Ammonium diuranate or (ADU) ((NH4)2U2O7), is one of the intermediate chemical forms of uranium produced during yellowcake production.

[1][2] Recent literature has shown that the structure more closely resembles the mineral metaschoepite, the partially dehydrated form of schoepite.

[3] It is precipitated by adding aqueous ammonium hydroxide after uranium extraction by tertiary amines in kerosene.

Canadian practice favours the production of uranium oxide from ammonium diuranate, rather than from uranyl nitrate as is the case elsewhere.

[citation needed] Ammonium diuranate was once used to produce colored glazes in ceramics.