Yellowcake

:"For the falsified documents, see Yellowcake forgery."Chembox new
Name = Yellowcake
ImageFile = Yellowcake.jpg
ImageSize = 250px
OtherNames = urania
Section1 = Chembox Identifiers
CASNo =

Section2 = Chembox Properties
Formula = variable, see text
MolarMass =
Appearance =
Density = 2.055 g/cm3, solid
Solubility =
MeltingPt = 2878°C
BoilingPt =

Yellowcakes (also called "urania") are uranium concentrates obtained from leach solutions. They represent an intermediate step in the processing of uranium ores. Yellowcake concentrates are prepared by various extraction and refining methods, depending on the types of ores. Typically yellowcakes are obtained through the milling and chemical processing of uranium ore forming a coarse powder which is insoluble in water and contains about 80% uranium oxide and which melts at approximately 2878°C.

The ore is first crushed to a fine powder by passing raw uranium ore through crushers and grinders to produce "pulped" ore. This is further processed with concentrated acid, alkaline, or peroxide solutions to leach out the uranium. Yellowcake is what remains after drying and filtering. The yellowcake produced by most modern mills is actually brown or black, not yellow; the name comes from the colour and texture of the concentrates produced by early mining operations.

Initially, the compounds formed in yellowcakes were not identified; in 1970, the U.S. Bureau of Mines still referred to yellowcakes as the final precipitate formed in the milling process and considered it to be ammonium diuranate or sodium diuranate. The compositions were variable and depended upon the leachant and subsequent precipitating conditions. Among the compounds identified in yellowcakes include: uranyl hydroxide, uranyl sulfate, sodium para-uranate, and uranyl peroxide, along with various uranium oxides. Modern yellowcake typically contains 70 to 90 percent triuranium octoxide (U3O8) by weight. Other oxides such as uranium dioxide (UO2) and uranium trioxide (UO3) exist.

Yellowcake is used in the preparation of fuel for nuclear reactors, where it is processed into purified UO2 for use in fuel rods for PHWR and other systems using unenriched uranium. It may also be enriched, by being converted to uranium hexafluoride gas (UF6), by isotope separation through gaseous diffusion or in a gas centrifuge to produce enriched uranium suitable for use in weapons and reactors.

Yellowcake is produced by all countries in which uranium is mined.

References

*Characterizing and Classifying Uranium Yellow Cakes: A Background "by Donald M. Hausen" JOM-9812-45F

ee also

*Uraninite
*Yellowcake forgery


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Look at other dictionaries:

  • Yellowcake — Eine Trommel mit Yellowcake Yellowcake (englisch ‚Gelbkuchen‘ oder ‚gelber Kuchen‘) ist ein gelbes, pulverförmiges Ge …   Deutsch Wikipedia

  • Yellowcake — en poudre Le yellowcake (de l anglais « gâteau jaune ») est un concentré d uranium. C est une poudre grossière qui n est pas soluble dans l eau et qui contient environ 80 % d uraninite, fondant à environ 2878 °C. Le yellowcake …   Wikipédia en Français

  • yellowcake — [yel′ōkāk΄] n. a uranium concentrate, primarily (NH4) 2U2O7 or Na2U2O7, obtained by the extraction of uranium from ores: also yellow cake …   English World dictionary

  • yellowcake — noun Yellowcake is used before these nouns: ↑uranium …   Collocations dictionary

  • Yellowcake —   A natural uranium concentrate that takes its name from its color and texture. Yellowcake typically contains 70 to 90 percent U3O8 (uranium oxide) by weight. It is used as feedstock for uranium fuel enrichment and fuel pellet fabrication …   Energy terms

  • yellowcake — /yel oh kayk /, n. a processed oxide of uranium, U3O8, extracted and concentrated from uranium ore: used as the raw material for commercial nuclear materials, esp. fuel elements in nuclear reactors. Also, yellow cake. [1945 50; YELLOW + CAKE] * * …   Universalium

  • yellowcake — noun A concentrated form of uranium ore containing a mixture of oxides Syn: urania …   Wiktionary

  • yellowcake — uranium ore (U3O8) …   Eponyms, nicknames, and geographical games

  • yellowcake — noun impure uranium oxide obtained during processing of uranium ore. Origin 1950s; so named because it is obtained as a yellow precipitate …   English new terms dictionary

  • yellowcake — /ˈjɛloʊkeɪk / (say yelohkayk) noun uranium oxide in an unprocessed form, which has low radioactivity …   Australian English dictionary

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