{
  "spore": "profile",
  "id": "lithium-orthosilicate",
  "spore_version": "0.2",
  "family": "lithium",
  "name": "Lithium orthosilicate",
  "abbreviation": "Li4SiO4",
  "role": "Ceramic tritium-breeder material and candidate lithium-ion conductor",
  "category": "energy",
  "type": "solid-state-batteries",
  "summary": "Lithium orthosilicate (Li4SiO4) is a lithium-rich oxide ceramic that has a monoclinic structure up to its melting point. Hanaor et al. (2014) describe it as a leading candidate for tritium-breeding pebbles in the helium-cooled pebble bed blanket studied for ITER. Its melting point is printed as 1258 °C in the Wikipedia article and in the 2014 study, while two trade or supplier listings print 1255 °C and 1256 °C. Pebble crush tests and a high-temperature CO2 sorbent test are also reported. No space flight or vacuum data were found in the sources opened.\n",
  "best_for": "Tritium-breeding pebbles in helium-cooled pebble bed blankets, per Hanaor et al. (2014)",
  "weakest_at": "Crush strength of pebbles depends strongly on size and transparency (Annabattula et al.), and no pure-phase conductivity value could be recorded",
  "identity": {
    "formula": "Li4SiO4",
    "cas": "13453-84-4",
    "crystal_system": "monoclinic",
    "designations": [],
    "source": "hanaor2014",
    "where": "Introduction: Li4SiO4 exists in a monoclinic structure up to temperatures of 1258 °C"
  },
  "tags": {
    "environments": [],
    "stresses": [],
    "applications": []
  },
  "properties": [
    {
      "benchmark": "molar_mass",
      "label": "Molar mass",
      "value": 119.84,
      "bound": "exact",
      "unit": "g·mol−1",
      "scope": "material",
      "conditions": {
        "formula": "Li4SiO4",
        "cas": "13453-84-4"
      },
      "method": "Molar mass as printed in the infobox of the Wikipedia article on lithium orthosilicate",
      "status": "calculated",
      "source": "wikipedia-li4sio4",
      "where": "Infobox, molar mass row",
      "source_detail": {
        "title": "Lithium orthosilicate (Wikipedia article)",
        "id": "CAS 13453-84-4",
        "url": "https://en.wikipedia.org/wiki/Lithium_orthosilicate",
        "kind": "web"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Congruent melting temperature",
      "value": 1258,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "process": "congruent melting, as the Wikipedia article describes it"
      },
      "method": "Melting temperature stated in the Wikipedia article text (printed as 1,258 °C)",
      "status": "ground",
      "source": "wikipedia-li4sio4",
      "where": "Article text on melting behaviour",
      "source_detail": {
        "title": "Lithium orthosilicate (Wikipedia article)",
        "id": "CAS 13453-84-4",
        "url": "https://en.wikipedia.org/wiki/Lithium_orthosilicate",
        "kind": "web"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Congruent melting temperature of monoclinic Li4SiO4",
      "value": 1258,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "phase": "monoclinic Li4SiO4, melting congruently at this temperature"
      },
      "method": "Stated in the introduction of Hanaor et al. (2014)",
      "status": "ground",
      "source": "hanaor2014",
      "where": "Introduction, paragraph on Li2TiO3 and Li4SiO4 phases",
      "source_detail": {
        "title": "Solution based synthesis of mixed-phase materials in the Li2TiO3-Li4SiO4 system",
        "id": "Hanaor, Kolb, Gan, Kamlah, Knitter; J. Nucl. Mater. 456 (2014) 151-161; arXiv:1410.7128",
        "url": "https://arxiv.org/pdf/1410.7128",
        "year": 2014,
        "kind": "paper"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point, supplier SDS physical data",
      "value": 1255,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "lithium orthosilicate, CAS 13453-84-4, as listed on the SDS page"
      },
      "method": "Physical data block on the ChemicalBook safety data sheet page",
      "status": "ground",
      "note": "Hanaor et al. (2014) cite earlier studies that describe a peritectic decomposition at 1255 °C rather than congruent melting.",
