Researchers develop method to recover rare earth elements from discarded EV engines

Rare earth elements are key ingredients in wind turbines and electric and hybrid vehicles, but retrieving the elements once the equipment hits the junk yard needed a solution.

Two researchers at Worcester Polytechnic Institute (WPI) have developed a method of extracting rare earths from the drive units and motors of discarded electric and hybrid cars.

Marion Emmert, assistant professor of chemistry, chemical engineering, and mechanical engineering at WPI, and postdoctoral fellow H.M. Dhammika Bandara were lauded for coming up with the procedure.

The pair created a novel method for processing drive units and electric motors to chemically separate rare earth elements – specifically neodymium, dysprosium, and praseodymium – from other materials used to make the devices.

The approach is documented in the Worchester Polytechnic Institute:

To test the process, the WPI researchers sliced the drive unit (which contains the electric motor and other components of the drive train) of an all-electric Chevrolet Spark vehicle into several pieces and then shredded the pieces. Using a two-step chemical extraction process, they were able to separate the rare earth elements and also recover other recyclable materials, including steel chips and other useful materials from the drive units.

In addition to recovering rare earths that would otherwise be lost in a sustainable and efficient manner, the method also has the added benefit of reducing the reliance on China's stranglehold on rare earth production.

"In the last 20 years, the United States has lost knowledge and expertise on how to mine, recover, and separate these materials," said Emmert. "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 beginning to market the technology in hopes of finding a licensee.

Image of WPI professor Marion Emmert holds the drive unit of an all-electric vehicle in her lab at Gateway Park, courtesy of Worcester Polytechnic Institute