An environmental-friendly alternative to recovery Rare Earth Elements from spent NdFeB permanent magnets by electrochemical recycling process

Informations projet

REEcycle

N° de convention de subvention: 101106819

DOI

10.3030/101106819

Projet clôturé

Date de signature de la CE 14 Mars 2023

Date de début 1 Mai 2023

Date de fin 30 Avril 2025

Financé au titre de

• Marie Skłodowska-Curie Actions (MSCA)

Coût total

Aucune donnée

Contribution de l’UE

€ 187 624,32

Coordonné par

TECHNISCHE UNIVERSITEIT DELFT
Netherlands

Periodic Reporting for period 1 - REEcycle (An environmental-friendly alternative to recovery Rare Earth Elements from spent NdFeB permanent magnets by electrochemical recycling process)

Période du rapport: 2023-05-01 au 2025-04-30

Résumé du contexte et des objectifs généraux du projet

Rare earth elements (REEs) are essential to many modern technologies, from wind turbines to electric vehicles and electronics. However, most REEs are currently sourced from a handful of countries, and their extraction often comes with high environmental costs.
To support a more resilient and sustainable European supply chain for these critical raw materials, innovative recycling solutions are urgently needed.
In my project REEcycle, I explored how to recover REEs from NdFeB permanent magnets, a common component in many electronic devices and motors. These magnets are often discarded at the end of a product's life, and despite their value, the REEs they contain are rarely recycled in practice.
One key challenge is that the magnets are made of a complex metallic structure, and current recycling methods often dissolve the entire material without selectivity, leading a long recycling route comprising of several steps and extensive use of water and chemicals.
My goal was to investigate a more controlled and sustainable way to dissolve and recover REEs, using organic acids in combination with electrochemical techniques.
This method avoids the use of harsh chemicals and enables the targeting of specific phases within the magnet structure, making the process potentially more efficient and environmentally friendly.
To achieve this, I designed the project around three main steps:

(1) identifying which organic acids and conditions work best for dissolving the magnets as a whole,
(2) using a high-resolution technique to study how specific parts of the magnet dissolve at the microscopic scale, and
(3) monitor surface changes during dissolution in real time, to better understand and control the process.

Through this project, I not only advanced the scientific understanding of REE dissolution, but also demonstrated a new path toward selective recycling. The findings can contribute to more circular use of critical materials in Europe and support future policy developments in sustainable product design and end-of-life recycling.

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

During the REEcycle project, I carried out a combination of laboratory experiments and advanced electrochemical analyses to understand how rare earth elements dissolve from NdFeB magnets when exposed to organic acids.
I started by testing different acids at a global (macroscale) level to identify the most suitable candidates for selective dissolution. Among the acids tested, acetic and citric acid showed the most promising behaviour, offering controlled leaching conditions that avoid complete breakdown of the material.
I then moved to the microscale, where I used a technique called scanning electrochemical cell microscopy (SECCM). This allowed me to study, with very high spatial resolution, how different areas of the magnet; particularly those rich in rare earth elements.
This was the first time SECCM had been used on such a complex material, especially in combination with organic acids. I developed a full experimental workflow, including the fabrication of nanoscale pipettes, electrochemical measurements, and post-analysis using scanning electron microscopy (SEM) to correlate structure and reactivity.
In the final phase of the project, I implemented a new method combining optical microscopy with electrochemical measurements. This setup allowed me to track surface changes during dissolution in real time.
I used it to measure and model the reaction kinetics in different acid environments and discovered that diluted citric acid (0.01 M) offered a balance between control and reactivity; making it a strong candidate for future selective recycling strategies.
Overall, I was able to generate high-quality data, validate a new methodology for studying selective leaching, and confirm that rare earth-rich areas within the magnet structure can be targeted for preferential dissolution.
These results open new possibilities for designing more efficient and environmentally friendly recycling processes for rare earth elements.

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

The REEcycle project brought several results that go beyond the current state of the art in the field of rare earth element recovery and hydrometallurgy.
First, I demonstrated that diluted organic acids, particularly citric acid at 0.01 M concentration, can be used to selectively dissolve specific regions of NdFeB magnets, offering an environmentally friendly alternative to traditional methods based on strong inorganic acids. This opens new possibilities for sustainable leaching processes that are more compatible with green chemistry principles and safer for industrial application.
Second, I was able to apply and adapt SECCM (scanning electrochemical cell microscopy) to a highly complex material system like NdFeB. This had not been done before. The technique allowed me to investigate the electrochemical response of microstructural features such as those enriched in rare-earth elements (grain boundaries and triple points), helping to identify preferential dissolution sites within the magnet. The workflows I mastered, including SEM correlation and Python-based data processing, can now be applied to other critical materials in need of selective recovery strategies.
Finally, I used an hyphenated optical–electrochemical method that enables real-time monitoring of surface changes during REE leaching. This setup is low-cost and easy to implement, which makes it accessible to many laboratories and suitable for further development in pilot or demonstration-scale studies.
For further uptake of these results, some steps are still needed. A life cycle assessment (LCA) should be carried out to quantify the environmental benefits of organic acids versus conventional acids. In parallel, policy support is essential to promote product designs that facilitate disassembly and recovery of permanent magnets. Industrial partnerships will also be key to bringing these methods closer to application.

REEcycled methodology