【摘要】 本文采用上升液滴法,研究了三辛基氧化膦（TOPO）-环己烷溶液从盐酸体系中萃取U（IV）的动力学.按实验结果在一定的盐酸浓度下,TOPO箤取U（IV）的速率可由下述萃取动力学方程式表示:R=K[U（IV）][TOPO]₀在[HCl]=3M和15℃时,计算得萃取速率常数K=3.7x10^-5.在不同盐酸浓度的溶液中,TOPO萃取U（IV）的速率与盐酸浓度的3/2次方成正比.测定了温度（15～45℃）对萃取速率的影响,求得萃取反应的表观活化能为10.8 kcal/mol. 由实验结果推测,TOPO从盐酸体系中萃取U（IV）的反应可能按下列两步进行:UCl₄+TOPO₀=UCl₄·TOPO₀ （1）UCl₄·TOPO₀+TOPO₀=UCl₄·2TOPO₀ （2）而生成界面溶剂配合物的反应（1）是萃取速率的控制步骤.更多还原

【Abstract】 The kinetics of the extraction of U（IV） chloride in the TOPO-HCl system has been studied using the single drop technique. The effects of the concentrations of U（IV）, TOPO and HCl on the extraction rate for U（IV） have been examined.The extraction rate measured were found to be of first order with respect to [U（IV）] and [TOPO]₀. Moreover, the rate varied with [HCl]^3/2 between 2～7 M hydrochloric acid. The extraction rate equation can be written as R=k[U（IV）][TOPO]₀ The rate constant k was evaluated to be 3.7×10^-5 at 3M HCl and 15℃.The extraction rate was increased with increasing temperature. The apparent activation energy was found to be 10.8 kcal/mol between 15 to 45℃. It is suggested that the rate-controlling step may be the chemical reaction of UC1₄ with TOPO at the interface and the formation of the interfacial complex UCl₄·TOPO.更多还原