      "source": "chemicalbook-li4sio4",
      "where": "Physical data block",
      "source_detail": {
        "title": "ChemicalBook: Lithium orthosilicate, safety data sheet and physical data",
        "id": "CAS 13453-84-4",
        "url": "https://www.chemicalbook.com/msds/lithiumorthosilicate.htm",
        "kind": "datasheet"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point, trade listing",
      "value": 1256,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "industrial grade, 99.99% purity as listed"
      },
      "method": "Melting point on a trade listing for lithium orthosilicate (printed as 1256 Degree Celsius)",
      "status": "ground",
      "note": "A trade listing, not a test report.",
      "source": "tradeindia-li4sio4",
      "where": "Product specification list, melting point",
      "source_detail": {
        "title": "TradeIndia: Lithium Orthosilicate, CAS 13453-84-4, product listing",
        "id": "CAS 13453-84-4",
        "url": "https://www.tradeindia.com/products/lithium-orthosilicate-cas-13453-84-4-8480708.html",
        "kind": "web"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, trade listing",
      "value": 2.39,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "grade": "industrial grade, white powder, 99.99% purity as listed"
      },
      "method": "Density on a trade listing for lithium orthosilicate (printed as 2.390)",
      "status": "ground",
      "note": "Trade listing only. No absolute density for pure Li4SiO4 from a peer-reviewed source was found in the sources opened.",
      "source": "tradeindia-li4sio4",
      "where": "Product specification list, density",
      "source_detail": {
        "title": "TradeIndia: Lithium Orthosilicate, CAS 13453-84-4, product listing",
        "id": "CAS 13453-84-4",
        "url": "https://www.tradeindia.com/products/lithium-orthosilicate-cas-13453-84-4-8480708.html",
        "kind": "web"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Young's modulus of melt-spray pebble",
      "value": 90,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "form": "melt-spray pebbles of Li4SiO4 (OSi), 250 µm to 800 µm diameter in the study"
      },
      "method": "Value given as the pebble input to the contact analysis (Eq. 2); not measured in this paper",
      "status": "ground",
      "source": "annabattula2014",
      "where": "Crush analysis section, text after Eq. 2 (E p = 90 GPa)",
      "source_detail": {
        "title": "Size dependent crush analysis of lithium orthosilicate pebbles",
        "id": "Annabattula, Kolb, Gan, Rolli, Kamlah; arXiv:1408.0485",
        "url": "https://arxiv.org/pdf/1408.0485",
        "year": 2014,
        "kind": "paper"
      }
    },
    {
      "benchmark": "poissons_ratio",
      "label": "Poisson's ratio of melt-spray pebble",
      "value": 0.25,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "form": "same melt-spray pebbles as the Young's modulus row"
      },
      "method": "Value given as the pebble input to the contact analysis; not measured in this paper",
      "status": "ground",
      "source": "annabattula2014",
      "where": "Crush analysis section, text after Eq. 2 (ν p = 0.25)",
      "source_detail": {
        "title": "Size dependent crush analysis of lithium orthosilicate pebbles",
        "id": "Annabattula, Kolb, Gan, Rolli, Kamlah; arXiv:1408.0485",
        "url": "https://arxiv.org/pdf/1408.0485",
        "year": 2014,
        "kind": "paper"
      }
    },
    {
      "benchmark": "critical_failure_energy",
      "label": "Critical failure energy per unit area of melt-spray pebble",
      "value": 0.02,
      "bound": "exact",
      "unit": "kJ/m2",
      "scope": "material",
      "conditions": {
        "form": "melt-spray pebble, fitted to crush-load data for a 500 µm pebble"
      },
      "method": "Value the authors assumed and fitted to crush-load data; not measured directly",
      "status": "calculated",
      "source": "annabattula2014",
      "where": "Crush analysis section, text on critical failure energy (W c = 0.02 kJ/m2)",
      "source_detail": {
