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Studies on the synergistic extraction of rare earths with a combination of 2‐ethylhexylphosphonic acid mono‐2‐ethylhexyl ester and trialkylphosphine oxide
Author(s) -
Sun Xiaobo,
Meng Shulan,
Li Deqian
Publication year - 2006
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.1487
Subject(s) - chemistry , lanthanide , extraction (chemistry) , ionic radius , oxide , equilibrium constant , rare earth , nuclear chemistry , stripping (fiber) , inorganic chemistry , medicinal chemistry , ion , chromatography , organic chemistry , mineralogy , electrical engineering , engineering
The synergistic extraction of rare earths (La, Nd, Gd, Y and Yb) with a mixture of 2‐ethylhexyl 2‐ethylhexylphosphonate (EHEHPA) (HA) and trialkylphosphine oxide (Cyanex 923) (B) from a hydrochloride medium was investigated. The mixed system significantly enhances the extraction efficiency for lighter lanthanides and the synergistic enhancement coefficients for La (4.52), Nd (3.35), Gd (2.08), Y (1.31) and Yb (1.08) decrease with decreasing ionic radius of the rare earths. The extraction equilibrium of La, Nd and Gd indicate that La and Nd were extracted as MA 3 ·B, whereas Gd was extracted as Gd(OH)A 2 (HA) 2 ·B. The equilibrium constants, thermodynamic functions such as Δ G , Δ H and Δ S and formation constants of the extracted species were determined. The stripping properties were also studied. Copyright © 2006 Society of Chemical Industry