Modified DGA-Associated Sorbent Media for Rare Earth Element Recovery

A novel hydrophobically modified diglycolamide (DGA) sorbent on organosilica enables selective, efficient, and sustainable recovery of rare earth elements (REEs) from low-grade and waste sources.

Technology Summary

This technology features a modified diglycolamide ligand, notably N,N,N,N-Tetraoctyl Diglycolamide (TODGA), functionalized with hydrophobic alkane chains and immobilized on a swellable organosilica support to create a stable sorbent media. It selectively extracts heavy rare earth elements (HREEs) from complex acidic solutions such as coal fly ash, phosphate fertilizers, and e-waste leachates without requiring pH adjustment. The sorbent is synthesized via a cost-effective, environmentally friendly process with near-complete solvent recovery and supports multiple reuse

cycles. The method enables rapid, high-capacity sorption and efficient stripping of REEs, enhancing sustainable resource recovery and mitigating environmental contamination. Efficient, Selective, Recovery of heavy rare earth elements from domestic sources is vital for securing US security and enabling advanced technologies.

Key Advantages

• High selectivity for heavy rare earth elements even in strongly acidic conditions (pH <1.5)
• Stable sorbent with multiple reuse capability and robust ligand immobilization
• Cost-effective and environmentally friendly synthesis with solvent recovery
• Effective extraction from diverse complex matrices including coal fly ash and phosphate fertilizers
• Reduces hazardous metal accumulation by selectively excluding unwanted metals
• Supports multiple recovery methods including precipitation, filtered leachate sorption, and resin-in-pulp (RIP)

Market Opportunities

• Recovery of rare earth elements from coal fly ash and e-waste recycling

• Extraction of REEs from phosphate fertilizer production by-products
• Industrial wastewater treatment to reclaim critical metals
• Supply chain diversification for high-value REEs in electronics, renewable energy, and defense sectors
• Environmental remediation of contaminated soils and industrial residues
• Integration into hydrometallurgical processing plants for sustainable metal recovery

Stage of Development

Prototype

Patent Status

Pending US Patent 19/321,813 – Filed 9/8/2025

References & Publications

2024 “Selective separation and recovery of rare-earth elements (REEs) from acidic solutions and coal fly ash leachate by novel TODGA Impregnated organosilica media”

https://doi.org/10.1016/j.cej.2024.156849