Groundbreaking Recycling Method Could Expand Access to Rare Earths
SUPERTRENDS – One of the main levers for making electric vehicles more sustainable and commercially viable is the sourcing of rare chemical elements used in components. Nissan Motor and Waseda University have begun testing a newly developed method for recycling rare-earth elements (REEs) from the motor magnets of electric vehicles, which, if successful, could help stabilize prices for electric motors and ease the increasing demand for certain scarce metals that are indispensable for the successful transition to a more sustainable energy system.
The innovative recycling process, jointly developed by the world’s leading e-vehicle manufacturer and one of Japan’s leading universities, offers a simpler and more economical way of retrieving valuable REEs from damaged or discarded motor blocks. It involves adding a carburizing material and pig iron while melting down the motor at a temperature of at least 1,400° C. Once the mixture is molten, iron oxide is added to the mix as a way of oxidizing the REEs, supplemented by a small amount of borate-based flux that can dissolve rare metals such as neodymium and dysprosium at lower temperatures and assist their recovery. The mixture then separates into two distinct layers: A higher-density layer of iron-carbon alloy and a lighter molten oxide slag from which the rare earths can be recovered.
Preliminary results have shown that this process allows 98 percent of the REEs to be reclaimed in a process that is about twice as fast as conventional recycling methods, where magnets must first be demagnetized, removed, and disassembled. The project partners plan to continue large-scale facility testing, using electric motors supplied by Nissan, to further refine the method.
Key elements of the digital revolution
Some chemical elements have unique properties not found in other materials, and are highly sought after for the manufacturing of advanced electric and digital products. Praseodymium, for example, can be used to make high-powered magnets.
Despite their name, not all rare-earth elements are in scarce supply globally, but they seldom appear in large seams or geological depots and are distributed unequally throughout the Earth’s crust. Some REEs have become highly sought-after commodities, especially in the wake of the digital revolution, since they are vital elements of many high-tech applications, with about one quarter of REE consumption currently related to catalysts and one quarter to magnets.
In the case of electromobility, the valuable materials are used to build lightweight magnets for electric vehicle motors, where the weight factor is a crucial part of determining performance and range. They are also used for fuel-cell batteries in hybrid cars. Looking beyond the automotive sector, REEs can be found other components of sustainable energy assets such as wind turbine generators as well.
Sustainable resource use
This means that more efficient recycling can bring down the cost of components and solutions by reducing the need for permanent resource extraction. Notably, mining, processing, and shipping the REEs from their natural deposits to the end-user also involves a huge environmental footprint that could be greatly reduced be re-using available materials.
Due to their uneven global distribution, there are concerns that a few countries with significant REE deposits could limit production or access, potentially creating bottlenecks and giving rise to trade disputes. China, one of the biggest suppliers of rare earths, has been criticized by other advanced industrialized economies for occasionally restricting exports or imposing quotas, ostensibly to prevent smuggling and protect the environment.
Nissan and Waseda University hope to introduce the recycling technology by the mid-2020s. In the face of increasing demand for these finite resources, any commercial-scale process that could expand access to recycled materials would no doubt be welcomed with open arms by manufacturers around the world. Cheaper sourcing of rare elements might also accelerate the process of electrification across numerous industry sectors.
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