Uranium yellow

Natural uranium consists of different isotopes of uranium. Natural uranium is 0.7% U-235 and 99.3% U-238. Uranium-238 is nonfissionable, and therefore naturally occurring uranium must be enriched to a concentration of approximately 4% to be used as fuel for nuclear reactors or 90% for weapons-grade uranium. Yellow cake is shipped to conversion plants... 

IJmnate. Sodium uranate, uranium yellow, Na2U04, yellow solid, insoluble, formed by reaction of soluble uranyl salt solution and excess sodium carbonate solution. Used (1) in the manufacture of yellowish-green fluorescent glass, (2) in ceramic enamels, (3) as a source of uranium for chemical reactions. 

Uses.—Uranium compounds are produced as by-products in the extraction of radium, and are consequently available in considerable quantity. They are not, however, as yet employed in industry to any great extent. Sodium uranate, or uranium yellow, is used to a limited extent for colouring glass, to which it imparts a yellow opalescence, and in the ceramic industries, as also is the oxide UjOg in the preparation of yellow, brown, and green glazes. - Certain salts are employed... 

Ammonium Diuranate, (NH4)2U207, is obtained as a yellow voluminous precipitate when solutions of uranyl salts are treated with ammonia. It is prepared commercially (see p. 277) by boiling a solution of sodium uranyl carbonate with ammonium sulphate, or by boiling a solution of sodium diuranate with concentrated ammonium chloride solution. It is a deep yellow powder, which may be dried at 100° C. at higher temperatures it yields urano-uranic oxide. When fused with ammonium chloride, uranous oxide is formed. It is known commercially as uranium yellow (see also sodium diuranate) and is used in making fluorescent uranium glass. It is insoluble in ammonium hydroxide solution, and this fact is sometimes made use of (see p. 388) in the analytical separation of uranium. 

The ionic compound sometimes called uranium yellow is used to produce colored glazes for ceramics. It is 7.252% sodium, 75.084% uranium, and 17.664% oxygen. Wliat is the empirical formula for this compound ... 

Among the other bulk inorganic chemicals whose manufacture includes the use of a decanter are aluminium and magnesium hydroxides, iron oxides and salts, calcium carbonate and other salts, silicon and silicates, caustic soda, sodium carbonate and other salts, graphite, uranium "yellow cake , gypsum, and zinc oxide and salts. Calcium carbonate is a particularly difficult material to treat in a decanter, in that it needs very high torque to achieve an adequate level of cake dryness. 

Barium uranate(IV) or barium uranium oxide (BaU702) which is orange or yellow in colour may be related to uranium yellow and orange pigments (qq.v.). It is thought perhaps to have been used in the late nineteenth and/or early twentieth century. Modem synthesis is described by Allpress (1964) and Klima c/a/. (1966). 

Uranium group Uranium orange Uranium yellow Allpress (1964) Klima et al. (1966)... 

Uraninm group Uianiiiite Uranium brown Uranium green Uranium orange Uranium red Uranium yellow... 

Uranium group Barium uranium oxide Ochre Pitchblende Uraninite Uranium yellow... 

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