Desorption-Controlled Selective Lithium Enrichment from Spodumene Leachate Using H2TiO3 Adsorbent

Abstract

The increasing demand for lithium has intensified the need for efficient lithium recovery processes. In this study, a selective adsorption–desorption strategy for selective lithium enrichment from spodumene leachate was developed using an H2TiO3 adsorbent. The adsorption behavior of lithium was investigated, confirming its high selectivity over competing ions with an equilibrium adsorption uptake of 27.12 mg/g. The desorption process was identified as a key step governing the achievable lithium concentration, and the solid-to-liquid (S/L) ratio was optimized to simultaneously achieve high desorption efficiency, reduced titanium dissolution, and enhanced lithium concentration. Under optimal conditions, titanium dissolution was significantly suppressed while maintaining high lithium recovery. Through four consecutive stepwise enrichments, the lithium concentration increased from approximately 100 mg/L to 4,330 mg/L, corresponding to a concentration factor of ∼43.4. These results demonstrate that H2TiO3 can function not only as a selective adsorbent but also as an effective enrichment medium for producing Li-concentrated solutions.