Secondary Resources

Acidic, metal- and sulfate-bearing drainage generated when mining exposes sulfide-bearing materials to oxidation. This record denotes the heterogeneous liquid mine-derived feed, distinct from natural ore, individual dissolved elements, coal-mine-drainage treatment solids, and isolated precipitate phases. The characterized Brazilian copper-mine and South African mining-facility waters below are separate source-specific samples, not a universal composition or interchangeable reactor feed. No constituent criticality designation or industrial recovery performance is transferred to this resource.

A rare-earth-bearing processing liquor generated from allanite ore, represented here by the chemically purified and reconstituted Halleck Creek, Wyoming feed used by Lu et al. (2026). Acid leaching, impurity precipitation, REE hydroxide precipitation and hydrochloric-acid redissolution precede the biological-reagent experiment. This processing intermediate is distinct from geological ore, beneficiated allanite concentrate, a pure allanite species and an isolated REE product. Its classification reflects chemical processing, not extraction alone. No criticality designation is inherited from its constituents.

• Pichia kudriavzevii

Salt-flux-bearing mixed slag from aluminium scrap remelting, containing process salts and oxide-rich solids. The accepted study sampled a rotary furnace batch from a Brazilian recycler using NaCl/KCl flux. This resource is defined by salt-flux remelting origin, distinct from the existing post-metal-recovery secondary aluminium dross specimen, generic smelting slag, bauxite residue, elemental aluminium or a single mineral. Laboratory water leaching and recovered salt crystals are documented; microbial action, inherited criticality and industrial deployment of this recipe are not.

Sludge generated by wastewater treatment at an automotive factory, represented by the nickel- and zinc-bearing feed studied by Yagnentkovsky et al. (2009). The paper does not identify the factory or resolve its individual contributing processes and mineral phases. This secondary-resource identity is distinct from untreated wastewater, municipal sewage sludge, pure nickel or zinc compounds, and spent automotive exhaust catalysts. The selected feed does not define all automotive treatment sludges, and no constituent-element criticality is inherited.

• Acidithiobacillus thiooxidans

Steelmaking slag identified by primary studies as basic-oxygen-furnace (BOF), or Linz-Donawitz converter, slag. The separately studied feeds are a December 2016 sample from Yarborough, Scunthorpe, UK, and a sample supplied by an unnamed Austrian steelmaking company in the 2022 study. This process-defined secondary resource is distinct from electric-arc-furnace slag or dust, blast-furnace residues, copper smelter slag, constituent elements and individual mineral species. These heterogeneous samples do not define all BOF slags. No inherited elemental identifier or criticality designation is assigned.

Dust generated by basic oxygen steelmaking, represented here by a stockpiled material from a historical iron and steelworks at Teesside, UK. This is a mixed processing residue, distinct from basic oxygen furnace slag, electric-arc-furnace dust and blast-furnace cast-house dust. The sampled dust contains iron, zinc and other elements; neither its constituents nor the paper's terminology establishes a criticality designation for the whole resource. Laboratory leaching evidence applies to the prepared source sample.

• Acidithiobacillus ferrooxidans

A heterogeneous powder stream produced by pretreatment of spent lithium-ion batteries. Composition depends on battery chemistry and processing; the curated experiment used nickel-manganese-cobalt battery material after discharging, dismantling, thermal treatment, crushing and sorting. This secondary resource is distinct from whole batteries, an individual cathode compound, cobalt or lithium elements, and recovered battery-grade products. Constituent-element criticality is not inherited by this mixed feed.

The heterogeneous residue from alkaline Bayer processing of bauxite for alumina production, commonly called red mud. It is distinct from bauxite ore, alumina commodity, aluminium element and any single mineral species. The curated assay used material collected from the Ajka spill site; its composition and treatment response do not define every bauxite residue. No criticality designation is inherited from constituent elements.

• Aspergillus niger

The aluminium-polymer-rich reject remaining after paper recovery by hydropulping discarded liquid beverage cartons, with residual cellulosic fibres and mixed plastics. This process-defined secondary resource is distinct from intact beverage cans, pharmaceutical blisters, aluminium as an element and purified polyethylene. The selected industrial-origin sample does not define a universal reject composition or inherit a criticality list.

• Acidithiobacillus thiooxidans
• Acidithiobacillus caldus

Sulfur-rich material recovered from biogas desulfurization, represented by dried powder obtained from a Danish biogas-plant desulfurization unit. Its process origin defines this secondary resource; it is not pure sulfur as an element, a natural sulfur mineral, commercial acid or the battery black mass subsequently leached with its conversion liquor. The selected study does not establish universal residue composition or inherited criticality.

Dust generated during periodic tapping and casting of liquid iron and slag from a blast furnace, represented by an iron-rich, zinc-bearing sample from an Austrian steelmaker. This process-defined secondary resource is distinct from blast-furnace flue-gas dust, electric-arc-furnace dust, slag, natural ore and its constituent elements or mineral phases. The selected sample does not establish a universal dust composition or inherit elemental criticality.

• Acidithiobacillus thiooxidans

Residual solids generated during concentration of boron-bearing ore. The curated feed is the minus-25-mm solid waste from the Espey concentrator of the Eti Mine Boric Acid Operation in Emet, Kütahya, Turkey. It contains colemanite, muscovite, quartz and dolomite according to the study's XRD characterization. This processing residue is distinct from unprocessed borate ore, traded borate products, elemental boron and a pure colemanite mineral. The sampled composition does not define every concentrator residue; no criticality designation is inherited from its constituents.

Processing-generated fragments of cadmium telluride (CdTe) thin-film photovoltaic modules constitute a composite feed for material recycling. The accepted experiment generated milled fragments from manufacturer-sourced modules; their service history and status before laboratory preparation were not reported. This record therefore does not establish postconsumer or industrial manufacturing-scrap provenance for those samples. The feed is distinct from crystalline-silicon and CIGS modules, a pure CdTe compound, and the cadmium or tellurium elements. Constituent criticality designations are not inherited.

Discarded lead-bearing cathode-ray-tube (CRT) glass is a composite secondary resource for lead recovery, distinct from elemental lead, a lead mineral, separated CRT fluorescent powder and spent fluorescent-lamp phosphor. The accepted laboratory feed is described as waste CRT glass and contains 22.08 wt.% PbO in the source composition table. Its exact component, supplier and device history are not reported. The source's general distinction between lead-bearing funnel/neck glass and typically non-leaded screen glass does not establish that this experimental sample was a separately collected funnel fraction. Constituent criticality designations are not inherited.

Discarded hardmetal production components composed of tungsten carbide with cobalt or cobalt-nickel binder, represented by rolling-mill rollers and brazed cutting tips in the Chaika study. This manufactured secondary resource is distinct from pure tungsten carbide, a mineral species, tungsten mining tailings and metal grinding sludge. The sampled shapes and compositions do not define every hardmetal waste stream. No criticality designation or industrial deployment is inferred.

