Materials recovery from end-of-life wind turbine magnets

Neodymium–iron–boron permanent magnets are increasingly used in green energy technologies, such as wind turbines and electric vehicles. In the near future, an increasing amount of magnets will reach their end-of-life stage, andtherefore, it is imperative to develop proper recycling routes aimed at the valorization of this waste fraction. In this work, a room temperature hydrometallurgical process was developed aimed at the recovery of both iron and rare earths contained in end-of-life wind turbine magnets. The process is based on a leaching step with nitric acid, followed by two precipitation steps and calcination. Iron hydroxide(III) and rare earth oxide with purity grade equal to 98% and 99%, respectively, were obtained. Based on these results, a process flowsheet was proposed for industrial implementation.