Energy reduction technology for aluminum electrolysis: Choice of the cell voltage

Abstract

In China, all the aluminum smelters are making efforts to reduce the electrical energy consumption of aluminum reduction by decreasing cell voltage. One measure is decreasing cell voltage without any cell structure change. Another measure of decreasing cell voltage is using novel structure carbon cathode. For the first measure, the current efficiency (CE) would be decreased because the anode-cathode-distance is reduced. For the second measure, if the cell voltage is reduced much more, the CE also can be lost. The best choice to decrease energy consumption is that the CE should be maintained when the cell voltage is reduced. It means that the cell should be operated at a reasonable low cell voltage, so that the CE could not be decreased or could be improved. In this paper, the CE and electrical energy consumption of aluminum smelters with different cell voltage operating are shown and the economic benefits are discussed.