• Acidithiobacillus ferrooxidans

Mixed residual mineral solids from physical beneficiation of chromite-bearing ore. The curated 2018 case is fresh superficial tailings collected in May 2017 at a beneficiation plant in Sukinda valley, Odisha, India, with a separate stockpiled-tailings core used for chemical extraction comparisons. The source describes comminution, desliming and gravity concentration, rather than chromate manufacture. These solids are distinct from the chromite mineral species, unprocessed ore, lateritic overburden, the plant's chromite concentrate and chemically processed chromite ore residues. Reported XRD phases include chromite, goethite, hematite, gibbsite and chlorite; Cr also occurs in nonchromite phases. Table 1 reports 56.7 wt% Fe2O3 and 18.1 wt% Cr2O3 on an XRF oxide-equivalent basis, not quantitative mineral fractions. A separate 2025 fungal study uses two Eti Krom enrichment-tailings feeds labelled olivine and serpentine; both are mixed mineral materials, distinct from the Odisha samples and from pure olivine or serpentine minerals. Neither constituent criticality nor industrial microbial processing is inferred from these feeds' compositions or industrial origins.

• Acidithiobacillus thiooxidans
• Pseudomonas capeferrum
• Trametes versicolor

Chromium-bearing waste from chemical processing of chromite ore, distinct from the chromite mineral species and physical-beneficiation tailings. The curated case is a cementitious, high-lime-process residue from a Glasgow waste-fill site that received material from the Rutherglen Chromite Processing Works. High-lime processing oxidized ore Cr(III) to soluble Cr(VI), followed by aqueous extraction. The 2015 study sampled field-moist material from an exploratory borehole during the M74 motorway project and initially identified it tentatively as COPR from its pale granular appearance and high-pH yellow leachate. Subsequent XRF and XRD characterized a mixed residue rather than proving a pure feed. XRD identified cementitious and hydrated phases, including calcite, portlandite, brownmillerite, pyroaurite, hydrogarnet and brucite; remnant chromite was not detected by that assay. Table 4 reports 3.8 wt% Cr in the XRF composition, without loss-on-ignition correction; this is neither a mineral fraction nor a field-wet feed concentration. This record does not confer a constituent element's criticality designation on the residue or assert commercial microbial processing.

• Geobacter sulfurreducens

Chromium-bearing collagenous shavings generated during leather manufacture after chrome tanning, represented here by wet-blue tannery waste from Poland. This processing residue is distinct from tannery wastewater-treatment sludge, tanning liquors, elemental chromium and purified collagen. The accepted laboratory evidence concerns yeast-associated matrix bioconversion and chromium partitioning, not an isolated chromium product or industrial deployment. Constituent criticality is not inherited.

• Yarrowia lipolytica

Residues from processing chrysotile-bearing ore for asbestos production, represented here by the Clinton Creek mill tailings in Yukon, Canada. These heterogeneous, magnesium-rich residues contain fibrous chrysotile, serpentinite and other phases, including weathering carbonates. They are distinct from a pure chrysotile mineral specimen, unprocessed serpentinite, mine waste rock and other ultramafic tailings streams. No criticality designation is inherited from magnesium or other constituents.

Heterogeneous discarded material generated by coal beneficiation, represented by gravity/flotation processing dumps of the Lviv-Volyn coal basin and the Chervonogradska central concentrating factory. This secondary resource is distinct from natural coal, coal combustion ash, mine-drainage treatment solids, a particular germanium mineral and elemental germanium. The studies describe native-community-associated laboratory leaching and an enlarged experimental cascade using selected dump samples; their compositions and outcomes are not universal waste properties. Constituent criticality, selective metal products and industrial deployment are not inferred.

• Acidithiobacillus ferrooxidans

Fine particulate residue from coal combustion carried with flue gas and collected as fly ash, distinct from coal, coal bottom ash, municipal-waste incineration ash and sewage-sludge incineration ash. It is a heterogeneous secondary resource rather than a mineral species or a rare-earth commodity. A selected power-plant sample underwent laboratory treatment with yeast culture supernatant; constituent-element criticality is not inherited by the ash.

• Starmerella bombicola

Heterogeneous solid residue generated by coal gasification, including source-defined crude/coarse and fine fractions. This processing-derived resource is distinct from coal, coal-beneficiation waste and combustion-derived coal fly ash; it is neither a mineral species nor an aluminium or iron commodity. The accepted experiment concerns one supplied coal gasification crude slag (CGCS) sample and does not establish the same behavior for fine slag or other plants. Laboratory abiotic acid leaching and conversion of the liquors into a mixed flocculant are documented; constituent-element criticality is not inherited.

Heterogeneous solids accumulated during treatment of drainage from coal mines, including metal-rich precipitates and coatings in passive remediation systems. Their processing origin distinguishes this secondary resource from untreated mine water, natural ore, coal combustion ash and an individual oxide mineral. The curated experiment used material from five Pennsylvania passive systems containing different proportions of manganese, iron, aluminium and rare-earth elements. Neither a universal composition nor a constituent's criticality designation is assigned to the resource. Laboratory culture-associated metal mobilization is documented; a purified recovered product, economic recovery yield and industrial deployment are not established.

• Bacillus mycoides
• Bacillus pseudomycoides

Heterogeneous residue generated during electrolytic refining of copper, containing feed-dependent mixtures of copper, precious metals, metalloids and other constituents. The studied Guixi-smelter material contained arsenic, antimony and bismuth together with copper, silver, selenium, tellurium, gold and lead. This owner denotes the refinery residue, not a mineral species, elemental copper, a standardized commodity, furnace flue dust, or the downstream copper autoclave slime already represented separately. Composition and processing behavior of the Guixi sample are not universal specifications. No criticality designation is inherited from its constituents.

Tellurium-containing processing residue described by Bonificio and Clarke as an effluent from processing tellurium from copper anode slime. The experimentally tested material was a dried powder supplied by the Freeport-McMoRan Copper and Gold refinery in El Paso, Texas. This downstream residue is distinct from untreated copper anode slime, copper ore, elemental tellurium and the separate commercial tellurium compounds used in the study. Its bulk elemental composition, mineral phases and original processing conditions were not reported. No criticality-list status is inferred from its constituents or the article's historical discussion of tellurium.

• Pseudoalteromonas

Residual solids from flotation concentration of copper-bearing ores, distinct from unprocessed ore, copper concentrate, smelter slag and heap-leach residues. The curated feed is the inactive Las Luces T1 tailings wall near Taltal, Chile. The operator describes sulfide-ore flotation and tailings thickening at the Las Luces concentrator; the experiment characterizes a heterogeneous, silicate-rich sample containing residual copper and other elements. Its composition does not define all copper flotation tailings. No constituent's criticality designation is inherited.

Dry-collected particulate residue from copper smelting and converting, represented here by a blend of dust from reverberatory and converter furnaces at the Sarcheshmeh Copper Complex, Iran. One week's samples were mixed in the production ratio of three parts reverberatory dust to two parts converter dust. This processing-derived feed is distinct from furnace slag, natural copper minerals, copper anode slime and its downstream autoclave residue, and the wet copper-shale blast-furnace gas-scrubbing residue curated as Theisen sludge. The study reported 35.8 wt% total copper in the original blend and about 70% of particles finer than 80 micrometers; these are sample-specific assays, not a universal dust specification or recoverable reserve. Acid-preleached dust is an experimental preparation of this owner, not another material record. No criticality-list designation is inherited from copper or other constituents.

