Abstract:Applying the water leaching solution obtained by roasting and water leaching of zinnwaldite ore as research object, the impact of calcium and magnesium ions in the solution on the separation of orgainc and aqueous phases during the extraction process was clearified. The effects of dosage of sodium carbonate and sodium hydroxide, and O/A on calcium and magnesium removal efficiency and extraction performance of lithium were illustrated. The results show that Na2CO3 and NaOH were used as calcium and magnesium removal reagent with Na2CO3 dosage of 100% lithium equivalent, NaOH dosage of four times the molar amount of magnesium under ambient temperature mixed for one hour, then liquid-solid separation was carried out to obtain impurity removed leaching solution. The removal efficiency of Ca and Mg is >99.9% and 82.53%, respectively. The self-modified M54-100-Cyanex923 - sulfonated kerosene extraction system was used to simulate three-stage countercurrent extraction at O/A=1.5, and the extraction rate of Li and Na is 90.85% and 0.04%, respectively. The lithium loaded organic phase is simulated by 5.5 mol/L HCl at O/A=25, the stripping rate of Li is >99.9%, and the lithium content in the Li-rich stripping solution is about 26 g/L, which realize the purification and enrichment of lithium in one step.