Rare Earth Recovery Breakthrough? Introducing BNMG-1 – A Two-Dimensional Metal Organic Framework

Highlights

• Multidisciplinary research team develops BNMG-1, a two-dimensional metal-organic framework for recovering rare earth elements from electronic waste
• BNMG-1 achieves benchmark performance with over 320 mg/g adsorption capacity and 99% efficiency across four recycling cycles
• Potential breakthrough in sustainable critical mineral recycling
• Reduces environmental impact of traditional rare earth mining processes

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A multidisciplinary team of authors spanning India, the United Kingdom, and beyond, a paper published in Separation and Purification Technology (opens in a new tab) (2025), introducing BNMG-1, a two-dimensional metal-organic framework (MOF), as a promising tool for recovering rare earth elements (REEs) from electronic waste. With affiliation at the Indian Institute of Technology Gandhinagar, University of Cambridge, University of Copenhagen, and other institutions, the authors position  BNMG-1 as a scalable, sustainable solution to a critical challenge in global rare earth supply chains. The authors target the dual issues of growing REE demand and the environmental impact of mining through recycling innovations.  Overall, if applied successfully at scale, this could represent a significant advancement in recycling rare earth minerals.

Hypothesis and Framework

The authors represented by Prathmesh Bhadane (opens in a new tab),

David Fairen-Jimenez (opens in a new tab), and Superb K. Misra (opens in a new tab) as well as colleagues hypothesize that BNMG-1’s unique 2D nanosheet structure, featuring densely packed active adsorption sites, enables high-capacity, efficient, and recyclable recovery of REEs from electronic waste. Further the team  highlight its potential scalability and robustness under harsh industrial conditions, such as variable pH and acidic environments.

The research adopts a twofold framework:

• Synthesis and Characterization: Developing BNMG-1 through a one-pot, room-temperature synthesis and verifying its structural properties using advanced imaging techniques like SEM, TEM, and XPS.
• Performance Testing: Assessing BNMG-1’s adsorption efficiency, capacity, and durability through batch experiments with both model solutions and real-world waste samples, including scrap magnets and fluorescent lamps.

Key Findings

The authors report exceptional adsorption capacity. Adsorption is a surface-based process in which atoms, ions, or molecules from a gas, liquid, or dissolved solid adhere to the surface of a material. Unlike absorption, where a substance diffuses into the bulk of material (like water into a sponge), adsorption occurs primarily on the surface.

BNMG-1 achieved benchmark-level performance with adsorption capacities exceeding 320 mg/g for key REEs, including neodymium (Nd), yttrium (Y), dysprosium (Dy), terbium (Tb), and europium (Eu).

Adsorption efficiencies remained above 99% over four cycles, demonstrating durability and repeatability.

When addressing real-world recovery, practical tests evidence BNMG-1 recovered 57% of Nd from scrap magnets and 27% of Y from fluorescent lamps, showcasing its industrial applicability.

But there is more.  The environmental and operational capabilities were notable.  BNMG-1 maintained performance across a pH range of 3–6 and in acidic conditions, addressing common barriers in REE recovery processes.

Not surprisingly, given what we have reported thus far, the topic of sustainability has become intriguing. The MOF synthesis employed a green solvent, aligning with environmental goals and making the process scalable for industrial adoption.

Strengths of this Study

The study exemplifies the use of cutting-edge material design. The use of a nanosheet-based MOF with high surface area and dense adsorption sites represents a significant leap in REE recovery technologies.

The authors performed comprehensive tests. Combining lab-based equilibrium studies with real-world waste samples strengthened the practical relevance of the findings.

The green synthesis process and the reusability of BNMG-1 support broader efforts to reduce the environmental footprint of REE extraction.

Limitations & Assumptions

Rare Earth Exchanges lists below the limitations identified concerning this paper.

• Selective Recovery: While effective for Nd and Y, the study provides limited insights into the recovery of other REEs commonly found in e-waste, such as cerium (Ce) or lanthanum (La).
• Economic Viability: The study lacks a cost-benefit analysis, leaving questions about the economic competitiveness of BNMG-1 compared to conventional methods unanswered.
• Scaling Challenges: Though scalable in principle, the study does not address logistical hurdles, such as large-scale synthesis or integration into existing recycling infrastructures.  Lots of development would be necessary to make this real world at scale.

We also identify some assumptions and possible biases. First, with an overemphasis on green metrics, meaning the focus on the “green” aspects of BNMG-1’s synthesis may overlook hidden costs, such as energy inputs or waste generated during precursor production.

Second, the study assumes consistent performance across diverse e-waste streams despite limited real-world testing with heterogeneous samples.  Finally, while the synthesis process is described as facile, real-world industrial scalability may face challenges that are not explored in detail.

Conclusion

This study showcases BNMG-1 as a promising advancement in rare earth recovery, particularly for its high adsorption capacity, durability, and environmental compatibility. However, questions about its economic scalability, recovery of diverse REEs, and long-term integration into industrial systems remain. By addressing these gaps, future research could better position BNMG-1 as a cornerstone technology in sustainable critical mineral recycling. This paper marks an important step toward reducing reliance on primary mining through innovative recycling methods.