Researchers have demonstrated the use of ionic liquids for recycling bonded neodymium (NdFeB) permanent magnets—-the type often used in EV motors. Their work, which could ease the strain on rare earth materials, is published in the open-access journal Green Chemistry. 

“Ionic liquids (ILs) are known to be excellent green solvents for many types of synthetic polymers and biopolymers,” wrote Mehmet Önal and his colleagues. “It has also been reported that Lewis-acidic chloroaluminate ionic liquids can be used to dissolve epoxy resins of tantalum capacitors. For these reasons, we decided to explore the use of ionic liquids for the recycling of bonded NdFeB magnets for the first time. The most promising solvent system was tested on a larger scale to prepare a batch of magnet powder that was used to produce new anisotropic epoxy-bonded magnets. The magnetic properties of these new magnets were measured and compared to those of commercial counterparts to assess the overall efficiency of the recycling process.”

Using this recycled magnet powder, the researchers produced two new epoxy-bonded magnets, which showed magnetic properties nearly as strong as those made from virgin material, demonstrating that ionic liquid processing of end-of-life bonded NdFeB magnets is a promising recycling method. In addition to being environmentally friendly, the process also enables the production of secondary bonded magnets with new design and polymeric material.

Source: Green Chemistry