二氯苯基二硫代膦酸对Pu(Ⅲ)的萃取行为

Extraction Behavior of Pu(Ⅲ) by Di(chlorophenyl)dithiophosphinic Acid

摘要: 研究了二氯苯基二硫代膦酸(DCPDTPA)在低浓度硝酸介质中对Pu(Ⅲ)的萃取行为，考察了萃取时间、萃取剂浓度、平衡水相pH值、盐析剂浓度以及温度等因素对萃取分配比的影响，确定了萃合物组成和萃取反应方程式。结果表明，DCPDTPA对Pu(Ⅲ)的萃取过程为阳离子交换机理，对应的反应为放热反应，萃取反应焓ΔH=(-11.7±0.7) kJ/mol，在298 K时萃取表观反应平衡常数为(0.18±0.03) L/mol。

Abstract: Extraction behavior of Pu(Ⅲ) from HNO₃ solution of low concentration with di (chlorophenyl) dithiophosphinic acid(DCPDTPA) in toluene was studied. The distribution ratios of Pu(Ⅲ) were determined as function of extraction time, pH of the aqueous phase, the concentration of NaNO₃, concentration of DCPDTPA as well as the ambient temperature. The composition of the extraction complex and the extraction reaction equation are discussed, suggesting that the extraction is mainly a cation exchange process, which is exothermic with the extraction enthalpy of (-11.7±0.7)kJ/mol and an equilibrium constant of (0.18±0.03)L/mol at 298 K.