{ "spore": "profile", "id": "tantalum", "spore_version": "0.2", "family": "refractory-metals", "name": "Tantalum", "abbreviation": "Ta", "role": "dense refractory metal (radiation spot shielding, capacitor anodes)", "category": "shielding", "type": "spot-shields", "summary": "Tantalum is the element Ta (atomic number 73), a dense, very high-melting refractory metal. Its solid density is 16650 kg/m3 and its melting point is 3017 degC (3290 K), so it is far denser than aluminium and close to tungsten in stopping power per unit thickness. It is used as thin spot shields around sensitive electronics on spacecraft, and as the anode material of tantalum capacitors, which take the largest share of its industrial demand.\n", "best_for": "Dense, high-melting spot shielding in thin sheet, such as the approximately 1 mm tantalum vault plate on NASA's Europa Clipper", "weakest_at": "Mass: the 16650 kg/m3 density makes it heavy for large areas, and the vault plate is only a local shield, not a full enclosure", "identity": { "formula": "Ta (element, atomic number 73); body-centred cubic alpha phase at all temperatures up to melting", "designations": [], "source": "webelements-physics", "where": "Atomic structure and solid-state properties sections of the WebElements tantalum page; the page lists atomic number 73 on the main tantalum page" }, "tags": { "environments": [], "stresses": [ "total-radiation-dose" ], "applications": [ "radiation-shielding", "electronics-and-chips" ] }, "properties": [ { "benchmark": "density", "label": "Density of solid", "value": 16650, "bound": "exact", "unit": "kg/m3", "scope": "material", "conditions": { "form": "solid elemental tantalum", "temperature": "not stated on the page" }, "method": "Value listed in the WebElements physical properties table", "status": "ground", "source": "webelements-physics", "where": "Physical properties table, row Density of solid", "source_detail": { "title": "Tantalum - 73Ta: physical properties", "url": "https://winter.group.shef.ac.uk/webelements/tantalum/physics.html", "year": 2024, "kind": "database", "license": "WebElements (University of Sheffield), free online reference" } }, { "benchmark": "melting_point", "label": "Melting point", "value": 3017, "bound": "exact", "unit": "degC", "scope": "material", "conditions": { "form": "elemental tantalum", "pressure": "not stated", "printed_as": "3290 K" }, "method": "Value listed in the WebElements tantalum page", "status": "ground", "source": "webelements-main", "where": "Melting point row, printed as 3290 [3017 degC (5463 degF)] K", "source_detail": { "title": "Tantalum - 73Ta: the essentials", "url": "https://winter.group.shef.ac.uk/webelements/tantalum/", "year": 2024, "kind": "database", "license": "WebElements (University of Sheffield), free online reference" } }, { "benchmark": "boiling_point", "label": "Boiling point", "value": 5458, "bound": "exact", "unit": "degC", "scope": "material", "conditions": { "form": "elemental tantalum", "pressure": "not stated", "printed_as": "5731 K" }, "method": "Value listed in the WebElements tantalum page", "status": "ground", "source": "webelements-main", "where": "Boiling point row, printed as 5731 [5458 degC (9856 degF)] K", "source_detail": { "title": "Tantalum - 73Ta: the essentials", "url": "https://winter.group.shef.ac.uk/webelements/tantalum/", "year": 2024, "kind": "database", "license": "WebElements (University of Sheffield), free online reference" } }, { "benchmark": "youngs_modulus", "label": "Young's modulus", "value": 186, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "form": "elemental tantalum", "temperature": "not stated on the page" }, "method": "Value listed in the WebElements physical properties table", "status": "ground", "source": "webelements-physics", "where": "Physical properties table, row Young's modulus", "source_detail": { "title": "Tantalum - 73Ta: physical properties", "url": "https://winter.group.shef.ac.uk/webelements/tantalum/physics.html", "year": 2024, "kind": "database", "license": "WebElements (University of Sheffield), free online reference" } }, { "benchmark": "bulk_modulus", "label": "Bulk modulus", "value": 200, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "form": "elemental tantalum", "temperature": "not