Enabling Urban Mining of Critical Minerals from Domestic Electronic Waste

The Science

Recovering critical minerals from complex unconventional feedstocks is crucial for achieving energy dominance, technological innovation, and domestic supply chain security in the United States. Researchers at Pacific Northwest National Laboratory’s Non-Equilibrium Transport Driven Separations (NETS) initiative developed an innovative technique that leverages the intrinsic differences in reactivity and diffusivity to separate critical minerals from solutions. The team targeted recovering critical minerals—dysprosium and neodymium—from simulated recycled electronic waste (e-waste). They effectively removed iron, a major e-waste component, in the first stage. The solution was therefore enriched in the critical minerals dysprosium and neodymium. This enrichment enabled the selective nucleation of a solid that was primarily dysprosium, followed by a second solid phase that was highly concentrated in neodymium, without any specialty chemicals or other energy-intensive processes.

The Impact

The rising industrial demand for critical minerals necessitates the development of new methods to recover them from unconventional feedstocks, such as e-waste. Traditional mining and separation methods are energy- and chemical-intensive, produce substantial waste, and require significant infrastructure investments. E-waste is a readily available, growing source of concentrated critical minerals. However, its complex composition necessitates the separation of individual elements from mixtures. Beyond simple efficacy, the reaction–diffusion process developed by the NETS team can be readily adapted for chemically diverse feedstocks without the need for designing costly specialty chemicals. This method’s flexibility, adaptability to chemical diversity, and energy-minimal requirements make it particularly promising for separating critical minerals from complex e-waste.

Summary

Discarded electronics present both a waste challenge and an opportunity to recover valuable materials. E-waste can be a significant source of critical minerals, but accessing these resources requires new approaches to extract individual elements with similar properties from complex mixtures. The NETS team developed an energy-minimal recovery process based on reaction–diffusion coupling to separate critical materials in model e-waste solutions. Their innovative approach uses hydrogel columns loaded with simple reagents to selectively precipitate critical materials. To demonstrate the effectiveness of their energy-minimal extraction method, the NETS team performed experiments using a solution of iron, neodymium, and dysprosium—mimicking the composition of permanent magnets. The process sequentially separated the three elements: iron first, then a solid enriched to over 70 percent dysprosium, and finally a precipitate that was over 95 percent neodymium. Neodymium and dysprosium are both critical elements widely used in advanced technologies. The method leverages subtle differences in the intrinsic properties of the target ions to achieve separation. By exploiting these fundamental properties, the process becomes less sensitive to variability in feedstock composition, enhancing its applicability and potential impact on critical domestic supply chains.

Contact

Elias Nakouzi, Pacific Northwest National Laboratory, elias.nakouzi@pnnl.gov

Funding

The systematic experimental study and numerical simulations were supported by the Laboratory Directed Research and Development program at Pacific Northwest National Laboratory under the NETS initiative. The scanning electron microscopy, energy-dispersive X-ray spectroscopy, Raman spectroscopy, and X-ray diffraction analyses were conducted at the Molecular Analysis Facility, a National Nanotechnology Coordinated Infrastructure site at the University of Washington, with partial support from the National Science Foundation via awards NNCI-2025489 and NNCI-1542101.