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Phosphate rock commodity Critical Material

Phosphate-bearing rock considered as a mined and beneficiated industrial raw material for phosphorus products, including phosphoric acid and fertilizers. The USGS marketable-product definition concerns beneficiated phosphate rock suitable for acid or elemental-phosphorus production; it does not identify one apatite species or a pure phosphate ion. The original EU 2024 list names phosphate rock separately from phosphorus. The US 2025 list names phosphate; its mapping here follows the USGS 2026 phosphate-rock chapter, which explicitly describes phosphate rock as the addition to that list. This mapping does not equate all chemical phosphates with phosphate rock. The microbial evidence concerns one characterized Araxa rock feed and does not establish a commodity-wide extraction yield.

Criticality Designations

Jurisdiction List Name Edition / Document Classification Source
European Union Regulation (EU) 2024/1252, Annex II critical raw materials Original act, 11 April 2024; OJ 3 May 2024 critical eu2024-original
United States Department of the Interior Final List of Critical Minerals 2025 final; 7 November 2025 critical us2025-final

Microbial & Biochemical Mechanisms (1)

Fungal mobilization of phosphate from Araxa rock phosphate with fluoride inhibition

bioleaching Microbial

Growth of the source-designated Aspergillus niger FS1 culture was associated with medium acidification and soluble phosphorus release from a characterized Araxa rock-phosphate feed. Added-fluoride experiments showed decreasing phosphate solubilization under the tested conditions. These observations support a bounded fungal mobilization process, without isolating an exclusive acid pathway or establishing isolated-product recovery.

Experimental Context & Analytical Limits:
Laboratory 125 mL flasks contained 50 mL NBRIP medium and 3 g/L Araxa rock phosphate from Brazil, with reported particle size below 75 micrometres. The paper describes the feed as mainly fluorapatite with some hydroxyapatite from XRD and chemical analysis, with 13.97% P. Flasks received 1 x 10^6 conidia and were incubated at 32 degrees C and 160 rpm. Medium pH was adjusted to 7 before adding the P source; the kinetic plot starts around pH 5.5, so these values are not interchangeable. The 10-day kinetics used three sampled flasks per time point, 0.45-micrometre filtrates, and uninoculated flasks at the beginning and end for dissolved-element determinations. Separate 60-hour fluoride-dose assays used either rock phosphate or soluble K2HPO4; their biomass and organic-acid results must not be treated as measurements from the rock-fed arm. No strain-level identifier or commercial-product specification is inferred.
Curated Evidence Points:
Materials and Methods, rock characterization, kinetics, Table 2 footnote and Figure 1 support the stated feed, assay conditions and solution-phase phosphorus increase. Figure 1 and Results show approximately 80 mg/L soluble P at 60 h, followed by non-monotonic concentrations during continued incubation; the figure gives three-replicate means and standard deviations. This is mobilized phosphorus in filtrate, not recovered phosphorus mass or complete dissolution of the feed.
The uninoculated comparison is described only at the beginning and end, and Figure 1 does not display a time-matched abiotic trajectory or acid-matched comparison. In Figure 4a, adding NaF over 0-50 mg F/L lowered soluble P after 60 h; the dose design used three replicates at the 25 mg/L central point rather than declaring every dose triplicated. Methods place biomass and organic-acid determinations in the soluble-K2HPO4 arm. Consequently the data do not establish the same organic-acid or growth response directly in rock-fed cultures. Reprecipitation discussed for the fluctuating dissolved P remains a proposed explanation. Supplementary numerical tables were not acquired as usable full text, and no values are imported from them.

Sources & References

  1. usgs-mcs2026: USGS Mineral Commodity Summaries 2026, Phosphate Rock, printed pp. 142-143 (PDF pp. 146-147): marketable-product definition and explicit mapping of the US 2025 phosphate designation
    https://pubs.usgs.gov/periodicals/mcs2026/mcs2026.pdf (accessed 2026-10-11)
  2. eu2024-original: Regulation (EU) 2024/1252, original act of 11 April 2024, OJ 3 May 2024: recital 8 and Annex II, Section 1
    https://eur-lex.europa.eu/eli/reg/2024/1252/oj/eng (accessed 2026-10-11)
  3. us2025-final: US Department of the Interior / USGS, Final 2025 List of Critical Minerals, 7 November 2025, 90 FR 50494-50497: Summary and final list
    https://www.govinfo.gov/content/pkg/FR-2025-11-07/html/2025-19813.htm (accessed 2026-10-11)
  4. mendes2013: Mendes et al. (2013), Inhibition of Aspergillus niger Phosphate Solubilization by Fluoride Released from Rock Phosphate, Applied and Environmental Microbiology 79:4906-4913; DOI 10.1128/AEM.01487-13; Materials and Methods, Tables 1-2, Figures 1 and 4
    https://pmc.ncbi.nlm.nih.gov/articles/PMC3754696/ (accessed 2026-10-11)
  5. mendes2013-doi: Mendes et al. (2013), publisher DOI identity for the same experiment; not an independent replication
    https://doi.org/10.1128/AEM.01487-13 (accessed 2026-10-11)

Curation History

Timestamp Curator Action Summary
2026-10-11T08:29:04Z codex (GPT-6; codex) CREATE Created the phosphate rock record with verified industrial scope and dated criticality; retained controlled laboratory Araxa phosphate mobilization and fluoride-inhibition limits.

Record source: data/records/phosphate-rock.yaml