Thorium Dioxide
IUPAC Name | Thorium dioxide, Thorium(IV) oxide |
Other names | Thoria, Thorium anhydride |
Cas No. | 1314-20-1 |
Chemical formula | ThO2 |
Molar mass | 264.037 g/mol[1] |
Appearance | white solid[1] |
Odor | odorless |
Density | 10.0 g/cm3[1] |
Melting point | 3,350 °C (6,060 °F; 3,620 K)[1] |
Boiling point | 4,400 °C (7,950 °F; 4,670 K)[1] |
Solubility in water | insoluble[1] |
Solubility | insoluble in alkali slightly soluble in acid[1] |
Magnetic susceptibility (χ) | −16.0·10−6 cm3/mol[2] |
Refractive index (nD) | 2.200 (thorianite)[3] |
Enterprise Specification for Thorium(TV) Oxide
Purity Min.99.9%, Whiteness Min.65, Typical Particle Size(D50) 20~9μm
What is Thorium Dioxide (ThO2) used for?
Thorium dioxide (thoria) has been used in high-temperature ceramics, gas mantles, nuclear fuel, flame spraying, crucibles, non-silicia optical glass, catalysis, filaments in incandescent lamps, cathodes in electron tubes and arc-melting electrodes.
Nuclear fuels
Thorium dioxide (thoria) can be used in nuclear reactors as ceramic fuel pellets, typically contained in nuclear fuel rods clad with zirconium alloys. Thorium is not fissile (but is "fertile", breeding fissile uranium-233 under neutron bombardment);
Alloys
Thorium dioxide is used as a stabilizer in tungsten electrodes in TIG welding, electron tubes, and aircraft gas turbine engines.
Catalysis
Thorium dioxide has almost no value as a commercial catalyst, but such applications have been well investigated. It is a catalyst in the Ruzicka large ring synthesis.
Radiocontrast agents
Thorium dioxide was the primary ingredient in Thorotrast, a once-common radiocontrast agent used for cerebral angiography, however, it causes a rare form of cancer (hepatic angiosarcoma) many years after administration.
Glass manufacture
When added to glass, thorium dioxide helps increase its refractive index and decrease dispersion. Such glass finds application in high-quality lenses for cameras and scientific instruments.