Effects of electrolysis process parameters on alumina dissolution and their optimization
(School of Energy Science and Engineering, Central South University, Changsha 410083, China)
Abstract: The Box–Behnken design and desirability approach were used to investigate and optimize the process parameters for aluminum reduction cells related to alumina dissolution. The bath temperature, alumina content, current and alumina temperature were chosen as the design parameters. The content of cumulative dissolved alumina (CCDA) and the relative deviation from the target content (RDTC) were adopted as the responses. The interactive influence results show that increasing the bath temperature and alumina temperature, as well as decreasing the alumina content, can increase CCDA. Increasing the bath temperature and lowering the current are beneficial for obtaining a more uniform alumina distribution. The optimal operating parameters were determined to be as follows: bath temperature of 958.8 °C, alumina content of 2.679 wt.%, current of 300 kA and alumina temperature of 200 °C.
Key words: aluminum reduction cell; alumina dissolution; response surface methodology; desirability approach; heat and mass transfer