Patent US3173755A successfully refreshed from Google Patents.
US3173755A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synthesis of calcium cyanamide
Assignee: Individual
•
Filing: 1962-09-26
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Granted: 1965-03-16
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Expires: 1982-09-26
Abstract
No abstract record available.
Inventors
- 👤 Jean P Picard
- 👤 Blais Marcel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:31
CPC Classifications
C; C01; C01C; C01C3/00; C01C3/16; C01C3/18
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
57 words
A METHOD OF MAKING GRAPHITE FREE CALCIUM CYANAMIDE WHICH COMPRISES REACTING UREA AND CALCIUM OXIDE IN A MOLAR RATIO OF ABOUT 3:1 IN A CLOSED KETTLE AT ABOUT 300*C. UNTIL A SOLID IS FORMED AND AMMONIA IS GIVEN OFF, CRUSHING THE SOLID AND REHEATING IN A KILN TO ABOUT 700*C. TO FORM CALCIUM CYANAMIDE AND CARBON DIOXIDE.
Claim 2
Independent Claim
57 words
A METHOD OF MAKING GRAPHITE FREE CALCIUM CYANAMIDE WHICH COMPRISES REACTING UREA AND CALCIUM OXIDE IN A MOLAR RATIO OF ABOUT 3:1 IN A CLOSED KETTLE AT ABOUT 300*C. UNTIL A SOLID IS FORMED AND AMMONIA IS GIVEN OFF, CRUSHING THE SOLID AND REHEATING IN A KILN TO ABOUT 700*C. TO FORM CALCIUM CYANAMIDE AND CARBON DIOXIDE.
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) | 1968-03-15 | 1968-09-14 | 1969-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-03-15 | 1972-09-14 | 1973-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-03-15 | 1976-09-14 | 1977-03-16 | $7700.00 | Window Closed / Lapsed |