stated on the page" }, "method": "Value listed in the WebElements physical properties table", "status": "ground", "source": "webelements-physics", "where": "Physical properties table, row Bulk modulus", "source_detail": { "title": "Tantalum - 73Ta: physical properties", "url": "https://winter.group.shef.ac.uk/webelements/tantalum/physics.html", "year": 2024, "kind": "database", "license": "WebElements (University of Sheffield), free online reference" } }, { "benchmark": "poissons_ratio", "label": "Poisson's ratio", "value": 0.34, "bound": "exact", "unit": "dimensionless", "scope": "material", "conditions": { "form": "elemental tantalum", "temperature": "not stated on the page" }, "method": "Value listed in the WebElements physical properties table", "status": "ground", "source": "webelements-physics", "where": "Physical properties table, row Poisson's ratio", "source_detail": { "title": "Tantalum - 73Ta: physical properties", "url": "https://winter.group.shef.ac.uk/webelements/tantalum/physics.html", "year": 2024, "kind": "database", "license": "WebElements (University of Sheffield), free online reference" } }, { "benchmark": "thermal_conductivity", "label": "Thermal conductivity", "value": 57, "bound": "exact", "unit": "W/(m·K)", "scope": "material", "conditions": { "form": "elemental tantalum", "temperature": "not stated on the page" }, "method": "Value listed in the WebElements physical properties table", "status": "ground", "source": "webelements-physics", "where": "Physical properties table, row Thermal conductivity", "source_detail": { "title": "Tantalum - 73Ta: physical properties", "url": "https://winter.group.shef.ac.uk/webelements/tantalum/physics.html", "year": 2024, "kind": "database", "license": "WebElements (University of Sheffield), free online reference" } }, { "benchmark": "thermal_expansion", "label": "Coefficient of linear thermal expansion", "value": 0.0000063, "bound": "exact", "unit": "1/K", "scope": "material", "conditions": { "form": "elemental tantalum", "temperature": "not stated on the page" }, "method": "Value listed in the WebElements physical properties table", "status": "ground", "source": "webelements-physics", "where": "Physical properties table, row Coefficient of linear thermal expansion", "source_detail": { "title": "Tantalum - 73Ta: physical properties", "url": "https://winter.group.shef.ac.uk/webelements/tantalum/physics.html", "year": 2024, "kind": "database", "license": "WebElements (University of Sheffield), free online reference" } }, { "benchmark": "electrical_resistivity", "label": "Electrical resistivity", "value": 1.35e-7, "bound": "exact", "unit": "ohm·m", "scope": "material", "conditions": { "form": "elemental tantalum", "temperature": "not stated on the page" }, "method": "Value listed in the WebElements physical properties table", "status": "ground", "source": "webelements-physics", "where": "Physical properties table, row Electrical resistivity (printed as 13.5 x 10-8 ohm m)", "source_detail": { "title": "Tantalum - 73Ta: physical properties", "url": "https://winter.group.shef.ac.uk/webelements/tantalum/physics.html", "year": 2024, "kind": "database", "license": "WebElements (University of Sheffield), free online reference" } }, { "benchmark": "vickers_hardness", "label": "Vickers hardness", "value": 873, "bound": "exact", "unit": "MN/m2", "scope": "material", "conditions": { "form": "elemental tantalum", "temperature": "not stated on the page" }, "method": "Value listed in the WebElements physical properties table", "status": "ground", "source": "webelements-physics", "where": "Physical properties table, row Vickers hardness", "source_detail": { "title": "Tantalum - 73Ta: physical properties", "url": "https://winter.group.shef.ac.uk/webelements/tantalum/physics.html", "year": 2024, "kind": "database", "license": "WebElements (University of Sheffield), free online reference" } }, { "benchmark": "brinell_hardness", "label": "Brinell hardness", "value": 800, "bound": "exact", "unit": "MN/m2", "scope": "material", "conditions": { "form": "elemental tantalum", "temperature": "not stated on the page" }, "method": "Value listed in the WebElements physical properties table", "status": "ground", "source": "webelements-physics", "where": "Physical