Abstract:
In aluminum electrolysis, understanding the anodic bubble behavior has been critical for bath flow field
simulation and anode effect investigation. In this paper, bubble behavior on graphite anodes with underside surface
area of 50 cm2
(10 cm×5 cm) was studied in a transparent Hall-Heroult electrolytic cell at 924 ℃. The results
indicate that the largest bubble coverage on the graphite anodes operated at 0.3−1.7 A/cm2
is in the range of
48%−65%, which agrees with the data obtained on industrial aluminum reduction cell, and lower than that of the
smaller anodes, 60%−100%, reported in literatures. Priority sites for bubble nucleation were found to be linked to a
highly layered carbon structure on the anode surface combined with SEM/EDS analysis. The layered carbon
structure illustrates good wettability to CO2 bubbles, preventing adhered bubbles from gliding across the anode to
result in the formation of large bubble.
