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Tennantite concentrate primary resource

A mixed mineral concentrate enriched in source-labelled tennantite, represented here by the feed studied by Kondo et al. (2024). This resource is distinct from a pure mineral species, the separately described tennantite-(In), and elemental copper or arsenic. The study reports mineral liberation analysis of about 60 wt% tennantite, 23% pyrite, 8.2% sphalerite, 6.3% gangue, 1.6% galena and 0.97% chalcopyrite (rounded values). Bulk elemental composition is reported as S 31%, Cu 23%, Fe 12%, Zn 10%, Sb 7.8% and As 6.2%, with median particle size 41 micrometres. Its geographic origin and beneficiation route are not given. Generic discussion of flotation wastes does not establish that this particular feed was discarded waste. The informal tennantite phase label does not resolve a modern mineral species or establish the ideal Cu12As4S13 composition of every grain. No criticality designation is transferred from a constituent element.

Microbial & Biochemical Mechanisms (1)

Acidophile-associated copper mobilization with variable carbon addition

bioleaching Microbial

Associated Organisms: Sulfobacillus thermosulfidooxidans (NCBITaxon:28034)

In inoculated acidic laboratory suspensions, copper entered the filtered liquid while the effect of activated carbon depended on culture history and experimental conditions. Source-reported final copper dissolution in 50-day flasks was about 70% with 0.01% activated carbon versus 45% without it; larger carbon additions gave 52% and 38% at 0.025% and 0.05%, respectively. In later 100-day pH-controlled reactors both carbon-free and 0.01% carbon systems reached about 60% copper dissolution. These percentages describe reported dissolved copper relative to the mixed feed inventory, not isolated metal recovery or a pure-tennantite yield. Carbon-free systems were also inoculated; no uninoculated leaching control is described. Redox profiles, cell growth and community composition are consistent with microbial involvement but do not isolate its advantage over matched chemical leaching or prove a particular member's necessity.

Experimental Context & Analytical Limits:
Unwashed, unsterilized concentrate was used. The initial inoculum contained source-labelled Acidimicrobium ferrooxidans ICP (DSM 10331), Acidiplasma sp. Fv-Ap, Acidithiobacillus caldus KU (DSM 8584), Sulfobacillus sibiricus N1 (DSM 17363), S. thermotolerans Kr1 (DSM 17362) and S. thermosulfidooxidans AT-1 (DSM 9293), with equal initial cell densities before pre-growth on concentrate. The paper's acknowledgement instead calls Fv-Ap Acidisphaera; that inconsistency is not resolved here. The structured organism denotes one reported community member, not the entire consortium or a verified strain accession. Terminal 16S V3-V4 amplicon analysis reported 99.9% S. thermosulfidooxidans in flask residue and dominance in reactor residue; this is not a time-resolved census or proof of strain identity or causality. Duplicate flasks contained 200 mL acidophile basal salts medium in 500 mL vessels, 0.02% yeast extract, 5 mM Fe(II), 5% w/v concentrate and 10% v/v pre-grown inoculum, initially pH 1.5 with sulfuric acid, at 45 degrees C and 150 rpm for 50 days. Carbon doses were 0, 0.01, 0.025 and 0.05% w/v; pH subsequently diverged, so the carbon comparison is not pH matched. Two later 2 L reactor systems contained 1.2 L medium, 0.02% yeast extract, 5% concentrate and 10% inoculum descended from flask cultures, at 45 degrees C and 150 rpm. Each carbon condition is one described reactor, not duplicate reactors. Sulfuric acid maintained pH 2.0 through day 37 and 1.5 from day 38. Day-53 Fe(II) additions differed: 20 mM without carbon and 10 mM with carbon. Terminal outcomes therefore cannot be treated as a clean factorial carbon effect or independent replication of the earlier flasks. Filtered 0.45-micrometre aliquots were measured by ICP-OES; plotted total-element concentrations do not identify oxidation state. No isolated copper product, complete sampling-corrected mass balance or industrial deployment was demonstrated.
Curated Evidence Points:
Sections 2.1-2.5, Figures 1-4 and Section 3 support the specific mixed-feed culture assays and their reported dissolved-metal outcomes. Figure 2 shows nonmonotonic carbon-dose effects and rising pH in carbon arms; Figure 4 shows similar later copper trajectories, unequal iron additions and the intervening pH change. These are two linked culture stages, not universal operating optima. Figure 3 derives rates from Figure 2 and is not an independent kinetic experiment.
Figures 5-6 and Section 3.2 show As/Fe/O/S/Sb-bearing secondary particles and declining relative tennantite diffraction peaks. They do not independently identify a pure ferric-arsenate or scorodite product, quantify phase-specific dissolution, or demonstrate long-term arsenic stability. Reported final dissolved arsenic is about 4% in the 0.01% carbon flask and 15% in both reactors, not an isolated arsenic recovery yield. The proposed ferric-arsenate/basic-ferric-sulfate association remains tentative. Iron percentages are especially difficult to interpret after unequal external iron additions. Terminal community dominance and separate tolerance tests in Table 1 cannot establish that selection caused every change in leaching.
Resolves the species label and type-strain aliases for the reported member; it does not verify the stock used or resolve the other consortium members and source naming discrepancy.

Sources & References

  1. kondo_2024: Kondo S, Hayashi K, Phann I and Okibe N (2024). Bioleaching of tennantite concentrate: influence of microbial community and solution redox potential. Frontiers in Microbiology 14:1339549. Published 8 January 2024 in volume designated 2023; DOI 10.3389/fmicb.2023.1339549. Sections 2-4, Figures 1-6, Table 1 and data availability statement.
    https://doi.org/10.3389/fmicb.2023.1339549 (accessed 2026-10-12)
  2. ncbi_sulfobacillus: NCBI Taxonomy 28034, Sulfobacillus thermosulfidooxidans, species; lists DSM 9293 and AT-1 as type-strain designations. Identifier context only, not independent authentication of the experimental culture.
    https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=28034&mode=Info (accessed 2026-10-12)

Curation History

Timestamp Curator Action Summary
2026-10-12T10:34:34.119493Z Codex (GPT-6) create Curated the mixed concentrate identity and separately scoped flask/reactor leaching observations from the complete Kondo2024 original, preserving controls, nonmonotonic carbon effects, source discrepancies and limits on phase identity, causal attribution and recovered product.
2026-10-12T10:44:51.012272Z Codex (GPT-6) edit Addressed independent review F1 and issue 167 by removing the unsupported claim of inconsistent early reactor redox maxima. The original Section 3.2 and Figure 4E agree; experimental qualifications remain unchanged.

Record source: data/records/tennantite-concentrate.yaml