properties table, row Brinell hardness", "source_detail": { "title": "Tantalum - 73Ta: physical properties", "url": "https://winter.group.shef.ac.uk/webelements/tantalum/physics.html", "year": 2024, "kind": "database", "license": "WebElements (University of Sheffield), free online reference" } }, { "benchmark": "speed_of_sound", "label": "Velocity of sound", "value": 3400, "bound": "exact", "unit": "m/s", "scope": "material", "conditions": { "form": "elemental tantalum", "temperature": "not stated on the page" }, "method": "Value listed in the WebElements physical properties table", "status": "ground", "source": "webelements-physics", "where": "Physical properties table, row Velocity of sound", "source_detail": { "title": "Tantalum - 73Ta: physical properties", "url": "https://winter.group.shef.ac.uk/webelements/tantalum/physics.html", "year": 2024, "kind": "database", "license": "WebElements (University of Sheffield), free online reference" } }, { "benchmark": "atomic_number", "label": "Atomic number", "value": 73, "bound": "exact", "unit": "dimensionless", "scope": "material", "conditions": { "element": "tantalum" }, "method": "Value listed in the WebElements tantalum page", "status": "ground", "source": "webelements-main", "where": "Atomic number row", "source_detail": { "title": "Tantalum - 73Ta: the essentials", "url": "https://winter.group.shef.ac.uk/webelements/tantalum/", "year": 2024, "kind": "database", "license": "WebElements (University of Sheffield), free online reference" } }, { "benchmark": "mass_attenuation_coefficient", "label": "Mass attenuation coefficient at 0.1 MeV", "value": 4.302, "bound": "exact", "unit": "cm2/g", "scope": "material", "conditions": { "energy": "0.1 MeV", "photon": "yes", "element": "tantalum" }, "method": "NIST X-ray mass attenuation table, total mass attenuation (mu/rho)", "status": "ground", "source": "nist-xray-z73", "where": "Row 1.00000E-01 MeV, mu/rho column", "source_detail": { "title": "X-Ray Mass Attenuation Coefficients: Tantalum (Z = 73)", "url": "https://physics.nist.gov/PhysRefData/XrayMassCoef/ElemTab/z73.html", "year": 2026, "kind": "database", "license": "NIST, public domain" } }, { "benchmark": "mass_attenuation_coefficient", "label": "Mass attenuation coefficient at 1 MeV", "value": 0.06567, "bound": "exact", "unit": "cm2/g", "scope": "material", "conditions": { "energy": "1 MeV", "photon": "yes", "element": "tantalum" }, "method": "NIST X-ray mass attenuation table, total mass attenuation (mu/rho)", "status": "ground", "source": "nist-xray-z73", "where": "Row 1.00000E+00 MeV, mu/rho column", "source_detail": { "title": "X-Ray Mass Attenuation Coefficients: Tantalum (Z = 73)", "url": "https://physics.nist.gov/PhysRefData/XrayMassCoef/ElemTab/z73.html", "year": 2026, "kind": "database", "license": "NIST, public domain" } }, { "benchmark": "mass_attenuation_coefficient", "label": "Mass attenuation coefficient at 10 MeV", "value": 0.04717, "bound": "exact", "unit": "cm2/g", "scope": "material", "conditions": { "energy": "10 MeV", "photon": "yes", "element": "tantalum" }, "method": "NIST X-ray mass attenuation table, total mass attenuation (mu/rho)", "status": "ground", "source": "nist-xray-z73", "where": "Row 1.00000E+01 MeV, mu/rho column", "source_detail": { "title": "X-Ray Mass Attenuation Coefficients: Tantalum (Z = 73)", "url": "https://physics.nist.gov/PhysRefData/XrayMassCoef/ElemTab/z73.html", "year": 2026, "kind": "database", "license": "NIST, public domain" } }, { "benchmark": "mass_attenuation_coefficient", "label": "Mass attenuation coefficient at 0.1 MeV (aluminium)", "value": 0.1704, "bound": "exact", "unit": "cm2/g", "scope": "material", "conditions": { "energy": "0.1 MeV", "photon": "yes", "element": "aluminium" }, "method": "NIST X-ray mass attenuation table, aluminium comparison", "status": "ground", "source": "nist-xray-z13", "where": "Row 1.00000E-01 MeV, mu/rho column", "source_detail": { "title": "X-Ray Mass Attenuation Coefficients: Aluminum (Z = 13)", "url": "https://physics.nist.gov/PhysRefData/XrayMassCoef/ElemTab/z13.html", "year": 2026, "kind": "database", "license": "NIST, public domain" } }, { "benchmark": "mass_attenuation_coefficient", "label": "Mass attenuation coefficient at 1 MeV (aluminium)", "value": 