Neodymium recovery from NdFeB magnet wastes using Primene 81R·Cyanex 572 IL by solvent extraction

Abstract

The necessity of Rare Earth Elements (REEs) recycling is crucial to minimizing their supply risk and provide an alternative to greener technologies. Hence, the REEs recovery from NdFeB magnet wastes using cationic extractants by solvent extraction technique has been investigated in this research. Due to the difficulty in maintaining the aqueous pH in the industrial counter-current devices when extractants like Cyanex 272 or Cyanex 572 are used, the Primene 81R·Cyanex 572 ionic liquid has been synthesised to overcome this. 99.99% Nd(III) recovery with a purity of 99.7% from an aqueous mixture of Nd/Tb/Dy in chloride medium, the three representative REEs present in the NdFeB magnets wastes, has been achieved after two stages counter-current extraction process using 0.30 M of Primene 81R·Cyanex 572 ionic liquid (1:4 A:O ratio) diluted in Solvesso 100, without any aqueous pH conditioning.

Keywords: Counter-current process; Ionic liquid; Neodymium recovery; Primene 81R·Cyanex 572 IL; Solvent extraction.