| Abstract Scope |
Critical minerals, especially rare earth elements (REEs), are essential for clean energy, electrification, defense, and advanced manufacturing, yet domestic supply remains limited by complex feedstocks and inefficient separations. Our work advances recovery and separation of REEs and other critical metals from unconventional and secondary resources, including mine tailings, coal byproducts, low-grade ores, and end-of-life magnets. We integrate advanced characterization tools, including coupled synchrotron X-ray fluorescence/XRD mapping, micro-/nano-computed tomography, ToF-SIMS, and AI/ML-driven electron microscopy, to determine how critical metals are hosted, released, transported, enriched, and separated. These measurements reveal that recovery efficiency and selectivity are governed by local coordination chemistry, oxidation state, mineral associations, nanoscale heterogeneity, interfacial reactions, and secondary phase formation. Guided by these insights, we develop ligand-mediated leaching, hydrothermal enrichment, electrochemical recovery, and molten-salt processing strategies to convert complex domestic resources into value-added feedstocks for resilient energy, manufacturing, and national security supply chains. |