0.06146, "bound": "exact", "unit": "cm2/g", "scope": "material", "conditions": { "energy": "1 MeV", "photon": "yes", "element": "aluminium" }, "method": "NIST X-ray mass attenuation table, aluminium comparison", "status": "ground", "source": "nist-xray-z13", "where": "Row 1.00000E+00 MeV, mu/rho column", "source_detail": { "title": "X-Ray Mass Attenuation Coefficients: Aluminum (Z = 13)", "url": "https://physics.nist.gov/PhysRefData/XrayMassCoef/ElemTab/z13.html", "year": 2026, "kind": "database", "license": "NIST, public domain" } }, { "benchmark": "mass_attenuation_coefficient", "label": "Mass attenuation coefficient at 10 MeV (aluminium)", "value": 0.02318, "bound": "exact", "unit": "cm2/g", "scope": "material", "conditions": { "energy": "10 MeV", "photon": "yes", "element": "aluminium" }, "method": "NIST X-ray mass attenuation table, aluminium comparison", "status": "ground", "source": "nist-xray-z13", "where": "Row 1.00000E+01 MeV, mu/rho column", "source_detail": { "title": "X-Ray Mass Attenuation Coefficients: Aluminum (Z = 13)", "url": "https://physics.nist.gov/PhysRefData/XrayMassCoef/ElemTab/z13.html", "year": 2026, "kind": "database", "license": "NIST, public domain" } } ], "corrosion": [ { "environment": "Air at room temperature", "headline": "Forms a very dense Ta2O5 oxide layer that protects the metal.", "effect": "Samaterials says that when exposed to air, tantalum forms a very dense oxide layer (Ta2O5), which protects the base metal. Wikipedia describes the oxide as the basis of tantalum capacitors, where the thin layer acts as the dielectric.", "rating": "unknown", "conditions": { "basis": "qualitative; no thickness or time given" }, "source": "samaterials-tantalum-corrosion", "where": "Introduction paragraph on oxide layer; Wikipedia Tantalum, Applications, capacitors paragraph" }, { "environment": "Most acids and aqua regia below 150 degC", "headline": "Almost immune to attack by aqua regia below 150 degC.", "effect": "Wikipedia says tantalum is almost completely immune to attack by the normally aggressive aqua regia at temperatures below 150 degC, and is inert to most acids.", "rating": "unknown", "conditions": { "temperature": "below 150 degC", "basis": "Wikipedia summary, no test data" }, "source": "wikipedia-tantalum", "where": "Properties section, paragraph on corrosion by acids" }, { "environment": "Hydrofluoric acid", "headline": "Unsuitable: attacked by hydrofluoric acid, the main exception.", "effect": "Samaterials lists hydrofluoric acid below 60 percent as not resistant, with no temperature given, and says tantalum is unsuitable for use in hydrofluoric acid. Wikipedia says it dissolves in hydrofluoric acid and in acidic solutions with fluoride ion.", "rating": "severe", "conditions": { "concentration": "below 60 percent", "temperature": "not stated" }, "source": "samaterials-tantalum-corrosion", "where": "Acid resistance table, row Hydrofluoric acid; Wikipedia Properties section" }, { "environment": "Hot sulfuric acid and hot alkaline solutions", "headline": "Hot sulfuric acid and hot alkaline solutions also corrode it.", "effect": "Wikipedia says tantalum is inert to most acids except hydrofluoric acid and hot sulfuric acid, and that hot alkaline solutions also cause corrosion. Molten potassium hydroxide also dissolves it.", "rating": "moderate", "conditions": { "temperature": "hot, not stated", "basis": "Wikipedia summary" }, "source": "wikipedia-tantalum", "where": "Properties section, corrosion paragraphs" }, { "environment": "Hot acids (hydrogen charging)", "headline": "Hydrogen enters the lattice and makes the metal brittle.", "effect": "Samaterials says that if tantalum is exposed to chemical aggression, hydrogen enters its metal lattice and the material becomes brittle. No hydrogen concentration is given on the page.", "rating": "moderate", "conditions": { "basis": "qualitative statement, no concentration given" }, "source": "samaterials-tantalum-corrosion", "where": "Hydrogen embrittlement paragraph" } ], "risks": { "hazards": [ { "text": "PubChem aggregates GHS reports for tantalum (CID 23956). The main entry, 56 percent of 455 company reports, gives H228 (flammable solid), signal word Danger, class Flam. Sol. 2. 