【摘要】 本文对HNO₃介质中的Np（V）-Np（VI）电极行为进行了研究。实验表明,电解过程可逆,Np（V）的还原有很高的超电位。在双区单级电解槽中,阴极电位700mV（S.C.E.）,电解还原10分钟,可使Np（VI）定量还原成Np（V）。在1.50mol/L HNO₃介质中,电解还原Np（VI）的半反应时间约1.5分钟。可以预见,在混合澄清槽中的镎将主要处于四价状态。 本文还介绍了研制阳阴极共区电解还原混合澄清槽的目的、设计、调试、铀酸冷运转的情况。并利用该槽进行了铀、钚、镎共存的运行试验,着重了解镎在铀、钚分离过程中的行为。实验证明,钚收率99.90—99.99%;钚中去铀分离系数3900～33000;铀、钚、酸物料衡算良好;镎在槽中的积累和内循环严重;镎在槽中主要以四价形态存在;在1B槽铀钚分离条件下,从单一产品液流（IBU或IBP）中定量回收镎是不太可能的。更多还原

【Abstract】 The electrolytic oxidation-reduction of Np(V, VI) in HNO3 solution was studied. Experimental results showed that the electrode process of Np(V)-Np (VI) couple is reversible, half reaction time of the process mentioned above is about 1.5 minutes under given conditions. The overpotential of reduction of Np(V) is high, which makes it difficult to reduce Np(V) into Np(IV) directly at cathode. Owing to a large quantity of U (VI) produced through electrolysis, it is presaged that neptunium will be mainly in tetravalent state in the electrolytic M-S battery.A new type of electrolytic M battery was developed,in which anodes were installed in each settling chamber without any specific anode chamber in the battery. Owing to using of the mechanical stirrer driven by a wheel gear, stage efficiency is high. Demonstration campaign was carried out.It follows from the results that the yield of Pu is 99.90^99.99%. Separation factor of U from Pu is 3900-^-33000. Material balance of U and Pu is satisfactory .Heavy accumulation of Np in the battery was observed.Np in the battery is mainly in the tetravalent state. It is believed that it is difficult to recover Np quantitatively from single fluent (e.g. iBP or iBU) under normal conditions of partitioning Step of the PUREX process.更多还原