In a recent study published in Engineering, researchers from Kyoto University have unveiled a novel method for the efficient separation and recycling of rare-earth elements (REEs) from end-of-life magnets. This innovative process, known as the selective extraction–evaporation–electrolysis (SEEE) process, promises to significantly advance recycling technology and support global efforts towards carbon neutrality.
REEs, particularly neodymium (Nd) and dysprosium (Dy), are essential components in high-performance magnets used in various green technologies, including electric vehicles (EVs) and wind turbines. With the surge in demand for these technologies, efficient recycling of these critical materials has become crucial. The new SEEE process addresses this need by offering a highly efficient and environmentally friendly alternative to traditional hydrometallurgical techniques.
The study, led by professor Toshiyuki Nohira and his team at the Institute of Advanced Energy, Kyoto University, explores how this new process can transform the recycling of Nd magnets, which are widely used in energy-efficient technologies. Traditional recycling methods often involve complex and energy-intensive processes with substantial environmental impact. In contrast, the SEEE process is designed to be more sustainable and precise.
The SEEE process involves three key stages:
Selective extraction: Using a molten salt mixture, including calcium chloride (CaCl 2 ) and magnesium chloride (MgCl 2 ), the process extracts REEs from magnet scraps. The addition of calcium fluoride (CaF 2 ) helps to control evaporation losses and improve extraction efficiency. Selective evaporation: The process then removes any remaining extraction agents and byproducts, concentrating the REEs. Selective electrolysis: Finally, the extracted REEs are separated electrochemically based on their different formation potentials. This step enables the recovery of high-purity Nd and Dy metals.
