Solvent extraction of lanthanides and yttrium from nitrate medium with CYANEX 925 in heptane |
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| Authors: | Wei Li Xianglan Wang Hui Zhang Shulan Meng Deqian Li |
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| Affiliation: | 1. Key laboratory of Rare Earth Chemistry and Physics, Changchun Institute of Applied Chemistry, Changchun 130022, China;2. Graduate School of Chinese Academy of Sciences, Beijing 100049, China |
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| Abstract: | The extraction behavior of lanthanides and yttrium usinsg CYANEX 925 (mixture of branched chain alkylated phosphine oxides) in n‐heptane from nitrate medium has been studied. The effects of aqueous phase ionic strength, CYANEX 925 concentration in the organic phase, and temperature on Sm3+, Nd3+ and Y3+ extraction have been investigated. The extractability of the lanthanides and yttrium increases with increasing nitrate concentration, as well as with increasing CYANEX 925 concentration. An extraction mechanism is proposed based on slope analysis. Furthermore, the infra‐red spectra of CYANEX 925 saturated with lanthanides are employed to provide evidence of the composition of the complex. The relationship between the logarithm of the distribution ratio and lanthanide atomic number is also discussed which indicates that yttrium can be separated from light lanthanides. In addition separation of the light and heavy lanthanide groups is also possible using CYANEX 925. From the temperature dependence data, the thermodynamic parameters values (ΔH, ΔS and ΔG) are calculated. Copyright © 2007 Society of Chemical Industry |
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| Keywords: | lanthanides yttrium CYANEX 925 extraction mechanism separation |
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