Sodium diuranate
Identifiers | |
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ECHA InfoCard
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100.033.882 |
PubChem CID
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UNII | |
Properties | |
Na2U2O7 | |
Density | 6.44 g/cm3 |
Melting point | 1,646 °C (2,995 °F; 1,919 K) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sodium diuranate, also known as the yellow oxide of uranium, is an
diuranate anion. It forms a hexahydrate Na2U2O7·6H2O. Sodium diuranate is commonly referred to by the initials SDU.[1] Along with ammonium diuranate it was a component in early yellowcakes.[2] The ratio of the two compounds is determined by process conditions; however, yellowcake is now largely a mix of uranium oxides.[3]
Preparation
In the classical procedure for extracting uranium,
precipitate as sodium diuranate.[5]
The leaching solution to produce the semi-refined product referred to as yellowcake.[6]
These older methods of extracting uranium from its
Sodium uranate may be obtained in the amorphous form by heating together urano-uranic oxide and sodium chlorate; or by heating sodium uranyl acetate or carbonate. The crystalline form is produced by adding the green oxide in small quantities to fused sodium chloride, or by dissolving the amorphous form in fused sodium chloride, and allowing crystallization to take place. It yields reddish-yellow to greenish-yellow prisms or leaflets.
Uses
In the past it was widely used to produce
silica
matrix during the firing of the initial melt.
It was also used in
teeth and once used in pottery to produce ivory to yellow shades in glazes.[9] It was added to these products as a mix with cerium oxide.[10]
The final uranium composition was from 0.008 to 0.1% by weight uranium with an average of about 0.02%. The practice appears to have stopped in the late 1980s.
References
- ^ Meredith, A. D.(2013). Modified Sodium Diuranate Process For the Recovery of Uranium From Uranium Hexafluoride Transport Cylinder Wash solution. (Doctoral dissertation). Retrieved from http://scholarcommons.sc.edu/etd/2466
- ISBN 978-0-387-27843-8.
- S2CID 97023067.
- ^ "MQes Uranium Inc". Retrieved 2016-06-01.
- ^ Purification of sodium diuranate. Retrieved 2020-04-30
- ^ Method of precipitation of sodium diuranate. Retrieved 2020-04-30
- ^ Gindler, J. E.(1962) The Radiochemistry of Uranium pp 39-235
- PMID 8316677.
- ^ "Uranium Containing Dentures (ca. 1960s, 1970s)". Retrieved 2016-06-01.
- PMID 33802821.
External links
- NRC Glossary
- Sodium Uranate Heats of Formation
- MSDS Archived 2021-03-02 at the Wayback Machine
- Gasperin, M (1986). "Na2U2O7: Synthèse et structure d'un monocristal". Journal of the Less Common Metals. 119: 83–90. .