PDF(Pubmed)
Abstract：
The increasing demand for rare earth elements (REEs), especially from new and innovative technology, has strained their supply, which makes the exploration of new REE sources necessary, for example, the recovery of REEs from phsophogypsum (PG). PG is a byproduct during the wet production of phosphoric acid, which is an attractive secondary resource for REEs due to a large amount of REEs locked in them. In most cases, REEs contained in PG are mainly encapsulated in the gypsum crystal, leading to a low leaching efficiency. Therefore, it is particularly important to use various methods to enhance the leaching of REEs from PG. In this review, we summarized and classified various enhanced leaching methods for the recovery of REEs from PG, and the advantages and disadvantages of different methods were compared. A joint method of recrystallization and RIL may be a promising enhanced leaching approach for the recovery of REEs from PG. Recrystallization could achieve both the complete REE release and simultaneous preparation of industrial materials with high value added, such as high-strength α-hemihydrate gypsum by phase transformation of PG, and the RIL technology could adsorb the releasing REEs and realize their efficient extraction. Such a combination appears to show significant advantages because of high REE recovery, as well as high value-added product preparation at low cost.
摘要：
对稀土元素（REE）的需求不断增加，特别是来自新的和创新的技术，使他们的供应紧张，这使得探索新的稀土来源成为必要，例如,从磷酸石膏（PG）中回收稀土元素。PG是磷酸湿法生产过程中的副产品，由于锁定了大量的REE，这是一个有吸引力的二次资源。在大多数情况下,PG中所含的稀土元素主要包封在石膏晶体中，导致浸出效率低。因此,使用各种方法增强从PG中浸出稀土元素尤为重要。在这次审查中,我们总结并分类了各种从PG中回收稀土的强化浸出方法，比较了不同方法的优缺点。重结晶和RIL的联合方法可能是从PG中回收稀土元素的有前途的增强浸出方法。重结晶既可以实现稀土的完全释放，又可以同时制备高附加值的工业材料。如高强度α-半水石膏通过PG的相变，RIL技术可以吸附释放的稀土元素，实现其高效提取。由于高REE回收率，这种组合似乎显示出显著的优势，以及低成本高附加值产品的制备。
