Fractional crystallization for extracting lithium from Cha'erhan tail brine

According to the solubility isotherms of the ternary system (LiCl + NH4Cl + H2O), fractional crystallization including primary crystallization and secondary crystallization, was designed to remove the maximum amount of NH4+ from Cha'erhan tail brine and raise the concentration of Li+. The particle size and surface topography during fractional crystallization were studied by XRD and SEM techniques. Then, sodium hydroxide was used for the removal of magnesium, and high purity sodium carbonate was obtained by the method of carbonation from Cha'erhan tail brine.