摘要
本文对过氧化氢沉淀的工艺条件和纯化效果开展了试验研究,从影响过氧化氢沉淀4个主要因素:pH值、过氧化氢用量、沉淀时间、沉淀温度,进行试验研究,pH值和过氧化氢用量是影响铀废料纯化效果和回收率的关键因素,综合考虑纯化效果和铀回收率,其最佳沉淀条件为:pH值为1.2~1.5、反应时间1 h、H_2O_2过量值为100%、反应温度为25℃。在试验得出的最佳沉淀条件下,进一步进行了杂质纯化能力的试验研究,以找到可处理的铀废料的杂质含量标准。研究的杂质种类主要依据:一是在核燃料元件制造过程中易引入且含量较高的杂质(Ni、Zn、Ca、Mg、Cr、Mn、Co、pb、Al),二是影响纯化效果最严重的杂质(Fe),三是中子毒物(Gd、B)。杂质试验分为单项杂质试验和综合杂质试验,通过这两种试验找出了H_2O_2沉淀法对这几种杂质的单项纯化能力极限值和总杂质纯化能力极限值。试验结果表明:在合适的条件下,最终产品U_3O_8粉末的杂质满足核纯要求,铀回收率达到99.8%已上,并找到了铀废料杂质的接收标准,为工业规模生产提供了依据。
In this paper,For hydrogen peroxide precipitation process conditions and purified special effects were studied.First,for the main factors influencing the effect of hydrogen peroxide precipitation:pH value,the amount of hydrogen peroxide,settling time and the precipitation temperature,pilot study to determine the key factors pH value and the amount of hydrogen peroxide is the impact effect of purification and recovery and find the optimum precipitation conditions.Under optimum precipitation conditions,further experimental research in purification ability to find the impurity content standards can be processed uranium waste.Impurities in purification experiment were divided into individual and total impurities purification tests.Through these two tests to find out the hydrogen peroxide precipitation purification capacity limits for individual and total impurities of these impurities purification capacity limit.The results showed:Hydrogen peroxide precipitation purification and recovery of relatively pure uranium waste is feasible,it is necessary to note that at the time of receiving the waste in which the uranium content of impurities were detected,in order to ensure to achieve a better purification effect.
引文
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