The “missing link” in critical minerals may have been in our junk drawers all along, according to new research from the University of Houston.

Jian Shi, an associate professor in the UH Cullen College of Engineering, and his team have unveiled a new supply chain model that aims to make e-waste economically viable and could help make large-scale recycling possible.

Shi, along with professor Kailai Wang and graduate researcher Chuyue Wang, published the work in a recent issue of Nature. Their study outlines how gold, lithium and cobalt from discarded electronics can be kept circulating in the U.S. through the process of “urban mining.” It was supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) through the Vehicle Technologies Office.

The team’s research found that e-waste is the fastest-growing solid waste stream in the world. When waste from smartphones or tablets is left unmanaged, the devices can leak hazardous waste and pose significant fire risks due to aging batteries. Additionally, when they are shipped off to foreign landfills, the U.S. loses the potential to recycle or reuse the critical minerals left inside.

“A lot of people have iPads or old iPhones sitting in their drawers right now, and that’s a waste of a critical resource,” Shi said in a news release. “Urban mining allows us to extract the same high-value materials found in traditional mines without the environmental destruction. More importantly, it helps secure our domestic supply chain for the technologies of tomorrow.”

According to UH, recycling e-waste has not succeeded in the U.S. due to a fragmented recycling system, in which manufacturers, collectors and recyclers operate separately, driving up costs.

The UH team's research looks to change that.

In the study, the researchers modeled streamlined recycling efforts by mapping the interactions between manufacturers and independent recycling markets. Their dual-channel closed-loop supply chain (CLSC) model identified how these players can transition from competitors to partners, which can distribute profits more equitably and make recycling efforts more financially attractive.

According to UH, the research has particular significance due to the growing demand for electronic vehicles and their batteries.

“We can improve the performance of the entire recycling ecosystem and make the profit distribution more balanced,” Wang said in the release. “This ensures that the materials we need for EVs and advanced electronics stay right here in the U.S.”

“By making recycling work at scale, we aren’t just cleaning up waste,” Shi added. “We’re building a foundation that benefits both our national security and our economy.”