*Article* **Comparative Studies of Digestion Techniques for the Dissolution of Neodymium-Based Magnets**

**Mélodie Bonin 1,2, Frédéric-Georges Fontaine 1,3 and Dominic Larivière 1,2,\***


**Abstract:** The digestion of neodymium (NdFeB) magnets was investigated in the context of recycling rare earth elements (i.e., Nd, Pr, Dy, and Tb). Among more conventional digestion techniques (microwave digestion, open vessel digestion, and alkaline fusion), focused infrared digestion (FID) was tested as a possible approach to rapidly and efficiently solubilize NdFeB magnets. FID parameters were initially optimized with unmagnetized magnet powder and subsequently used on magnet pieces, demonstrating that the demagnetization and grinding steps are optional.

**Keywords:** NdFeB magnets; critical metals; rare earth elements (REEs); recycling; focus infrared digestion; ICP-OES; electronic waste
