A novel constant interfacial area cell(NCIAC),by spatially separating the agitation from liquid flow circulation of organic and aqueous two phases,was suggested to obtain detailed kinetic data for Er(Ⅲ) extraction fr...A novel constant interfacial area cell(NCIAC),by spatially separating the agitation from liquid flow circulation of organic and aqueous two phases,was suggested to obtain detailed kinetic data for Er(Ⅲ) extraction from chloride medium by 2-ethyl-hexyl-phosphonic acid mono-(2-ethylhexyl) ester(EHEHPA).Different from the traditional Lewis cell and the constant interfacial area cell with laminar flow,the concentrations of Er(Ⅲ) in organic and aqueous two phases were uniform,and the stability of the interfacial area between the two phases could be controlled effectively.Therefore,the special requirements for the design of agitators in the traditional Lewis cell and the constant interfacial area cell for minimizing the influence of diffusion resistance could be avoided.Experimental results indicated that the extraction kinetics was mainly affected by the aqueous flow rate,interfacial area between organic and aqueous two phases,and the aqueous p H values.An extraction kinetic equation was suggested based on the experimental data.展开更多
The cyclic voltammetry, current time curve at potential step and potential time curve of galvanostatic method were used to investigate the electrochemical behavior of Er(Ⅲ) in ErCl 3 LiClO 4 DMF(N, N dimethylformamid...The cyclic voltammetry, current time curve at potential step and potential time curve of galvanostatic method were used to investigate the electrochemical behavior of Er(Ⅲ) in ErCl 3 LiClO 4 DMF(N, N dimethylformamide) system on Pt and Cu electrodes. Results indicate that the electroreducation of Er(Ⅲ) to Er(0) is irreversible on Pt and Cu electrodes, the diffusion coefficient and electron transfer coefficient of Er(Ⅲ) in 0.01 mol/L ErCl 3 0.1 mol/L LiClO 4 DMF system at 303 K are 1.96×10 -6 cm 2·s -1 and 0.081 respectively. The Er metal film was prepared by galvanostatic electrolysis on Cu electrode in ErCl 3 LiClO 4 DMF system at 40 A·m -2 (current density). The deposites composed of Er over 95%(mass fraction) were obtained.展开更多
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
基金Supported by the National Natural Science Foundation of China(51574213,51074150)the Key Project of Chinese National Programs for Fundamental Research and Development(2012CBA01203,2013CB632602)
文摘A novel constant interfacial area cell(NCIAC),by spatially separating the agitation from liquid flow circulation of organic and aqueous two phases,was suggested to obtain detailed kinetic data for Er(Ⅲ) extraction from chloride medium by 2-ethyl-hexyl-phosphonic acid mono-(2-ethylhexyl) ester(EHEHPA).Different from the traditional Lewis cell and the constant interfacial area cell with laminar flow,the concentrations of Er(Ⅲ) in organic and aqueous two phases were uniform,and the stability of the interfacial area between the two phases could be controlled effectively.Therefore,the special requirements for the design of agitators in the traditional Lewis cell and the constant interfacial area cell for minimizing the influence of diffusion resistance could be avoided.Experimental results indicated that the extraction kinetics was mainly affected by the aqueous flow rate,interfacial area between organic and aqueous two phases,and the aqueous p H values.An extraction kinetic equation was suggested based on the experimental data.
文摘The cyclic voltammetry, current time curve at potential step and potential time curve of galvanostatic method were used to investigate the electrochemical behavior of Er(Ⅲ) in ErCl 3 LiClO 4 DMF(N, N dimethylformamide) system on Pt and Cu electrodes. Results indicate that the electroreducation of Er(Ⅲ) to Er(0) is irreversible on Pt and Cu electrodes, the diffusion coefficient and electron transfer coefficient of Er(Ⅲ) in 0.01 mol/L ErCl 3 0.1 mol/L LiClO 4 DMF system at 303 K are 1.96×10 -6 cm 2·s -1 and 0.081 respectively. The Er metal film was prepared by galvanostatic electrolysis on Cu electrode in ErCl 3 LiClO 4 DMF system at 40 A·m -2 (current density). The deposites composed of Er over 95%(mass fraction) were obtained.
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.