• Acidithiobacillus ferrooxidans
• Acidithiobacillus thiooxidans
• Leptospirillum ferrooxidans

Heterogeneous slag generated by copper smelting, distinct from copper ore, flotation tailings, a pure mineral or a recovered copper product. The curated experiment used two historical Polish copper-production slags: crystalline fayalite/glass-rich material (CS) and predominantly glassy material (AS), with different residual copper-bearing phases. These characterized feeds do not define all copper smelter slags. No constituent's criticality designation is inherited.

• Acidithiobacillus thiooxidans

Discarded LED lighting assemblies and their prepared mixed powder, represented here by lamps collected from electrical stores. This manufactured waste resource is distinct from fluorescent-lamp phosphor, LCD panels, an isolated LED semiconductor or its constituent elements. The selected study does not establish a universal lamp composition or which components were removed before milling. No constituent-element criticality designation is inherited.

• Acidithiobacillus thiooxidans

Zinc-bearing dust generated by electric-arc-furnace steelmaking, represented here by two actual dusts supplied by an unnamed steelmaking company. This process-defined secondary resource is distinct from cast-house dust, blast-furnace flue-gas dust, steelmaking slag, zinc ore and elemental zinc. The two samples do not define a universal composition. No elemental identifier or criticality designation is assigned to the dust.

• Acidithiobacillus thiooxidans

Metal- and polymer-bearing residual material generated during physical recycling of electrical cables. The accepted experiment uses the low-density fraction remaining after knife milling and two-step gravity separation of end-of-life vehicle cables, rather than intact cable, a high-grade copper concentrate, printed circuit boards or undifferentiated vehicle shredder residue. This process-defined secondary feed is not a mineral species or elemental copper commodity. One laboratory study compares inoculated and bactericide-treated acidic ferric leaching, with only limited evidence for microbial enhancement; neither isolated copper production nor industrial deployment is demonstrated. Constituent-metal criticality is not inherited.

Defective electroformed copper components retaining an inner silver-bearing conductive coating from manufacture on expendable wax mandrels. The studied tube-shaped rejects had incomplete copper deposition or uneven wall thickness. This manufacturing-derived secondary resource is distinct from elemental copper or silver, printed circuit boards, electroplating sludge and multilayer beverage packaging. Its selected composition does not define all electroforming waste or confer a jurisdictional criticality designation.

• Acidithiobacillus ferruginosus

Process residue from electrolytic manganese production, including the manganese-electrolysed slag sampled from a disposal dam near Jishou, Hunan, in Cao et al. This heterogeneous secondary resource is distinct from manganese ore, elemental manganese, and manufactured electrolytic manganese metal or dioxide. Its composition is sample dependent; no constituent-element criticality designation is inherited.

• Fusarium

Metal-bearing liquids originating from industrial electroplating baths, represented by five Cu, Ni, Pd and Au bath effluents supplied by Galvanica Aricci Srl, Ghisalba, Italy, in Ciani et al. (2026). These compositionally different process liquids are distinct from electroplating wastewater-treatment sludge, metallic electroforming scrap and laboratory metal-salt solutions. The study's Ni(1)+Cu mixture is an experimental combination of two supplied liquids, not a sixth independently sampled waste stream. No criticality designation is inherited from constituent metals.

• Dactylococcopsis salina 16Som2
• Cyanothece sp. CE4

Metal-bearing solids generated by treatment of electroplating wastewater, represented here by the Chennai effluent-treatment sludge of Prabhu and Baskar (2015) and the compositionally different electroplating sludge of Kordloo et al. (2026). The latter paper does not name its sludge supplier or sampling site. These heterogeneous wastes are not pure metal compounds, untreated plating baths, metallic electroforming scrap, GaAs-production hydroxide sludge, or the existing automotive-factory sludge whose contributing process is unresolved. The two studies are separate assays, not pooled feeds or a replication. No constituent-element criticality is inherited.

• Acidithiobacillus ferrooxidans

Discarded copper-indium-gallium-selenide (CIGS) thin-film photovoltaic modules and their separated coated-glass fractions are a composite secondary resource. The curated study explicitly describes end-of-life Q-Smart panels supplied by Polyeco S.A. This scope excludes crystalline-silicon and CdTe modules, sputtering targets, production-chamber scrap, and factory-supplied cells without documented end-of-life provenance. The resource is distinct from its constituent elements and from a pure CIGS compound or mineral species. Constituent criticality designations are not inherited.

Discarded crystalline-silicon photovoltaic modules and their separated cell fractions are a composite secondary resource generated by photovoltaic equipment use and dismantling. Their silicon wafers, metal contacts, glass and encapsulants remain distinct from elemental silicon, silicon-metal commodity, silver and mineral species. This record excludes CdTe and CIGS thin-film modules, manufacturing scrap of unspecified origin and generic electronic waste. The curated experiment used a chemical extract from end-of-life Hyundai m-Si units, not intact modules in direct contact with microorganisms. Criticality designations of constituent elements are not inherited by this waste feed.

Mixed slag generated during smelting of chromite-bearing feed to produce ferrochrome alloy. The curated experiment used waste supplied by Zimasco at Kwekwe, Zimbabwe. This processing-derived resource is distinct from chromite ore, physical beneficiation tailings, chromite ore processing residue from chemical chromium extraction, the ferrochrome alloy product and individual slag mineral phases. Composition varies with feed and process; the selected sample is not a universal specification. No constituent criticality designation or mineral identifier is inherited.

Phosphorus-bearing fish-bone residues investigated as a secondary feed for nutrient reuse, represented by fish bones of unspecified species and supply provenance ground and sieved to below 1 mm in the selected laboratory studies. The organic-mineral feed is distinct from elemental phosphorus, purified hydroxyapatite, phosphate rock, manure and bone-incineration ash. The inspected methods do not establish a cooking or industrial processing history for this fish-bone feed. Material composition and treatment effects remain specimen-specific; no constituent criticality designation is inherited.

• Priestia megaterium
• Acidithiobacillus ferrooxidans

Liquid residual streams generated by wet flue-gas desulfurization and associated wastewater treatment, distinct from solid FGD gypsum, coal ash, elemental selenium and natural mineral resources. The accepted experiment concerns a particular coal-power-plant effluent after physical/chemical pretreatment and dilution, not an invariant composition or all FGD streams. Its selenium-bearing residuals were investigated for treatment; no marketable recovered selenium product or inherited criticality is asserted.

A mixed secondary resource from spent fluorescent lamps. The curated assay concerns retorted phosphor powder supplied by Idaho National Laboratory, rather than untreated whole lamps, a single mineral species, an element, or a purified rare-earth commodity. Its total rare-earth leaching outcome is not assigned to any individual element. No criticality designation is inherited from the elements present in this waste.

• Gluconobacter oxydans

Heterogeneous metal-hydroxide sludge generated by neutralizing waste streams from industrial gallium arsenide wafer production. The curated evidence concerns the sludge supplied for Fritze et al. (2026), not crystalline GaAs, a pure iron mineral or all semiconductor wastes. Table 1 reports 32.81% Si, 6.97% Fe, 1.21% Ga, 1.34% As, 0.27% P and 1.83% Ca by handheld XRF; Section 2.1 separately reports 0.538% fluoride by ion-selective electrodes. These are the study's reported composition percentages, not a complete phase analysis or a specification for every sludge batch. No elemental identifier or constituent criticality designation is assigned to this waste. The gallium and arsenic records describe constituent outcomes from the same experiment; they are not independent replications.