        "title": "Size dependent crush analysis of lithium orthosilicate pebbles",
        "id": "Annabattula, Kolb, Gan, Rolli, Kamlah; arXiv:1408.0485",
        "url": "https://arxiv.org/pdf/1408.0485",
        "year": 2014,
        "kind": "paper"
      }
    },
    {
      "benchmark": "co2_uptake",
      "label": "CO2 uptake of sol-gel Li4SiO4 nanoparticle sorbent",
      "value": 6.9,
      "bound": "exact",
      "unit": "mmol CO2/g sorbent",
      "scope": "material",
      "conditions": {
        "temperature": "700 °C",
        "co2_pressure": "0.6 atm CO2",
        "measurement": "thermogravimetric analysis",
        "form": "sol-gel nanoparticles"
      },
      "method": "Uptake reported in the abstract of the 2017 sol-gel study (printed as 6.9 mmol of CO2/g sorbent)",
      "status": "ground",
      "note": "A result for a nanoparticle sorbent, not for the bulk powder.",
      "source": "cet-sol-gel",
      "where": "Abstract",
      "source_detail": {
        "title": "Sol-gel Synthesis of Li4SiO4 Nanoparticles for CO2 Capture at High Temperature (Chemical Engineering Transactions)",
        "id": "Chemical Engineering Transactions, article 2255",
        "url": "https://cetjournal.it/index.php/cet/article/view/2255",
        "kind": "paper"
      }
    },
    {
      "benchmark": "carbonation_conversion",
      "label": "Conversion of lithium orthosilicate in CO2 sorbent test",
      "value": 82.4,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "temperature": "700 °C",
        "co2_pressure": "0.6 atm CO2",
        "form": "sol-gel nanoparticles"
      },
      "method": "Conversion reported in the abstract of the sol-gel study",
      "status": "ground",
      "note": "A sorbent result for nanoparticles.",
      "source": "cet-sol-gel",
      "where": "Abstract",
      "source_detail": {
        "title": "Sol-gel Synthesis of Li4SiO4 Nanoparticles for CO2 Capture at High Temperature (Chemical Engineering Transactions)",
        "id": "Chemical Engineering Transactions, article 2255",
        "url": "https://cetjournal.it/index.php/cet/article/view/2255",
        "kind": "paper"
      }
    },
    {
      "benchmark": "purity",
      "label": "Purity, industrial grade listing",
      "value": 99.99,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "grade": "industrial grade, as listed"
      },
      "method": "Purity stated in the product title of a trade listing",
      "status": "ground",
      "note": "Listing specification, not a measured value.",
      "source": "tradeindia-li4sio4",
      "where": "Product title",
      "source_detail": {
        "title": "TradeIndia: Lithium Orthosilicate, CAS 13453-84-4, product listing",
        "id": "CAS 13453-84-4",
        "url": "https://www.tradeindia.com/products/lithium-orthosilicate-cas-13453-84-4-8480708.html",
        "kind": "web"
      }
    }
  ],
  "corrosion": [],
  "risks": {
    "hazards": [
      {
        "text": "Harmful if swallowed (H302, signal word Warning) on the ChemicalBook SDS page. The same page lists skin irritation (H315), serious eye irritation (H319) and possible respiratory irritation (H335) in its full hazard list.",
        "ghs": [
          "H302",
          "H315",
          "H319",
          "H335"
        ],
        "source": "chemicalbook-li4sio4",
        "where": "GHS hazard statements, Section 2 (H302) and Section 16 (H315, H319, H335)"
      }
    ],
    "failure_risks": [
      {
        "mode": "Lithium loss from the silicate during high-temperature firing",
        "trigger": "Firing above 800 °C in the synthesis of lithium-bearing ceramic breeder materials",
        "consequence": "The abstract ties a lithium deficiency in the region of 5% to lithium sublimation from Li4SiO4, and the results describe lithium loss during firing, particularly above 800 °C.",
        "severity": "moderate",
        "source": "hanaor2014",
        "where": "Abstract; results on lithium loss during firing"
      },
      {
        "mode": "Pebble crushing with size-dependent strength",
