Despite rare earth elements' importance in manufacturing cell phones, magnets and a host of other consumer and commercial electronics, the lack of a sustainable, environmentally friendly approach to obtaining these metals has led to a global shortage, according to Amir Sheikhi, associate professor of chemical engineering.
Sheikhi is the principal investigator on a paper, recently published in Advanced Functional Materials, that proposes a novel technology of isolating and recovering dysprosium, a rare earth element used to manufacture semiconductors, engines, generators and more. The team used cellulose - an abundant and critical building block found in the walls of plant cells - to selectively separate dysprosium from other elements. According to the researchers, the approach is more environmentally friendly, as well as more sustainable and efficient than other commercial approaches.
The 17 metals classified as rare earth elements can be further categorized as heavy or light depending on their chemical makeup, according to Sheikhi, who also holds the title of Dorothy Foehr Huck and J. Lloyd Huck Early Career Chair in Biomaterials and Regenerative Engineering. His team had previously used cellulose-based compounds to successfully salvage neodymium, a light rare earth element used to develop powerful magnets, from e-waste like recycled circuit boards from computers.
However, this approach had not yet been used to isolate and recover dysprosium specifically, a heavy rare earth element that can be used to do things like keep nuclear control rods thermally stable.
"As technology advances, manufacturers will need more and more dysprosium - some forecasts estimate the demand for this material may surge over 2,500% in the next 25 years," said Sheikhi, founding director of the Bio-Soft Materials Laboratory. "Having a sustainable and environmentally friendly way to recover this material will strategically help the U.S. stay competitive with countries like China."
Commercialized approaches to separating rare earth elements primarily use solvents, dissolved liquids or solids that can break apart minerals, and require rooms full of machinery and chemicals to function, according to Sheikhi.
"Separating rare earth elements from one another has been extremely difficult, due to the metals' very similar chemical structures," Sheikhi said. "We have been looking for a reliable way to separate heavy elements like dysprosium from lighter elements like neodymium, while avoiding the negative environmental side effects that come from current separation approaches."
