23 Jul 2024


Researchers recover rare-earths from old EV motors

American researchers have developed a method for extracting rare-earth materials from the drives and motors of discarded electric and hybrid vehicles. Their aim is to help develop a sustainable domestic supply of rare earth-elements in the US, and to reduce the nation’s dependence on China for materials that are vital to the production of high-efficiency motors, wind turbines and other technologies.

The researchers, from the Center for Resource Recovery and Recycling at Worcester Polytechnic Institute (WPI) in Massachusetts, have developed a method for chemically separating rare-earth elements – specifically neodymium, dysprosium, and praseodymium – from other materials used in the EV drives.

To test the process, the researchers sliced the drive from a Chevrolet Spark electric vehicle – consisting of the electric motor and other components of the drivetrain – into several pieces, and then shredded the pieces. Using a two-step chemical extraction process, they then separated the rare-earth elements and recovered other recyclable materials, including steel chips, from the fragments.

The researchers believe that the technology could offer an alternative source of rare-earths, which could lessen the need to import these elements from China, which currently supplies about 97% of the rare-earths used in manufacturing. Furthermore, because magnets containing rare-earths are used in a wide range of technologies, manufacturers would be able to improve the sustainability of their products by recycling these materials.

“The fact that China has the majority of operable separation facilities in the world is a huge problem for the United States,” explains Marion Emmert, assistant professor of chemistry, chemical engineering, and mechanical engineering at WPI. “Large car manufacturers are dependent on the magnets composed of these elements for car production, so it’s really critical for rare-earth recovery and separation technologies to take hold here.

“In the last 20 years, the United States has lost knowledge and expertise on how to mine, recover, and separate these materials,” she adds. “We’re hoping that starts to change and that the United States becomes less dependent on foreign countries to recover rare-earth elements.”

WPI’s intellectual property and innovation department has filed a provisional patent on the recovery technology, and is hoping to find a licensee for the technology.

The research dates back to 2014, when WPI was named the lead institution in a $7.4m, multi-university award from the US Army that supported the development of new metallurgical methods and lightweight alloys to help the military to build more effective and durable vehicles and systems. Part of that research explored methods for extracting rare-earth elements from ores, and for recovering those elements from recycled materials.