Uranium tetrafluoride

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Uranium tetrafluoride
Kristallstruktur Uran(IV)-fluorid.png
Identifiers
CAS number 10049-14-6 YesY
ChemSpider 14676181 YesY
Jmol-3D images Image 1
Properties
Molecular formula UF4
Molar mass 314.02 g/mol
Appearance Green crystalline solid.
Density 6.70 g/cm3, solid.
Melting point 1036 °C
Boiling point 1417 °C
Solubility in water Insoluble.
Structure
Crystal structure Monoclinic, mS60
Space group C2/c, No. 15
Hazards
MSDS External MSDS
EU Index 092-002-00-3
EU classification Very toxic (T+)
Dangerous for the environment (N)
R-phrases R26/28, R33, R51/53
S-phrases (S1/2), S20/21, S45, S61
Flash point Non-flammable
Related compounds
Other anions Uranium(IV) chloride
Uranium(IV) bromide
Uranium(IV) iodide
Uranium dioxide
Other cations Thorium(IV) fluoride
Protactinium(IV) fluoride
Neptunium(IV) fluoride
Plutonium(IV) fluoride
Related compounds Uranium hexafluoride
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
Infobox references

Uranium tetrafluoride (UF4) is a green crystalline solid compound of uranium with an insignificant vapor pressure and very slight solubility in water. Uranium in its tetravalent (uranous) state is very important in different technological processes. In the uranium refining industry it is known as green salt.

UF4 is generally an intermediate in the conversion of uranium hexafluoride (UF6) to either uranium oxides (U3O8 or UO2) or uranium metal. It is formed by the reaction of UF6 with hydrogen gas in a vertical tube-type reactor or by the action of hydrogen fluoride (HF) on uranium dioxide. UF4 is less stable than the uranium oxides and reacts slowly with moisture at ambient temperature, forming UO2 and HF, which are very corrosive; it is thus a less favorable form for long-term disposal. The bulk density of UF4 varies from about 2.0 g/cm3 to about 4.5 g/cm3 depending on the production process and the properties of the starting uranium compounds.

A molten salt reactor design, a type of nuclear reactor where the working fluid is a molten salt, would use UF4 as the core material. UF4 is generally chosen over other salts because of the usefulness of the elements without isotope separation, better neutron economy and moderating efficiency, lower vapor pressure and better chemical stability.

Like all uranium salts UF4 is toxic and thus harmful by inhalation, ingestion and through skin contact.

References[edit]

  • Booth, H. S.; Krasny-Ergen, W.; Heath, R. E. (1946). Journal of the American Chemical Society 68 (10): 1969. doi:10.1021/ja01214a028.  edit
  • Kern, S.; Hayward, J.; Roberts, S.; Richardson, J. W.; Rotella, F. J.; Soderholm, L.; Cort, B.; Tinkle, M.; West, M.; Hoisington, D.; Lander, G. A. (1994). "Temperature Variation of the Structural Parameters in Actinide Tetrafluorides". The Journal of Chemical Physics 101 (11): 9333–9337. Bibcode:1994JChPh.101.9333K. doi:10.1063/1.467963.  edit

External links[edit]

  • "Uranium Tetrafluoride". Appendix A of the PEIS (DOE/EIS-0269). Argonne National Laboratory. Retrieved 22 November 2011.