Recovery of Critical Rare Earth Elements with α-Aminobis(phosphonates)
Jani Moilanen
α-Aminophosphonates are organophosphorus compounds that were investigated as extraction agents for rare earth elements (REE) for the first time in the 1960s.[1] However, their more systematic investigations did not start until the 2010s, and recent studies have shown that these α-amino-functionalized compounds can outperform the commercial organophosphorus extraction agents in the recovery of REEs.[2,3] If one also considers the facile synthesis of α-aminophosphonates from simple starting materials through Kabachnik–Fields and Podovik reactions as well as their stability in acidic solutions, α-aminophosphonates are ideal scavengers for REEs from various waste streams, which are alternative sources for these critical elements. The demand of REEs has lately increased due to the green transition in the transportation and energy production.[4,5]
In this talk, I summarize our group’s recent findings related to the chemistry of α-aminobis(phosphonates) and discuss their utilization to recover REEs from waste streams. Our results show that α-aminobis(phosphonates) are not only suitable precipitation agents for REEs but also good additive materials for 3D-printed metal scavengers that can be used in the solid-phase extraction of REEs from waste streams.
References
[1] V. Jacodić; et al. J. Inorg. Nucl. Chem., 1970, 32, 1323.
[2] S. Kuang; et al. Sci. China Technol. Sci. 2018, 61, 1319.
[3] E. Kukkonen; et al. Molecules, 2022, 27, 3465.
[4] K. Binnemans; et al. J. Clean. Prod. 2015, 99, 17.
[5] P. Alves Dias; et al. The Role of Rare Earth Elements in Wind Energy and Electric Mobility: An Analysis of Future Supply/Demand Balances; Publications Office of the European Union: Luxembourg, 2020.
