Thorium Oxide ThO2 CAS 1314-20-1

Thorium Oxide (ThO₂) – High‑Purity Material for Ceramics, Nuclear, and Optical Applications

Basic Information

• Product: Thorium dioxide (Thoria)

• CAS Number: 1314-20-1

• Molecular Formula: ThO₂

• Molecular Weight: 264.04 g/mol

• EINECS Number: 215-225-1

• Purity: ≥99.9%

• Appearance: White powder

• Density: ~9.86 g/cm³

• Melting Point: ~3350°C (one of the highest melting points among oxides)

• Crystal Structure: Fluorite cubic

Overview
Thorium oxide (thoria) is a white, highly refractory oxide with exceptional thermal stability and chemical inertness. Its high melting point, low volatility, and good thermal conductivity make it indispensable in demanding high‑temperature and specialty applications. It is produced with high purity (99.9%) to meet stringent industrial and research requirements.

Key Applications

• High‑temperature ceramics: Used in crucibles, thermocouple sheaths, and furnace components that operate above 2000°C.

• Nuclear fuel: Mixed with uranium or plutonium oxides as a fertile material in nuclear reactors (e.g., in thorium‑based fuel cycles).

• Incandescent lamps: Coated on tungsten filaments to improve light output and reduce evaporation (gas‑mantle type).

• Electron tubes and cathodes: Employed as a thermionic emitter material due to its low work function.

• Arc melting electrodes: Used as non‑consumable electrodes in arc welding and melting processes.

• Optical glass: Added to glass formulations to increase refractive index and reduce dispersion.

• Refractories: As a lining material for high‑temperature kilns and furnaces.

• Catalysts: Used as a support or promoter in certain catalytic reactions (e.g., in automotive catalysts).

Key Properties

• Extremely high melting point (~3350°C) – stable under severe thermal stress.

• High density and chemical inertness – resistant to most acids and alkalis.

• Good thermal neutron capture cross‑section – relevant to nuclear applications.

• Low vapor pressure – suitable for high‑vacuum applications.

• Radioactive (α‑emitter) – requires careful handling and waste management.

Handling and Storage

• Thorium oxide is radioactive and should be handled with appropriate shielding and monitoring.

• Store in sealed, labeled containers in a designated radiation area.

• Use personal protective equipment including gloves, lab coat, and respirator where dust may be generated.

• Avoid inhalation of dust; work in a fume hood or glove box when handling powders.

• Disposal must comply with national regulations for radioactive materials.

Packaging
Available in 100 g, 500 g, 1 kg, and 5 kg containers, with radiation‑warning labels. Custom packaging upon request.

Quality Assurance
Each batch is analyzed for purity (ICP‑MS), particle size, and radionuclide composition to ensure consistency and compliance.