        "trigger": "Uniaxial compression of melt-spray pebbles of 250 µm to 800 µm diameter",
        "consequence": "Transparent pebbles fail at much lower load than opaque ones, and voids left during solidification lower the mechanical strength of the pebble.",
        "severity": "moderate",
        "source": "annabattula2014",
        "where": "Results: crush load versus pebble size and failure regions A to C"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "Avoid contact with skin and eyes and avoid forming dust and aerosols (ChemicalBook SDS, Section 7).",
        "source": "chemicalbook-li4sio4",
        "where": "Handling and storage, Section 7"
      },
      {
        "text": "Keep in a dry area at room temperature (ChemicalBook SDS, Section 7).",
        "source": "chemicalbook-li4sio4",
        "where": "Handling and storage, Section 7"
      }
    ],
    "mitigations": [
      {
        "text": "Store the powder dry and keep the container closed, as the SDS advises.",
        "source": "chemicalbook-li4sio4",
        "where": "Handling and storage, Section 7"
      }
    ]
  },
  "uses": [
    {
      "application": "radiation-shielding",
      "device": "Tritium-breeding pebble bed in a helium-cooled blanket (ITER concept)",
      "example": "Hanaor et al. (2014) describe Li4SiO4 and Li2TiO3 as leading candidate materials for tritium-breeding pebbles in the helium-cooled pebble bed concept. The source describes tritium breeding, not shielding; the application slug is the nearest in the site list.",
      "source": "hanaor2014",
      "where": "Introduction, first two paragraphs"
    },
    {
      "application": "batteries",
      "device": "Lithium-ion conductor additive in a sulfide solid electrolyte (Li7P2S8I)",
      "example": "Adding 10 mol% Li4SiO4 raised the room-temperature ionic conductivity of Li7P2S8I to 0.85 mS cm−1, compared with 0.35 mS cm−1 for the undoped sulfide, in samples made by liquid-phase shaking. This is a composite result, not a value for pure Li4SiO4.",
      "source": "pmc-li7p2s8i",
      "where": "Abstract and results; liquid-phase shaking samples at x = 0 and x = 10"
    }
  ],
  "supply": [
    {
      "subject": "Lithium",
      "producers": [
        {
          "country": "Australia",
          "year": 2025
        },
        {
          "country": "China",
          "year": 2025
        },
        {
          "country": "Chile",
          "year": 2025
        },
        {
          "country": "Zimbabwe",
          "year": 2025
        },
        {
          "country": "Argentina",
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS 2025 List of Critical Minerals (Lithium, used in rechargeable batteries)",
          "listed": true
        }
      ],
      "recycling": "USGS: construction of lithium battery recycling plants continued throughout 2025.",
      "substitutes": [
        "USGS: substitution for lithium compounds is possible in batteries, ceramics, greases, and manufactured glass."
      ],
      "source": "usgs-mcs2026-lithium",
      "where": "World Mine Production and Reserves table, 2025 column (Australia 92,000 t, China 62,000 t, Chile 56,000 t, Zimbabwe 28,000 t, Argentina 23,000 t, world total 290,000 t). Shares are not printed and are not recorded here. Critical list: USGS final 2025 list page."
    },
    {
      "subject": "Silicon",
      "producers": [
        {
          "country": "China",
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS 2025 List of Critical Minerals (Silicon, used in silicon wafers fundamental to semiconductors)",
          "listed": true
        }
      ],
      "recycling": "USGS silicon chapter: recycling is insignificant.",
      "substitutes": [
        "USGS: gallium arsenide and germanium are the principal substitutes for silicon in semiconductor and infrared applications."
      ],
      "source": "usgs-mcs2026-silicon",
      "where": "Events, Trends and Issues: China accounted for almost 80% of total global estimated production of silicon materials in 2025. The chapter covers ferrosilicon and silicon metal, not the silica or TEOS precursors used in sol-gel synthesis."
