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Uranium element Critical Material

Uranium (U), represented here as an element distinct from the dissolved U(VI) feed and electrode-associated material in a laboratory bioelectrochemical separation study. The United States 2025 designation applies to the named uranium commodity; it does not identify a uranium mineral species or establish the criticality of every uranium compound.

Identifiers & Classification

System Identifier Label
CHEBI CHEBI:27214 uranium atom

Criticality Designations

Jurisdiction List Name Edition / Document Classification Source
United States of America U.S. Department of the Interior Final List of Critical Minerals 2025 (published November 7, 2025; 90 FR 50494-50497) critical usgs_2025

Microbial & Biochemical Mechanisms (1)

Uranium separation in an MR-1-inoculated electrochemical system

separation Microbial

Associated Organisms: Shewanella oneidensis MR-1 (NCBITaxon:211586)

A laboratory electrochemical system inoculated with Shewanella oneidensis MR-1 showed aqueous uranium depletion and uranium associated with the carbon-felt working electrode. Abiotic systems also removed uranium. This supports separation in the combined biological and electrical system, with partial evidence for a microbial mechanism; microbial necessity, a specific electron-transfer pathway and a purified uranium product are not established by this record.

Experimental Context & Analytical Limits:
Defined electrolyte, not ore or industrial waste: 100 mL working and counter chambers separated by Nafion 117, with carbon-felt electrodes. The working solution contained 30 mM bicarbonate, 10 mM PIPES, 30 mM ammonium acetate, 40 mM NaCl, and Wolfe's vitamins and trace metals. Dissolved U(VI) was prepared from U metal in HCl and hydrogen peroxide. Chambers were purged with nitrogen containing 400 ppm CO2. After equilibration and the second solution sample, the biotic system was inoculated and the working electrode poised at -800 mV versus saturated Ag/AgCl. The metadata specifies ambient-temperature equilibration and experiments lasting 72-574 h, with a shorter abiotic U repeat; it does not provide an exact controlled assay temperature or inoculum density/preparation. The original biotic U series has recorded pH values of 7.01-8.21 after inoculation, so this was not a constant-pH assay. Filtered samples were measured by ICP-OES. Electrode material underwent carbonate extraction followed by concentrated acid extraction. Independent replicate counts and a statistical microbial-effect estimate are not assigned here. Neither stable mineral identity nor industrial deployment is claimed.
Curated Evidence Points:
FGDC process steps 1-4 and tables T1-T3 and T6 support the laboratory separation observation. In T3, the original biotic series has 975 mg/kg U at BESU.8Vb_W.EQ and less than 0.1 mg/kg at BESU.8Vb_W.END; the latter is encoded as -0.1, a detection limit, not zero or a negative concentration. T6 reports uranium in the subsequent electrode acid extract. These observations are not a mass-balanced recovery percentage or product purity measurement.
Abiotic T3 samples also decrease, from 914 mg/kg at BESU.8Va_W.t0 to 0.819 mg/kg at BESU.8Va_W.END. T2 shows different pH histories, and the source reports pre-electrolysis sorption. T6 original biotic and abiotic acid extracts use concentrated HCl and HNO3 respectively, so their amounts are not a matched assay of microbial enhancement. These controls limit attribution of the observed separation specifically to MR-1 metabolism.
T9_SEM.pdf pages 2-6 show deposits and U-labelled EDS signals on both abiotic and biotic U electrodes, supporting electrode association. T8_XRD.csv supplies diffraction counts for these conditions and a carbon-felt blank, but this curation does not assign a crystalline phase or oxidation state from those data.

Sources & References

  1. kane_2026_bes: Kane, Selvage, Ciechanowicz and Campbell (2026). Data acquired in experiments on bioelectrochemical systems for critical mineral recovery. U.S. Geological Survey data release, published September 15, 2026. DOI 10.5066/P9ERLSM6.
    https://doi.org/10.5066/P9ERLSM6 (accessed 2026-10-09)
  2. usgs_2025: U.S. Geological Survey (2025). Final 2025 List of Critical Minerals. Federal Register 90 FR 50494-50497, November 7, 2025.
    https://www.govinfo.gov/content/pkg/FR-2025-11-07/html/2025-19813.htm (accessed 2026-10-09)
  3. chebi_uranium: ChEBI:27214 - uranium atom
    https://www.ebi.ac.uk/chebi/CHEBI:27214 (accessed 2026-10-09)
  4. ncbi_oneidensis_mr1: NCBI Taxonomy: Shewanella oneidensis MR-1 (Taxonomy ID 211586)
    https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=211586 (accessed 2026-10-09)

Curation History

Timestamp Curator Action Summary
2026-10-09T04:48:34Z Codex (GPT-6; Codex) create_record Curated element identity, US 2025 designation and laboratory BES separation observations with abiotic and analytical limitations.
2026-10-09T05:49:58Z Codex (GPT-6; Codex) curate_source_observations Added four exact T3 uranium concentration cells with raw values, censored-result handling and separate analysis/sample provenance. Preserved prior claims and histories; no recovery yield was inferred.

Record source: data/records/uranium.yaml