PChem Seminar – Caleb Swain

About the event

Speaker: Caleb Swain

Group: Xiaofeng Guo Group

Title: Modern methods of recycling neodymium and other rare earth elements from spent magnet scrap and electrical components.

Abstract:

Industrial use of neodymium and other rare earth elements (REEs) in magnets and myriad technology makes REEs an important resource to protect and bolster the supply of. While neodymium is present in relatively large quantities in earth’s crust, its distribution is uneven, leaving certain areas of the world without significant neodymium mining opportunities. Currently, the United States imports most of the neodymium it uses from abroad, particularly from China. In an effort to foster independence for neodymium use in US industry, methods of recycling neodymium from spent magnets and electronics are investigated, and industrial-scale implementation of such recycling is considered. This talk will highlight three research groups who use different approaches to isolate neodymium and other chemically similar elements. Methods range from classic hydrometallurgy to electrolytic separation, each with specific optimization designs to improve element selectivity and efficiency. In the electrolytic separation of Dy from Nd dissolved in molten calcium chloride, for example, fluoride is added to the molten salt solution, which helps speed up the rate of specific alloy formation at the electrode during electrolysis while maintaining a high separation ratio of Dy/Nd. [1] In another example, spent electronic capacitors are identified as being Nd-rich or Nd-poor through the use of multi-energy X-ray transmittance testing. [3] Once identified, Nd-rich capacitors are used in hydrometallurgical methods to extract neodymium and produce neodymium-based ceramics.

Articles referenced:

(1)

Hua, H.; Yasuda, K.; Nohira, T. Highly Efficient and Precise Electrolysis Separation of Dysprosium from Neodymium for Magnet Scrap Recycling in Molten Salt. ACS Sustainable Chem. Eng. 2022, 10 (28), 9225–9231. https://doi.org/10.1021/acssuschemeng.2c02482.

(2)

Chung, H.; Prasakti, L.; Stopic, S. R.; Feldhaus, D.; Cvetković, V. S.; Friedrich, B. Recovery of Rare Earth Elements from Spent NdFeB Magnets: Metal Extraction by Molten Salt Electrolysis (Third Part). Metals 2023, 13 (3), 559. https://doi.org/10.3390/met13030559.

(3)

Xia, D.; Charpentier, N. M.; Maurice, A. A.; Brambilla, A.; Yan, Q.; Gabriel, J.-C. P. Sustainable Route for Nd Recycling from Waste Electronic Components Featured with Unique Element-Specific Sorting Enabling Simplified Hydrometallurgy. Chemical Engineering Journal 2022, 441, 135886. https://doi.org/10.1016/j.cej.2022.135886.