Role of Vanadium in Aluminum Electrolyzer Melts

Resumo

The article provides results of testing excess introduction of vanadium into a molten aluminum cell through baked anodes. This stage of special technology is preliminary and required before the boriding heavy metal impurities in molten aluminum. The requirement of a preliminary stage is dictated by the presence of an insulating aluminum carbide layer on the surface of the carbon hearth that reduces the efficiency of aluminum boriding technology. The specific properties of vanadium and its compounds make it possible to organize chemical cleaning of the cathode from an Al₄C₃ layer, replacing it with a VC substrate. It is shown that with constant introduction of vanadium into melt dynamic equilibrium is established between vanadium and its compounds entering the cell and removed from it. Stabilization of a VC-coating requires organization of boriding technology for molten electrolyte and aluminum, creating a viscous low-mobility layer of a metal-boride Me–B suspension wetted with aluminum on the hearth.