US4325843A
Expired / Lapsed
US
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Process for preparing a supported tungsten carbide composition
Assignee: Shell USA Inc
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Filing: 1980-12-08
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Granted: 1982-04-20
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Expires: 2000-12-08
Abstract
Abstract A process for preparing a supported tungsten carbide composition which comprises first forming a supported tungsten oxide composition, converting the oxide to the nitride by heating in an ammonia atmosphere, and then converting the nitride to the carbide by heating in a carbiding atmosphere.
Inventors
- 👤 Lynn H. Slaugh
- 👤 Ronald J. Hoxmeier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:14
CPC Classifications
B; B01; B01J; B01J27/00; B01J27/20; B01J27/22; Y; Y10; Y10S; Y10S502/00; Y10S502/506
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
127 words
A process for preparing a supported tungsten carbide composition which comprises: (a) impregnating a porous oxidic support with a solution of a tungsten salt decomposable upon calcining to an oxide dissolved in a suitable solvent, (b) drying the support to remove the solvent, (c) calcining the impregnated support at a temperature ranging up to about 450° C. to about 750° C., (d) heating the support in an ammonia atmosphere at a temperature ranging from about 700° C. to about 800° C., and (e) heating the resultant composition at a temperature ranging from about 700° C. to about 800° C. in a carbiding gas mixture which comprises hydrogen and a carbiding component selected from the group consisting of carbon monoxide methane, ethane, propane, ethylene, propylene, and mixtures thereof.
Claim 2
Dependent Claim
127 words
A process for preparing a supported tungsten carbide composition which comprises: (a) impregnating a porous oxidic support with a solution of a tungsten salt decomposable upon calcining to an oxide dissolved in a suitable solvent, (b) drying the support to remove the solvent, (c) calcining the impregnated support at a temperature ranging up to about 450° C. to about 750° C., (d) heating the support in an ammonia atmosphere at a temperature ranging from about 700° C. to about 800° C., and (e) heating the resultant composition at a temperature ranging from about 700° C. to about 800° C. in a carbiding gas mixture which comprises hydrogen and a carbiding component selected from the group consisting of carbon monoxide methane, ethane, propane, ethylene, propylene, and mixtures thereof.
Claim 3
Dependent Claim
37 words
The process of claim 1 wherein the surface area of the oxidic support is greater than 20 square meters per gram and the molar ratio of hydrogen to carbiding component ranges from about 2 to about 100.
Claim 4
Dependent Claim
14 words
The process of claim 1 wherein the carbiding gas mixture additionally comprises hydrogen iodide.
Claim 5
Dependent Claim
38 words
The process of claim 3 wherein the molar ratio of hydrogen to carbiding component ranges from about 2 to about 100 and the molar ratio of hydrogen iodide to carbiding component ranges from about 0.1 to about 4.
Claim 6
Dependent Claim
19 words
The process of claims 1, 2, 3 or 4 wherein the carbiding gas mixture additionally comprises a noble gas.
Claim 7
Dependent Claim
34 words
The process of claims 1, 2, 3 or 4 wherein the carbiding gas mixture comprises additionally a noble gas wherein the molar ratio of noble gas to carbiding component ranges up to about 100.
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) | 1985-04-19 | 1985-10-19 | 1986-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-19 | 1989-10-19 | 1990-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-19 | 1993-10-19 | 1994-04-20 | $7700.00 | Window Closed / Lapsed |