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Title: Liquid-liquid separation of zirconium and hafnium from nitric liquor in order to obtain nuclear zirconium oxide using TBP as extractant
Title of periodic: Chemical Engineering Communications
Authors: Amaral, Janubia C. B. S.
Souza, Adalberto L.
Morais, Carlos A.
Affiliation: Centro de Desenvolvimento da Tecnologia Nuclear, CDTN, Belo Horizonte, MG, Brasil
Issue Date: 2019
Keywords: Hafnium;Solvent extraction;Zirconium
Abstract: A specific process to obtain nuclear grade zirconium oxide from a nitric acid liquor is described in this work. The liquor was obtained after alkali fusion and water leaching of a zircon concentrate. The production of nuclear zirconium oxide is possible when tributyl phosphate (TBP) is used as extractant with a high acidity nitric liquor. This study comprises steps: (i) batch experiments in order to select the best conditions for the process and (ii) continuous experiments carried out in counter current mixer-settler circuits. The batch experiments indicated that an increase in nitrate concentration did not correspond to a rise in the separation factor among Zr and Hf. Acidity has a significant influence on the Zr/Hf separation. For the organic phase containing 2.5 mol L-1 of TBP and an aqueous/organic ratio of the 1/1, 94% of the Zr was extracted and a separation factor of the 13.8 was obtained in one contact of the aqueous and organic phase. In the optimized continuous circuit, a product containing 99% of Zr and 0.03% of Hf (200 mg kg(-1)), which meets the nuclear zirconium specifications, was obtained.
Access: R
Appears in Collections:Artigo de periódico

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