离子交换法提取大量钍中微量铀

摘要

This work describes the ion exchange separation of trace amounts of uranium from large quantities of thorium and fission product elements .The fission elements were investi‐gated including Cs ,Sr ,Y ,Zr ,Nb ,Ru ,Rh ,La ,Ce and Eu .The separation method employed Dowex1 × 8 as anion exchanger and Dowex50 × 8 as cation exchanger . U was strongly adsorbed on the Dowex1 × 8 resin from a medium of 8 mol/L HCl .Then washed the column by 8 mol/L HCl‐0.2 mol/L NH4 F mixture .The large quantities of Th as well as other elements concerned passed into the effluent and were thus separated .U was eluted using 0.05 mol/L HNO3 .The U product contaminated pud with even equal concentration of Th can be satisfactorily purified by feeding directly to the cation exchange column and stripping using 2 mol/L HNO3 to achieve the final purification of U from Th .%采用浓盐酸溶解ThO2和U3 O8、以Dowex1×8阴离子交换树脂和Dowex50×8阳离子交换树脂作离子交换剂，研究了从大量钍及微量裂变产物（FPs）中提取微量铀的方法。考察了裂变产物元素Cs、Sr、Y、Zr、Nb、Ru、Rh、La、Ce、Eu的去污效果。结果表明，用离子交换法可以实现从百克每升 Th及FPs中分离出微量U。最优工艺条件是料液调至8 mol／L HCl介质，大量T h和微量的FPs在8 mol／L HCl‐0.2 mol／L N H4 F洗涤条件下直接通过阴离子交换柱，而U吸附于树脂上，再用0.05 mol／L HNO3淋洗 U。低 HNO3淋洗 U后，直接过阳离子柱吸附微量Th ，再用2 mol／L HNO3淋洗得到纯U。结果表明，U收率大于98％，产品中T h及FPs的含量均小于0.05μg／L。