ELECTROLYSIS OF ALUMINUM IN THE LOW MELTING ELECTROLYTES BASED ON POTASSIUM CRYOLITE

摘要

The aluminum electrolysis in electrolytes with composition (mas.%): KF(47,37)-AlF{sub}3(52,63) with CR=1,3 and KF(49,0)-AlF{sub}3(49,0)-LiF(2,0) with CR{sub}(KF)=1,58 at temperature 750°C was carried out in the lab scale cell with liquid aluminum cathode. As anodes, metallic Al-Cu and Ni-Cu-Al-Fe; cermet Cu-Cu{sub}2O; ceramic SnO{sub}2 materials were used. The alumina concentration was kept on the 4,5 mas.% level. The region of anode current density was 0,4÷0,6 A/cm{sup}2. Duration of experiments reached 96 hours. Temperature, voltage and current on the cell during electrolysis, voltage at the moment of current interruption were recorded. The most suitable anode materials have proved to be Cu-Al(3 or 5 mas.%) and Cu{sub}2O-Cu(15 mas.%) and ceramic based on SnO{sub}2.