【摘要】 研究了在 (2 5± 0 2 )℃条件下 ,草酸钚 (Ⅳ )沉淀沉降达到平衡所需的时间和草酸钚 (Ⅳ )沉淀在不同浓度HNO3 H2 C2 O4 混合液中的溶解度。研究结果表明 ,将 1mL 1mol/LH2 C2 O4 溶液加到9mL含 0 9mg/mLPu(Ⅳ )的 4 0mol/LHNO3溶液中 ,混匀 5min后得到黄绿色的草酸钚 (Ⅳ )晶体 ,静置 2 2h以上 ,沉淀沉降达到平衡 ;草酸钚 (Ⅳ )沉淀在HNO3 H2 C2 O4 混合液中的溶解度随混合液中H2 C2 O4 浓度增大而增大 ,随混合液中的HNO3 浓度增大而减小 ;在TRPO流程中Np ,Pu的反萃液酸度 (0 5 6mol/LHNO3 0 3mol/LH2 C2 O4 )下 ,草酸钚 (Ⅳ )沉淀的溶解度为S(Pu(Ⅳ ) )≈ 110mg/L。TRPO萃取流程热实验溶液中的 ρ(Pu(Ⅳ ) ) 10 0mg/L ,因此 ,Pu(Ⅳ )在该溶液中不会产生沉淀更多还原

【Abstract】 Under the condition of (25±0 2) ℃, the balance time for the precipitating reaction of plutonium(Ⅳ) oxalate and the solubility of plutonium(Ⅳ) oxalate precipitate in mixed solution of HNO 3 H 2C 2O 4 with different concentration have been studied. 1 mL of 1 mol/L H 2C 2O 4 is added into the 9 mL solution containing 0.9 mg/mL Pu(Ⅳ) and 4.0 mol/L HNO 3. After mixing for 5 min, the yellow green precipitate of plutonium(Ⅳ) oxalate is obtained. Standing for more than 22 h, the precipitating reaction reaches equilibrium. The solubility of plutonium(Ⅳ) oxalate precipitate in the mixed solution of HNO 3 H 2C 2O 4 is increased with the concentration increasing of H 2C 2O 4 and decreased with the concentration increasing of HNO 3 in the mixed solution. In the TRPO process, The solubility of plutonium(Ⅳ) oxalate precipitate in the stripping solution of Pu and Np(mixed solution of 0.56 mol/L HNO 3 0.3 mol/L H 2C 2O 4)≈110 mg/L, but in hot cell experiment of TRPO process, the concentration of Pu(Ⅳ) in the solution is less than 100 mg/L. Therefore plutonium(Ⅳ) can not be precipitated in the solution.更多还原