肼为还原剂催化还原U(Ⅵ)制备U(Ⅳ)的工艺条件

Platinum-Catalyzed Reduction of U(Ⅵ) With Hydrazine in Nitric Acid Solutions

摘要: 研究了硝酸体系中以铂黑为催化剂、肼为还原剂还原制备U(Ⅳ)的工艺条件，考察了硝酸浓度、肼浓度、反应温度、催化剂用量等对U(Ⅵ)转化率及副反应的影响。当铀浓度为0.90mol/L时，优化的工艺条件为：初始硝酸浓度0.80mol/L，初始肼浓度1.0mol/L左右，反应温度60℃，反应液25mL时催化剂铂黑用量为0.2g，反应3h后U(Ⅵ)的转化率大于99%。

Abstract: The platinum-catalyzed reduction of U(Ⅵ) by hydrazine in HNO₃ solutions was studied. The influence of hydrazine concentration, acidity, catalyst amounts and temperature on the reduction reaction was investigated. The optimal process parameters for the reduction of c(U)=0.90mol/L(25mL) uranyl ion are 0.80mol/L HNO₃, 1.0mol/L N₂H₄ and 0.2g catalyst. More than 99% U(Ⅵ) is reduced in 3h at 60℃.