Matthew Mettler
Colorado School of Mines

Extraction of PGMs, Nickel, Copper and Cobalt from Eagle Mine Tailings

More progress has been made on the recovery and beneficiation of PGMs, nickel, copper, and cobalt from the Eagle Mine tailings. Results include an in-depth flotation kinetic analysis that display how fast the particles float and the determining kinetic factors. In addition, further flotation results show the impact of pH, agitator apparatus, acid type, and collector on flotation response. An update on the results and mechanisms behind the Eagle Mine tailings flotation system will be presented.

R M Shahbab
University of Arizona

Techno-Economic and Life Cycle Analyses of Sm2Fe17N3 Magnet Production

Sm2Fe17N3 can potentially substitute SmCo magnets and heavy rare-earth element-containing NdFeB magnets, providing an alternative, cheaper solution. This study presents a techno-economic analysis (TEA) and life cycle assessment (LCA) of SmFeN magnet production, modeled at a 90-tonne/year production scale. The process involves the key steps of mixing, reduction-diffusion, nitridation, washing, jet milling, and sintering. Two different sintering routes were explored − spark plasma sintering (SPS) and hot pressing. SPS enables rapid powder consolidation but is limited to small samples, making it suitable only for laboratory work. Hot pressing, in contrast, can handle much larger parts; therefore, scalable for industrial production. Our TEA shows that hot-pressing-based magnet production results in an annual cost of $4-$7 million. In contrast, SPS-based production requires $12 – $51 million per annum due to its limited throughput, demanding a large amount of parallel equipment and operating labor. Preliminary cradle-to-gate LCA showed that 1 kg of SmFeN magnet has a global warming impact of 14 – 29 kg CO2 eq, substantially lower than NdFeB and SmCo at 82 and 54 kg CO2 eq, respectively.

Elizabeth Garcia
Pacific Northwest National Laboratory

Separation of REE from phosphogypsum leachates through solvent extraction in centrifugal contactors Up to 280 million tonnes of phosphogypsum (PG) are generated each year as a byproduct of phosphoric acid production, with ~85% landfilled. PG is mainly composed of gypsum (CaSO4), phosphates, and trace metals, making it potentially useful for cement production. PG contains ≤0.4 wt% REE, making it a viable secondary feedstock for critical materials. Our research focuses on the recovery of REE by leaching and solvent extraction. We previously demonstrated that moderately concentrated (>3 M) HNO3 successfully leached REE from PG. The leachate was extracted with TODGA, a tridentate ligand with an affinity towards Ln, and Exxal-8 in Isopar-M. TODGA preferentially extracts REE, but Ca2+ partially extracts due to its high concentrations in PG leachate (1000-fold over Ln) creating a challenge. Prior testing was done as batch contacts, generating information for developing a dynamic flowsheet with three major steps, 1) REE extraction from PG leachate, 2) scrubs for removing impurities, and 3) preferential stripping of REE. Ra-226 is also a concern and is tracked throughout. Here we present updated results with Riverview PG (~0.03 wt% REE) using a dynamic flowsheet in centrifugal contactors.

Lesta Fletcher
Oak Ridge National Laboratory

Harnessing Coordination Chemistry to Achieve Selective Leaching of Rare Earth Elements

Domestic separation of rare earth elements (REEs) is one of the most pressing scientific challenges in the United States. The first industrial step in REE separations is non-selective leaching of a feedstock using a strong acid, while the majority of research efforts focus on post- leaching separation techniques such as solvent extraction or selective crystallization. Selective leaching using strategically designed leaching agents, or chelators, remains an underexplored yet potentially transformative approach to REE separations. In this presentation, we share our selective leaching results from a complex rare earth hydroxide sample derived from authentic domestic mining waste, demonstrating how leaching selectivity can be effectively tuned through chelator design. Furthermore, our research highlights how core principles of coordination chemistry can be harnessed to enhance industrial processes such as hydrometallurgical leaching, offering a pathway to more efficient and economical recovery of REEs.

