Inert electrode containing metal oxides, copper and noble metal
AssigneeAlcoa Inc.
InventorsSiba P. Ray, Robert W. Woods, Robert K. Dawless, Robert B. Hosler
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Abstract
A cermet composite material is made by treating at an elevated temperature a mixture comprising a compound of iron and a compound of at least one other metal, together with an alloy or mixture of copper and a noble metal. The alloy or mixture preferably comprises particles having an interior portion containing more copper than noble metal and an exterior portion containing more noble metal than copper. The noble metal is preferably silver. The cermet composite material preferably includes alloy phase portions and a ceramic phase portion. At least part of the ceramic phase portion preferably has a spinel structure.
Claims20
A process for making a cermet composite material suitable for use in an inert electrode for production of a metal by electrolytic reduction in a molten salt bath, comprising treating at an elevated temperature and in an atmosphere containing oxygen, a starting mixture comprising:
- (a) a compound of iron and a compound of at least one other metal selected from the group consisting of nickel, tin, zinc, yttrium, chromium, and tantalum;
- and
- (b) an alloy or mixture of copper and a noble metal selected from the group consisting of silver, gold, platinum, palladium, rhodium, and iridium, said alloy or mixture containing more of the copper than the noble metal.
An inert anode suitable for use in a molten salt bath, said inert anode being made by treating at an elevated temperature, in the presence of oxygen, a mixture comprising:
- (a) a compound of iron and a compound of at least one other metal selected from the group consisting of nickel, tin, zinc, yttrium, zirconium, chromium, and tantalum;
- and
- (b) an alloy or mixture containing about 70-99.8 wt. % copper and about 0.2-30 wt. % of at least one noble metal selected from the group consisting of silver, gold, platinum, palladium, rhodium, and iridium,
- said inert anode comprising at least one ceramic phase portion comprising iron oxide and at least one oxide of said other metal, and a plurality of alloy phase portions comprising copper and at least one said noble metal.
Dependencies are inferred from the claim text.