Solvent extraction kinetics of lanthanum with purified Cyanex 923 in heptane from nitrate medium was investigated by using a constant interfacial cell with laminar flow at 303 K. The effects of stirring speed, tempera...Solvent extraction kinetics of lanthanum with purified Cyanex 923 in heptane from nitrate medium was investigated by using a constant interfacial cell with laminar flow at 303 K. The effects of stirring speed, temperature and specific interface on the extraction rate were studied. The experimental results showed that the extraction apparent activation energy was 32.0 kJ\5mol -1 and the extraction process was controlled by both chemical reaction and diffusion. The extraction rates were measured at different chemical compositions by varying ionic strength, pH value and the concentration of purified Cyanex 923. The initial extraction rate equation was obtained.展开更多
The phase-separation glasses with composition of Na 2O(9.0)B 2O 3(25.0)-SiO 2(66.0)(in mole ratio)were leached with hydrochloric acid,and porous glasses were prepared.The dynamics of the acid treatment was investi...The phase-separation glasses with composition of Na 2O(9.0)B 2O 3(25.0)-SiO 2(66.0)(in mole ratio)were leached with hydrochloric acid,and porous glasses were prepared.The dynamics of the acid treatment was investigated.The effects of treatment time,temperature and acid concentration on the acid treatment process were studied using HCl as treatment solution.The dynamics equation and apparent activation energy obtained in acid treatment process were dw/dt=a/2t and E=57.74 kJ·mol -1,respectively.The constants of the reaction rate at different temperatures were calculated.On the basis of experimental data the mechanism of acid treatment process and the source of swollen stress,which was the main stress during treatment process,were discussed.展开更多
文摘Solvent extraction kinetics of lanthanum with purified Cyanex 923 in heptane from nitrate medium was investigated by using a constant interfacial cell with laminar flow at 303 K. The effects of stirring speed, temperature and specific interface on the extraction rate were studied. The experimental results showed that the extraction apparent activation energy was 32.0 kJ\5mol -1 and the extraction process was controlled by both chemical reaction and diffusion. The extraction rates were measured at different chemical compositions by varying ionic strength, pH value and the concentration of purified Cyanex 923. The initial extraction rate equation was obtained.
基金FundedbytheNationalNaturalScienceFoundationofChi na (No .5 0 2 72 0 4 8)andtheNationalNaturalScienceFoundationofHubeiProvince (No .2 0 0 1ABB0 76 )
文摘The phase-separation glasses with composition of Na 2O(9.0)B 2O 3(25.0)-SiO 2(66.0)(in mole ratio)were leached with hydrochloric acid,and porous glasses were prepared.The dynamics of the acid treatment was investigated.The effects of treatment time,temperature and acid concentration on the acid treatment process were studied using HCl as treatment solution.The dynamics equation and apparent activation energy obtained in acid treatment process were dw/dt=a/2t and E=57.74 kJ·mol -1,respectively.The constants of the reaction rate at different temperatures were calculated.On the basis of experimental data the mechanism of acid treatment process and the source of swollen stress,which was the main stress during treatment process,were discussed.