At present, in the mining process of ionic rare earths, the separation of rare earth element (REEt) from aqueous solution still relies on natural sedimentation, which has the disadvantage of low efficiency. Additionally, there will be a significant amount of rare earth ions (∼ 30 ppm) remaining in the supernatant. In this work, the use of flat ceramic membranes to separate REEt from aqueous solution is innovatively proposed. Firstly, the performance of REEt separation by flat ceramic membrane process was determined. It was found that the flat ceramic membrane process had good interception performance for REEt separation, and the concentration of rare earth ions in the supernatant was close to 0 ppm. Then, the impacts of different operating conditions (including operating time, backwash duration and concentration times) on the membrane fouling process were investigated. It was demonstrated that the shorter the operating time, the less the degree of membrane fouling. The operation of back washing was greatly beneficial to renew membrane flow. The change of reversible pollution resistance was calculated, the process of membrane pollution was analyzed by four pollution models, and the pollution mechanism was discussed in detail. Furthermore, the recovery of membrane flow after chemical cleaning and non-agent cleaning, and the changes in reversible fouling resistance under different concentration multiples were also studied. It is proved that the immersed flat ceramic membrane has the characteristics of low membrane fouling, high solid–liquid separation efficiency, and good stability for the separation and enrichment of rare earth particles, which shows great potential in industrial applications.

中文翻译：

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平板陶瓷膜法从水溶液中分离稀土富集的性能及污染控制策略

目前，在离子稀土的开采过程中，稀土元素 （REEt） 与水溶液的分离仍然依赖于自然沉降，存在效率低的缺点。此外，上清液中会残留大量稀土离子 （∼ 30 ppm）。在这项工作中，创新性地提出了使用扁平陶瓷膜将 REEt 与水溶液分离。首先，确定了平板陶瓷膜工艺对 REEt 分离的性能。研究发现，平板陶瓷膜工艺对 REEt 分离具有良好的拦截性能，上清液中稀土离子浓度接近 0 ppm。然后，研究了不同作条件（包括作时间、反冲洗持续时间和浓缩时间）对膜污染过程的影响。结果表明，作时间越短，膜污染程度越小。反冲洗作对更新膜流非常有益。计算了可逆抗污染性的变化，用 4 个污染模型分析了膜污染的过程，并详细讨论了污染机理。此外，还研究了化学清洗和非试剂清洗后膜流的恢复情况，以及不同浓度倍数下可逆防污性的变化。事实证明，浸没式扁平陶瓷膜具有膜污染少、固液分离效率高、对稀土颗粒分离富集稳定性好等特点，在工业应用中显示出巨大的潜力。