• Acidithiobacillus thiooxidans

Processing-derived residual material from gold production, distinct from unprocessed gold ore, elemental gold, individual mineral species and isolated rare-earth products. The curated experiment concerns one air-dried, sieved batch obtained from the Mouteh Gold Factory tailings dam. It supports qualified chemical pretreatment and culture-associated praseodymium, cerium and europium mobilization at laboratory scale; its composition and behavior do not define all gold-mine tailings. No criticality designation is inherited from constituents.

• Acidithiobacillus thiooxidans

Ground rubber recovered from used tires, containing a crosslinked polymer matrix, fillers and zinc-bearing additives. The selected study used 400-600 micrometre particles from an unnamed waste-tire recycling facility. This secondary resource is distinct from elemental zinc, zinc mineral species, tire combustion ash, pyrolysis char, rubber-manufacturing waste and natural-rubber gloves. Chemical pretreatment does not create a separate material identity, and the feed does not inherit a criticality designation from a constituent element.

• Rhodococcus rhodochrous

Heterogeneous ash generated by burning heavy fuel oil, represented here by an oil-fired thermal-power-plant residue. This combustion resource is distinct from coal fly ash, petroleum coke, refinery catalysts and its constituent elements. The selected study does not establish the collection fraction needed to identify its sample specifically as fly ash. No constituent-element criticality status is inherited by this resource.

• Aspergillus niger

A processed, mixed mineral residue remaining after ammonium-sulfate extraction of ion-exchangeable rare earths from weathered ion-adsorption ore. Zhang and colleagues (2024) prepared the studied material in the laboratory from Guangdong, China ore; this is not evidence of sampling an industrial tailings deposit. It is distinct from the natural ion-adsorption rare-earth clay feed, individual mineral species and isolated rare-earth products. The preparation included repeated salt leaching, rinsing, 60-mesh sieving, drying and crushing. The authors' ion-unexchangeable designation is operational, referring to the rare earths remaining after that pretreatment. It does not mean resistance to every subsequent extractant. The experimental feed contains mainly kaolinite, quartz, orthoclase and muscovite, with minor Fe-bearing and rare-earth-bearing phases. Its composition is not a universal tailings specification, and no criticality designation is inherited from its constituent elements.

• Aspergillus niger

Iron-ore tailings are processing-derived residual feeds from iron-ore production, distinct from natural iron ore, elemental iron and individual iron minerals. This record curates a mixed goethite/hematite/quartz tailing used as a source of biologically mobilized iron in a laboratory two-stage manganese-leaching experiment. The unnamed facility and tested composition do not define all iron-ore tailings. No criticality designation is inherited from constituents.

Kaolin-bearing material discarded into mine waste dumps because iron impurities prevented commercialization, represented by high- and low-iron samples supplied by Caobar SA from Poveda de la Sierra, Guadalajara, Spain. The source describes waste from beds not exploited for sale; it does not establish that this is processing tailings. The mixed kaolinite-rich feed is distinct from a kaolinite mineral species, natural kaolin resource, elemental iron or an isolated recovered product. Secondary-resource scope follows its mine-discard status, not the source's conflicting descriptions of primary versus secondary geological origin. No criticality designation is inferred from constituents.

• Bacillus thuringiensis

Partly vitrified residue generated during lead blast-furnace smelting. The curated example is granulated slag from the former lead-zinc smelter at Noyelles-Godault, northern France, containing a silicate glass matrix, crystalline phases and metallic lead droplets. It is a process-defined secondary resource, distinct from elemental lead or zinc, a pure mineral, copper-smelter slag, steelmaking slag, furnace dust or zinc-leach residue. Its composition is sample-specific. No criticality designation is inherited from constituent elements.

• Pseudomonas aeruginosa

Sludge generated during grinding of metal workpieces with cooling fluids, represented by an iron-rich sample from Tatra Koprivnice. Material collected from grinding-fluid traps contains metal particles and other phases; it is distinct from elemental iron, a specified alloy and coal-combustion cinder or slag. The evidence concerns the sampled processing residue, not every grinding sludge or an industrial bioleaching operation. No criticality designation is inferred from the metals it contains.

• Acidithiobacillus ferrooxidans

Metal-rich solid burrs generated by machining, represented here by an industrial sample obtained in Mexico City and mechanically reduced before laboratory testing. This resource denotes machining offcuts rather than a particular alloy, elemental metal, smelting slag or coolant-trap grinding sludge. The sampled batch was iron-rich but its alloy and phase identities, facility, collection date and machining operation were not specified. Industrial origin does not establish industrial bioleaching deployment, and no criticality designation is inferred from its constituents.

• Acidithiobacillus thiooxidans

Unincinerated sludge generated by municipal wastewater treatment, represented here by partially dewatered sludge from Kuopio, Finland, and sludge from a municipal treatment plant in Tianjin, China. These heterogeneous processed residues contain organic matter, nutrients and metals; their precise upstream treatment histories and mineral hosts are not fully resolved. This secondary resource is distinct from sewage-sludge incineration ash, untreated wastewater, factory-specific treatment sludge and purified phosphorus or metal products. The selected specimens do not define every municipal sludge.

• Acidithiobacillus ferrooxidans
• Acidithiobacillus thiooxidans

Ash resulting from municipal-waste thermal treatment, a heterogeneous secondary resource distinct from coal fly ash and sewage-sludge incineration ash. The curated study calls its feed ash A without identifying whether it is fly ash, bottom ash, or a mixture; this record does not resolve that fraction by inference. Criticality of individual constituents does not designate the whole ash. The selected experiment is shared with the niobium element record, not an independent replication.

Source-designated industrial superalloy residue powders considered as secondary metal feeds, distinct from nickel or cobalt elements, certified alloy grades and recovered metal products. The accepted primary study tested three supplied stocks SAR-Ni 30167, SAR-In 32083 and SAR-Re 30168 within one resource family. Their feed compositions and leaching responses remain separate; no one stock represents all superalloys. Laboratory culture-filtrate experiments do not establish post-consumer provenance, industrial deployment or complete feed recovery.

• Acidithiobacillus thiooxidans

Residual mixed solids from flotation in nickel-ore beneficiation, distinct from the recovered flotation concentrate, unprocessed ore, a pure sulfide mineral and downstream smelter slag. The curated case is the material called lama in a 2010 UNESP thesis, supplied by Votorantim Metais from flotation at its Serra de Fortaleza-MG nickel extraction operation in Brazil. Original particles were reported as 50-100 micrometres. XRD indicated a heterogeneous silicate/carbonate assemblage with pyrrhotite; no pure-pyrrhotite feed or quantitatively established sulfide-hosted nickel fraction is assigned. Table 7 gives total Ni 0.30%, Cu 0.03% and Co 0.01%, versus aqua-regia-soluble Ni 0.25%, Cu 0.03% and Co 0.01%. The digestion-defined soluble fraction is not water-soluble metal. These are feed-specific measurements, not a universal tailings composition or an inherited criticality claim.

