LIT Assets and Processing Technology, page-43

An ion-exchange column was included for the first time into the final L-Max® precipitation stage, which significantly reduced impurity levels prior to the final lithium recovery stage. Lithium carbonate grading 99.5% or more was consistently produced during the continuous operations phase of the trial. A final re-precipitation was employed to further clean the product and resulted in the production of 99.9% Lithium carbonate with very low levels of critical impurities.