US2573704A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Making calcium fluoride
Assignee: Tennessee Valley Authority
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Filing: 1950-02-27
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Granted: 1951-11-06
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Expires: 1970-02-27
Abstract
No abstract record available.
Inventors
- 👤 Gilbert Nathan
- 👤 Isaac A Hobbs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:54
CPC Classifications
C; C01; C01F; C01F11/00; C01F11/20; C01F11/22
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
73 words
IN A PROCESS FOR THE PRODUCTION OF CALCIUM FLUORIDE WHEREIN GASES CONTAINING HYDROGEN FLUORIDE BUT WHICH ARE OTHERWISE INERT TOWARD LIMESTONE ARE PASSED OVER AND IN INTIMATE CONTACT WITH LIMESTONE AND THE RESULTING CALCIUM FLUORIDE IS SEPARATED FROM UNREACTED LIMESTONE, THAT IMPROVEMENT WHICH COMPRISES PASSING SUCH GASES CONTAINING HYDROGEN FLUORIDE UPWARD THROUGH A BED OF COARSE PARTICLES OF A MATERIAL SELECTED FROM THE GROUP CONSISTING OF OOLITIC AND PISOLITIC LIMESTONE; MAINTAINING THE TEMPERATURE
Claim 2
Dependent Claim
73 words
IN A PROCESS FOR THE PRODUCTION OF CALCIUM FLUORIDE WHEREIN GASES CONTAINING HYDROGEN FLUORIDE BUT WHICH ARE OTHERWISE INERT TOWARD LIMESTONE ARE PASSED OVER AND IN INTIMATE CONTACT WITH LIMESTONE AND THE RESULTING CALCIUM FLUORIDE IS SEPARATED FROM UNREACTED LIMESTONE, THAT IMPROVEMENT WHICH COMPRISES PASSING SUCH GASES CONTAINING HYDROGEN FLUORIDE UPWARD THROUGH A BED OF COARSE PARTICLES OF A MATERIAL SELECTED FROM THE GROUP CONSISTING OF OOLITIC AND PISOLITIC LIMESTONE; MAINTAINING THE TEMPERATURE
References Cited (Backward Citations)
US2410043A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-11-05 | 1955-05-07 | 1955-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-11-05 | 1959-05-07 | 1959-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-11-05 | 1963-05-07 | 1963-11-06 | $7700.00 | Window Closed / Lapsed |