稀释剂极性对萃取动力学的影响 Ⅰ.HEHEHP萃取Fe(Ⅲ)

Effects of Diluent Polarity on the Extraction Kinetics I . Extraction of Fe(III) by HEHEHP

考察了正辛烷等六种常用稀释剂中2-乙基己基膦酸单2-乙基已基酯从硝酸介质中萃取Fe(Ⅲ)的动力学行为.观察到稀释剂的极性不仅影响萃取速率的大小,而且会引起萃取过程控制模式的改变,即随着稀释剂极性的增加,萃取过程由界面化学反应和水相化学反应共同控制模式向单一的界面化学反应控制模式转变.

The extraction kinetics of iron( III) by 2- ethylhexyl - 2 - ethylhexyl phosphonic acid in different diluents was investigated. The results indicate that the diluent polarity can change not only the extraction rate,but also the kinetic regime, i. e. with the increase in diluent polarity, a transition from a controlling regime of both an interfacial reaction and an aqueous phase reaction to a pure controlling regime of an interfacial reaction would be occurred.