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "ChemicalBook: lithium orthosilicate safety data sheet and physical data",
      "type": "sds",
      "url": "https://www.chemicalbook.com/msds/lithiumorthosilicate.htm"
    },
    {
      "title": "TradeIndia: lithium orthosilicate product listing",
      "type": "datasheet",
      "url": "https://www.tradeindia.com/products/lithium-orthosilicate-cas-13453-84-4-8480708.html"
    },
    {
      "title": "Hanaor et al., Solution based synthesis of mixed-phase materials in the Li2TiO3-Li4SiO4 system (arXiv:1410.7128)",
      "type": "paper",
      "url": "https://arxiv.org/pdf/1410.7128",
      "year": 2014
    },
    {
      "title": "Annabattula et al., Size dependent crush analysis of lithium orthosilicate pebbles (arXiv:1408.0485)",
      "type": "paper",
      "url": "https://arxiv.org/pdf/1408.0485",
      "year": 2014
    },
    {
      "title": "Sol-gel Synthesis of Li4SiO4 Nanoparticles for CO2 Capture at High Temperature (Chemical Engineering Transactions, article 2255)",
      "type": "paper",
      "url": "https://cetjournal.it/index.php/cet/article/view/2255"
    },
    {
      "title": "Li4SiO4 Doped-Li7P2S8I solid electrolytes (PMC8982210)",
      "type": "paper",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC8982210"
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Lithium",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-lithium.pdf",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Silicon",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-silicon.pdf",
      "year": 2026
    }
  ],
  "gaps": [
    "No thermal conductivity, specific heat or thermal expansion value for pure Li4SiO4 was found in the sources opened. The Springer (Journal of Advanced Ceramics) and MDPI pages were blocked or redirected to a login.",
    "The Pisa 2021 Fusion Engineering and Design paper on Li4SiO4 pebble mechanics could not be opened; only its landing page was readable.",
    "No peer-reviewed absolute density for pure Li4SiO4 was found. The only density (2.39 g/cm3) is from a trade listing. A ChemicalBook relative density of 2.326 has no printed unit, so it is left out.",
    "Melting point differs between sources: 1258 °C (Wikipedia and Hanaor et al.), 1255 °C (ChemicalBook SDS and an earlier peritectic report), 1256 °C (trade listing). All are recorded side by side.",
    "No crystal space group or lattice parameters were found. Only the monoclinic description is recorded.",
    "Ionic conductivity of pure Li4SiO4 was not recorded: the values found in the literature are printed in scientific notation (exponent form), which the verification step cannot match, so they were left out. The only conductivity recorded is for a Li7P2S8I composite.",
    "Molecular weight is printed without a unit on the ChemicalBook and trade pages (119.85), so those rows are left out. Only the Wikipedia molar mass (119.84 g·mol−1) is recorded.",
    "The site's application list has no fusion-breeding or CO2-capture slug. The fusion use is recorded under radiation-shielding, the nearest slug, and the source describes tritium breeding, not shielding. The CO2 result is in the properties and story, not in uses.",
    "Hazard data rest on one supplier SDS (ChemicalBook). The American Elements SDS and the PubChem GHS page could not be read (403 and reCAPTCHA), so the hazard classification could not be cross-checked.",
    "No corrosion, humidity or ageing data for Li4SiO4 were found in any source opened.",
    "Crustal abundance of silicon or lithium in the Earth's crust was not sourced in this run. Producer shares are not printed in the USGS tables, so none are recorded.",
    "Silicon producers are given only as China (almost 80% of global silicon materials production, USGS). The silicon chapter does not cover the silica or TEOS precursors used in sol-gel synthesis.",
    "The CO2 uptake (6.9 mmol CO2/g sorbent) and 82.4 % conversion are for a nanoparticle sorbent at 700 °C and 0.6 atm CO2. Whether the full text is open access was not confirmed.",
    "Property names molar_mass, co2_uptake, carbonation_conversion and critical_failure_energy are not in the canonical list in spores/property-canon.yaml; they are short snake_case names used here.",
    "Purity (99.99 %) is a listing specification from a trade seller, not a measured value."
  ],
  "story": {
    "why": "Lithium orthosilicate (Li4SiO4) is a lithium-rich oxide ceramic. Hanaor et al. (2014) describe it as a leading candidate for tritium-breeding pebbles in the helium-cooled pebble bed concept, which is studied for the ITER breeding blanket. Its melting point is printed as 1258 °C in the Wikipedia article and in the 2014 study. The same material also absorbs CO2 at high temperature: a 2017 sol-gel study reports 6.9 mmol CO2/g sorbent at 700 °C.",
    "uses": [
      {
        "where": "Fusion breeder blankets",
        "line": "Hanaor et al. (2014) describe Li4SiO4 and Li2TiO3 as leading candidate materials for tritium-breeding pebbles in the helium-cooled pebble bed concept. The source describes tritium breeding, not shielding."
      },
      {
        "where": "Solid electrolyte additive",
        "line": "In a sulfide solid electrolyte, adding 10 mol% Li4SiO4 raised the room-temperature ionic conductivity of Li7P2S8I to 0.85 mS cm−1, from 0.35 mS cm−1 without it. This is a composite result, not a value for pure Li4SiO4."
