US2907668A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Calcination of gypsum
Assignee: United States Gypsum Co
•
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
- 👤 Brainard W Nies
- 👤 Elmer S Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:29
CPC Classifications
C; C04; C04B; C04B11/00; C04B11/02; C04B11/028; C04B11/032; C01; C01F; C01F11/00; C01F11/46; C01F11/466
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
37 words
THE PROCESS OF PRODUCING CALCIUM SULFATE HEMIHYDRATE COMPRISING HEATING GUPSUM PARTICLES, WETTED WITH A VOLUME OF A CRYSTAL-HABIT-MODIFIER SOLUTION INSUFFICIENT TO SUBMERGE SAID PARTICLES, IN AN ATMOSPHERE OF SATURATED STEAM UNTIL CRYSTALS OF CALCINED GYPSUM ARE FORMED.
Claim 2
Dependent Claim
37 words
THE PROCESS OF PRODUCING CALCIUM SULFATE HEMIHYDRATE COMPRISING HEATING GUPSUM PARTICLES, WETTED WITH A VOLUME OF A CRYSTAL-HABIT-MODIFIER SOLUTION INSUFFICIENT TO SUBMERGE SAID PARTICLES, IN AN ATMOSPHERE OF SATURATED STEAM UNTIL CRYSTALS OF CALCINED GYPSUM 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 |