To separate molybdenum-99 from fission products of low enriched uranium (LEU)by precipitation with α-benzoin oxime (α-BO),influences of temperature,con-centration of nitrate,molar ratio ofα-BO to Mo,radiation dose and uranium concentra-tion on precipitating molybdenum with α-BO had been evaluated.Re-dissolution of MoO2 (α-BO)2 was performed.The decontamination factors of impurity elements inclu-ding strontium、zirconium、ruthenium、cesium、cerium、iodine-131 and uranium had been determined.The recovery yield of Mo for the separation procedure was calculated. It showed that,at the room temperature,with 1 mol/L of nitric acid concentration , higher than 2 of molar ratio ofα-BO to Mo,whenα-BO was dissolved in anhydrous eth-anol or 0.4 mol/L sodium hydroxide solution,higher than 95% of Mo recovery yield could be obtained.Under the radiation dose rate of 5 000 Gy/h,when the radiation dose increased,Mo recovery yield decreased instead.When the total radiation dose of α-BO was below 8.25×10 5 Gy,Mo recovery yield was higher than 85%.When uranium con-centration increased,Mo recovery yield decreased.MoO2 (α-BO)2 precipitate could be dissolved in sodium hydroxide of 0.5 mol/L within 15 minutes.Effective decontamina-tion for all major impurity elements including strontium, zirconium, ruthenium, cesium,cerium,iodine and uranium were observed.This study has paved the pay for further research for fission 9 9 Mo production.%为研究α-安息香肟(α-BO)沉淀法从低浓铀裂变产物中提取裂变99 Mo 工艺,考察了α-BO 沉淀法提取99 Mo 的条件,包括温度、HNO3浓度、α-BO 与 Mo 摩尔比、辐照剂量、U 浓度对α-BO 沉淀 Mo 的影响,探索了 MoO2(α-BO)2沉淀的再溶解条件,测定了α-BO 沉淀法对131 I、Sr、Zr、Ru、Cs、Ce、U 等杂质元素的去污系数,以及 Mo 回收率。结果表明,在室温下,当 HNO3浓度为1 mol/L,α-BO 与 Mo 摩尔比大于2时,在无水乙醇和0.4 mol/L NaOH 两种α-BO 溶解体系下,Mo 回收率均大于95%。保持辐照剂量率为5000 Gy/h,α-BO 沉淀法提取 Mo 的回收率随α-BO 辐照剂量的增大而降低。辐照剂量低于8.25×105 Gy 时,两种α-BO 溶解体系下,Mo 回收率均大于85%。随着 U 浓度的上升,Mo 回收率逐渐下降。MoO2(α-BO)2沉淀可在15 min 内溶于0.5 mol/L NaOH 溶液中。以上结果表明,采用α-BO 沉淀法分离靶件溶解模拟液时,对 Sr、Zr、Ru、Cs、Ce、I、U 等杂质元素有较好的去污效果。研究结果可为低浓铀生产裂变99 Mo 提供参考。
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