Selective recovery of lithium from seawater using a novel MnO2 type adsorbent. II – Enhancement of lithium ion selectivity of the adsorbent

A novel spinel-type manganese dioxide adsorbent has been developed for the selective recovery of Li+ from seawater. The adsorbent can be prepared from a lithium-rich component of spinel-type lithium dimanganese tetraoxide Li1.5Mn2O4, followed by ion exchange of Li+ by H+ with diluted hydrochloric acid. The X-ray analysis of the adsorbent suggests the adsorption-elution cycle of Li+ progresses under γ expansion-shrinking mechanism of the adsorbent. The adsorption of Li+ progresses via cation exchange, and the selective recovery of Li+ can be carried out, even when the large amount of Na+ coexists in seawater. The chromatographic selective recovery of Li+ from the artificial seawater shows that Li+ can be selectively adsorbed with remaining most of Na+ in the feed solution in the break through step, while Li+ of high purity can recover and concentrate into the elutant in the elution step.