Asif Hasan Ridoy
University of South Florida

Development of Scalable Graphene–Polysulfone Membranes for Enhanced Lithium Recovery

Lithium recovery from saline sources is vital to meet the growing demand for sustainable energy storage materials. Membrane-based electrodialysis provides a promising route for selective ion transport; however, achieving high lithium selectivity remains challenging due to the similar hydrated sizes of competing cations. In this study, a graphene–polysulfone composite membrane was fabricated and tested under varying thermal conditions. The membrane was prepared by exfoliating graphite into graphene within polymer, followed by heat-pressing into circular films. Oxygen plasma treatment was applied to introduce functional groups that enhance ion selectivity. At room temperature (≈25 °C), the membrane achieved a Li⁺/Na⁺ selectivity of ~3 and lithium recovery near 20 %, while effectively rejecting K⁺, Mg²⁺, and Ca²⁺. When the operating temperature increased to ≈70 °C, performance improved significantly, with Li⁺/Na⁺ selectivity exceeding 10 and recovery surpassing 25 %. This enhancement is attributed to partial dehydration of Li⁺ at elevated temperatures, reducing its hydrated radius and enabling preferential transport through plasma-modified nanochannels.

Zachary Adler
Idaho National Laboratory

Electrodialysis for the upgrading of Lithium concentration in brines

Li is classified as a critical mineral, having applications in energy storage, ceramics and glass manufacturing, and lubrication. As a result, the demand for lithium has increased significantly over recent years. Global lithium demand was 101,000 tons in 2021, and is expected to reach 503,000 tons by 2030, a ~5-fold increase. Moreover, 85%+ of the lithium supply comes from just three countries, creating a supply chain risk. There is thus a desire to source Li domestically. Brines comprise a large portion of the US Li reserves. In these brines, however, Li represents a small component, necessitating a strategy to concentrate and purify the product. Currently, Li is extracted from brines via solar evaporation, although this method requires significant time and is land- and water-intensive. As an alternative, we have developed an electrodialysis technique for direct Li extraction from brines. Utilizing our methodology, we can significantly upgrade the Li concentration, achieving an impressive 5 to 10-fold increase over 24 hours. A higher Li concentration will serve as an excellent feedstock for subsequent Li purification.

Albin John
Purdue

Computationally Guided Scale-Up of Biomass-Derived Synthetic Graphite

High-performance Li-ion batteries rely on synthetic graphite, yet conventional production routes are highly energy-intensive. A preliminary static techno-economic assessment showed that a biomass pathway using woodchip pyrolysis followed by electrochemical graphitization is promising, motivating deeper investigation beyond single-point assumptions to capture reaction behavior, process continuity, & variability. We present a dynamic TEA of a biomass-based synthetic graphite process that integrates reaction-informed models for pyrolysis and electrochemical graphitization in a continuous framework. Unlike static TEA, yields, energy demand, throughput, and equipment utilization vary with operating conditions, enabling systematic exploration of operating ranges & uncertainty rather than single-point evaluation. The results reveal key trade-offs between reaction conditions, energy use, & economic performance, showing how dynamic, computation-driven TEA can complement experimental materials research. The approach bridges laboratory-scale synthesis and industrially relevant process design, while laying the groundwork for future digital-twin development in sustainable graphite production.

Humaira Nafisa Ahmed
University of Arizona

Techno-Economic and Life Cycle Analyses of Electrochemically Enabled CdTe PV Solar Panels Recycling

This study presents a life cycle analysis (LCA) and techno-economic analysis (TEA) of recycling cadmium telluride (CdTe) photovoltaic (PV) module through electrochemically (EC) generated hydrogen peroxide-based chemical leaching. The system boundary was from crushed end-of-life (EOL) CdTe PV to solubilized Te and Cd, as well as recovered glass. The Ecoinvent 3.10 database and the TRACI 2.1 method were used to evaluate environmental impacts across ten categories. The primary environmental hotspot was identified as oxygen, followed by electricity. Improvement opportunities include recycling excess oxygen and use of solar energy. When compared with the current state-of-the-art leaching method, the proposed technology yielded lower environmental impacts in four categories including ecotoxicity. TEA assumed a hypothetical plant capable of recycling 5,000 metric tons of CdTe PV annually over 20 years. The annual cost was estimated to be $8 million. The main cost driver was bipolar membrane (BPM) and the gas diffusion electrode (GDE), which highlights the importance of adopting more durable, high-performance BPMs and GDEs.

