【作者】 李斌； 何辉； 张秋月； 黄小红； 周贤明； 叶国安；

【机构】 中国原子能科学研究院放射化学研究所；

【摘要】 本论文研究了硝酸体系中以铂黑或负载铂为催化剂、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（Ⅳ）生成速率及转化率的影响。铂黑为催化剂,优化反应条件下U（Ⅳ）的转化率超过99%;Pt/SiO₂为催化剂,优化反应条件下U（Ⅳ）的转化率超过98%。比较了采用两种催化剂时反应存在的差异并探讨了原因。更多还原

【Abstract】 The reduction of U（Ⅵ） by hydrazine catalyzed with platinum black or Pt/SiO₂ as catalyst in HNO₃ solutions was studied.The influence of such factors as concentration of nitric acid,hydrazine,reaction temperature,the dosage of catalysts on the production rate of U（Ⅳ）,the inversion rate of U（Ⅳ） were studied.The inversion rate of U（Ⅳ） could be higher than 99% at optimized reaction condition with platinum as catalyst.Meanwhile,the inversion rate of U（Ⅳ） could be surpassed 98% at optimized reaction condition with Pt/SiO₂ as catalyst.The difference between the two catalysts was compared,and the different catalytic mechanism were investigated.更多还原