Selective Recovery Process of Lithium from Seawater Using Integrated Ion Exchange Methods

Abstract Selective recovery of lithium from seawater was conducted by using two successive processes of ion exchange methods. The preliminary concentration process of lithium from seawater, using the benchmark-scale chromatographic operation with a granulated λ-MnO2 adsorbent, showed the recovery efficiency of lithium at ca. 33%. The purification of lithium from concentrated liquor from the benchmark plant was then conducted with a novel separation process which was developed by a combination of ion exchange methods using cation exchange resin and solvent impregnated resin. The purification process of lithium consists of the removal of divalent metal ions in the liquor with strongly acidic cation exchange resin; the removal of Na+ and K+ with the β-diketone/TOPO impregnated resin; and lastly the recovery of Li+ as precipitates of Li2CO3 using (NH4)2CO3 saturated solution. The yield of recovered Li2CO3 with the present recovery process was 56% with more than 99.9% purity.