30%TBP/煤油-硝酸溶液体系中镎的化学行为
Chemical Behavior of Neptunium in the System of 30%TBP/Kerosene-Nitric Acid Solution
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摘要: 为了解镎在萃取过程中的化学行为，采用单级萃取研究了硝酸溶液中Np(Ⅴ)氧化为Np(Ⅵ)的行为和此过程中TBP萃取Np(Ⅵ)的性能。实验结果表明，提高硝酸浓度有利于Np(Ⅴ)的氧化，提高了萃取体系对Np(Ⅵ)的萃取；提高亚硝酸浓度加快了Np(Ⅵ)和Np(Ⅴ)之间氧化还原反应的进行，但是会降低平衡后萃取系统中Np(Ⅵ)的比例；升高温度可以提高Np(Ⅴ)转化为Np(Ⅵ)的速率。通过模拟1AF料液的混合澄清槽台架实验表明，自1AX中引入0.01 mol/L HNO2，同时将萃取温度升高到45 ℃，在1AF硝酸浓度为3.5 mol/L的条件下，1A槽镎的萃取率可以达到80%。Abstract: In order to understand the chemical behavior of neptunium during the extraction process, the oxidation behavior of Np(Ⅴ) to Np(Ⅵ) in nitric acid solution and the extraction performance of Np(Ⅵ) by 30%TBP/kerosene was studied by single stage extraction. The experiment results indicate that the increasing of the concentrations of nitric acid and nitrous acid are in favor of the production of Np(Ⅵ). The reaction rate of Np(Ⅴ) to Np(Ⅵ) by oxidation increases with increasing the reaction temperature. The simulated experiment on the mixer-setter set indicates that the extraction ratio of neptunium in 1A extraction section is approximately 80% when the HNO2 concentration in 1AX is 0.01 mol/L, the extraction temperature is 45 ℃ and the HNO3 concentration in 1AF is 3.5 mol/L HNO3.
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Keywords:
- neptunium /
- extraction /
- redox /
- co-decontamination /
- PUREX process
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