Lithium Recovery from Brines with Novel λ-MnO2 Adsorbent Synthesized by Hydrometallurgical Method

Abstract

ABSTRACT Salt-lake brines containing high lithium (Li) contents are highly saline solutions with total dissolved solids on the order 300 g/L with Li+ concentrations around 1 g/L only. A drastic increase in the molar ratio of Li+ to other cations is the most important issue for practical Li recovery. We developed a novel λ-MnO2 adsorbent in order to selectively recover lithium from such brine. In this study, we investigated the adsorption characteristics such as adsorption capacity and selectivity of Li+ by batch adsorption and chromatographic separation using seawater and brine. The λ-MnO2 adsorbent synthesized by a hydrometallurgical method had higher adsorption capacity for Li+ than the adsorbent prepared by a pyrometallurgical process. The λ-MnO2 adsorbent shows an effective separation and recovery ability for Li+ from the large amounts of alkali and alkali earth metals such as Na+, K+, Mg2+, and Ca2+. The selective recovery of Li+ from the artificial seawater was performed by using chromatographic separation to achieve 200 times concentration of Li+.