预处理过程对Np(Ⅴ)稳定性的影响

Influence of Pretreatment on the Stability of Np(Ⅴ)

为了提高Purex流程铀纯化循环2D槽中镎的净化效果,研究了Np(Ⅳ)氧化条件,考察了用硝酸肼对钌进行预处理的过程中,预处理试剂浓度、酸度、温度、时间等不同预处理条件对Np(Ⅴ)稳定性的影响。结果表明,在0.2 mol/L酸度、85℃下保温2 h,可以将料液中97%的Np(Ⅳ)氧化为Np(Ⅴ)或Np(Ⅵ)。预处理时离子强度和硝酸肼浓度对Np(Ⅴ)稳定性没有显著影响;随预处理温度提高和时间延长,体系中Np(Ⅳ)含量增多;预处理酸度增加,Np(Ⅴ)稳定性降低。

In order to improve the decontamination of neptunium in 2D extractor for uranium purification cycle,the oxidation conditions of Np（Ⅳ） and the effect of the pretreatment on the stability of Np（Ⅴ） have been studied.The results show that in 0.2 mol/L nitric acid feed solution,97% Np（Ⅳ） can be oxidized to Np（Ⅴ） or Np（Ⅵ） within 2 h at 85 ℃.During the pretreatment,the ionic strength and the concentration of hydrazine has little influence on the stability of Np（Ⅴ）.The concentration of Np（Ⅳ） increases with the temperature,pretreatment time and acidity.