Abstract The noble application of the neodymium on the technological field provides its high aggregate value. However, the future supply depends on the recycle, which still needs the improvement of the classical separation methods. In this study, expanded vermiculite was employed as an adsorbent to neodymium recovery from aqueous solution in batch mode. The specific properties of this phyllosilicate such as the lamellar structure were confirmed by different analytical techniques. The equilibrium of adsorption was well explained by Langmuir achieving the maximum adsorption capacity of 0.48 mmol/g at 283 K. The process was exothermic, spontaneous, and classified as physical adsorption. Desorption experimental conditions were optimized using the response surface methodology. The calcium chloride (0.3 mol/L) as eluent guaranteed a high recovery of neodymium and great reusability to the adsorbent material, achieving an uptake efficiency of 94% and a neodymium recovery of 95% in the fifth cycle. Thus, this commercial clay mineral demonstrated a great potential to recover neodymium from aqueous solution, due to the high adsorption and desorption efficiency after successive cycles of reuse.

中文翻译：

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通过在膨胀蛭石上的吸附/解吸从水溶液中回收钕

摘要 钕在技术领域的高贵应用使其具有很高的综合价值。然而，未来的供应取决于回收，这仍然需要对经典分离方法进行改进。在这项研究中，膨胀蛭石被用作吸附剂，以批量模式从水溶液中回收钕。这种页状硅酸盐的特殊性质，如层状结构，已通过不同的分析技术得到证实。Langmuir 在 283 K 下达到 0.48 mmol/g 的最大吸附容量很好地解释了吸附平衡。该过程是放热的、自发的，并归类为物理吸附。使用响应面方法优化解吸实验条件。氯化钙 (0. 3 mol/L) 作为洗脱液，保证了钕的高回收率和吸附材料的良好重复使用性，在第五个循环中实现了 94% 的吸收效率和 95% 的钕回收率。因此，这种商业粘土矿物表现出从水溶液中回收钕的巨大潜力，因为在连续重复使用后具有高吸附和解吸效率。