Recovery of lithium from salt-brine eluates by direct crystallization as lithium sulfate

Two types of eluate were prepared by the batchwise adsorption of Li+ from brine followed by desorption with 2 M sulfuric acid. Evaporation of an eluate with a Li+ concentration of 1370 mM to a Dcon of 8.6 at 323 K produced high-purity (97%) Li2SO4·H2O crystals in 43% yield after the CaSO4·2H2O had been removed at a Dcon of around 3. The evaporation of the eluate to dryness at 323 K followed by rinsing with water afforded Li2SO4·H2O crystals in 83% yield and in 84% purity. This simple evaporation method can be applied to lithium extraction from salt lakes in arid areas.