Refining aluminum process in ionic liquids

The authors studied an aluminum refining process that utilizes low temperature ionic liquids as the electrolyte. The experiment was conducted using 1-metheyl-3-butyl imidazolium chloride (BMIC) and anhydrous aluminum chloride (AlCl3) with a copper cathode and an aluminum alloy anode. In the experiments, the cell voltage range was from 1.1V to 1.7V, the concentration ratio range of AlCl3 to BMIC from 1.3 to 1.9 and the electrolysis temperature at 105 +/- 2 degrees C. After analyzing the deposits by SEM and XRD, the optimum parameters of the electrolyte concentration ratio and the cell voltage were found out. The current densities increased with the increase of the cell voltage and the concentration ratio. However, the best cathode morphology was obtained at 1.3V similar to 1.5V with the concentration ratio 1.6, the current efficiency (CE) reached 89.5% and specific energy consumption was 4.66Wh/kg Al when the cell voltage was 1.4V.