Bornite mineral
Bornite is the Cu5FeS4 mineral species listed as approved, with the notation 1962 s.p., in the September 2026 IMA list. It is distinct from copper metal, chalcocite, chalcopyrite, mixed copper ores and processing residues. The natural specimens below contain other phases; their solution measurements cannot be treated as selective conversion of pure endmember bornite. No criticality designation is inherited from copper or iron.
Microbial & Biochemical Mechanisms (2)
Culture-associated copper mobilization from a natural bornite specimen
bioleaching
Microbial
Associated Organisms:
Acidithiobacillus ferrooxidans (NCBITaxon:920)
In the source's shaken acidic assays, the source-labelled A. ferrooxidans culture was associated with greater aqueous copper release from the bornite specimen than the uninoculated system. Iron oxidation and ferric-mediated mineral attack are the authors' interpretation; the study does not isolate direct enzymatic attack on bornite. Adding iron-bearing sphalerite called marmatite also accelerated early copper release, and this addition had a stronger effect without bacteria than with them.
Experimental Context & Analytical Limits:
Laboratory experiment using a Guangxi geological-museum specimen, ground below 0.074 mm and UV treated for 20 minutes. Table S1 reports 62.301 wt% Cu, 9.982 wt% Fe and 24.222 wt% S. The claimed greater-than-90% purity is based on elemental XRF, not an independently quantified phase fraction. The unaccessioned culture came from Central South University and was pre-grown with ferrous sulfate, collected and rinsed; its species ID does not establish stock identity or exclude residual inoculum iron. Assays used 250 mL flasks, 99 mL sterile 9K basal medium plus 1 mL inoculum, 30 degrees C, 170 rpm and 14 days. Sulfuric acid maintained pH 1.70-1.80. This external pH control does not demonstrate microbial acid production. Pure-bornite and mixed-mineral arms are separately plotted; the methods call their labels mass ratios while Figure 4 labels them in grams, so equal total solid loadings across ratios are not assumed. Sampling losses were replaced with water; cumulative copper accounting and the meaning of plotted error bars are not specified. Three microscope counts are described, but independent leaching-flask replication is not established. Copper was measured by ICP-AES. No isolated copper product or industrial operation was demonstrated.
Laboratory experiment using a Guangxi geological-museum specimen, ground below 0.074 mm and UV treated for 20 minutes. Table S1 reports 62.301 wt% Cu, 9.982 wt% Fe and 24.222 wt% S. The claimed greater-than-90% purity is based on elemental XRF, not an independently quantified phase fraction. The unaccessioned culture came from Central South University and was pre-grown with ferrous sulfate, collected and rinsed; its species ID does not establish stock identity or exclude residual inoculum iron. Assays used 250 mL flasks, 99 mL sterile 9K basal medium plus 1 mL inoculum, 30 degrees C, 170 rpm and 14 days. Sulfuric acid maintained pH 1.70-1.80. This external pH control does not demonstrate microbial acid production. Pure-bornite and mixed-mineral arms are separately plotted; the methods call their labels mass ratios while Figure 4 labels them in grams, so equal total solid loadings across ratios are not assumed. Sampling losses were replaced with water; cumulative copper accounting and the meaning of plotted error bars are not specified. Three microscope counts are described, but independent leaching-flask replication is not established. Copper was measured by ICP-AES. No isolated copper product or industrial operation was demonstrated.
Curated Evidence Points:
Support
Source:
zhang2019
Sections 2.1-2.3 and Figure 1b,d support the culture-associated solution-copper difference under externally controlled acidity. Figure 4d reports ferric iron; Figure 3 shows different residual phases by SR-XRD and Raman. These observations support a bounded specimen-level leaching association, not complete selective bornite conversion or a demonstrated molecular pathway.
Partial
Source:
zhang2019
Section 3.1.1 calls final biotic copper extractions greater than 90%, but original Figure 1d peaks near day 12 and ends below 90% at day 14. The discrepancy and decline are unresolved; no single final yield is adopted here. The plotted biomass unit in Figure 4c also differs from the cell-per-mL statement in the discussion and is not converted into a curated biomass measurement. The absence of strong galvanic current in Figure 2 concerns separate graphite/paraffin electrodes, not a measurement of all interparticle currents in the culture. Figure 5 is an interpretive schematic, not evidence of heap deployment.
Context_only
Source:
zhang2019_correction
The inspected publisher correction changes an author-name spelling. It does not reconcile the copper endpoint or biomass-unit conflicts.
Biofilm-associated copper mobilization in a laminar-flow assay
bioleaching
Microbial
A Chilean ore-derived enrichment containing Leptospirillum spp. and Acidithiobacillus thiooxidans was associated with copper release and attached biofilm on a mixed bornite specimen in a laminar-flow chamber. The authors propose complementary planktonic iron oxidation and attached sulfur oxidation. FISH supports Acidithiobacillus at genus resolution in the biofilm; it does not alone establish a species-specific catalytic role. Unidentified organisms, possibly native to the specimen, also appeared in these nonsterile assays.