44 percent of reports do not meet GHS criteria. PubChem does not separate bulk metal from powder, so check the SDS for the form you handle.", "ghs": [ "H228: Flammable solid" ], "source": "pubchem-tantalum", "where": "Safety and Hazards, GHS Classification" }, { "text": "Other ECHA C&L notifications listed by PubChem give H335 (may cause respiratory irritation, signal word Warning) and H302 (harmful if swallowed, signal word Warning).", "ghs": [ "H335: May cause respiratory irritation", "H302: Harmful if swallowed" ], "source": "pubchem-tantalum", "where": "Safety and Hazards, GHS Classification, ECHA entries" }, { "text": "Precautionary statement codes listed by PubChem include P210 (keep away from heat, sparks and open flames), P240 and P241 (grounding, explosion-proof equipment), P280 (protective equipment), P370+P378 (in case of fire, use suitable extinguishing media) and P407.", "ghs": [], "source": "pubchem-tantalum", "where": "Safety and Hazards, Precautionary Statement Codes" } ], "failure_risks": [ { "mode": "Hydrogen embrittlement in hot acids", "trigger": "Chemical aggression that lets hydrogen enter the lattice", "consequence": "The metal becomes brittle (samaterials, no concentration given).", "source": "samaterials-tantalum-corrosion", "where": "Hydrogen embrittlement paragraph" }, { "mode": "Attack by hydrofluoric acid", "trigger": "Contact with hydrofluoric acid below 60 percent", "consequence": "Tantalum is not resistant and is unsuitable for the service (samaterials).", "source": "samaterials-tantalum-corrosion", "where": "Acid resistance table" } ], "side_effects": [], "handling": [ { "text": "Keep away from heat, sparks and open flames, and ground equipment when handling powder or swarf (PubChem P210, P240, P241).", "source": "pubchem-tantalum", "where": "Safety and Hazards, Precautionary Statement Codes" }, { "text": "Wear protective gloves and avoid breathing dust (PubChem P280, H335).", "source": "pubchem-tantalum", "where": "Safety and Hazards, Precautionary Statement Codes" }, { "text": "Keep away from hydrofluoric acid and hot alkaline solutions (corrosion section).", "source": "pubchem-tantalum", "where": "Corrosion section, hydrofluoric acid row" } ], "mitigations": [] }, "uses": [ { "application": "radiation-shielding", "device": "Spot shield on spacecraft electronics vault", "example": "NASA Europa Clipper: a tantalum vault plate about 1 mm thick, 18 by 28 cm, part of the structure that protects the orbiter electronics from Jupiter radiation", "source": "nasa-europa-clipper", "where": "Placing the Europa Clipper vault plate article, material and purpose paragraphs" }, { "application": "electronics-and-chips", "device": "Tantalum capacitor anode", "example": "Electronics takes about 55 percent of tantalum demand (2019 estimate by Paumanok), mainly as capacitor anodes", "source": "passive-components-tantalum", "where": "Paragraph on 2019 consumption and electronics share" }, { "application": "radiation-shielding", "device": "Spot shield (NIST attenuation context)", "example": "Photon mass attenuation values in the properties list compare tantalum with aluminium per gram.", "source": "nist-xray-z73", "where": "Mass attenuation table, Z = 73" } ], "supply": [ { "subject": "Tantalum", "abundance": "Share of demand from electronics: about 55 percent in 2019 (Paumanok estimate); averaged 50 to 70 percent of total tantalum demand over the past 30 years", "producers": [], "critical_lists": [], "recycling": "Not sourced in this profile", "substitutes": [], "source": "passive-components-tantalum", "where": "Paragraph on 2019 consumption and multi-year electronics share" }, { "subject": "Tantalum mine production, 2025 estimate (USGS)", "abundance": "World mine total 2,500 t (rounded). Congo (Kinshasa) 1,300 t, Rwanda 400 t, Nigeria 390 t, China 80 t, Australia 50 t. Shares below are each printed value divided by the printed world total.", "producers": [ { "country": "Congo (Kinshasa)", "share_percent": 52, "year": 2025 }, { "country": "Rwanda", "share_percent": 16, "year": 2025 }, { "country": "Nigeria", "share_percent": 15.6, "year": 2025 }, { "country": "China", "share_percent": 3.2, "year": 2025 }, { "country": "Australia", "share_percent": 2, "year": 2025 } ], "critical_lists": [], "recycling": "USGS: recycled mostly