Chen Kunkun, Li Linbo, Yang Kai, Cao Qigao, Chen Yunfei
School of Metallurgical Engineering, Xi'an University of Architecture and Technology Xi'an 710055 China
Electronic Material Research Center, Northwest Institute for Nonferrous Metal Research Xi'an 710016 China.
RSC Adv. 2025 Jan 17;15(3):1604-1617. doi: 10.1039/d4ra08404g. eCollection 2025 Jan 16.
Potassium is a harmful impurity in the rhenium sinter, which adversely affects its mechanical properties by significantly reducing the density of sintered rhenium. Cationic resin is a promising material for potassium removal. In this study, the strong acid cationic exchange resin C160H was pretreated with an HNO solution to enhance its performance in potassium removal. The pretreated C160H resin was characterized using BET, SEM and point of zero charge (PZC) measurements to understand its physicochemical properties. It was verified that the lower PZC value of C160H than that of pristine C160 resin resulted in increased potassium adsorption efficiency. Moreover, the pretreated C160H resin exhibited a maximum potassium adsorption efficiency of 99.28% for 2.00 g L KReO at 25 °C and pH 7.0 for 6 h, with a solid-to-liquid ratio of 1 : 20. The cation sequence affecting potassium adsorption efficiency was found to be Na < Ca < Fe < NH . Isothermal adsorption thermodynamics showed that potassium adsorption by C160H resin followed a heterogeneous and exothermic process. The pseudo-second-order kinetics model best fitted the data, suggesting that potassium adsorption was primarily chemical in nature. DFT calculations confirmed that the adsorption mechanism was based on ion exchange between H and K, with electrostatic interactions serving as the primary driving force for adsorption. The C160H resin demonstrated outstanding regeneration performance, maintaining an adsorption efficiency above 99% after ten cycles. These findings could contribute to improve the potassium adsorption capacity of the resin, thereby reducing both resin dosage and cost in the purification of perrhenate salts.
钾是铼烧结物中的有害杂质，它会显著降低烧结铼的密度，从而对其机械性能产生不利影响。阳离子树脂是一种很有前景的除钾材料。在本研究中，用硝酸溶液对强酸阳离子交换树脂C160H进行预处理，以提高其除钾性能。使用BET、扫描电子显微镜（SEM）和零电荷点（PZC）测量对预处理后的C160H树脂进行表征，以了解其物理化学性质。已证实，C160H的PZC值低于原始C160树脂，这导致钾吸附效率提高。此外，预处理后的C160H树脂在25℃、pH值为7.0、固液比为1∶20的条件下，对2.00 g/L高铼酸钾（KReO）吸附6小时，最大钾吸附效率为99.28%。发现影响钾吸附效率的阳离子顺序为Na＜Ca＜Fe＜NH 。等温吸附热力学表明，C160H树脂对钾的吸附遵循非均相放热过程。准二级动力学模型最能拟合数据，这表明钾吸附主要是化学吸附。密度泛函理论（DFT）计算证实，吸附机制基于H与K之间的离子交换，静电相互作用是吸附的主要驱动力。C160H树脂表现出出色的再生性能，经过十次循环后吸附效率仍保持在99%以上。这些发现有助于提高树脂的钾吸附能力，从而在高铼酸盐纯化过程中降低树脂用量和成本。
