The precipitation of strontium in highly concentrated nitric acid is often used in standard radiochemical methods for ⁹⁰Sr separation. In this work, the description of Sr behavior in such conditions was studied in the point of speciation simulation. Standard speciation method based on Phreeqc software was considered but two problems underlined the limits of this approach to study this process: inappropriate ionic strength correction model (for I > 10 M) and the particular dissociation of nitric acid. To overcome these issues, a multipurpose-fitting routine, Minuit, was used to fit chemical model parameters. A polynomial expression was also added to the model in order to take into account nitric acid dissociation. This alternative was proved successful to calculate the Sr precipitate in highly concentrated nitric acid. Comparison was made with the results obtained with Design of Experiment methodology.

锶在高浓度硝酸中的沉淀常用于标准放射化学方法⁹⁰Sr 分离。在这项工作中，从物种形成模拟的角度研究了在这种条件下 Sr 行为的描述。考虑了基于 Phreeqc 软件的标准形态分析方法，但有两个问题突出了这种方法研究该过程的局限性：不适当的离子强度校正模型（对于 I > 10 M）和硝酸的特定解离。为了克服这些问题，使用多功能拟合程序 Minuit 来拟合化学模型参数。为了考虑硝酸解离，还向模型中添加了多项式表达式。这种替代方法被证明成功地计算了高浓度硝酸中的 Sr 沉淀。与使用实验设计方法获得的结果进行了比较。