HEH[EHP]萃取Fe(Ⅲ)的动力学研究

Studies on the Extraction Kinetic of Fed(Ⅲ) with 2-Ethyl Hexyl 2-Ethyl Hexyl Phosphonic Acid(HEH[EHP])

用两相充分混合法,在298±1K下研究了HEH[EHP]-正庚烷-1.0mpL·L-1(Na,H)NO3体系中萃取Fe(Ⅲ)的动力学过程。认为界面慢反应为速率控制步骤。

The extraction kinetics of the system Fe(Ⅲ)/1.0mol.L^(-1)(Na,H)NO_(3)/HFH[FHP]-heptane has been studied at 298±1K with highly stirred tanks.The change of concentration of Fe(Ⅲ)in the aqueous phase with the extraction time is determined by potentiometry.The experimental results show that the extraction mechanism might be described by the following interfacial reaction.■And Equ.(2),slow reaction taking place at the interface between two phases,may be the rate determining step of this extraction system.The following equations were so obtained.where,and[Fe],[Fe](0)and[HA](i),being the concentrations of species in the aqueous phase,organic phase and interface between two phases respectively.ai the specific interfacial area.