Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10528901 | Analytica Chimica Acta | 2005 | 6 Pages |
Abstract
Synergistic extraction and separation of yttrium (Y) from heavy rare earths (HRE) in chloride medium using mixture of sec-octylphenoxy acetic acid (CA-12, HA) and bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex272, HL) in n-heptane has been investigated. The synergistic enhancement coefficients, Rmax, were obtained for Ho3+ (5.12), Y3+ (5.34), Er3+ (7.04), Tm3+ (7.50), Yb3+ (13.12) and Lu3+ (17.58). The separation factors (SF) between Y3+ and HRE were obtained, and it was found that Er3+ would form the new complex as ErH6A4L5 in the mixture system. A cation exchange mechanism was proposed. The equilibrium constant, formation constant and thermodynamic parameters such as ÎGÂ =Â â18.48Â kJ/mol, ÎHÂ =Â â1.36Â kJ/mol and ÎSÂ =Â 0.058Â kJ/mol were determined. The CA-12 and Cyanex272 mixture system showed higher extraction efficiency, larger separation factors as well as excellent stripping behaviors. The application potential of the mixture system to separate Y from HRE has been discussed.
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Authors
Xiaobo Sun, Junmei Zhao, Shulan Meng, Deqian Li,