Boosting Lithium Extraction Process with Ion-Selective Solar Crystallizers Through Interfacial Evaporation

Bulk evaporation of brine is a sustainable method for extract minerals, particularly lithium, by utilizing selective crystallization based on ion solubility differences. However, this method requires a prolonged time period. In contrast, solar crystallizers, which use interfacial evaporation, can reduce processing time but lack adequate ion-selectivity due to insufficient re-dissolution and re-crystallization processes. This study presents a novel ion-selective solar crystallizer. The nature-inspired hierarchical water path, fabricated in an evaporative wind blade (EWB), facilitates water transport through centrifugal force induced by wind-driven rotation. The continuous supply of unsaturated solution promotes re-dissolution and re-crystallization of salts at the edges, leading to high ion-selectivity. Using the EWB to evaporate brine containing Na⁺ and Li⁺ ions, the ionic ratio of Na⁺ to Li⁺ increased from 31 in the initial solution to 651 in the crystallized salt, achieving an ion-selectivity of 20.8. This innovation can significantly improve the lithium extraction process from brine by selectively removing Na⁺ and enriching LI⁺ in solution.