from new scrap; may account for as much as 30 percent of consumption by domestic primary processors. US recycled amount not available.", "substitutes": [ "niobium and tungsten in carbides", "aluminum, ceramics and niobium in electronic capacitors", "glass, molybdenum, nickel, niobium, platinum, stainless steel, titanium and zirconium in corrosion-resistant uses", "hafnium, iridium, molybdenum, niobium, rhenium and tungsten in high-temperature uses" ], "source": "usgs-mcs-2026-tantalum", "where": "Salient Statistics table (2025e apparent consumption 890 t, net import reliance 100 percent); World Mine Production table, 2025e column; Recycling and Substitutes paragraphs" } ], "media": [], "documents": [ { "title": "USGS Mineral Commodity Summaries 2026: Tantalum", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tantalum.pdf", "year": 2026 }, { "title": "PubChem: Tantalum (CID 23956), GHS classification", "type": "database", "url": "https://pubchem.ncbi.nlm.nih.gov/compound/Tantalum", "year": 2026 } ], "gaps": [ "Dose reduction or areal density for a tantalum vault against the Jupiter radiation environment: the Juno/Europa vault paper was not found by search in this run, so no mission attenuation figure is recorded.", "Corrosion rates in mm/year or mpy: no source with a rate was read in this run.", "The hydrogen concentration threshold for embrittlement (a patent gives 100 ppm): the patent page was not fetched, so no value is recorded.", "Mozambique and Brazil mine production rows in the USGS 2026 table are garbled in the PDF text, so they are left out of the shares.", "Melting and boiling point and density are printed at the temperature stated in the source only; the density temperature is not stated.", "Capacitor-share figures (about 55 percent electronics, 2019) are industry estimates from the Paumanok passive-components article, not a USGS statistic.", "US production: none, USGS 2025e apparent consumption 890 t, net import reliance 100 percent.", "Sensitive-electronics radiation dose tests for a tantalum vault: none sourced." ], "story": { "why": "Tantalum is dense and melts at 3017 degC, so a thin sheet can block radiation locally without a heavy enclosure. The NASA Europa Clipper vault plate is the sourced example of it on a spacecraft.", "uses": [], "can_do": [ { "label": "Give a dense,", "line": "Give a dense, high-melting shield in thin sheet on a spacecraft.", "scope": "material", "value": "" }, { "label": "Serve as the", "line": "Serve as the anode material of capacitors, which take the largest share of tantalum demand.", "scope": "material", "value": "" } ], "compare": "Tantalum is 16650 kg/m3 and melts at 3017 degC; aluminium, the usual spacecraft shield metal, is far lighter and melts much lower. Its photon mass attenuation is 4.302 cm2/g at 0.1 MeV, against 0.170 cm2/g for aluminium, and 0.06567 cm2/g against 0.06146 cm2/g at 1 MeV (NIST, per gram). Per gram the two are close at 1 MeV, so tantalum wins mainly on density for a thin plate.", "compare_rows": [ { "label": "Density", "benchmark": "density", "scope": "material" }, { "label": "Melting point", "benchmark": "melting_point", "scope": "material" }, { "label": "Thermal conductivity", "benchmark": "thermal_conductivity", "scope": "material" } ], "handling": [ "Keep away from heat, sparks and open flames, and ground equipment when handling powder or swarf (PubChem P210, P240, P241).", "Wear protective gloves and avoid breathing dust (PubChem P280, H335).", "Keep away from hydrofluoric acid and hot alkaline solutions (corrosion section)." ], "good_for": [ "Local radiation spot shields around sensitive electronics." ], "watch_out": [ "Its mass is high for large areas.", "Hydrofluoric acid and hydrogen uptake in hot acids limit its use in chemical service.", "The NIST values are per gram of material; no dose reduction in a spacecraft vault was sourced in this run." ], "verdict": "Tantalum is a dense, high-melting metal used as local spot shielding and as capacitor anode material. This deepened draft adds recipe, supply shares from the USGS 2026 summary, corrosion, hazards from PubChem, and NIST photon attenuation against aluminium.", "recipe": { "line": "Tantalum is the element Ta, atomic number 73, a single-element metal with