      }
    ],
    "can_do": [
      {
        "label": "CO2 capture",
        "line": "Absorbs CO2 at high temperature: 6.9 mmol CO2 per gram of sorbent at 700 °C and 0.6 atm CO2 in a sol-gel nanoparticle study, with 82.4 % conversion.",
        "scope": "material",
        "value": "6.9 mmol CO2/g sorbent"
      },
      {
        "label": "Fusion breeding",
        "line": "Serves as a candidate tritium-breeding pebble in a helium-cooled pebble bed blanket, per Hanaor et al. (2014).",
        "scope": "material"
      },
      {
        "label": "Melting point",
        "line": "Melts at 1255 to 1258 °C, depending on the source. Wikipedia and the 2014 study print 1258 °C.",
        "scope": "material",
        "value": "1255 to 1258 °C"
      },
      {
        "label": "Pebble stiffness",
        "line": "Carries a load as pebbles: the crush analysis uses a Young's modulus of 90 GPa and a Poisson's ratio of 0.25 for the pebble.",
        "scope": "material",
        "value": "90 GPa"
      }
    ],
    "compare": "Hanaor et al. (2014) describe Li4SiO4 and Li2TiO3 as the two leading candidates for tritium-breeding pebbles. They report that Li2TiO3 melts congruently, while Li4SiO4 melts congruently at 1258 °C. The two form a quasi-binary system, so pebbles of mixed composition are studied as well. The table compares the melting point, density and pebble stiffness recorded for Li4SiO4.",
    "compare_rows": [
      {
        "label": "Melting point",
        "benchmark": "melting_point",
        "scope": "material"
      },
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Young's modulus of pebble",
        "benchmark": "elastic_modulus",
        "scope": "material"
      }
    ],
    "handling": [
      "Keep the powder dry and at room temperature, as the SDS advises.",
      "Avoid contact with skin and eyes, and avoid forming dust.",
      "Treat the powder as harmful if swallowed, per the SDS classification."
    ],
    "good_for": [
      "Tritium breeding research. Hanaor et al. (2014) describe it as a leading candidate for helium-cooled pebble bed blankets.",
      "High-temperature CO2 capture in a laboratory sorbent test: 6.9 mmol CO2/g sorbent at 700 °C."
    ],
    "watch_out": [
      "Melting point differs between sources: 1255 °C, 1256 °C and 1258 °C.",
      "Pebble strength depends on size and transparency. Transparent pebbles fail at much lower load (Annabattula et al.).",
      "The density figure comes from a trade listing, and no pure-phase conductivity value could be recorded."
    ],
    "verdict": "Li4SiO4 is a well-studied breeder ceramic with melting data from three sources. Its density and hazard classification rest on thin sources, and the gaps are listed.",
    "recipe": {
      "line": "Lithium orthosilicate has the formula Li4SiO4: four lithium atoms, one silicon atom and four oxygen atoms per formula unit (Wikipedia). Hanaor et al. (2014) describe solution-based routes to the silicate and its mixtures with Li2TiO3. The 2017 CO2 sorbent study made Li4SiO4 nanoparticles by a sol-gel route.",
      "parts": [
        {
          "name": "Lithium",
          "symbol": "Li",
          "role": "Lithium-bearing breeder: the source describes lithium-bearing ceramic pebbles for tritium breeding."
        },
        {
          "name": "Silicon",
          "symbol": "Si",
          "role": "The network-forming element of the silicate. Hanaor et al. use tetraethyl orthosilicate as a silicon precursor in their sol-gel work."
        },
        {
          "name": "Oxygen",
          "symbol": "O",
          "role": "Oxygen forms the SiO4 unit that the silicate is built from."
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The supplier SDS classifies lithium orthosilicate as harmful if swallowed and as an irritant (H302, H315, H319, H335).",
        "points": [
          {
            "label": "Swallowing",
            "line": "The SDS lists H302, harmful if swallowed, and advises calling a poison centre or doctor if you feel unwell."
          },
          {
            "label": "Skin and eyes",
            "line": "H315 causes skin irritation and H319 causes serious eye irritation. The SDS advises washing with soap and water and rinsing the eyes thoroughly."
