Researchers at West Virginia University (WVU) have developed a method to extract heavy rare earth minerals from acid mine drainage, a significant step toward establishing a domestic supply chain for these critical materials. The process transforms polluted water leaking from abandoned coal mines into a potential source for minerals essential for modern technology, including smartphones, electric vehicles, and advanced military systems.
The United States currently depends heavily on foreign suppliers, particularly China, for many rare earth elements. Heavy rare earth minerals are especially valuable due to their use in defense applications and advanced energy technologies.
WVU scientists discovered that valuable rare earth elements were present in the acidic water flowing from retired coal mines. Initially, the research focused on treating acid mine drainage to clean up watersheds. During this process, the presence of rare earth elements was identified.
"There’s an opportunity to generate revenue out of this AMD treatment," said Steve Dunmead, CEO of Mission Critical Materials, a company formed to commercialize the technology. "Originally, the entire focus of this effort was just simply cleaning up the watersheds."
WVU's research indicates that acid mine drainage can contain a significantly higher percentage of heavy rare earth elements compared to traditional sources. While traditional sources might yield about 2% heavies, the coal mine drainage studied by WVU contained approximately 50% heavy rare earths, which are among the most valuable and difficult minerals to source.
The WVU Rare Earth Elements Initiative began nearly a decade ago. In 2022, the university partnered with the West Virginia Department of Environmental Protection to establish the A34 AMDREE Processing Facility in Mount Storm. This facility is the first integrated pilot-scale rare earth recovery facility of its kind in the United States.
The technology aims to reduce U.S. reliance on foreign sources by creating a new domestic supply chain. Rare earth elements are crucial components in everyday products like cell phones, wind turbines, electric vehicles, fighter jets, and missile defense systems.
Mission Critical Materials is working to expand the technology beyond coal mine pollution to include other sources of critical minerals, such as hard rock mines and other industrial waste streams. "And in the process, [we] also figured out it is not unique to coal mines but hard rock mines as well," Dunmead noted. "So copper mines, gold mines, also have acid mine drainage."
An advantage of this approach is that it utilizes existing polluted sites, eliminating the need for new mine construction. "The regulatory pathway for a traditional mine can take years," Dunmead said. "This technology can go into an existing acid mine drainage site using an existing water permit."
Researchers believe this process offers an environmentally friendly solution to two challenges simultaneously: mitigating water pollution and producing essential materials for the nation's future. The next phase involves constructing a larger-scale facility with the goal of beginning domestic production and sales of heavy rare earth materials.