Development of Chemical Process for Recovering High-quality Rare-earth Oxides from HV Motor Magnets

In the automobile industry, interest in the prevention of global warming has always been high. The development of eco cars (HV, EV etc.), aimed at reducing CO2 emissions during operation, has been progressing. In the announcement of its "Toyota Environmental Challenge 2050", Toyota declared its commitment to creating a future in which people, cars, and nature coexist in harmony. In this declaration, Toyota committed to reducing CO₂ emissions not only during operation but also over the entire life cycle of vehicles, and to using resources effectively based on a 4 R’s approach (refuse, reduce, reuse, and recycle). Although eco cars decrease CO₂ emissions during operation, most of them increase CO₂ emissions during manufacturing. For example, the rare-earths (Nd, Dy etc.) used in the magnets of driving motors are extracted through processes that produce a significant amount of CO₂ emissions. The common process for recycling the rare-earths used in magnets can recover high-purity rare-earths by electrolysis. However, this process is costly and also produces a significant amount of CO₂. Toyota has developed a chemical recycling process for producing high-quality rare-earth oxides that is economical and reduces CO₂ emission during material production by 80% without the use of electrolytic refining. This paper describes this chemical recycling process for rare earth components and, in addition, introduces an energy-saving, vehicle-to-vehicle resource recycling flow.