• Acidithiobacillus ferrooxidans

Mixed solid residue from pyrometallurgical smelting in nickel extraction, distinct from nickel ore, flotation concentrate, flotation tailings and an individual constituent mineral. The curated case is the flash-furnace slag supplied by Votorantim Metais from its Serra de Fortaleza-MG nickel extraction operation in Brazil for a 2010 doctoral thesis. The source reports original particles of 100-500 micrometres and a dominant fayalite/forsterite-type iron-magnesium silicate diffraction pattern; that assignment does not make the bulk slag a pure mineral. Table 7 reports total Ni 0.26%, Cu 0.27% and Co 0.06%, versus aqua-regia-soluble Ni 0.07%, Cu 0.06% and Co 0.06%. The latter is an operational digestion fraction, not water solubility. These feed-specific assays do not define every nickel slag. No constituent criticality status or industrial microbial deployment is inferred.

• Acidithiobacillus ferrooxidans

Water brought to the surface as a byproduct of hydrocarbon production and considered here as a secondary feed for constituent recovery. It can contain formation water, returned injected fluids, condensed water and mixtures of these; its composition and salinity vary by reservoir and operation. This record concerns the generated oil-and-gas production stream, not an untouched geological brine resource, geothermal extraction feed, individual dissolved element or mineral species. Some produced waters are investigated as sources of lithium and other constituents, without implying that every sample contains economically recoverable quantities. USGS resource research supplies context, not a criticality-list designation for this mixture. Microbial treatment and recovery mechanisms remain unasserted pending verification of full experimental methods, controls and outcomes; no deployment or product yield is claimed.

Mineral-bearing residue from bitumen froth treatment, represented here by naphtha-process tailings from Plant 6 at the Mildred Lake Settling Basin, Alberta, Canada. The heterogeneous solids include quartz, titanium-bearing minerals, zircon, sulfides and carbonates, with residual hydrocarbons. This processing waste is distinct from its constituent elements or mineral species, underlying straight coarse tailings, fluid fine tailings and petroleum coke. These site-specific studies do not define all froth-treatment processes or establish an economic reserve, a criticality designation or industrial metal recovery.

Carbon-rich solid produced from heavy petroleum-processing residues, treated here as a residual material resource rather than coal-derived coke, coking coal, the carbon element, graphite, combustion ash or oil-sands tailings. The accepted experiment uses material described by its authors as petroleum coke from Navanagar Metcoke Limited, Jamnagar, Gujarat. The paper also calls the sample metcoke; its precise manufacturing route and green, calcined or needle-coke grade are not established. This record retains that source-assigned feed identity without creating a grade-specific owner. Laboratory sulfur-content reduction does not establish recovered sulfur, metal recovery, retained fuel quality or industrial deployment.

• Acidithiobacillus thiooxidans

Heterogeneous oil-, water- and solid-bearing residues generated in petroleum handling and processing, with feed-dependent metals and metalloids. This resource context includes the characterized crude-oil tank-bottom sludge from Karoon Oil and Gas Company in Iran studied by Nejad et al. (2020), and the distinct weathering-pit refinery sludge collected in Bahrain in March 2020 studied by Hentati et al. (2022). It is not raw crude oil, produced water, petroleum coke, combustion ash, or oil-sands froth-treatment tailings. Neither constituent criticality nor economic recoverability is assigned to the mixed residue. Lower reported residual metal concentrations in one laboratory treatment do not establish metal extraction, biomass capture, or recovery.

• Stutzerimonas balearica

Discarded multilayer pharmaceutical blister packaging containing aluminium, polymers and adhesives, represented by hospital-collected transparent, white and silver-coloured fractions. This manufactured waste resource is distinct from aluminium as an element, beverage cans, beverage-carton hydropulping reject and the sulfur feed used to produce its leaching acid. Its composition varies with packaging construction; no element-level criticality is inherited.

• Acidithiobacillus thiooxidans
• Acidithiobacillus caldus

Residual material from phosphate-ore processing, distinct from phosphate rock as a commodity, a phosphate concentrate, phosphogypsum and a pure phosphate mineral. The curated example is the Florida phosphate tailings specimen studied by Somasundaran and colleagues, described as predominantly clay-bearing and supplied by Florida University, USA. The paper does not identify its mine or processing plant. Composition and leaching behavior are specimen-specific; constituent rare earth elements do not confer a criticality designation on this resource.

• Acidithiobacillus ferrooxidans
• Aspergillus niger

A heterogeneous calcium-sulfate-rich residue generated during wet-process phosphoric acid manufacture from phosphate rock. It is distinct from natural gypsum mineral, phosphate-rock commodity and individual rare-earth elements. Curated laboratory evidence separates synthetic single-REE-doped model powders from an industrial residue sample. Neither experiment establishes industrial recovery, and constituent-element criticality is not inherited by the residue.

• Gluconobacter oxydans

Unincinerated manure generated by pig husbandry, represented here by fresh material collected from a pig farm in Tianjin, China, and studied as a diluted slurry. This heterogeneous agricultural residue contains nutrients and metals. Its origin is distinct from municipal sewage sludge, poultry litter, manure incineration ash and isolated fertilizer or metal products. The selected farm sample does not characterize all pig manure, and its liquid and solid fractions are not separate resource owners.

Mixed fly and bottom ash deposited in coal-combustion ash ponds, represented here by a sample from a Philippine circulating-fluidized-bed power plant burning local and imported coal. The mixture is a distinct secondary resource from separately collected coal fly ash, pure coal bottom ash and coal-gasification slag. Its fly-to-bottom ratio, residence time and plant identity are unreported. A laboratory mixed-culture study supports qualified metal mobilization from the mixed feed; it does not resolve either ash component's individual response or establish an isolated metal product, criticality designation or industrial deployment.

• Acidithiobacillus albertensis
• Acidithiobacillus thiooxidans

Phosphorus-bearing poultry-bone residues investigated as a secondary feed for nutrient reuse, represented by cooked or boiled poultry bones ground and sieved to below 1 mm in the selected laboratory studies. The organic-mineral feed is distinct from elemental phosphorus, purified hydroxyapatite, phosphate rock, manure and bone-incineration ash. The animal species, supplier and exact cooking procedure are not reported; poultry is not silently narrowed to chicken. Material composition and treatment effects remain specimen-specific; no constituent criticality designation is inherited.

• Priestia megaterium
• Acidithiobacillus ferrooxidans

Solid residue generated by roasting or calcining pyrite-bearing feed, also described as pyrite ash. The curated experiments concern calcined waste supplied by the Eti Mining Bandırma Borax Plant, Turkey, and a separately characterized, weathered pyrite-ash sample from São Domingos, Portugal. This processing residue is distinct from natural pyrite, unroasted mine tailings, smelting slag and spent sulfuric-acid-production catalyst. Its composition varies with feed, processing and weathering; neither study establishes a uniform mineral formula or commercial product specification. No criticality-list designation is inferred from constituent elements.

• Saccharomyces cerevisiae
• Acetobacter aceti
• Sulfobacillus thermosulfidooxidans
• +2 more

Concentrated aqueous reject stream generated during reverse-osmosis water treatment, considered here as a secondary feed for constituent separation and recovery. Its salts, nutrients, contaminants and treatment additives depend on the source water and process. The curated experiment used concentrate produced in the laboratory from Arkansas River water, not natural geothermal brine or oil-and-gas produced water. This process-generated mixture is distinct from its dissolved elements, precipitated mineral phases and traded products. No criticality designation is inherited from a constituent.

