Journal of the Brazilian Chemical Society
On-line version ISSN 1678-4790
PRASAD, Shiva. Studies on the Hall-Heroult aluminum electrowinning process. J. Braz. Chem. Soc. [online]. 2000, vol.11, n.3, pp. 245-251. ISSN 1678-4790. http://dx.doi.org/10.1590/S0103-50532000000300008.
Studies on the electrolysis of cryolite-alumina melt showed that even the best equipped smelter, functioning at 960 oC, has only 33% energy efficiency. For stable functioning of the smelter at 3% alumina the minimum wt% ratio NaF/AlF3 was found to be 1.11. The anodes located on down-stream row were found to face more turbulence; raising their level by 4 cm resulted in decreasing the number of burnoffs. A careful selection of potlining material improved the pot life. The stability of the aluminum-bath interface is one of the major factors affecting the current efficiency. An improved cell design has been proposed to achieve the ultimate aluminum-bath interface stability. The proposed cell design should allow a reduction of the cathode-to-anode distance producing a lower voltage and improving the power efficiency.
Keywords : aluminum electrowinning; Hall-Heroult process; electroreduction.