Rare Earth Recovery from Polishing Powder Waste: Methods and Challenges

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Highlights

• Chinese researchers explored advanced techniques for recovering rare earth elements from polishing powder waste, with recovery rates exceeding 98%.
• The study identified acid-leaching and acid-roasting methods as most efficient for REE extraction, emphasizing environmental sustainability.
• Research highlights the potential for reducing waste and improving resource recovery in rare earth element production processes.

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A review by Guojian Lu, Lianyungang Normal College and Hao Liang, Jiangsu Guangsheng Jianfa Renewable Resources Co., LTD, both from the People’s Republic of China, examine techniques for recovering rare earth elements (REEs) from rare earth polishing powder waste (REPPW), a byproduct of high-precision surface polishing. The study highlights methods such as acid-leaching, alkali roasting, and acid roasting, noting recovery rates exceeding 98% in certain cases. These approaches aim to minimize waste and enhance sustainability by reclaiming valuable REEs like cerium and lanthanum. The researchers emphasize the acid-leaching-reducing agent method and acid roasting-water leaching as the most efficient, with high recovery rates and reduced environmental impact.

Their output was published in peer-reviewed Heliyon (opens in a new tab).

Key Findings

The study found that REPPW contains significant REE content (10.31%–86.93%), making recycling economically viable. Methods like acid roasting and water leaching demonstrated high recovery rates, stable product quality, and lower environmental costs compared to traditional processes.

The inclusion of advanced techniques, such as synergistic reducing agents and optimized roasting parameters, further enhanced efficiency and reduced waste.

Limitations and Assumptions

The review assumes ideal laboratory conditions that may not translate directly to industrial settings. Current methods involve high energy consumption, significant wastewater generation, and complex processes, limiting their scalability. The study also overlooks the economic feasibility of large-scale applications, which could pose challenges for industries adopting these methods.

Conclusion

While the research highlights innovative techniques for recovering REEs from REPPW, it underscores the need for environmentally sustainable and cost-effective solutions.

Future studies should focus on optimizing processes, integrating microbiological methods, and exploring new applications for recycled materials. This work contributes to addressing the global challenge of resource sustainability and reducing environmental impact in rare earth production.