Source-labelled samarium-cobalt magnet scrap supplied by the Defence Metallurgical Research Laboratory, Hyderabad, India. Its preceding service history and manufacturing-waste category were not disclosed, so the feed is not asserted to be end-of-life devices. It is distinct from NdFeB magnet waste, the broad rare-earth permanent-magnet commodity grouping, pure Sm2Co17 and its constituent elements. The characterized preparation includes oxide phases as well as a Sm2Co17 assignment. No criticality designation or microbial recovery is inherited from the feed's constituents.

Heterogeneous residual aluminium dross after an earlier recovery of metallic aluminium from primary dross by screening or flux-assisted remelting. This source-defined secondary dross is narrower than the umbrella aluminium-dross category; the accepted specimen came from an aluminium remelting plant in Guangxi, China. It contains metallic aluminium, aluminium oxides and nitride, magnesium-aluminium spinel, and other oxides and process salts. It is not a mineral species, elemental aluminium, bauxite residue, spent potlining, or an automatically equivalent feed to an unspecified aluminium-smelting slag. Laboratory chemical extraction is documented without a microbial mechanism, inherited criticality designation, or demonstrated industrial deployment.

Ash from thermal treatment of sewage sludge, distinct from unburned sludge, municipal-solid-waste incineration ash and coal fly ash. It is a heterogeneous secondary resource rather than a phosphate mineral species or individual critical element. The selected ash-B feed has unresolved fly/bottom fraction and host phases. Its source also supplies the separate municipal-waste ash and niobium records; those are linked views of one study, not additional experiments.

End-of-life non-button alkaline and zinc-carbon batteries, represented by a mixed AA-cell powder after dismantling, electrolyte washing and drying. This secondary resource is distinct from the curated watch/button-cell powder, nickel-metal-hydride batteries and lithium-ion battery black mass. The selected experiment treats the two primary-cell chemistries together; it does not establish separate chemistry-specific performance or a universal battery composition. Constituent-element criticality is not inherited.

• Acidithiobacillus thiooxidans

Used automotive three-way catalytic-converter material, represented here by a real vehicle-treatment-centre catalyst containing a ceramic support and metal-bearing coating. This use-defined secondary resource is distinct from its constituent platinum-group elements, fresh catalyst, refinery hydrocracking or hydrodesulfurization catalysts, and automotive wastewater-treatment sludge. The selected cryomilled feed does not define every converter formulation. No constituent criticality designation is inherited.

• Acidithiobacillus thiooxidans

Used aqueous glass-polishing suspension containing ceria-based abrasive, fine glass particles and other process-derived components. The curated 2015 case is waste collected in several portions over six months from the Dioptra optical-glass-polishing factory in Turnov, Czech Republic, which used Cerox-type ceria polishing powders. Sedimentation partially dewatered the waste to approximately 50% water before treatment. Table 1 reports dry-solid XRF composition as oxide equivalents, including 8.85 wt% CeO2, 1.49 wt% La2O3 and 57.6 wt% SiO2. These are a reported waste-composition example, not universal proportions or quantitative mineral abundances. The mixed used slurry is distinct from pure cerium, reagent ceria, fresh polishing powder and the recovered ceria-rich product. Constituent criticality is not inherited by this resource.

Used CuO-ZnO-Al2O3 catalyst material from synthesis-gas processing, including low-temperature carbon monoxide conversion. This composition-defined secondary resource is distinct from fresh catalyst, its constituent oxides, elemental copper/zinc and spent refinery hydroprocessing catalysts. The selected Polish-market sample had 35.1 wt% Cu, 29.9 wt% Zn and 9.2 wt% Al by AAS; these are sample measurements, not a universal formulation. Its plant and service history are unspecified. No constituent criticality is inherited.

Used petroleum-refinery fluid catalytic cracking (FCC) catalyst, a heterogeneous alumina/silica-rich secondary resource that may contain rare earths and accumulated metals. It is distinct from fresh catalyst, spent hydrocracking or hydrotreating catalyst, automotive catalyst, constituent elements and mineral species. The selected evidence concerns one Valero FCC feed and filtered microbial culture supernatant; it does not confer criticality on all FCC wastes.

• Gluconobacter oxydans

Used refinery catalyst from hydrocracking, which combines cracking and hydrogenation of hydrocarbon feeds. This secondary-resource class is distinct from spent fluid catalytic cracking catalyst, automotive catalyst and the broader category of all hydroprocessing catalysts. The selected Thai refinery material was decoked before laboratory leaching; its composition is not a universal catalyst formulation, and no constituent-element criticality is inherited.

• Aspergillus aculeatus

Used catalyst from hydrodesulfurization of petroleum feeds, represented here by a characterized raw catalyst from a Brazilian diesel-treatment unit. This process-defined secondary resource is distinct from spent fluid catalytic cracking and hydrocracking catalysts, from fresh catalyst formulations, and from its constituent elements. The selected material was described as CoMo on alumina, but its measured composition and microbial response do not define all spent HDS catalysts. No constituent-element criticality designation is inherited.

• Acidithiobacillus thiooxidans

Used iron-molybdate catalyst from methanol oxidation for formaldehyde production. This process-defined secondary resource contains iron molybdate and excess molybdenum oxide, with feed-specific impurities and amorphous material. It is distinct from molybdenite, elemental molybdenum, fresh catalyst and spent Ni/Co-Mo refinery catalysts. Two primary studies examine different spent feeds; their compositions and yields are not interchangeable. No mineral identifier or constituent-element criticality is assigned.

Spent indium-tin oxide targets are a solid secondary resource associated with sputtering-target use, distinct from elemental indium or tin, virgin ITO products, LCD glass panels and dissolved etching wastewater. Gu and colleagues identify their supplied Wako material as spent ITO target material and analyze its ground powder. The specific prior sputtering history and service conditions are not documented in the accessible main article, so the spent designation is retained as the study's feed description. Its mixed oxide composition and impurities are sample-specific, not a universal target specification. No criticality designation is inherited from constituent elements.

Waste acidic electrolyte drained from used lead-acid batteries and its chemically pretreated liquid effluent. The accepted biological experiment concerns the residual sulfate-, Pb- and Cd-bearing liquid after lime precipitation and carbonation, not untreated concentrated acid, solid lead paste, battery grids or an intact battery. This use-derived liquid resource is distinct from elemental lead, galena and other spent-battery chemistries. No constituent criticality designation is inherited.

Discarded neodymium-iron-boron permanent-magnet material considered as a secondary resource, distinct from the neodymium element, a fixed-purity Nd2Fe14B compound, all rare-earth magnets, and the broader commodity grouping of raw materials for permanent magnets. Actual feeds can contain other rare earths, alloying elements, coatings and impurities; no universal composition is assigned. Riano and Binnemans document an end-of-life NdFeB feed. The microbial-origin biomass assay curated here instead used chemically prepared hard-disk-magnet leachate; its precise device history and waste collection provenance were not reported. This is the same Kucuker experiment represented under neodymium, not an independent replication or a criticality designation inherited from its constituent elements.

• Chlorella vulgaris

End-of-life nickel-cadmium batteries, represented here by prepared active electrode powder from dismantled cells. The accepted experiment concerns the cathode fraction, not an intact battery or a pooled whole-cell metal inventory. This Ni/Cd secondary-cell resource is distinct from nickel-metal-hydride batteries, mixed alkaline/zinc-carbon primary cells, button-cell powder and lithium-ion black mass. Constituent-element criticality is not inherited.

