US3884679A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing a stable mixture of calcium with a compound yielding water at elevated temperature
Assignee: Evonik Operations GmbH
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Filing: 1974-05-13
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Granted: 1975-05-20
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Expires: 1994-05-13
Abstract
Abstract A stable desulfurizing composition for pig iron containing at least 50% calcium carbide and a compound yielding water for developing acetylene from the carbide at the melting temperature of the pig iron is produced by grinding the calcium carbide and the water-bearing compound, preferably calcium hydroxide or colemanite, at 50* to 250*C in an inert atmosphere to an average grain size of approximately 0.1 mm or less. It may safely be stored in gas-tight containers.
Inventors
- 👤 Rudolf Mitteldorf
- 👤 Erich Pfluger
- 👤 Werner Steinicke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:27
CPC Classifications
C; C21; C21C; C21C1/00; C21C1/02; C21C1/025; C22; C22B; C22B9/00; C22B9/10
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
105 words
A METHOD OF PRODUCING A STABLE DESULFURIZING COMPOSITION FOR MOLTEN METAL WHICH COMPRISES: A. MIXING PARTICULATE YIELDING WATER WHEN HEATED IN THE PRESSOLID AT 20*C, SAID COMPOUND YIELDING WATER WHEN HEATED IN THE PRESENCE OF CALCIUM CARBIDE TO A TEMPERATURE ABOVE 250*C WHILE BEING STABLE IN AIR TEMPERATURES BELOW 250*C; AND B. GRINDING THE RESULTING MIXTURE AT 50*C TO 250*C IN AN ATMOSPHERE INERT TO SAID CALCIUM CARBIDE AND TO SAID COMPOUND TO A PARTICLE SIZE NOT GREATER THAN 2MM, THE AMOUNT OF CALCIUM CARBIDE IN SAID MIXTURE BEING BETWEEN 50 AND 97% OF THE COMBINED WEIGHT OF SAID CALCIUM CARBIDE AND OF SAID COMPOUND.
Claim 2
Independent Claim
105 words
A METHOD OF PRODUCING A STABLE DESULFURIZING COMPOSITION FOR MOLTEN METAL WHICH COMPRISES: A. MIXING PARTICULATE YIELDING WATER WHEN HEATED IN THE PRESSOLID AT 20*C, SAID COMPOUND YIELDING WATER WHEN HEATED IN THE PRESENCE OF CALCIUM CARBIDE TO A TEMPERATURE ABOVE 250*C WHILE BEING STABLE IN AIR TEMPERATURES BELOW 250*C; AND B. GRINDING THE RESULTING MIXTURE AT 50*C TO 250*C IN AN ATMOSPHERE INERT TO SAID CALCIUM CARBIDE AND TO SAID COMPOUND TO A PARTICLE SIZE NOT GREATER THAN 2MM, THE AMOUNT OF CALCIUM CARBIDE IN SAID MIXTURE BEING BETWEEN 50 AND 97% OF THE COMBINED WEIGHT OF SAID CALCIUM CARBIDE AND OF SAID COMPOUND.
Claim 3
Dependent Claim
28 words
A method as set forth in claim 1, wherein the weight ratio of said calcium carbide and of said compound in said mixture is between 60:40 and 90:10.
Claim 4
Dependent Claim
24 words
A method as set forth in claim 2, wherein said resulting mixture is ground to an average particle size not greater than 0.1 mm.
Claim 5
Dependent Claim
17 words
A method as set forth in claim 3, wherein said mixture is ground together with elementary carbon.
Claim 6
Dependent Claim
30 words
A method as set forth in claim 2, wherein said resulting mixture is ground at least until the rate of acetylene development from the ground mixture reaches a constant value.
Claim 7
Dependent Claim
37 words
A method as set forth in claim 2, wherein said resulting mixture is ground in a grinding zone, said inert atmosphere being replaced in said zone at a rate of two times to ten times per hour.
Claim 8
Dependent Claim
16 words
A method as set forth in claim 2, wherein said compound is calcium hydroxide or colemanite.
Claim 9
Dependent Claim
25 words
A method as set forth in claim 1, wherein said mixture is stored in a gas-tight container after said grinding for at least two months.
Claim 10
Dependent Claim
27 words
A method as set forth in claim 8, wherein said compound yields water when heated to a temperature between 250*C and the melting temperature of pig iron.
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) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |