Patent US2884307A successfully refreshed from Google Patents.
US2884307A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of white calcium cyanamid
Assignee: Evonik Operations GmbH
•
Filing: 1957-09-12
•
Granted: 1959-04-28
•
Expires: 1977-09-12
Abstract
No abstract record available.
Inventors
- 👤 Kaess Franz
- 👤 Kronacher Hermann
- 👤 Erich H Becker-Boost
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:10
CPC Classifications
C; C05; C05C; C05C7/00; C01; C01C; C01C3/00; C01C3/16; C01C3/18
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
125 words
A PROCESS FOR THE PREPARATION OF CALCIUM CYANAMIDE FROM LIME AND A HYDROGEN CYANIDE FORMING GAS MIXTURE OF CARBON MOMOXIDE AND AMMONIA COMPRISING PROVIDING AT LEAST TWO SUPERPOSED TUBELENT REACTION ZONES, PASSING SAID GAS MIXTURE UPWARDLY THROUGH SAID REACTION ZONES AT A TEMPERATURE OF ABOUT 750 TO 800* C., PLACING FINELY GRANULATED LIME IN THE UPPERMOST REACTION ZONE AND MAINTAINING THE SAME THEREIN IN TURBULENT MOTION BY THE UPWARDLY PASSING GAS MIXTURE UNTIL SAID LIME CONTAINS ABOUT 10 TO 15 PERCENT OF NITROGEN IN FORM OF CALCIUM CYANAMIDE, SUBSEQUENTLY TRANSFERRING SAID CALCIUM CYANIDE CONTAINING MATERIAL FROM SAID UPPERMOST ZONE INTO THE NEXT LOWER ZONE SEPARATELY FROM THE UP-STREAMING GAS, AND MAINTAINING SAID MATERIAL IN SAID LOWER TURBULENT REACTION ZONES UNTIL THE NITROGENATION IS SUBSTANTIALLY COMPLETED.
Claim 2
Dependent Claim
125 words
A PROCESS FOR THE PREPARATION OF CALCIUM CYANAMIDE FROM LIME AND A HYDROGEN CYANIDE FORMING GAS MIXTURE OF CARBON MOMOXIDE AND AMMONIA COMPRISING PROVIDING AT LEAST TWO SUPERPOSED TUBELENT REACTION ZONES, PASSING SAID GAS MIXTURE UPWARDLY THROUGH SAID REACTION ZONES AT A TEMPERATURE OF ABOUT 750 TO 800* C., PLACING FINELY GRANULATED LIME IN THE UPPERMOST REACTION ZONE AND MAINTAINING THE SAME THEREIN IN TURBULENT MOTION BY THE UPWARDLY PASSING GAS MIXTURE UNTIL SAID LIME CONTAINS ABOUT 10 TO 15 PERCENT OF NITROGEN IN FORM OF CALCIUM CYANAMIDE, SUBSEQUENTLY TRANSFERRING SAID CALCIUM CYANIDE CONTAINING MATERIAL FROM SAID UPPERMOST ZONE INTO THE NEXT LOWER ZONE SEPARATELY FROM THE UP-STREAMING GAS, AND MAINTAINING SAID MATERIAL IN SAID LOWER TURBULENT REACTION ZONES UNTIL THE NITROGENATION IS SUBSTANTIALLY COMPLETED.
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) | 1962-04-27 | 1962-10-27 | 1963-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-04-27 | 1966-10-27 | 1967-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-04-27 | 1970-10-27 | 1971-04-28 | $7700.00 | Window Closed / Lapsed |