• Acidithiobacillus ferrooxidans

End-of-life nickel-metal-hydride batteries, represented by mixed battery powder supplied by a recycler. This secondary resource is distinct from lithium-ion battery black mass, pure electrode compounds, and its constituent elements. Battery formulations and upstream recycling steps are not fully specified for the selected feed. No constituent-element criticality status is inherited by this waste resource.

• Gluconobacter oxydans
• Streptomyces pilosus

Used nickel-bearing catalyst from primary steam reforming, represented by a spent nickel-oxide/alumina formulation supplied by an unnamed fertilizer plant. This use-defined secondary resource is distinct from vegetable-oil hydrogenation catalyst, platinum petroleum-reforming catalyst, fresh catalyst and elemental nickel. The selected feed composition does not define every steam-reforming formulation. No constituent criticality or mineral identifier is inherited.

Used platinum-bearing catalyst from petroleum reforming, represented by a source-described monometallic Pt/Al2O3 catalyst. This use-defined secondary resource is distinct from automotive converters, nickel steam-reforming catalysts, refinery hydroprocessing catalysts, fresh catalyst and elemental platinum. The selected feed composition does not define every reforming formulation. No constituent criticality or mineral identifier is inherited.

Exhausted aluminium-smelting cell lining containing variable proportions of carbonaceous cathode material, refractory cement and brick, and accumulated process salts. The accepted study used real mixed-cut waste supplied by Trimet Aluminium, Essen, Germany, with three visually selected grades from refractory-rich to mainly graphitic material. Exact cell and service histories were not resolved. This solid waste is distinct from aluminium dross, waste electrolyte, red mud, graphite as a mineral or commodity, and its constituent elements. Laboratory chemical extraction is documented without a microbial mechanism or an inherited criticality designation.

Used vanadia-tungsta/titania catalysts from coal-fired power-plant flue-gas denitrification, represented by separately characterized laboratory feeds. Niu and colleagues studied an arsenic-contaminated honeycomb catalyst from a Xinjiang plant; Su and colleagues separately studied gray and yellow regions of three spent honeycomb catalysts, S3–S5. This manufactured, heterogeneous secondary resource is distinct from refinery hydroprocessing, fluid catalytic cracking and sulfuric-acid-production catalysts, pure constituent oxides, mineral species and elemental vanadium or tungsten. V2O5-WO3/TiO2 is the sources' catalyst formulation notation, not proof of three separately quantified crystalline phases. Fresh catalysts S1–S2 in Su's study are comparators, not spent-resource observations. No criticality designation is inherited from the constituents.

• Acidithiobacillus thiooxidans ATCC 19377

Discarded button cells identified by the primary source as silver-oxide–zinc batteries, distinct from zinc–manganese button cells, other battery chemistries, elemental silver or zinc and isolated recovered products. The accepted experiment used powder manually removed from market-collected waste cells, not intact batteries or an authenticated pure oxide feed. It supports laboratory metal mobilization with a filtered fungal culture medium, with unresolved experimental-condition and yield conflicts.

• Aspergillus niger

Acidic metal-bearing process liquids remaining after removal of oxide scale from steel surfaces. The accepted experiment uses hydrochloric-acid liquor collected from a steel-processing plant's pickling bath, subsequently filtered and diluted with laboratory 9K medium. This liquid feed is distinct from steelmaking slag, mill scale, electroplating-bath effluents, treatment sludge and synthetic iron-salt solutions. It is represented as one process-resource identity, without separate owners for acid recipes or facilities. Evidence here concerns culture-associated iron redox transformation and sediment formation in the hydrochloric-liquor arm; it does not establish performance for every steel-pickling liquor, isolated metal recovery or criticality.

• Acidithiobacillus ferrooxidans

Used catalyst from sulfur-dioxide oxidation in sulfuric-acid production, represented here by vanadium-bearing material from a copper-smelter acid unit. This process-defined secondary resource is distinct from petroleum hydrodesulfurization catalysts, automotive converters, fresh catalyst and its constituent elements or mineral phases. The selected silica-rich feed does not define every spent acid-plant catalyst. No constituent-element criticality designation is inherited.

• Acidithiobacillus thiooxidans

Discarded tantalum capacitor components separated from electronic equipment, distinct from tantalum element, whole printed circuit boards, other capacitor technologies and a recovered tantalum product. The accepted laboratory feed comprised visually identified surface-mounted capacitors manually removed from spent mobile phones and milled. One primary study supports qualified base-metal mobilization by acidophile cultures and a fungal-culture filtrate, while tantalum was not detected in the reported leachates. It does not establish industrial deployment, pure feed phases or isolated-metal recovery.

Sulfuric-acid electrolyte containing dissolved vanadium in multiple oxidation states after use in all-vanadium redox flow batteries. This use-derived liquid resource is distinct from elemental vanadium, fresh electrolyte products, spent vanadium catalysts, and solid battery scrap. The two studies below concern different feeds: company-supplied failed positive/negative electrolytes and electrolyte deliberately cycled to capacity loss in a laboratory cell. Their outcomes are not interchangeable. No constituent criticality designation or microbial mechanism is inherited.

Used nickel-bearing catalyst from vegetable-oil hydrogenation for oil hardening, including catalyst-bearing filter-aid mixtures. This process-defined secondary resource differs from fresh catalyst, nickel metal, spent bleaching earth and refinery cracking or desulfurization catalysts. Bosio et al. describe a particular feed containing organic residues and diatomaceous-earth filtering aid; that composition is not a universal formulation. IFC process guidance independently identifies spent hydrogenation catalyst and its associated filtering aid. This identity-only record inherits no constituent criticality. Microbial leaching and sulfide recovery reported by Bosio remain uncurated because complete methods, figures and product characterization were not acquired.

End-of-life zinc-manganese button cells, represented by mixed powder from discarded watch batteries. This secondary resource is distinct from NiMH and lithium-ion batteries, silver-oxide button cells, pure electrode phases and the constituent elements. The selected study identifies its mixed feed as Zn-Mn button cells but does not independently document the chemistry of every collected cell. No constituent-element criticality is inherited.

Chromium-bearing solids from tannery wastewater treatment, represented here by the Xiamen factory sludge tested by Wang et al. (2019). This heterogeneous secondary resource is distinct from untreated tanning liquor, leather shavings, pyrolyzed tannery residue, electroplating sludge and elemental chromium. The experiment does not establish a universal sludge composition or inherit constituent-element criticality.

• Acidithiobacillus ferrooxidans
• Acidithiobacillus thiooxidans

Aqueous waste streams from tanning operations, represented here by conventionally treated effluent from the Acque del Chiampo plant in Arzignano, Italy. This heterogeneous secondary resource is distinct from wastewater-treatment sludge, chromium-tanned leather shavings, synthetic chromium solutions and elemental chromium. The accepted laboratory study concerns further removal of residual source-assigned Cr(III) using dead fungal biomass; composition and performance are specific to the tested feeds. No constituent criticality is inherited.

