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

• Published in: Journal of environmental management 2018-09, Vol.222, p.359-367
• Main Authors: Pavón, S., Fortuny, A., Coll, M.T., Sastre, A.M.
• Format: Article
• Language: English
• Subjects: Counter-current process; Enginyeria química; Ionic liquid; Ionic solutions; Minimització; Neodymium recovery; Primene 81R·Cyanex 572 IL; Reciclatge de residus; Residus; Solucions iòniques; Solvent extraction; Solvent wastes; Àrees temàtiques de la UPC
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2018.05.054

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. [Display omitted] •Urban mining is a feasible alternative to the primary REE sources.•This paper outlines a potential hydrometallurgical process for Nd(III) recovery.•Nd (99.7% purity) recovery is possible using a two stages counter-current process.•P81R·Cy572 IL allows separating REEs in Cl− medium by SX without pH conditioning.