Patent ID: 8366891

Claim:
A metallic oxygen evolving anode for electrowinning aluminium by decomposition of alumina dissolved in a fluoride-containing molten electrolyte, comprising an alloy consisting essentially of nickel, iron, manganese, optionally copper, and silicon, characterized by the following composition and relative proportions: Nickel (Ni) 62-68 w % Iron (Fe) 24-28 w % Manganese (Mn) 6-10 w % Copper (Cu) 0-0.9 w % Silicon (Si) 0.3-0.7 w %, and possibly other trace elements in a total amount up to 0.5w %, wherein: the weight ratio Ni/Fe is in the range 2.1 to 2.89, the weight ratio Ni/(Ni+Cu) is greater than 0.98, the weight ratio Cu/Ni is less than 0.01, and the weight ratio Mn/Ni is from 0.09 to 0.15.