Claims
- 1. In a process for production of a tungsten carbide-activated electrode used for acid electrolysis, which consists essentially of an electrically-conductive substrate comprising graphite or a graphite-like material, said substrate having a surface active layer of tungsten carbide; the improvement comprising applying tungsten oxide or a compound which is thermally decomposable into tungsten oxide onto the surface of said substrate, converting said tungsten compound through thermal decomposition into tungsten oxide followed by reduction on said substrate to form tungsten carbide, including thermal treatment at temperatures of up to 950.degree. C. in a CO/CO.sub.2 environment, and as such bonding said tungsten carbide with said substrate.
- 2. Process as claimed in claim 1, comprising applying tungsten oxide powder on said substrate by means of a carbonizable binder.
- 3. Process as claimed in claim 2, comprising a binder medium having graphite powder admixed therewith for increasing the conductivity of said binder is been carbonized after carburizing.
- 4. Process as claimed in claim 3, wherein said binder medium comprises a phenolic resin.
- 5. Process as claimed in claim 3, wherein said substrate comprises a base material formed of a binder material containing a graphite powder.
- 6. Process as claimed in claim 5, wherein said substrate includes 10 to 40% by weight of a binder material.
- 7. Process as claimed in claim 1, wherein said substrate comprises a porous diaphragm of graphite.
- 8. Process as claimed in claim 1, comprising forming tungsten oxide powder from a para-ammonium tungstate through a precipitation reaction into tungstic acid, and subsequent decomposition in air at about 550.degree. C. to tungsten oxide or direct thermal decomposition of para-ammonium tungstate to tungsten oxide.
- 9. Process as claimed in claim 8, wherein the specific surface of the tungsten oxide powder is greater than 10m.sup.2 /g.
- 10. Process as claimed in claim 1, comprising applying tungstic acid or para-ammonium tungstate on said substrate, and thermally decomposing said tungstic acid or ammonium tungstate into tungsten oxide, prior to said reduction and carburization on said substrate.
- 11. Process as claimed in claim 1, wherein said substrate with the tungsten oxide applied thereon is reduced by heating in a hydrogen atmosphere or hydrogen-inert gas atmosphere to a temperature of from about 350.degree. C. to about 600.degree. C.
- 12. Process as claimed in claim 1, where the volumetric ratio of CO/CO.sub.2 is from about 2:1 to about 30:1.
- 13. Process as claimed in claim 1, wherein said substrate with said tungsten oxide applied thereon is heated for the carburization thereof to within a temperature range of 620.degree. to 950.degree. C. at a temperature rise of about 1.degree.K./min. in a flowing CO/CO.sub.2 atmosphere.
- 14. Process as claimed in claim 13, wherein subsequent to said carburization, said substrate with said formed tungsten carbide layer is maintained at 750.degree. C. under a flowing hydrogen gas for reduction of any carbon on said substrate surface.
- 15. A process comprising a sulfuric acid-hybrid continuous cycle using, as a cathode in an electrolytic cell, a tungsten carbide-activated electrode made according to the process of claim 1.
- 16. A process comprising anodic oxidation of SO.sub.2 waste gases in an electrolytic cell at a concurrent cathodic hydrogen formation using a tungsten carbide-activated electrode made according to the process of claim 1.
Priority Claims (1)
Number |
Date |
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3222436 |
Jun 1982 |
DEX |
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Parent Case Info
This application is a continuation-in-part application of U.S. patent application Ser. No. 502,478, filed Jun. 9, 1983, now abandoned.
US Referenced Citations (10)
Foreign Referenced Citations (2)
Number |
Date |
Country |
0062308 |
Apr 1968 |
DDX |
0116653 |
Jan 1959 |
SUX |
Non-Patent Literature Citations (2)
Entry |
Li, K. C. et al., Tungsten, pp. 155-157, 182, Reinhold Publ. Corp., N.Y., 43. |
Ivory, R. A., "Tungsten Carbide Research in Germany", BIOS Final Report No. 925, Item Nos. 21 and 22, PB79296, 1947, pp. 27-33. |
Continuation in Parts (1)
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502478 |
Jun 1983 |
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