          },
          {
            "label": "Dust",
            "line": "Avoid forming dust and aerosols, and avoid contact with skin and eyes."
          }
        ],
        "level": 0,
        "verdict": "Harmful if swallowed; irritant"
      },
      {
        "title": "In service",
        "lead": "These results come from firing tests and pebble tests in the laboratory, not from field incidents.",
        "points": [
          {
            "label": "Lithium loss",
            "line": "Lithium sublimes during high-temperature firing, particularly above 800 °C. The abstract ties a lithium deficiency in the region of 5% to this loss."
          },
          {
            "label": "Pebble strength",
            "line": "Melt-spray pebbles of 250 µm to 800 µm were crush-tested. Transparent pebbles fail at much lower load than opaque ones."
          }
        ]
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Storage",
            "line": "Keep the powder in a dry area at room temperature, and keep the container closed."
          },
          {
            "label": "Dust",
            "line": "Avoid forming dust and aerosols."
          }
        ]
      }
    ]
  },
  "updated": "2026-11-01",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 12,
    "unreachable": 0,
    "caveats": 0,
    "note": "Written by an AI assistant on 2026-11-01 from pages opened in this run. Values were checked against their cited pages with scripts/verify-values.mjs; see the gate results in the run log."
  },
  "sources": {
    "wikipedia-li4sio4": {
      "title": "Lithium orthosilicate (Wikipedia article)",
      "id": "CAS 13453-84-4",
      "url": "https://en.wikipedia.org/wiki/Lithium_orthosilicate",
      "kind": "web"
    },
    "chemicalbook-li4sio4": {
      "title": "ChemicalBook: Lithium orthosilicate, safety data sheet and physical data",
      "id": "CAS 13453-84-4",
      "url": "https://www.chemicalbook.com/msds/lithiumorthosilicate.htm",
      "kind": "datasheet"
    },
    "tradeindia-li4sio4": {
      "title": "TradeIndia: Lithium Orthosilicate, CAS 13453-84-4, product listing",
      "id": "CAS 13453-84-4",
      "url": "https://www.tradeindia.com/products/lithium-orthosilicate-cas-13453-84-4-8480708.html",
      "kind": "web"
    },
    "hanaor2014": {
      "title": "Solution based synthesis of mixed-phase materials in the Li2TiO3-Li4SiO4 system",
      "id": "Hanaor, Kolb, Gan, Kamlah, Knitter; J. Nucl. Mater. 456 (2014) 151-161; arXiv:1410.7128",
      "url": "https://arxiv.org/pdf/1410.7128",
      "year": 2014,
      "kind": "paper"
    },
    "annabattula2014": {
      "title": "Size dependent crush analysis of lithium orthosilicate pebbles",
      "id": "Annabattula, Kolb, Gan, Rolli, Kamlah; arXiv:1408.0485",
      "url": "https://arxiv.org/pdf/1408.0485",
      "year": 2014,
      "kind": "paper"
    },
    "cet-sol-gel": {
      "title": "Sol-gel Synthesis of Li4SiO4 Nanoparticles for CO2 Capture at High Temperature (Chemical Engineering Transactions)",
      "id": "Chemical Engineering Transactions, article 2255",
      "url": "https://cetjournal.it/index.php/cet/article/view/2255",
      "kind": "paper"
    },
    "pmc-li7p2s8i": {
      "title": "Li4SiO4 Doped-Li7P2S8I solid electrolytes with high lithium stability synthesised using liquid-phase shaking",
      "id": "PMC8982210; Royal Society of Chemistry",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC8982210",
      "kind": "paper"
    },
    "usgs-mcs2026-lithium": {
      "title": "Mineral Commodity Summaries 2026, Lithium",
      "id": "USGS MCS 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-lithium.pdf",
      "year": 2026,
      "kind": "report"
    },
    "usgs-mcs2026-silicon": {
      "title": "Mineral Commodity Summaries 2026, Silicon",
      "id": "USGS MCS 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-silicon.pdf",
      "year": 2026,
      "kind": "report"
    },
    "usgs-crit2025": {
      "title": "About the 2025 List of Critical Minerals (USGS)",
      "id": "Final 2025 List of Critical Minerals",
      "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals",
      "year": 2025,
      "kind": "web"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/lithium-orthosilicate/"
}