Xiaoyu Zhou
Purdue

Techno-economic assessment (TEA) of lithium extraction: comparing traditional and novel processes

Lithium is an essential enabler for emerging technologies such as electric vehicles (EVs) and grid-scale batteries owing to its properties. In the U.S., brine extraction is presently the principal domestic source of lithium. However, as lithium heavily depends on imports, researchers are turning to alternative resources to enhance supply chain resilience and incentivize domestic manufacturing, one of which is spodumene. The traditional industrial process for lithium extraction from spodumene has energy-intensive and time-consuming steps; new processes developed by CMI scientists successfully avoid those procedures. A collaboration with these scientists is analyzing the economic performance of different methods. This presentation will discuss this collaboration and describe the techno-economic assessment (TEA) results of three processes: (i) sulfuric acid roasting, (ii) mechanochemical extraction at low temperature, and (iii) vacuum-induced thermal extraction from α-spodumene. The TEA results will show the cost breakdown and identify the main cost driver for each process. Sensitivity analysis will examine how changes in material/product price affect overall profitability.

Anna (Anya) Berseneva
National Lab of the Rockies (formerly NREL)

Mechanistic studies of rare-earth permanents synthesis via calciothermic reduction-diffusion

As a part of a mission of 1) developing novel magnetic materials that are either free of rare earth (RE) elements or use less-critical RE elements, such as Sm, and 2) introducing novel, more-efficient synthesis methods for known strong RE magnets, we investigated the calciothermic reduction-diffusion (RD) process of Sm2Fe17N3 (1) and Nd2Fe14B (2) by in situ x-ray diffraction. This synthetic method involves the calciothermic reduction of RE oxides in the presence of Fe and is an environmentally friendly and economical process to produce high-performance magnets. Mechanistic understanding of the rapid exothermic reactions that occur during this process is crucial for future control of process time, temperature, and possible additives in this process. Therefore, we performed several synchrotron experiments at SSRL, ALS and APS to derive the reaction paths and intermediates for and Sm2O3 + 3Ca + 17Fe and Nd2O3 + 3Ca + 13Fe +FeB mixtures up to 900 °C. This talk will present our sample preparation journey which was crucial to understand the reaction pathways we discovered in the process.

Taylor Quinn
Argonne National Laboratory

Bridging Data Gaps in Critical Material Cost Curve Analysis

Cost curves are a classic tool within the mining industry that are useful for evaluating supply and demand, mine competitiveness, and the impacts of price changes. However, a major gap in cost curve analysis lies in data availability and accuracy, particularly for rare earth oxides (REOs). Cost estimates are most often reported by public firms, but in nations where firm reporting is not commonplace, assumptions are often made to address substantial uncertainty about key metrics. Thus, cost curves produced on a global scale may lead to a misrepresentation of the mineral market. This effort aims to improve data transparency for critical materials by applying econometric methods to estimate costs and production capacities for mining projects where data are not available. The authors test both a frequentist and Bayesian statistical method and compare the results against previously developed cost curves. The model is applied to REO mines, given their opaque markets and concentrated production in China. The results are used to develop updated cost curves, including producers not previously accounted for and ultimately creating a more complete representation of the global market.

Hojun Choi
Colorado School of Mines

Optimal clearing of two-class queues with social contagion effects

Nickel supply chains have experienced repeated disruptions following Indonesia’s export controls aimed at promoting domestic processing. Yet, early project delays, environmental scrutiny, and technical setbacks led to visible exits by miners, refiners, and downstream manufacturers, which in turn triggered follow-on withdrawals, feedstock diversion, and substitution toward lower-nickel chemistries. Motivated by this setting, we study a transient clearing system with two competing queues sharing limited service capacity, where abandonment decisions depend not only on individual impatience but also on social contagion. We characterize optimal dynamic allocation policies and show that an optimal policy allocates all capacity to one queue at a time, with strict priority or switching behavior arising across parameter regions. Numerical results indicate that a simple heuristic prioritizing the class with the higher effective abandonment rate performs near-optimally. These findings explain why proportional allocation can fail in critical-mineral supply chains and offer guidance for resilient industrial policy under belief-driven exit dynamics.

