在不同稀释剂中二（2－乙基己基）磷酸萃取Ni（Ⅱ）的热力学

Extraction Equilibrium of Ni(Ⅱ) with Bis(2-ethylhexyl) Phosphoric Acid in Different Diluents

研究了在不同稀释剂如苯、甲苯、正己烷、环己烷、四氯化碳、氯仿中萃取剂浓度、水相酸度以及温度对二（２－乙基己基）磷酸萃取Ｎｉ（Ⅱ）的平衡的影响，借助萃合物红外光谱，确定了萃合物组成和萃取反应机理。讨论了稀释剂的影响，利用多参数方程将萃取平衡常数以及分配比与稀释剂的物理常数和经验参数进行了定量关联。

The extraction of Ni(Ⅱ) from 0.100 mol/L CH_3COO(H,Na) with HDEHP in different diluents, such as benzene,toluene,n-hexane, cyclohexane, CCl4 and chloroform, has been studied. The species formed in the extraction and the extraction machanism have been examined by means of IR spectra. It shows that the complex formed in chloroform is different from that formed in other diluents. The effect of diluents is discussed. The extraction equilibrium constants and the extraction distribution are correlated with the physical constants and(or) experimental parameters of diluents, respectively. The effect of temperature has also been investigated, and the thermodynamic constants △G￣0, △H￣0 and △S￣0 at 298 K are obtained.