Lu Guojian, Liang Hao
Lianyungang Normal College, Lianyungang, Jiangsu, 222006, China.
Jiangsu Guangsheng Jianfa Renewable Resources Co., LTD, Lianyungang, Jiangsu, 222006, China.
Heliyon. 2024 Nov 29;10(23):e40785. doi: 10.1016/j.heliyon.2024.e40785. eCollection 2024 Dec 15.
Rare earth polishing powder has gained widespread usage in the surface polishing of high-precision materials, exhibiting an annual growth rate exceeding 10 %. However, a significant portion of this powder is discarded due to impurities and the need for particle size refinement. The waste generated from polishing powder contains 10.31 %-86.93 % rare earth elements, making secondary recycling economically viable. This work critically analyses and verifies existing methods for recovering rare earths(REs)from rare earth polishing powder waste (REPPW). It concludes that the acid roasting, water leaching, and reduction, coordination acid-leaching methods can achieve rare earth recovery rates exceeding 98 %, offering a relatively simple and environmentally friendly process. We highlight various rare earth recovery processes from REPPW, including alkaline roasting with acid-leaching, acid roasting with water-leaching, acid-leaching with alkali dissolution and washing, and acid-leaching with the aid of reducing agents. It is found that the acid-leaching-water leaching process and the acid-leaching-reducing agent synergy process demonstrate high recovery rates, ease of operation, reduced environmental impact, and stable product quality. It is recommended that researchers focus on refining leaching theories, optimizing process conditions and determining key parameters to further advance the production of rare earth recovery from REPPW. The findings of this study contribute to the development of sustainable practices for the recovery of valuable REs from industrial waste streams.
稀土抛光粉已广泛应用于高精度材料的表面抛光，年增长率超过10%。然而，由于杂质和粒度细化的需要，这种粉末的很大一部分被丢弃。抛光粉产生的废料含有10.31%-86.93%的稀土元素，使得二次回收在经济上可行。这项工作批判性地分析和验证了从稀土抛光粉废料（REPPW）中回收稀土（REs）的现有方法。得出的结论是，酸焙烧、水浸出和还原、配位酸浸出方法可以实现超过98%的稀土回收率，提供了一个相对简单且环保的工艺。我们重点介绍了从REPPW中回收稀土的各种工艺，包括碱焙烧酸浸出、酸焙烧水浸出、酸浸出碱溶解和洗涤以及借助还原剂的酸浸出。发现酸浸-水浸工艺和酸浸-还原剂协同工艺具有回收率高、操作简便、环境影响小和产品质量稳定的特点。建议研究人员专注于完善浸出理论、优化工艺条件和确定关键参数，以进一步推进从REPPW中回收稀土的生产。本研究结果有助于开发从工业废物流中回收有价值稀土的可持续实践方法。
