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US 4,396,482 AGranted
Composite cathode
AssigneeAluminum Company of America
InventorsSubodh K. Das, Perry A. Foster, Jr., Gregory J. Hildeman
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AssigneeAluminum Company of America
InventorsSubodh K. Das, Perry A. Foster, Jr., Gregory J. Hildeman
Estimating the term…
An improved electrolytic cell is provided for production of a metal such as aluminum by electrolysis of a compound of the metal in a solvent or bath such as molten salt. Electrolysis is carried out by passing a current from an anode to a cathode between which the solvent bath is situated. The cathode comprises a base cathode and cathode extension surfaces comprising graphite and at least 90% refractory hard metal such as titanium diboride. The cathode extension surfaces are produced from a mixture comprising at least 90% refractory hard metal and a carbonaceous binder with little or substantially no particulate carbonaceous material and graphitizing said mixture above 2350.degree. C. to graphitize the carbonaceous material therein to exhibit the graphitic structure.
In an electrolytic cell for the production of molten metal and including an anode and a base cathode spaced from said anode for passage of electric current therebetween through an electrolyte, and means to collect molten metal upon said base cathode, the improvement wherein one or more cathode surfaces extends outwardly from said base cathode toward said anode, said cathode surface being provided as a graphitized composite comprising graphite impregnated with at least 85% refractory hard metal and produced from a composite mixture comprising said refractory hard metal and a carbonaceous binder and graphitizing said composite mixture at a temperature of at least 2350.degree. C. in a non-oxidizing atmosphere to convert carbonaceous material therein to the graphitic structure.
In an electrolytic cell for the production of molten metal and including an anode and a base cathode spaced from said anode for passage of electric current therebetween through an electrolyte, and means to collect molten metal upon said base cathode, the improvement wherein one or more cathode surfaces extends outwardly from said base cathode toward said anode, said cathode surface being provided as a graphitized composite comprising graphite impregnated with at least 85% refractory hard metal selected from the carbides, silicides, borides and nitrides of the fourth, fifth and sixth groups of the Periodic Table and produced from a composite mixture comprising said refractory hard metal and a carbonaceous binder and graphitizing said composite mixture at a temperature of above 2400.degree. C. in a non-oxidizing atmosphere to convert carbonaceous material therein to the graphitic structure exhibiting an L.sub.c dimension greater than 400 A and a d.sub.002 dimension less than 3.4 A.
Dependencies are inferred from the claim text.