Ammonium diuranate or (ADU) ((NH4)2U2O7), is one of the radioactive intermediate chemical forms of uranium produced during yellowcake production. The name "yellowcake" originally given to this bright yellow substance, now applies to mixtures of uranium oxides which are actually hardly ever yellow. It also is an intermediate in mixed-oxide (MOX) fuel fabrication.
|Molar mass||624.129 g·mol−1|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
It is precipitated by adding aqueous ammonium hydroxide after uranium extraction by tertiary amines in kerosene. This precipitate is then thickened and centrifuged before being calcined to uranium oxide. Canadian practice favours the production of uranium oxide from ammonium diuranate, rather than from uranyl nitrate as is the case elsewhere.
Ammonium diuranate was once used to produce colored glazes in ceramics. However when being fired this will decompose to uranium oxide, so the uranate was only used as a lower cost material than the fully purified uranium oxide.