Colorado School of Mines–ElementUSA REE plant: process and tailings notes for engineers
Reviewed by Tom Sullivan
First reported on International Mining – News
30 Second Briefing
Colorado School of Mines and ElementUSA have secured US$67 million from the US Department of Energy to build a rare earth element extraction and processing plant treating alumina refinery tailings at Gramercy, Louisiana. The DOE Office of Critical Minerals and Materials is backing the project as one of only two funded initiatives, targeting recovery of REEs from existing bauxite residue streams rather than new mining. For process engineers and tailings specialists, the scheme signals growing support for hydrometallurgical upgrading and reprocessing of legacy red mud deposits.
Technical Brief
- Alumina tailings (bauxite residue/red mud) present alkaline, fine-grained feed, influencing leach chemistry and materials handling.
- Process design must manage co-extraction of iron, aluminium and other gangue from residue, requiring selective hydromet circuits.
- Tailings retreatment will necessitate upgraded residue management, including secondary waste streams from REE extraction reagents.
- Similar DOE-backed critical mineral projects are increasingly targeting industrial residues, not greenfield orebodies, to shorten permitting.
Our Take
Because this is tagged both Projects and Sustainability, it aligns with a cluster of U.S. pieces where tailings or waste streams are being reclassified as strategic feedstock, which can materially change closure liabilities and permitting narratives for operators handling legacy REE-bearing residues.
Financing-led items involving the U.S. Department of Energy in our coverage often precede follow-on private capital or technology-partner announcements, suggesting ElementUSA and Colorado School of Mines may now be better positioned to attract process-technology vendors focused on complex REE recovery from tailings.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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