γ辐照后TBP-煤油对^(95)Zr的萃取和保留

EXTRACTION AND RETENTION OF ZIRCONIUM WITH GAMMA-IRRADIATED TBP-KEROSENE

研究了用不同浓度HNO_3预平衡和经γ辐照不同剂量后的TBP-煤油对^(95)Zr的萃取行为。测定了0.01mol/1HNO_3,5%Na_2CO_3洗涤后的有机相中^(95)Zr的保留百分率。比较了辐照后的TBP-煤油用碱和水萃洗分离得到的三个组份以及HDBP等7种辐解产物对^(95)Zr的萃取和洗涤后有机相中的保留情况。结果表明^(95)Zr的萃取和洗涤后的保留与溶剂所受的辐照剂量和预平衡酸度均有关系。在辐解产物中,单烷基长链酸性磷酸酯和异羟肟酸对Zr的萃取影响都较严重。前者在碱洗时容易产生乳化,而后者在碱洗后对Zr的保留更为严重。

The extraction behaviour of ^(95)Zr with TBP-Kerosene irradiated by variousgamma doses (10~2--10~6Gy) is investigated. The distribution coefficient of ^(95)Zr andretentive percentages of ^(95)Zr in organic phase after scrubbing by 0.01 mol/1 HNO_3and 5% Na_2 CO_3 solution are determined. The TBP-Kerosene used in these tests ispre-equilibrated with various HNO_3 solution(0.5--5 mol/1) before irradiation. Theexperimental results show that the distribution coefficient of ^(95)Zr and retained^(95)Zr in scrubbed organic phase increase as doses and concentration of HNO_3increase. At doses>5×10~4 Gy, the extraction of ^(95)Zr sharply increase with doses.At doses>10~5Gy, ^(95)Zr in the orgenic phase is difficulty stripped by 5% Na_2CO_3solution and emulsion is easily formed. At doses 2×10~6Gy and HNO_3≥3 mol/1,the retentive percentage of ^(95)Zr is >95%. Effect of seven degradation products added to 30% TBP-Kerosene on the extrac-tion and retention of ^(95)Zr are researched. The results indicate that the distributioncoefficients of ^(95)Zr with long chain monoalkylphosphate and hydroxamic acid arelarger than other compounds. When the organic phase is scrubbed with 5%Na_2 CO_3solution, the long chain monoalkylphosphate easily causes emulsion. But thehydroxamic acid is more difficultly scrubbed than long chain monoalkylphosphate by 5% Na_2 CO_3 solution.