You are here:
Critical Mineral Recovery from Mine Influenced Waters – Literature Review and Technology Evaluation
Citation:
Bronstein, K., K. Whiting, C. Schroer, L. Mulrooney, A. Neisess, N. Norris, R. Olsen, AND N. Revetta. Critical Mineral Recovery from Mine Influenced Waters – Literature Review and Technology Evaluation. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-25/038, 2025.
Impact/Purpose:
This report provides a comprehensive overview of the literature review and technology screening conducted for critical mineral (CM) extraction from mine wastes and mining-influenced waters (MIW). The primary objectives were to identify and evaluate technologies that could potentially enhance the efficiency and sustainability of Superfund remedial and response actions by facilitating alternative and supplemental CM recovery. The report highlights the diverse and adaptable technologies available for CM, specifically REE recovery, acknowledging the unique challenges posed by their chemical similarities. Due to the experimental nature of a few of the identified technologies, further research will be crucial to determine their viability. This report serves as a foundational document for advancing critical mineral recovery efforts, emphasizing the importance of continued research and evaluation to support sustainable practices in mineral resource and waste management.
Description:
This report provides a comprehensive overview of the literature review and technology screening conducted for critical mineral (CM) extraction from mine wastes and mining-influenced waters (MIW). The primary objectives were to identify and evaluate technologies that could potentially enhance the efficiency and sustainability of Superfund remedial and response actions by facilitating alternative and supplemental CM recovery. To achieve these objectives, a detailed literature search was conducted, categorizing the findings into four key CM processing stages: · Beneficiation: Separation of CMs from gangue minerals or ions. · Extraction: Purification to approximately 70% CM. · Separation: Final purification to over 99% CM, including the separation of individual rare earth elements (REEs). · Alloying: Creation of saleable products for industrial use. Given the array of CM across the periodic table of elements, it was decided to pursure recovery technologies that focused on a family of elements for this work, Rare Earth Elements (REEs). REEs and elements of interest in this study include atomic numbers 57-60, 62-71, 3, 21, 27, 51 and 39. The literature reviewed included a range of studies, from bench-scale laboratory tests to analyses of actual mine water effluent, tailings, leachate, and coal ash samples. Given the vast array of prospective technologies, an initial high-level screening was conducted to filter out less viable options, ultimately identifying 47 technologies. From these 47, a scoring system was then established to retain the most promising recovery technologies, with the intent of narrowing the list to a manageable number for potential future field or laboratory testing. This scoring methodology resulted in the identification of 15 CM recovery technologies. From the scoring methodology results, a short list of 6 proposed technologies (3 primary and 3 alternate) for continued research and evaluation from the beneficiation, extraction, and separation categories are provided for future consideration. The report highlights the diverse and adaptable technologies available for CM, specifically REE recovery, acknowledging the unique challenges posed by their chemical similarities. Due to the experimental nature of a few of the identified technologies, further research will be crucial to determine their viability. This report serves as a foundational document for advancing critical mineral recovery efforts, emphasizing the importance of continued research and evaluation to support sustainable practices in mineral resource and waste management.