Experimental Context & Analytical Limits:
Natural hand-picked material from the Universidad de Chile, sieved below 0.044 mm and deliberately not acid-cleaned or autoclaved. Optical mineralogy reports 74.91% bornite and 15.89% source-labelled Cc, plus other phases; QEMSCAN instead detects about 32% bornite with a large unclassified fraction. These estimates are not reconciled into a pure-mineral loading. Mineral was fixed to tape over approximately 1.5 by 1.5 cm. Flow cells recirculated 100-200 mL modified 9K medium at 30 degrees C, with reported velocity 0.02 cm/s and Reynolds number below 10; inoculation was 10^6 cells/g mineral, approximately 3:1 Leptospirillum to the source-labelled sulfur oxidizer. Methods specify 0.7 g/L Fe(II), whereas the screening schematic labels 0.5 g/L; that discrepancy is retained. Screening wells used 8 mL, 150 rpm and ferrous or ferric additions. Flow-cell conditions were triplicated; screening had three to five replicates per condition and time. Although screening methods mention uninoculated conditions, bornite control time courses are not separately displayed. Apparatus, volume, specimen orientation and hydrodynamics differ together; the comparison does not isolate biofilm as the sole cause of a rate change.
Natural hand-picked material from the Universidad de Chile, sieved below 0.044 mm and deliberately not acid-cleaned or autoclaved. Optical mineralogy reports 74.91% bornite and 15.89% source-labelled Cc, plus other phases; QEMSCAN instead detects about 32% bornite with a large unclassified fraction. These estimates are not reconciled into a pure-mineral loading. Mineral was fixed to tape over approximately 1.5 by 1.5 cm. Flow cells recirculated 100-200 mL modified 9K medium at 30 degrees C, with reported velocity 0.02 cm/s and Reynolds number below 10; inoculation was 10^6 cells/g mineral, approximately 3:1 Leptospirillum to the source-labelled sulfur oxidizer. Methods specify 0.7 g/L Fe(II), whereas the screening schematic labels 0.5 g/L; that discrepancy is retained. Screening wells used 8 mL, 150 rpm and ferrous or ferric additions. Flow-cell conditions were triplicated; screening had three to five replicates per condition and time. Although screening methods mention uninoculated conditions, bornite control time courses are not separately displayed. Apparatus, volume, specimen orientation and hydrodynamics differ together; the comparison does not isolate biofilm as the sole cause of a rate change.
Curated Evidence Points:
Support
Source:
bobadilla2021
Methods and Figures 3-5 show copper in solution, ferric-iron profiles, surface-associated material and microbial signals. The authors report about 54% of feed copper released by day 32 in the laminar assay, versus about 30% by day 48 in ferrous-fed screening wells; ferric-fed wells reached about 40% by day 10. These are source-reported feed-level values measured using atomic absorption, not bornite-specific yields or recovered metal products. Figure 3C ends at day 46 while the prose mentions day 48; day 32 is the supported comparison point retained here.
Partial
Source:
bobadilla2021
FISH probes are genus-level and native organisms are unresolved. QEMSCAN relative abundances are affected by surface coverage and unclassified material, so loss of a bornite signal is not a mineral mass balance. The proposed idaite pathway, acid production and precipitation control are interpretations without a selective biofilm-removal or species-removal test. Exact solid masses, raw copper denominators and sampling mass corrections are not supplied for independent reconstruction. A laboratory flow-cell analogy to heaps establishes neither pilot nor industrial deployment.
Sources & References
-
ima_2026_09: IMA-CNMNC. The New IMA List of Minerals, September 2026. Bornite row on PDF page 29; column definitions on page 1 and distribution terms on page 2.
https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-11) -
zhang2019: Zhang et al. (2019). Interactions between marmatite and bornite during the oxidative dissolution process in abiotic and biotic systems. RSC Advances 9, 26609-26618. Sections 2-3, Figures 1-5 and original supplementary Table S1 and Figure S1; author-name correction cited separately.
https://doi.org/10.1039/C9RA03658J (accessed 2026-10-11) -
zhang2019_correction: Zhang et al. (2019). Correction to Interactions between marmatite and bornite during the oxidative dissolution process in abiotic and biotic systems. RSC Advances 9, 33428. Corrects Hussnain Ahmed Janjua's name; the notice does not revise experimental results.
https://doi.org/10.1039/C9RA90072A (accessed 2026-10-11) -
bobadilla2021: Bobadilla-Fazzini and Poblete-Castro (2021). Biofilm Formation Is Crucial for Efficient Copper Bioleaching From Bornite Under Mesophilic Conditions: Unveiling the Lifestyle and Catalytic Role of Sulfur-Oxidizing Bacteria. Frontiers in Microbiology 12, 761997. Methods and Figures 1-6, especially bornite Figures 3-5 and the proposed mechanism in Figure 6.
https://doi.org/10.3389/fmicb.2021.761997 (accessed 2026-10-11) -
ncbi_ferrooxidans: NCBI Taxonomy 920. Acidithiobacillus ferrooxidans, species rank. Identifier and current name verified through the Taxonomy Browser and Datasets API; this does not identify the unaccessioned experimental stock.
https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=920&mode=Info (accessed 2026-10-11)
Curation History
| Timestamp | Curator | Action | Summary |
|---|---|---|---|
2026-10-11T19:48:13.137407+00:00 |
codex (GPT-6; codex) | CREATE | Created bornite mineral identity and qualified culture- and biofilm-associated leaching observations, preserving source corrections, conflicting values, specimen mixtures, uncertain causality and laboratory scale. |
Record source: data/records/bornite.yaml