Consecutive recovery of rare earth and alkaline earth elements by countercurrent electromigration in room temperature molten salts

We have suggested the novel environmental harmonization process applying the countercurrent electromigration technique utilizing the room temperature molten salts substituted for the pyrometallurgical processes aiming at the recovery of the electrochemically base metals such as the rare earth and the alkaline-earth elements in spent catalysts. According to the batch experiments using ammonium imide type room temperature molten salts, the trivalent ions are drastically enriched at the anode and the results have lead to an efficient enrichment process under high-current density. Moreover, the development of the consecutive electromigration cell enables us to demonstrate that it is feasible to enrich the rare earth and the alkaline earth elements and to recover their salts in continuous parallel and multistage cleaning process.