WATER TO SAID SCRUBBING LIQUID TO MAINTAIN THE WATER CONCENTRATION BETWEEN 1 PART BY WEIGHT WATER TO 9 PARTS BY WEIGHT HYDROGEN FLUORIDE AND 1 PART BY WEIGHT WATER TO 500 PARTS BY WEIGHT HYDROGEN FLUORIDE WHEREBY TO RETAIN SAID PHOSPHORUS AND SAID SULFUR IN SAID SCRUBBING LIQUID AND TO REDUCE THE PHOSPHORUS CONTENT AND THE SULFUR CONTENT OF SAID GASEOUS HYDROGEN FLOURIDE AND TO RECOVER SUBSTANTIALLY PURE ANHYDROUS HYDROGEN FLUORIDE.
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) | 1968-01-26 | 1968-07-27 | 1969-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-01-26 | 1972-07-27 | 1973-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-01-26 | 1976-07-27 | 1977-01-26 | $7700.00 | Window Closed / Lapsed |