Optimization and Scale-Up of a Two-Level Electrodialysis Process for the Concentration of Lithium Chloride with High Energy Efficiency

Traditional thermal concentration processes for LiCl, such as multi-effect evaporation and mechanical vapor recompression (MVR), suffer from drawbacks including high energy consumption and severe equipment corrosion. However, electrodialysis (ED) technology offers several advantages in the concentration process, including high efficiency, energy conservation, selective separation, and the absence of phase-change requirements. This study presents an innovative two-level ED process for efficient LiCl concentration, addressing the limitations of conventional thermal methods. Through systematic small-scale and scale-up experiments, we developed an optimized process achieving exceptional performance. The system attained Li⁺ concentrations of 22.17 g/L in the concentrated solution and 21.17 g/L in the recycled dilute solution, while reducing residual Li⁺ in discharge water to just 1.08 g/L. Remarkably, the process demonstrated significant energy efficiency, with a total consumption of only 85.22 kWh/t LiCl and a minimal water migration amount of 4.21 L/(m²·h). Economic analysis revealed substantial cost savings of 14.66 USD/t LiCl compared to traditional evaporation methods. These findings establish ED as a technically and economically viable solution for industrial LiCl concentration, offering both high efficiency and environmental benefits.