Cathode process at the electrolysis of KF-AlF3-Al2O3 melts and suspensions

Abstract

The kinetics of the cathode process on tungsten in KF-AlF3-Al2O3 melts and suspensions was studied by means of voltammetry and galvanostatic polarization. The effects of the temperature, [KF]/[AlF3] ratio, Al2O3 content on the kinetic parameters of electrowinning of aluminum from the KF-AlF3-Al2O3 melts and suspensions were determined. Introducing Al2O3 slurry into the suspension and increasing its proportion make the diffusion of the electroactive ions to the cathode more difficult. The parameters for the suspension electrolysis were chosen on the basis of electrochemical measurements. The possibility of aluminum production during the electrolysis of KF-AlF3-Al2O3 suspension with 45 wt% Al2O3 in the solid phase was demonstrated.