The study presented here focuses on the development of a phenomenological model based on the Nernst-Planck equation for the separation of neodymium (Nd) and praseodymium (Pr) from a mixture containing cerium (Ce) and lanthanum (La) using chelated-assisted electrodialysis with hydroxyethylethylenediaminetriacetic acid (HEDTA) tri disodium salt as the chelating agent. This model considers solution selectivity, membrane selectivity, and ion migration within the membrane. The model is then used to study the optimal concentration of the chelating agent and pH conditions. It is demonstrated that the efficiency of the separation process could be enhanced through a multistage approach where the chelating agent concentration is maintained below the stoichiometric ratio of the elements to be masked. The model's predictive capabilities were evaluated by comparing its results with experimental data obtained at a HEDTA/Nd molar ratio of 1 and pH 3. The model showed an error of less than 26% for removal efficiency for all rare earth elements (REEs), and error values of 3% for purity and 9% for yield. These results indicate that the model can reasonably predict experimental outcomes with an acceptable level of accuracy. The developed model has the potential to be expanded for investigating chelation chemistry and electrodialysis operations involving various combinations of REEs and concentrations. It can be used to design experimental setups to study the effect of chelating agent to REE ratios and pH on key performance factors such as purity, yield, and separation factor. The versatility of the model makes it a valuable tool in the field of electrodialysis for the separation of rare earth metal ions using chelating agents.

本文介绍的研究重点是开发基于 Nernst-Planck 方程的唯象模型，用于使用螯合辅助电渗析从含有铈 (Ce) 和镧 (La) 的混合物中分离钕 (Nd) 和镨 (Pr)以羟乙基乙二胺三乙酸（HEDTA）三二钠盐为螯合剂。该模型考虑了溶液选择性、膜选择性和膜内离子迁移。然后使用该模型研究螯合剂的最佳浓度和 pH 条件。事实证明，通过多级方法可以提高分离过程的效率，其中螯合剂浓度保持低于要掩蔽元素的化学计量比。通过将其结果与 HEDTA/Nd 摩尔比为 1、pH 为 3 时获得的实验数据进行比较来评估模型的预测能力。该模型显示所有稀土元素 (REE) 的去除效率误差小于 26%，并且纯度误差值为 3%，收率误差值为 9%。这些结果表明该模型可以以可接受的准确度合理地预测实验结果。开发的模型有可能扩展到研究涉及稀土元素和浓度的各种组合的螯合化学和电渗析操作。它可用于设计实验装置，以研究螯合剂与 REE 的比例和 pH 值对纯度、产量和分离因子等关键性能因素的影响。该模型的多功能性使其成为电渗析领域使用螯合剂分离稀土金属离子的宝贵工具。