• Cunninghamella elegans

Fine-grained flue-dust residue from top-gas scrubbing during copper-shale smelting in a blast furnace, also called Theisenschlamm. The resource scope here is the historical processing waste represented by the Helbra mono-landfill in Saxony-Anhalt, Germany. It is distinct from unprocessed copper shale, a mineral species, an elemental commodity and a prepared leaching solution. Meschke et al. (2016) sampled material at a depth of 4 m in May 2015. They measured Cu, Mo, Pb, Sn, Sb and Zn by energy-dispersive X-ray fluorescence and Ag, Co, Ge and Re in an aqua-regia extract by ICP-MS. Their Figure 5A identifies zinc and lead as major measured components and reports other measured constituents; the two analytical fractions are not interchangeable measures of complete extractability. This sampled-feed characterization does not establish uniform composition throughout the landfill or a recoverable reserve. The same paper's membrane experiments used prepared Ge/Mo/Re solutions, rather than the sampled sludge or its actual leachate, and its Figure 2 reproduces bioleaching-solution information attributed to Klink et al. (2016). Those distinct evidence streams do not establish a newly verified microbial mechanism, isolated-metal yield or industrial recovery process for this record. No criticality designation is inherited from constituent elements.

Heterogeneous solid residue described by the source as titanium gypsum or titanogypsum from titanium-dioxide production. The curated feed is a real Taizhou, Jiangsu plant waste, distinct from natural gypsum, titanium dioxide, phosphogypsum from phosphoric-acid manufacture and a purified calcium-sulfate product. Its unusual reported bulk composition and mixed phase assignments are retained rather than imposing pure-gypsum stoichiometry. Laboratory culture-associated redistribution of fluorine does not establish recovery of a fluorine product, a safe agricultural amendment or industrial deployment. No constituent-element criticality is inherited.

• Rhodotorula mucilaginosa

Residual solids from acid leaching in wet recovery of nickel or cobalt from waste traction-battery cathode materials and other recycled wastes. The curated study used separate nickel-line and cobalt-line residues from an unnamed Chinese enterprise; their compositions are not pooled. The source calls these residues slags, but does not establish molten-slag origin. They are downstream processing residues, distinct from mechanically prepared battery black mass, intact batteries, a pure cathode compound and isolated nickel or cobalt products. Exact incoming battery chemistries and the contribution of other wastes are unspecified. No constituent-element criticality is inherited.

• Acidithiobacillus ferrooxidans
• Leptospirillum ferriphilum
• Acidithiobacillus thiooxidans
• +2 more

Discarded tungsten-nickel-iron heavy-alloy components, represented by decommissioned projectile cores identified as VNZh in the Baranov study. This manufactured secondary resource is distinct from elemental tungsten, cemented tungsten carbide scrap, mining tailings and grinding-fluid sludge. The reported feed composition describes the tested material, not every VNZh grade or tungsten-alloy waste. No criticality designation, standardized product specification or industrial deployment is inferred.

Residual mineral solids generated by processing tungsten-bearing skarn ore. The curated case is historical tailings in the Smaltjärnen repository at the closed Yxsjöberg tungsten, copper and fluorspar mine in Sweden. The processing plant used gravity separation, magnetic separation and flotation. The characterized layered material contains scheelite among mixed silicate, carbonate, sulfide and other minerals; composition and particle liberation vary by sampled layer. This resource is distinct from tungsten as an element, pure scheelite, unprocessed ore, waste rock and a saleable concentrate. Hällström et al. document scheelite alteration, hydrous ferric oxide associations and tungsten transport in a field investigation of this repository; those geochemical observations do not establish microbial causation. No criticality designation is inherited from constituents, and the laboratory results below do not characterize all tungsten tailings.

Heterogeneous residual solids in uranium-mine tailings management areas, represented here by DT and RAT samples from two decommissioned Elliot Lake, Ontario sites. These are secondary mining residues, distinct from unprocessed uranium ore, individual uranium minerals, drainage water and purified elements. The original processing flowsheets and the expansions of the two sample-site abbreviations are not established by the curated study. Laboratory evidence concerns culture-associated metal solubilization and a separate resin screen; it does not establish industrial recovery or a resolved uranium extraction yield. No constituent-element criticality designation is inherited by these tailings.

Silver-bearing liquid discarded after photographic fixing, represented here by used black-and-white film fixer collected from a local processing unit. This secondary feed is distinct from discarded solid films, unused fixer, developer solutions and prepared silver salts. Its composition is source-specific; constituent criticality is not inherited.

• Thiobacillus thioparus
• Cladosporium cladosporioides

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.

• Acidithiobacillus ferrooxidans
• Acidithiobacillus thiooxidans

Discarded multilayer ceramic capacitor components, represented here by components removed from printed circuit boards of twenty post-consumer computers. This feed is distinct from whole printed circuit boards, tantalum capacitors, pure barium titanate and its constituent elements. The characterized batch contained ceramic and metallic phases; neither a universal capacitor composition nor a criticality designation is assigned. The accepted experiment uses chemical deep eutectic solvents and provides no microbial mechanism or industrial deployment evidence.

Waste printed circuit boards are end-of-life conductive circuit layers on insulating substrates, often retaining mounted electronic components and solders. They are a heterogeneous secondary feed generated by equipment use and disposal, distinct from whole electronic waste, individual removed tantalum capacitors, elemental copper and a mineral species. The curated studies concern waste-computer boards, recycler-supplied mixed boards and ground mobile-phone board material; their compositions and outcomes do not define every board type. No criticality designation is inherited from constituent metals.

Used silver-bearing radiographic films obtained from medical facilities, comprising a gelatin-silver emulsion on a polymer base. The curated feeds are discarded X-ray films, not unused film stock, photographic processing liquids, elemental silver or all photographic wastes. Laboratory studies distinguish microbial-enzyme stripping of the emulsion from subsequent thermal production of silver metal. No constituent criticality designation or industrial deployment is inherited.

• Conidiobolus coronatus
• Bacillus spizizenii ATCC 6633 = JCM 2499

Heterogeneous mineral-rich residue of wood combustion, represented here by hardened wood ash supplied by Ljungbyverket, Sydkraft varme, Sweden. The tested ash was ground to 0.10-0.25 mm and used as a nutrient-bearing amendment in laboratory seedling pots. Its composition and treatment are sample-specific; the paper does not resolve a bottom-ash versus fly-ash fraction or a detailed wood-fuel blend. This resource is distinct from coal fly ash, sewage-sludge incineration ash, mixed municipal-waste ash, unburned wood and isolated phosphate minerals. No constituent criticality designation is inherited.

Mixed residual solids from acid leaching in zinc hydrometallurgy, including zinc retained in ferrite, sulfide and other specimen-dependent phases. The accepted studies used separate industrial residues from Hunan and Yunnan, China; their compositions and treatment outcomes are not interchangeable. This processing-generated resource is distinct from elemental zinc, a pure zinc-ferrite phase, zinc calcine before leaching, and zinc-purification waste. Two laboratory abiotic treatments are documented. No criticality designation, microbial mechanism, isolated zinc-product yield or deployment of these particular experimental protocols is inferred.

Mixed precipitated solids removed during the hot purification of zinc leach liquor, before the subsequent zinc-powder cementation stage. The accepted specimen is hot filter press cake (HFC) from the National Iranian Lead and Zinc Company in Zandjan, Iran, containing zinc, cobalt and manganese. This processing residue is distinct from zinc leach residue, cold purification filter cake, a pure oxide mineral, or elemental zinc. Its laboratory chemical leaching does not establish a microbial mechanism, a criticality designation, purified-metal production or industrial deployment of the tested treatment.