Effects of additives on the electrolytic consumption of carbon anodes in aluminium electrolysis Original Research Article

The effect of impurities on the anode carbon consumption in aluminium electrolysis was studied in a closed laboratory cell, which allowed the determination of the total carbon consumption (CC), the carbon gasification (CG) and the formation of carbon dust (CD). Addition of V2O3 made CC, CG and CD all increase while LiCl addition caused CC and CG to increase, and CD to remain constant. Addition of 0.5 wt% AlF3 lowered CC, but higher contents had a negative effect. Increasing sulphur content in the petroleum coke caused a marked decrease in CG, which was partly counteracted by rising CD. Literature data on the effect of additives are discussed together with the results.