The extraction behavior of N,N,N’,N’-tetrabutylglutaramide（TBGA）employing cyclohexane as diluent toward La（Ⅲ）,Pr（Ⅲ）,Gd（Ⅲ）and Er（Ⅲ） investigated.The effect of the concentrations of nitric acid,lithium n...The extraction behavior of N,N,N’,N’-tetrabutylglutaramide（TBGA）employing cyclohexane as diluent toward La（Ⅲ）,Pr（Ⅲ）,Gd（Ⅲ）and Er（Ⅲ） investigated.The effect of the concentrations of nitric acid,lithium nitrate and extractant and also the temperature on the extraction distribution ratio was studied.The stoichiometry of the extracted species was Found to be M（NO3）3·3TBGA（M=La,Pr,Gd,Er）.The extraction mechanism was also discussed and the values of the enthalpy of extraction reaction was calculated.展开更多
In this work, the feasibility of using a macroporous strong acid ion exchange resin (D72) as an adsorbent for praseodymium (Ⅲ) was examined. The adsorption behavior and mechanism were investigated with various chemic...In this work, the feasibility of using a macroporous strong acid ion exchange resin (D72) as an adsorbent for praseodymium (Ⅲ) was examined. The adsorption behavior and mechanism were investigated with various chemical methods and IR spectrometry. The results showed that the loading of Pr (III) ions was strongly dependent on pH of the medium and the optimal adsorption condition is in HAc-NaAc medium with pH value of 3.0. Adsorption kinetics of Pr (III) ions onto D72 resin could be best described by pseudo-second-order model. The maximum adsorption capacity of D72 for Pr (Ⅲ) was evaluated to be 294 mg·g 1 for the Langmuir model at 298K. The apparent activation energy, E a , was 14.71 kJ·mol 1 . The calculated data of thermodynamic parameters, ΔSΘ value of 100 J·mol 1 ·K 1 and ΔHΘ value of 8.89 kJ·mol 1 , indicate the endothermic nature of the adsorption process, while a decrease of ΔGΘ with increasing temperature indicates the spontaneous nature of the adsorption process. Finally, Pr (Ⅲ) can be eluted by using 1.00 mol·L 1 HCl-0.50 mol·L 1 NaCl solution and the D72 resin can be regenerated and reused. Thomas model was successfully applied to experimental data to predict the breakthrough curves and to determine the characteristic parameters of the column useful for process design. The characterization before and after adsorption of Pr (Ⅲ) ions on D72 resin was conformed by IR.展开更多
文摘The extraction behavior of N,N,N’,N’-tetrabutylglutaramide（TBGA）employing cyclohexane as diluent toward La（Ⅲ）,Pr（Ⅲ）,Gd（Ⅲ）and Er（Ⅲ） investigated.The effect of the concentrations of nitric acid,lithium nitrate and extractant and also the temperature on the extraction distribution ratio was studied.The stoichiometry of the extracted species was Found to be M（NO3）3·3TBGA（M=La,Pr,Gd,Er）.The extraction mechanism was also discussed and the values of the enthalpy of extraction reaction was calculated.
基金Supported by the National Key Technologies Research and Development Program of China (2008BAD94B09)the Key Laboratory of Advanced Textile Materials and Manufacturing Technology (Zhejiang Sci-Tech University)+1 种基金the Ministry of Education(2011007)the Zhejiang Provincial Scientific Research Project (Y201223624)
文摘In this work, the feasibility of using a macroporous strong acid ion exchange resin (D72) as an adsorbent for praseodymium (Ⅲ) was examined. The adsorption behavior and mechanism were investigated with various chemical methods and IR spectrometry. The results showed that the loading of Pr (III) ions was strongly dependent on pH of the medium and the optimal adsorption condition is in HAc-NaAc medium with pH value of 3.0. Adsorption kinetics of Pr (III) ions onto D72 resin could be best described by pseudo-second-order model. The maximum adsorption capacity of D72 for Pr (Ⅲ) was evaluated to be 294 mg·g 1 for the Langmuir model at 298K. The apparent activation energy, E a , was 14.71 kJ·mol 1 . The calculated data of thermodynamic parameters, ΔSΘ value of 100 J·mol 1 ·K 1 and ΔHΘ value of 8.89 kJ·mol 1 , indicate the endothermic nature of the adsorption process, while a decrease of ΔGΘ with increasing temperature indicates the spontaneous nature of the adsorption process. Finally, Pr (Ⅲ) can be eluted by using 1.00 mol·L 1 HCl-0.50 mol·L 1 NaCl solution and the D72 resin can be regenerated and reused. Thomas model was successfully applied to experimental data to predict the breakthrough curves and to determine the characteristic parameters of the column useful for process design. The characterization before and after adsorption of Pr (Ⅲ) ions on D72 resin was conformed by IR.
