Process for producing aluminum

摘要

In a process for producing aluminum, which process conventionally includes electrolytically decomposing alumina to aluminum metal in a molten electrolyte bath between a carbon anode and a cathodic interface formed between a molten aluminum metal pad and sides electrolyte bath, the bath A. BEING PREDOMINANTLY NaF and AlF3, b. containing CaF2 and Al2O3, and C. BEING COVERED BY A FROZEN CRUST, THE IMPROVEMENT INCLUDING PROVIDING IN THE BATH 5 TO 10 WEIGHT-% LiF, while maintaining in the bath a weight ratio NaF to AlF3 of 1.04 to 1.15, and while maintaining a frozen layer bounding the sizes of the aluminum metal pad and bath.