Waste liquid-crystal display panels secondary resource
Discarded liquid-crystal display (LCD) panels, a manufactured composite resource containing glass and indium-tin-oxide-bearing layers. The curated experiment used dismantled panels from spent mobile phones, not whole devices, pure indium tin oxide, a single mineral or all display technologies. Its prepared powder is a study-specific fraction of this resource. No criticality designation is inherited from indium or tin.
Microbial & Biochemical Mechanisms (1)
Culture-associated indium mobilization from prepared waste LCD powder
bioleaching
Microbial
Associated Organisms:
Acidithiobacillus ferrooxidans (NCBITaxon:920), Acidithiobacillus thiooxidans (NCBITaxon:930)
An adapted mixed acidophile culture increased indium in filtered leachate relative to sterile controls in the tested laboratory systems. Tin also entered solution, but the iron-containing sterile control performed comparably or better for tin. Changing acidity, iron chemistry and precipitation prevent assignment of the observed contrast to one organism or a demonstrated direct biological oxidation of the oxide feed.
Experimental Context & Analytical Limits:
Panels from different mobile-phone models were manually dismantled; glass bearing ITO was crushed and sieved below 1.0 mm. Material still adhering to plastic was milled below 0.5 mm, and its recovered fraction was combined and homogenized with the first fraction. Section 2 reports 0.1% In and 0.025% Sn by MP-AES, without a complete digestion protocol. The A. ferrooxidans isolate originated from Polish ferruginous mineral water and A. thiooxidans from Smolnik mine water; no strain accession or mixture ratio is supplied. Species identifiers do not identify these isolates. Living cultures were serially transferred in modified 9K medium and adapted for four weeks with LCD additions every three days. Laboratory flasks at 30 degrees C used 2.5% w/v prepared powder, 10 mL mixed inoculum, nominal initial pH 1.9 and either modified 9K containing ferrous sulfate or sulfuric-acid solution, both with 2 g elemental sulfur. The stated modified 9K recipe includes 44.2 g/L FeSO4.7H2O and 10 g/L sulfur; the relationship to the separate 2 g addition is not fully specified. Sterile controls ran in parallel for 35 days. Regular 5 mL samples were filtered and measured by MP-AES. The paper describes two experimental series but does not establish independent replicate numbers, error bars, assay working volume, sampling replacement or a complete metal mass balance. Controls do not match the changing pH and redox trajectories of inoculated flasks.
Panels from different mobile-phone models were manually dismantled; glass bearing ITO was crushed and sieved below 1.0 mm. Material still adhering to plastic was milled below 0.5 mm, and its recovered fraction was combined and homogenized with the first fraction. Section 2 reports 0.1% In and 0.025% Sn by MP-AES, without a complete digestion protocol. The A. ferrooxidans isolate originated from Polish ferruginous mineral water and A. thiooxidans from Smolnik mine water; no strain accession or mixture ratio is supplied. Species identifiers do not identify these isolates. Living cultures were serially transferred in modified 9K medium and adapted for four weeks with LCD additions every three days. Laboratory flasks at 30 degrees C used 2.5% w/v prepared powder, 10 mL mixed inoculum, nominal initial pH 1.9 and either modified 9K containing ferrous sulfate or sulfuric-acid solution, both with 2 g elemental sulfur. The stated modified 9K recipe includes 44.2 g/L FeSO4.7H2O and 10 g/L sulfur; the relationship to the separate 2 g addition is not fully specified. Sterile controls ran in parallel for 35 days. Regular 5 mL samples were filtered and measured by MP-AES. The paper describes two experimental series but does not establish independent replicate numbers, error bars, assay working volume, sampling replacement or a complete metal mass balance. Controls do not match the changing pH and redox trajectories of inoculated flasks.
Curated Evidence Points:
Support
Source:
willner2018
Section 2 and Figure 1 establish the actual waste-panel feed. Section 3.2, Figure 4A and Table 2 support increased indium in the inoculated 9K filtrate: day-35 concentrations are 13.90 versus 0.82 mg/dm3 in the sterile control. The authors report 55.6% extraction in the inoculated system relative to the feed inventory; this is a reported solution-based endpoint, not isolated indium yield or recovery from whole phones. Figure 2 shows different chemical trajectories, limiting causal interpretation of the contrast.
Partial
Source:
willner2018
Figure 4B and Table 2 limit any general microbial advantage: at day 35 the 9K inoculated and sterile filtrates contain 3.15 and 4.59 mg/dm3 Sn, respectively. The author-reported maxima of 90.2% and 93.4% occur on different days, 14 and 21. Concentrations then decline. The text's peak tin concentration and percentage do not exactly agree with the nominal feed inventory, and its common 3.4% indium-control statement does not reconcile both control concentrations in Table 2. These are unresolved source quantities, not a basis for corrected or pooled yields.
Partial
Source:
willner2018
Sections 3.1-3.2, Figure 3 and Table 1 provide SEM-EDS and solution measurements, not definitive crystalline jarosite or tin precipitate identification, metal-valence measurements or proof of an exclusive Fe-mediated pathway. Proposed reprecipitation, indium oxidation and separation remain interpretations. The EDS spectrum is labelled pt1 whereas Table 1 names pt2. Neither isolated metal product, closed mass balance nor industrial deployment was demonstrated.
Sources & References
-
willner2018: Willner, Fornalczyk, Gajda and Saternus (2018). Bioleaching of indium and tin from used LCD panels. Physicochemical Problems of Mineral Processing 54(3):639-645, DOI 10.5277/ppmp1878; Sections 2-4, Figures 1-4 and Tables 1-2. Institutional copy of published article.
https://dbc.wroc.pl/Content/43709/PDF/PPoMP_2018_54_3_639_645.pdf (accessed 2026-10-11) -
ncbi_ferrooxidans: NCBI Taxonomy 920: Acidithiobacillus ferrooxidans; species, not experimental isolate
https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=920&mode=info (accessed 2026-10-11) -
ncbi_thiooxidans: NCBI Taxonomy 930: Acidithiobacillus thiooxidans; species, not experimental isolate
https://www.ncbi.nlm.nih.gov/taxonomy/930 (accessed 2026-10-11)
Curation History
| Timestamp | Curator | Action | Summary |
|---|---|---|---|
2026-10-11T13:46:10Z |
Codex (GPT-6; Codex) | CREATE | Added the waste LCD panel resource and primary mixed-culture leaching evidence, preserving sterile tin comparisons, source discrepancies, uncertain phase and causal interpretations, and laboratory scale. Independent scientific review is separate. |
Record source: data/records/waste-liquid-crystal-display-panels.yaml