Patent US2907667A successfully refreshed from Google Patents.
US2907667A
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Process of calcining gypsum
Assignee: United States Gypsum Co
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Filing: 1956-03-30
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Granted: 1959-10-06
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Expires: 1976-03-30
Abstract
No abstract record available.
Inventors
- 👤 Elmer S Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:49
CPC Classifications
C; C04; C04B; C04B11/00; C04B11/02; C04B11/024; C01; C01F; C01F11/00; C01F11/46; C01F11/466
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
48 words
THE PROCESS OF PRODUCILNG CALCIUM SULFATE HEMIHYDRATE WHICH COMPRISES WETTING THE EXTERIOR SURFACES OF GYPSUM PARTICLES WITH A CRYSTAL-HABIT-MODIFIER, DRAINING ANY EXCESS CRYSTAL-HABIT-MODIFIER FROM BETWEEN SAID PARTICLES AND THEREAFTER HEATING THE THUS TREATED GYPSUM IN AN ATMOSPHERE OF SATURATED STEAM UNTIL CRYSTALS OF CALCIUM SULFATE HEMIHYDRATE ARE FORMED.
Claim 2
Dependent Claim
48 words
THE PROCESS OF PRODUCILNG CALCIUM SULFATE HEMIHYDRATE WHICH COMPRISES WETTING THE EXTERIOR SURFACES OF GYPSUM PARTICLES WITH A CRYSTAL-HABIT-MODIFIER, DRAINING ANY EXCESS CRYSTAL-HABIT-MODIFIER FROM BETWEEN SAID PARTICLES AND THEREAFTER HEATING THE THUS TREATED GYPSUM IN AN ATMOSPHERE OF SATURATED STEAM UNTIL CRYSTALS OF CALCIUM SULFATE HEMIHYDRATE ARE FORMED.
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) | 1962-10-05 | 1963-04-06 | 1963-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-10-05 | 1967-04-06 | 1967-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-10-05 | 1971-04-06 | 1971-10-06 | $7700.00 | Window Closed / Lapsed |