The extraction and stripping of ytterbium（Ⅲ） from sulfuric acid medium using Cyanex 923 in heptane solution was investigated. The effects of extractant concentration, pH and sulfate ion as well as stripping agents, acidity and temperature on the extraction and stripping were studied. The equilibrium constants and thermodynamic parameters, such as ΔH （10.76 kJ·mol -1 ）, ΔG （-79.26 kJ·mol -1 ） and ΔS （292.41 J·K -1 ·mol -1 ）, were calculated. The extraction mechanism and the complex species extracted were determined by slope analysis and FTIR spectra. Furthermore, it was found that the extraction of Yb （Ⅲ） from sulfuric acid medium by Cyanex 923 increased with pH, concentration of SO4 2- , HSO4-, and extractant concentration, and approximately a quantitative extraction of Yb（Ⅲ） was achieved at an equilibrium pH near 3.0, and the extracted complex was YbSO4（HSO4）·2Cyanex923 （o） .
A novel bifunctional task-specific ionic liquid(TSIL),i.e.[trialkylmethylammonium][sec-nonylphenoxy acetate]([A336] [CA-100]) was impregnated on intermediate polarized XAD-7 resin,and the prepared solvent impreganated resin(SIR) was studied for rare earth(RE) separation.Adsorption ability of the SIR was indicated to be obviously higher than that prepared by [A336][NO3] because of the functional anion of [A336][CA-100].Adsorption kinetics,adsorption isotherm,separation and desorption of the SIR were also studied.
The extraction of Yttrium (Ⅲ) into [Cnmim][PF6] (n= 4, 6, 8) containing Cyanex 923 was studied in this paper. The mechanism of this extraction was indicated to be cation exchange. In addition, the extraction process is an endothermic reaction. The RTILs with shorter alkyl chain behave higher extraction efficiency during the extraction, however, which has also more loss to aqueous phase since the cation exchange mechanism.
