Ildarabadi Amin, Khajenoori Maryam, Zahakifar Fazel, Ghadiri Ahmad
Faculty of Chemical, Petroleum and Gas Engineering, Semnan University, Semnan, Iran.
Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, Tehran, Iran.
Sci Rep. 2025 Jul 22;15(1):26586. doi: 10.1038/s41598-025-11640-4.
The solutions obtained from rare earth element (REE) processing are often acidic. The low pH is a challenge in the separation of REE. Hence, this study focuses on separating Ce(III) from acidic solutions by the ion exchange method using Dowex 50W-X8 resin. In the batch system, the maximum of Ce(III) exchange occurred at a resin dosage of 0.16 g, temperature of 35 °C, and sulfuric acid concentration of 0.2 M. The Ce(III) exchange process achieved equilibrium in 6 h with a capacity of 10.34 mg g, and the kinetic behavior was best fitted with the pseudo-second-order model (R = 0.999). The Langmuir model was followed among the isotherm models, which showed that adsorption occurred in the monolayer. The thermodynamic study revealed that the process was endothermic and spontaneous. In the continuous system, the Ce(III) exchange was carried out for 26 h, and the breakthrough curve obtained was the best fit with the Thomas kinetic model (R = 0.963). Resin regeneration was performed by passing a 3 M sulfuric acid solution through a fixed bed column, resulting in 98.81% desorption. Finally, to understand the Ce(III) exchange behavior in a real medium, the process was investigated in a simulated solution containing Th(IV) and Fe(II) ions.
从稀土元素（REE）加工过程中获得的溶液通常呈酸性。低pH值对稀土元素的分离是一项挑战。因此，本研究聚焦于使用Dowex 50W-X8树脂通过离子交换法从酸性溶液中分离Ce(III)。在间歇系统中，Ce(III)交换量最大时的树脂用量为0.16 g、温度为35℃、硫酸浓度为0.2 M。Ce(III)交换过程在6小时内达到平衡，交换容量为10.34 mg/g，其动力学行为最符合准二级模型（R = 0.999）。在等温模型中符合Langmuir模型，表明吸附以单分子层形式发生。热力学研究表明该过程是吸热且自发的。在连续系统中，Ce(III)交换进行了26小时，获得的穿透曲线最符合Thomas动力学模型（R = 0.963）。通过让3 M硫酸溶液通过固定床柱进行树脂再生，解吸率达98.81%。最后，为了解Ce(III)在实际介质中的交换行为，在含有Th(IV)和Fe(II)离子的模拟溶液中对该过程进行了研究。
