PRELIMINARY RESEARCH OF LEACHING OF SPENT NIMH BATTERIES WITH CHOSEN ORGANIC ACIDS

Critical raw materials, such as rare earths (REEs), have a high economic importance for the EU, combined with a high risk associated with their supply depending on very limited sources. Therefore, the recovery of the RE elements is extremely important for both economic and environmental reasons. NiMH batteries contain nickel, cobalt, lanthanum and other REEs and can be used as a secondary source of those metals. One of possible methods of their recovery is a hydrometalurgicall process consisting of following steps: leaching of batteries, separation of metal ions from leach pregnant solution (LPS) and obtaining of final products (metals or their compounds). The presented paper deals with leaching of spent NiMH batteries in aqueous solutions of chosen organic acids (like acetic, lactic or tartaric). As a result, solutions containing nickel(11), cobalt(II), lanthanum(III), and cerium(III) ions with concentration up to 2.5, 0.4, 0.5, and 0.2 g/dm(3), respectively, were obtained.