US team recovers rare earth elements from discarded vehicles

With rare earth elements vital to the production of a wide range of technologies, industry is increasingly concerned that it is overly reliant on one country – China – to supply these vital materials.

In an effort to address this researchers at Worcester Polytechnic Institute (WPI) in the US have developed a chemical method for recovering rare earths from the drive units and motors of discarded electric and hybrid cars.

The process, developed by Marion Emmert, assistant professor of chemistry at WPI, and researcher H.M. Dhammika Bandara, uses a two-step chemical extraction process to recover rare earth elements - specifically neodymium, dysprosium, and praseodymium - from other materials used to make the devices.

To test the process, the team 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. 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.

The group says the technology has the potential to be an alternative source of rare earths, which could lessen the need to import these vital elements from China, which currently supplys about 97 per cent of rare earths used in manufacturing.

“The fact that China has the majority of operable separation facilities in the world is a huge problem for the United States,” said Emmert. “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.”