Electrochemical description of the interfacial tension between the liquid metal pad and cryolitic melts in industrial electrolysis cells

•An original modelling of the interfacial tension between Al-Na-O and cryolitic melts is proposed•The model variables are temperature, elctrolyte compositions, impurities in Al & current density•Good predictive capability in a wide range of compositions, temp. & current density•The flux of undissolved alumina piercing the bath/metal interface is calculated.