Electrolytic production of aluminium. Review. Part 2. Development prospects

Abstract

This paper looks at the evolution and the current status of inert electrodes. It also describes attempts to design new-generation aluminium cells with wettable cathodes and vertical electrodes. Numerous laboratory studies and pilot tests demonstrate that aluminium cells equipped with inert electrodes are environmentally safe and can deliver a breakthrough technology enabling to bring the power consumption down below 10 kWt·h/kg Al and at the same time increase the production even in the limited capacity of the electrolytic bath. There exists a number of projects aimed at commercializing the inert electrode technology. And despite the apparent loss of interest in this technology on the part of researchers and aluminium producers, relevant pilot tests are scheduled for 2024. A number of alternative innovative power saving cryolite-alumina bath techniques are being discussed, which should allow to get close to the theoretical level of power consumption and provide a dramatic boost in the cell capacity. The paper examines potential application of thermoelectric generators to reduce heat losses, the use of minimum anode-to-cathode distance and vertical nonwettable electrodes, and a transition to 3D electrodeposition of aluminium with cathode polarization.