no alloying in pure form. Its ore is mainly tantalite, (Fe,Mn)Ta2O6, usually mined with columbite, the niobium ore. Ore is concentrated by gravity separation, leached with hydrofluoric acid and sulfuric or hydrochloric acid, and purified by solvent extraction into an organic solvent. Niobium is removed by lowering the acid ionic strength, and the tantalum is then precipitated with ammonia and calcined to Ta2O5. The metal is made by reducing the purified salt or oxide; The first metal was made by reducing tantalum chloride in hydrogen, as de Marignac did in the 19th century. The metal powder is pressed into pellets for capacitors.", "parts": [ { "name": "Tantalum", "symbol": "Ta", "role": "The whole material. WebElements prints the relative atomic mass as 180.94788 (2). Natural tantalum is almost entirely one isotope, with a very small share of a metastable isomer (Wikipedia).", "atoms": 1, "atomic_weight": 180.94788 } ] }, "risk_groups": [ { "title": "For people", "lead": "This profile has no sourced health data for tantalum metal.", "points": [ { "label": "Metal in use", "line": "Tantalum metal is used as a sealed shield and inside capacitors. No hazard classification was read in this run, so none is stated here." } ], "level": 1, "verdict": "Not assessed in this run" }, { "title": "If it fails", "lead": "No sourced failure mode was found in this run.", "points": [ { "label": "Mechanical", "line": "The sheet is a local shield. Its density is 16650 kg/m3, and its Vickers hardness is 873 MN/m2." } ], "level": 1, "verdict": "Not assessed" } ] }, "updated": "2026-10-16", "review": { "status": "draft", "method": "assistant", "checked_values": 0, "unreachable": 0, "caveats": 0 }, "sources": { "webelements-physics": { "title": "Tantalum - 73Ta: physical properties", "url": "https://winter.group.shef.ac.uk/webelements/tantalum/physics.html", "year": 2024, "kind": "database", "license": "WebElements (University of Sheffield), free online reference" }, "webelements-main": { "title": "Tantalum - 73Ta: the essentials", "url": "https://winter.group.shef.ac.uk/webelements/tantalum/", "year": 2024, "kind": "database", "license": "WebElements (University of Sheffield), free online reference" }, "nasa-europa-clipper": { "title": "Placing the Europa Clipper vault plate", "url": "https://science.nasa.gov/missions/europa-clipper/placing-the-europa-clipper-vault-plate", "year": 2024, "kind": "web", "license": "public domain (NASA)" }, "passive-components-tantalum": { "title": "Tantalum Supply Routes for Mil-Spec Capacitors: From Ore, to Powder, to Part", "url": "https://passive-components.eu/tantalum-supply-routes-for-mil-spec-capacitors-from-ore-to-powder-to-part", "year": 2020, "kind": "web", "license": "Industry trade article, all rights reserved" }, "pubchem-tantalum": { "title": "Tantalum (CID 23956): safety and hazards, GHS classification", "url": "https://pubchem.ncbi.nlm.nih.gov/compound/Tantalum", "year": 2026, "kind": "database", "license": "PubChem, public domain" }, "wikipedia-tantalum": { "title": "Tantalum", "url": "https://en.wikipedia.org/wiki/Tantalum", "year": 2026, "kind": "web", "license": "CC BY-SA 4.0" }, "usgs-mcs-2026-tantalum": { "title": "Mineral Commodity Summaries 2026: Tantalum", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tantalum.pdf", "year": 2026, "kind": "report", "license": "US government work, public domain" }, "nist-xray-z73": { "title": "X-Ray Mass Attenuation Coefficients: Tantalum (Z = 73)", "url": "https://physics.nist.gov/PhysRefData/XrayMassCoef/ElemTab/z73.html", "year": 2026, "kind": "database", "license": "NIST, public domain" }, "nist-xray-z13": { "title": "X-Ray Mass Attenuation Coefficients: Aluminum (Z = 13)", "url": "https://physics.nist.gov/PhysRefData/XrayMassCoef/ElemTab/z13.html", "year": 2026, "kind": "database", "license": "NIST, public domain" }, "samaterials-tantalum-corrosion": { "title": "Corrosion resistance of tantalum to water, aqueous solutions and non-metals", "url": "https://samaterials.com/content/corrosion-resistance-of-tantalum-to-water-aqueous-solutions-and-non-metals.html", "year": 2026, "kind": "web", "license": "Vendor web page, all rights reserved" } }, "license": "CC-BY-4.0", "url": "https://spacemushroom.com/profiles/tantalum/" }