Based on some defect of traditional mixer-settler[1],we proposed a novel gas-assistant column extractor to perform large phase ratio extraction and enrichment of rare-earth ions[2].The column consists of air-inlet,solvent-inlet,aqueous-inlet,distributor,aqueous-outlet and solvent-outlet.Fig.1 shows the structural details of the column.Batch and continuous experiments were conducted to test extraction and enrichment efficiency of rare-earth ions.The feed-in solution containing low concentrations of rare-earth ions was pumped firstly into the column until the feed level lies somewhere between solvent-outlet and aqueous-inlet,then air bubbles were introduced into the column through the gas-inlet and the organic solvent was pumped into the column through the solvent-inlet.The batch experiments were performed with the aqueous-outlet closed during the extraction process.The continuous operations were realized with the feed-in solution flowing into the column and the extracted raffinates were allowed to flow out off the column from the aqueous-outlet.Experimental investigation on two feed-in solutions containing,respectively,La(III) and Lu(III) about 10 to 100 mg/L were carried out in order to determine the extraction performance of the gas-assistant column.The results demonstrated that extraction and enrichment efficiency of La(III) and Lu(III) is dependent on air bubbling rate,solvent flow rate and oil-to-water phase ratio.The operational oil-to-water phase ratio was high than 1:200,and percent extraction of two rare-earth ions were all above than 95% after 5min.of air bubbling.The present work indicates that the new equipment we proposed can be used for performing extraction process with high oil-to-water phase ratio,and rare-earth ions with low concentrations (<100 mg/L) can be effectively enriched.