Lun An
Ames National Laboratory

Automation, Lixiviant Innovation, and Process Design to Accelerate Critical Material Manufacturing

Accelerating the research, development, and deployment (RD&D) of sustainable processes to manufacture rare earth elements (REEs) requires both efficient, scalable synthesis of extractive ligands and rapid evaluation of process conditions. In this presentation, I will showcase an integrated RD&D methodology that couples at-scale ligand synthesis with automated high-throughput extraction studies. We further incorporate artificial intelligence and machine learning (AI/ML)–augmented process optimization to streamline decision-making and improve experimental efficiency. Together, these capabilities lay the foundation for fully closed-loop, AI-controlled platforms that enable smart, autonomous manufacturing of critical materials.

Hannah Gates
Iowa State University

REEFit for designing Lanmodulin variants with lanthanide target selectivity

Rare earth elements (REEs), whose distinct electronic and electrochemical properties support applications from healthcare to defense, are vital to the USA’s technological development and ongoing innovation, highlighting the need for efficient avenues for REE recovery. Lanmodulin (LanM) is a highly selective LnIII binding protein that is characterized by its four metal binding EF hand motifs that each demonstrates a distinct binding affinity profile. Although experimental work delivers evidence of LanM selectivity for light and heavy LnIII through the total metal binding, this analysis and metric does not quantify the per EF hand selectivity. This work bridges in silico molecular modeling and in vitro experimental methodologies to elucidate the mechanistic basis of REEs binding to specific EF hands. We present a mixed integer programming model for the optimization of the partial binding probability that effectively captures the relationship between experimental findings and computational analysis. Thereby, enabling a deeper understanding of per EF hand partial binding probability and informing strategies for rational optimization of LanM variant design for REE selectivity.

Sangita Gayatri Kannan
Argonne National Laboratory

Modeling stockpiling strategies to enhance rare earth supply chain resilience

Rare earth oxides (REOs) are indispensable inputs to energy, transportation, and defense technologies, yet their supply is highly concentrated and exposed to supply-side shocks stemming from geopolitical tensions and market volatility. Stockpiling is often proposed as a strategy to enhance supply resilience in the short-term, though its effectiveness under realistic market behavior is less understood. This study leverages Argonne’s Global Critical Materials (GCMat) agent-based model to evaluate strategic stockpiling of REOs under various implementation mechanisms and supply disruption scenarios, such as export restrictions. The model captures interactions among agents—producers, processors, downstream manufacturers, and stockpile managers–and simulates how stockpiling rules influence supply stability and price outcomes when shocks occur. By comparing price-triggered, quantity-targeted, and hybrid stockpiling mechanisms, the study identifies whether, when, and how stockpiling can meaningfully reduce risk for downstream producers. The resulting framework provides decision-support insight into how stockpiles can be designed to mitigate vulnerabilities in global REO supply chains.

Andrew Villalobos
Case Western Reserve University

Molten salt electrowinning of Nd enabling low-cost and scalable domestic metal production

Electrification of transportation and defense equipment relies on magnets such as neodymium-iron-boron (NdFeB). Currently, neodymium metal is available through a fragile overseas supply chain where neodymium oxide is converted to metal with fluoride-based molten salt electrolysis (MSE) using a consumable graphite anode, leading to the formation of perfluorocarbons (PFCs). Permitting issues due to PFCs and the growing cost of graphite make it difficult and expensive to practice this process in the U.S. Our team is developing an alternative process that utilizes chloride-based MSE of neodymium chloride producing chlorine gas as a recyclable value-added byproduct. This enables high purity (>99 wt.%) metal production rates that are an order of magnitude higher than the state-of-the-art fluoride process at high coulombic efficiencies (>70%) and eliminates a consumable graphite anode. In this talk, we will present our ongoing work aimed at enabling a continuous process with high feedstock conversion to further improve operating costs. Aspects of electrolyte design to minimize evaporation loss, oxychloride’s impact on production yield, and a dimensionally stable anode will be highlighted.

