三烷基氧膦对硝酸介质中钌的萃取行为

Extraction of Ruthenium From Nitric Acid Medium by Trialkylphosphine Oxide

研究了三烷基氧膦(TRPO)对硝酸介质中钌的萃取行为。使用TRPO为萃取剂,煤油(OK)为稀释剂,重点考察了萃取平衡时间、水相硝酸浓度、温度、萃取剂浓度、亚硝酸盐浓度等因素对钌的萃取影响,并进行了钌的三级错流萃取实验。另外,还研究了硝酸浓度、温度等因素对钌的反萃过程影响。结果表明,由于钌在水相和有机相中存在着多个种态的平衡和转化过程,热力学和动力学作用相互影响,使得TRPO对钌的萃取行为以及有机相中钌的反萃行为均十分复杂。为进一步了解TRPO对高放废液中钌的萃取行为,进行了TRPO/煤油对不同酸度、浓缩倍数的模拟高放废液中钌的萃取和反萃实验,相关结果为进一步优化TRPO流程工艺提供了重要参考。

The extraction of ruthenium from nitric acid medium by trialkylphosphine oxide(TRPO)was studied under a variety of experimental conditions.The influence factors such as contacting time,nitric acid concentration,temperature,TRPO concentration,etc.,on the extraction behavior were systematically investigated.Three-stage cross-current extractions were further conducted to reveal the extraction behavior.Moreover,the stripping of ruthenium from the loaded organic phase by nitric acid was also studied.The results from this study indicate that the thermodynamics and kinetics of the speciation and chemical equilibrium of ruthenium in nitric acid medium are quite interactive and thus resulting in complicated extraction behaviors.Furthermore,the extraction of ruthenium from a series of simulated HLLW was conducted and the results provide additional information for the optimization of TRPO process regarding the decontamination of ruthenium from HLLW.