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Rhenium element Critical Material

Rhenium (Re), represented as an element distinct from its ions, compounds, isotopes, host minerals, alloys and commodity streams. The US 2025 designation names the rhenium commodity and does not designate every compound or host material. A laboratory batch study tested inactive brewer's yeast biomass for rhenium association from synthetic perrhenate solutions. This biosorption record does not assert microbial rhenium reduction or isolated-metal recovery.

Identifiers & Classification

System Identifier Label
CHEBI CHEBI:49882 rhenium 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)

Rhenium association with dried brewer's yeast from synthetic perrhenate solutions

biosorption Microbial

Associated Organisms: Saccharomyces cerevisiae (NCBITaxon:4932)

Prepared inactive brewer's yeast biomass retained rhenium in laboratory batches containing sodium perrhenate, either alone or with copper and/or molybdenum. Uptake depended strongly on acidity and solution composition. Biomass association and FTIR changes support biosorption, while the exact binding chemistry remains unresolved. The treatment used microbial-origin biomass dried at 105 degrees Celsius; microbial true does not imply living-cell metabolism. No Re oxidation-state conversion or purified recovered product was demonstrated.

Experimental Context & Analytical Limits:
Zinicovscaia et al., Sections 2.1-2.5: biomass was obtained from brewing residues in Chisinau, Moldova, dried at 105 degrees Celsius and homogenized; no strain accession was provided. Each batch mixed 500 mg dried biomass with 50 mL deionized-water-based synthetic solution and shook at 200 rpm. Standard feeds contained 10 mg/L Re supplied as NaReO4, with 5 mg/L Cu and/or Mo supplied as CuSO4 and Na2MoO4 in the mixed systems. Separate studies varied pH 2-6, contact time 5-120 min, initial Re 10-100 mg/L or temperature 20-50 degrees Celsius. The pH series contacted biomass for 1 h and used NaOH/HNO3 adjustment; the article does not explicitly give all fixed conditions for each parameter series. After filtration the biomass was dried again at 105 degrees Celsius and weighed for neutron activation analysis of Re and Mo; Cu was assayed in solution by atomic absorption. No post-contact biomass wash is described. Experiments were duplicated, but biological versus technical replication and the meaning of graph error bars are not specified. Supplementary Figure S1 confirms the analytical split, not a whole-feed mass balance. This study's feeds were synthetic; brewery origin of the sorbent does not make them industrial wastewater.
Curated Evidence Points:
Support Source: primary
Section 3.2 and Figure 2 report the strongest Re association at pH 2: reported removal efficiencies were 84% for Re alone, 76% with Cu, 80% with Mo and 75% with both. At pH 6 the reported efficiencies were about 5%. These are source-reported batch removal estimates, not independently verified solution-depletion measurements or isolated-product yields; the methods explicitly assay Re in the filtered biomass.
Partial Source: primary
Section 2.4 defines removal/capacity using initial and final solution concentrations, while Sections 2.3 and 2.5 describe Re measurement by neutron activation of filtered, dried biomass and reserve direct solution analysis for Cu. No direct Re filtrate assay, no-biomass vessel/filter control, post-contact wash or complete recovery of all Re fractions is documented in the inspected article or two-page supplement. Entrained solution and other non-specific retention are not resolved. FTIR control biomass in Figure 9 is a spectral comparison, not an abiotic batch-removal control.
Partial Source: primary
Table 2 reports an experimental Re-only capacity of 0.74 mg/g for the kinetic series; Figure 4 distinguishes experimental points from fitted curves. In contrast, Table 3's Langmuir qm values of 13, 20, 33 and 7.7 mg/g for Re, Re-Cu, Re-Mo and Re-Mo-Cu are fitted extrapolations, explicitly higher than measured capacities in Section 3.5. Figure 8 uses a generic concentration axis labelled C, despite equilibrium-model definitions using Ce, leaving the fitting concentration basis insufficiently documented. The Conclusion prints 7.7-33 mg/kg, conflicting with Tables 3-4 and the abstract in mg/g. These source inconsistencies are preserved rather than silently converted or treated as measured maximum capacity.
Partial Source: primary
Section 3.6 and Figure 9 show FTIR differences between untreated and metal-loaded biomass consistent with altered functional-group environments. This does not uniquely identify Re coordination, prove a single electrostatic or chemisorption mechanism, or determine Re oxidation state. The article alternately invokes physical and chemical sorption from empirical fits; neither the fitted model preference nor the thermodynamic estimates establish molecular causality. Supplementary Figure S2 also has an anomalous scale in its three-metal panel, so its thermodynamic claims are not adopted here.
Partial Source: primary
The main article contains no tested Re desorption cycle, isolated product purity or industrial process demonstration. Literature comparisons with other organisms and real industrial effluents in Table 4 and the Introduction are separate studies. Positive or null Re reduction results from other bacteria would concern different mechanisms and conditions and do not validate a redox interpretation of this dried-yeast assay.

Sources & References

  1. chebi_rhenium: ChEBI:49882 - rhenium atom; elemental symbol Re, net charge zero.
    https://www.ebi.ac.uk/chebi/CHEBI:49882 (accessed 2026-10-11)
  2. usgs_2025: U.S. Geological Survey (2025). Final 2025 List of Critical Minerals. Federal Register 90 FR 50494-50497, November 7, 2025; Rhenium row in the final commodity table. The adjacent Yes/No column describes byproduct/co-product occurrence, not criticality.
    https://www.govinfo.gov/content/pkg/FR-2025-11-07/html/2025-19813.htm (accessed 2026-10-11)
  3. primary: Zinicovscaia, Yushin, Grozdov, Vergel, Nekhoroshkov and Rodlovskaya (2021). Treatment of Rhenium-Containing Effluents Using Environmentally Friendly Sorbent, Saccharomyces cerevisiae Biomass. Materials 14(16):4763. DOI 10.3390/ma14164763; PMID 34443283; PMC8400443. Sections 2.1-2.5, 3.2-3.6, Tables 2-4, Figures 2-9 and supplementary Figures S1-S2.
    https://doi.org/10.3390/ma14164763 (accessed 2026-10-11)
  4. ncbi_cerevisiae: NCBI Taxonomy 4932 - Saccharomyces cerevisiae, species. The source identifies brewer's yeast but supplies no strain accession or axenicity characterization.
    https://api.ncbi.nlm.nih.gov/datasets/v2/taxonomy/taxon/4932/dataset_report (accessed 2026-10-11)

Curation History

Timestamp Curator Action Summary
2026-10-11T07:53:00Z codex (GPT-6) CREATE Curated dried brewer yeast association with synthetic perrhenate, preserving analytical, control and fitted-capacity limitations and excluding redox/product claims; attached the actual canonical CREATE sidecar.

Record source: data/records/rhenium.yaml