TEVA-TEVA色层分离大量铀中的微量镎

建立了高效分离高铀镎比样品中微量镎的方法。采用TEVA-TEVA萃取色层柱分离铀产品中微量镎，经3.0 mol/L HNO₃淋洗过后以0.5 mol/L (NH₄)₂CO₃洗脱TEVA树脂上的镎，加入HNO₃分解洗脱液中的碳酸镎酰离子并将溶液调至3.0 mol/L HNO₃，进行TEVA柱二次分离，最后采用0.02 mol/L HNO₃-0.02 mol/L HF洗脱。结果表明：该法稳定性较好，测量相对标准偏差优于4%（n=3），镎的平均回收率大于86%，铀的去污因子大于10⁵，适用于高铀镎比样品中微量镎的分离，在乏燃料后处理工艺中铀线尾端的微量镎分析中具有较好的应用前景。

Separation of Trace Neptunium in Bulk Uranium Using TEVA-TEVA Extraction Chromatography

A new separation method by combining two TEVA extraction chromatographic columns was studied for analysis of trace neptunium in bulk uranium. The absorbed Np(Ⅳ) and residual uranium remaining on the first TEVA column will be eluted by ammonium carbonate after uranium matrix is removed with 3.0 mol/L HNO₃. After the carbonate complexation of Np(Ⅳ) ion in the elutant is destroyed with nitric acid, the sample is loaded on the second TEVA column, uranium may then be rinsed with 3.0 mol/L HNO₃ while neptunium remains on the TEVA resin. Then Np can be stripped out of the resin with 0.02 mol/L HF-0.02 mol/L HNO₃. The average recovery of neptunium is greater than 86% while the relative standard deviation is less than 4%(n=3), and the decontamination coefficient of uranium is more than 10⁵. This method has a good application prospect in separation neptunium from high U/Np mass ratio samples in nuclear fuel reprocessing plant.