Aqueous hydroxylation mediated synthesis of crystalline calcium uranate particles

JOURNAL OF ALLOYS AND COMPOUNDS

卷:688

Article

Ding, Weixuan¹  Botha, Johannes A.¹  Hanson, Bruce C.¹  Burke, Ian T.² 

[1] Univ Leeds, Sch Chem & Proc Engn, Leeds LS2 9JT, W Yorkshire, England

[2] Univ Leeds, Sch Earth & Environm, Leeds LS2 9JT, W Yorkshire, England

关键词: Uranate;    U(VI);    Synthesis;    Precipitation;    Particles;    Crystallisation;   

DOI  :  10.1016/j.jallcom.2016.07.140

来源: Elsevier

【 摘 要 】

Metal uranates(VI) are solubility limiting U(VI) phases under high pH conditions and may act as suitable long-term wasteforms. The precipitation and thermal phase development mechanisms of calcium uranate particles formed via aqueous hydroxylation reactions are studied in order to address the lack of aqueous synthesis methods currently available. Hydrous Ca-deficient uranate particles formed from aqueous solutions saturated in U(VI) oligomers were found to thermally decompose via several weight-loss steps between 100 and 800 degrees C. Crystalline calcium uranate (Ca2U3O11) is initially formed at 700 degrees C via dehydration and dehydroxylation-olation reactions under redox-neutral conditions. This initial phase decomposes to biphasic CaUO4-UO2 particles at 800 degrees C via a reductive pathway. (C) 2016 The Authors. Published by Elsevier B.V.

【 授权许可】

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