硝酸铝存在下稀TBP/煤油对低浓度UO_2(NO_3)_2和HNO_3的萃取

THE EXTRACTION OF LOW-CONCENTRATION URANYL NITRATE AND NITRIC ACID BY DILUTE TBP/KEROSENE IN THE PRESENCE OF Al(NO_3)_3

硝酸铝存在下 ,测定了UO2 (NO3 ) 2 (初始质量浓度为 2 5 g/L)和HNO3 (初始浓度为 0～ 2mol/L)在稀TBP/煤油 (φ≤ 10 % )和水相溶液之间的分配比 ,并采用非线性最小二乘法拟合了UO2 (NO3 )和HNO3 的表观萃取平衡常数表达式。利用拟合得到的平衡常数计算得到的D(U (Ⅵ ) )和D (H+ )与实验值符合较好 ,D(U(Ⅵ ) )平均偏差约为 10 % ,D(H+ )的平均偏差小于 5 %。

The distribution ratios of low concentration UO 2(NO 3) 2(initial mass concentration lower than 10 g/L) and HNO 3(initial concentration 0～2 mol/L) between dilute TBP/kerosene(lower than 10%) and aqueous solution in the presence of Al(NO 3) 3 are determined. Based on these data, the empirical functions of extraction equilibrium concentration quotients K (U(Ⅵ)) and K (H +) are founded by non linear least square fitting method. According to these functions, D (U(Ⅵ)) and D (H +) can be calculated out and they are in good agreement with observed values. The mean error of calculated D (U(Ⅵ)) is about 10%; and the mean error of calculated D (H +) is less than 5%.