辐照TBP-正十二烷萃取体系对钌的保留行为

Retention of Nitrato Complexes of Nitrosylruthenium by Radiolyzed TBP-n-Dodecane-HNO_3

采用系列相比法研究了吸收剂量、辐照前预平衡硝酸浓度、辐照前体系中含钌、萃取水相的硝酸浓度等对钌保留的影响,并测定了几种模拟辐解产物对钌的萃取。结果表明,γ辐照后的TBP-正十二烷萃取钌达平衡很慢,碱洗涤平衡较快;随着吸收剂量、辐照前预平衡硝酸浓度、循环使用次数的增加,钌保留增加;辐照前体系中含钌时,则钌保留较大;含钌的有机相放置后,保留先增大后减小;若体系不含稀释剂正十二烷和硝酸时,则辐照后对钌的保留都很小;TBP-正十二烷停止辐照后,陈化时间对钌的保留影响不大;萃取水相的硝酸浓度对钌的保留影响不大。保留钌的强络合辐解产物是硝化的磷酸酯。

The retention of the nitrato complexes of nitrosylruthenium by the irradiated TBP-n-dodecane-HNO3 is studied.The extraction equilibrium time of the nitrato complex of nitrosylruthenium by the irradiated TBP-n-dodecane-HNO3 and the washing equilibrium time by sodium carbonate were determined.The distribution coefficients of ruthenium by several model radiolysis products were determined.The effects of absorbed dose,the nitric acid concentration of the nitrosylruthenium nitrato complex,the nitric acid concentration for preequilibration with TBP before irradiation,ruthenium extracted by the TBP-n-dodecane-HNO3 before irradiation on Ru retention percent were studied by phase ratio variation method.The results show that the extraction equilibrium time is quite long.The wash equilibrium time by sodium carbonate is faster.The Ru retention in irradiated TBP extraction system increases with absorbed dose,the concentration of preequilibrating nitric acid before irradiation,and the cycle number.The Ru retention is larger when Ru is extracted by the TBP-n-dodecane-HNO3 before irradiation.The organic phase is placed for several days after Ru is extracted by the irradiated TBP-n-dodecane-HNO3.The Ru retention increases when the aging time is one day then gradually decreases.The Ru retention is small when there is no diluent or nitric acid in the extraction system before irradiation.The Ru retention changes little with the aging time of the irradiated TBP-n-dodecane-HNO3 and the concentration of extracting nitric acid.Nitric organophosphates are the main complexing agents that can coordinate with Ru.