Dung Thi Hanh To
Idaho National Laboratory

Electrochemical Recovery of Tellurium from End-of-life CdTe Photovoltaic Solar Panels

Cadmium telluride (CdTe) photovoltaics (PV) represent >50% of new commercial scale solar panel installations in the United States. A robust and secure supply chain of Tellurium (Te) for such growth of solar industries can be supported by recycling end-of-life (EOL) CdTe PV solar panels. Current industrial recycling process uses chemical leaching using hydrogen peroxide (H2O2) and sulfuric acid, representing high costs and environmental impacts. In this study, we have developed a novel technology based on electrochemical leaching (ECL) of EOL CdTe PVs where H2O2 is electrochemically generated onsite from oxygen. ECL allows 99% metal extraction efficiency at ambient conditions and offers >5 times faster leaching rates than conventional process. To isolate the pure form of Te from the leachate containing mixture of metals, we have developed an ion-exchange chromatography method allowing separating Te ions from the mixed-metal leachate, followed by an electrowinning method to isolate Te metal with 72% yield and 93% purity. Systems modeling through techno-economic analysis and life cycle assessment helped identify the potential bottlenecks of the process for improvement and scalability.

Xianxian Zhou
Penn State

Fused lanmodulin dimers for enhanced rare-earth separation

Our previous work has shown enhanced intra-RE selectivity and separation performance of a lanmodulin ortholog, Hans-LanM, that dimerizes in a RE-dependent manner. However, the current immobilization strategy results in LanM monomers that cannot dimerize on-column, preventing us from potentially taking advantage of the beneficial effect of dimerization on selectivity. Here, we present the tethering of two LanM protomers capable of dimerization in a single polypeptide chain. The ability of these tandem dimer proteins to self-dimerize (form intramolecular rather than intermolecular dimers) was evaluated in solution. We also present the in-solution and on-column separation performance of the tandem dimer.

Dennis Dadzie
Missouri S&T

Life Cycle Assessment Modeling to Support Process Development for Germanium Processing

Critical mineral recovery efforts in the extractive industry include improving the environmental impact of processing techniques. LCA modeling helps compare the environmental burden of conventional and promising processing techniques for process improvement. This study provides an LCA comparison of the cradle-to-gate production of single-crystal germanium from coal fly ash by conventional chlorinated distillation and CAT-TOA solvent extraction. A comparison of the two recovery techniques shows chlorinated distillation route has a net environmental benefit over solvent extraction in terms of global warming potential, cumulative energy demand, and water consumption, while solvent extraction performs better in terrestrial acidification and fine particulate matter formation. To reduce potential environmental impacts of solvent extraction, the system should reduce electricity use, increase reuse of the organic phase, and adopt a less emissions-intensive kerosene substitute. Environmental burden of chlorinated distillation can be enhanced by utilizing waste energy from re-volatilization, adopting more efficient combustion and reduction technologies, and optimizing chlorine gas usage.

Carl Gorski
Colorado School of Mines

Scrub n’ Sort: Producing A Dry RE Mineral Concentrate Through Preferential Breakage At Bear Lodge

Bear Lodge is a high-grade rare-earth (RE) deposit that’s positioned to become one of the largest Nd-Pr oxide producers in the United States. The Department of Energy, recognizing this, has funded the site’s current mineral processing research through the Critical Materials Innovation Hub (CMI). CMI’s initial material characterization of Bear Lodge ore revealed that fine-grained RE minerals preferentially liberate from veins when comminuted, forming a RE concentrate. Further research found that scrubbing the crushed rock liberates remnant, surficial RE minerals, creating additional concentrate without the need for additional comminution. After scrubbing, the rocks were subject to ore-sortation technology, which uses X-ray transmission (XRT) to delineate ore from waste. XRT suggests that much of the deposit’s coarse rock can be ‘rejected’ & sent to stacked tailings before further processing. Cumulatively, this scrub-and-sort process has the potential to recover 90%+ of the ore’s TREO, with a concentrate mass pull of ~25% & a concentrate grade of 10%+ TREO without the need for water, & at lower capital & operating expenditures than traditional RE mineral processing facilities.

