Computational fluid dynamics study on the effect of stirring parameters on solid-liquid suspension in the slurry electrolysis square tank

As a sustainable hydrometallurgical technology, slurry electrolysis (SE) offers certain advantages in the treatment of complex ores and secondary electronic waste. It is therefore of considerable interest to understand the solid-liquid suspension in the stirred tank for overall process control. Here, a computa-tional fluid dynamics (CFD) model based on the Eulerian-Eulerian framework combined with the kinetic theory of granular flow was employed to investigate the effects of varying the impeller speed (70- 150 rpm), solids volume fraction (8-21 %), and particle specific gravity (2-6.7) on solid-liquid suspension behavior in a square tank equipped with electrodes and impeller. The results show that as the impeller rotating speed increases, turbulent kinetic energy is gradually transferred from the lower part of the elec-trodes to the region near the impeller shaft and between the membrane bags. The solids volume fraction was found to have little effect on the final liquid flow fields, but significantly increased the power con-sumption. The homogeneity and power consumption were quantified as functions of specific gravity, allowing the degree of homogeneity to be predicted under different operating conditions. (c) 2023 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan. All rights reserved.