Ines Flores Aroni
Colorado School of Mines

Enhanced Domestic Extraction of PGMs, Nickel, Copper, and Cobalt from Smelting By-Products

Smelting by-products such as spent furnace bricks retain appreciable concentrations of PGMs and base metals, representing a potential source of valuable materials compared to primary ores. The limited domestic supply of these metals, alongside rising demand, highlights the need for improved recovery strategies. This study focuses on optimizing froth flotation for metal recovery from finely crushed brick material. Microflotation and laboratory-scale tests were conducted to assess the influence of reagent schemes, particle size, pH, and depressants on metallurgical performance, enabling the identification of conditions that improve selectivity and recovery. Magnetic separation was also evaluated as a complementary stage to better understand the behavior of metal-bearing phases not effectively treated by flotation. Tests were applied to both feed material and flotation tailings, providing insights into potential pathways for improving overall circuit efficiency. The combined results establish the basis for integrating flotation with magnetic separation in the treatment of spent refractory bricks and guide future work toward a refined beneficiation flowsheet.

Sophia O’Barr Rogers
Oregon State University

Geochemical Characterization of Li-Clay from McDermitt OR/NV and Implications for Enrichment

McDermitt caldera in OR/NV hosts potentially the largest domestic Li-clay deposits in the United States. We examined intracaldera Li-claystones from drill core and surface samples on the Jindalee Mining Property, Oregon, to identify dominant Li-hosting clay minerals and the chemical signatures correlated with Li ore grade. Detailed in-situ major and trace elemental composition were systematically collected via portable  pXRF and LIBS, and clay mineralogy and calcite were identified by SWIR. We quantified diagnostic elements and minerals in the ore environment (e.g. Hg, As, Calcite) that must be considered for   production methods. Portable Li and trace element quantification methods are being validated by LA-ICP-MS, and SWIR identifications (Smectite vs Hectorite clay) are being validated by XRD. Initial results revealed associations between Li and certain diagnostic elements suggesting genetic links between hydrothermal activity and Li distribution and grade. We will present data assessing relationships between Li concentration, clay mineralogy, and stratigraphy to inform ore genesis, possible co products (Mg, Ga), and possible challenges to extraction.

Subhamay Pramanik
Oak Ridge National Laboratory

Enhancing Critical Mineral Separation for Sustainable Extraction

Rare earth elements (REEs)—are critical to the U.S. economy, energy security, and national defense due to their essential roles in advanced technologies. Conventional industrial separation processes rely on solvent extraction using phosphorus-based extractants such as PC88A, controlled through pH adjustments. These methods are inherently complex, chemically intensive, and generate substantial waste.

Abigail Boafo
Missouri S&T

Social Acceptance of Proposed Lithium Projects in McDermitt Caldera, Jindalee – Oregon

Lithium development in the McDermitt Caldera has drawn national attention as the U.S. seeks to secure critical mineral supplies for the energy transition. These dynamic places strain on local communities, making social acceptance a decisive barrier to project viability. Understanding how residents evaluate trade-offs is essential for sustainable resource governance. This study applies a discrete choice analysis (DCA) framework to quantify stakeholder priorities and identify which attributes promote or constrain acceptance of lithium projects. We test three hypotheses reflecting an expected hierarchy of values: (1) acceptance increases with favorable resource impacts; (2) fair, participatory permitting processes shape acceptance more than project scale; and (3) cleaner, less intrusive extraction and processing technologies garner stronger support. By operationalizing social acceptance through DCA, this research provides a structured, replicable pathway for integrating community priorities into project evaluation. This approach positions the proposed lithium development in the McDermitt Caldera as a testbed for aligning energy security, resource policy, and local justice imperatives.