abstract
The search for new sources of rare earth metals (REM), such as neodymium and dysprosium, has ensued globally due to their strategic value for the sustainability of the energy sector. In this context, this work explored the potential of vermiculite as a sorbent for recovering rare earth cations from the leachate of end-of-life NdFeB magnets by kinetic, equilibrium, and desorption investigations. In which the REM uptake on vermiculite occurred by fast kinetics, and the significant sorbate-sorbate interactions at the equilibrium indicated that the REM sorption was a cooperative process; vermiculite sorbed the metals from the acid leachate in the following order: Fe(III) > Nd(III) > Zn(II) > Pr(III) > Co(II) > Dy(III) > Ni(II) > Al(III) > Mn(II); and the chelating agent ethylenediaminetetraacetic acid desorbed Nd(III) preferably over other metals, indicating the potential for further selective recovery processes. The characterization analyses indicated that the loaded vermiculite preserved the original structure, composition, functional groups, and thermal stability. Also, X-ray photoelectron spectroscopy corroborated the cation exchange mechanism between interlayer magnesium in the REM sorption. Thus, the experimental findings and a cost analysis compared to the literature demonstrated the costeffectiveness and potential of vermiculite for the valorization of NdFeB magnet leachates.
keywords
ADSORPTION; VERMICULITE; NEODYMIUM; REMOVAL
subject category
Chemistry; Engineering
authors
Briao, GD; Lopes, CB; Trindade, T; Silva, CM; Silva, MGCD; Vieira, MGA
our authors
Carlos Manuel Silva
Associate Professor
Cláudia Batista Lopes
Assistant Researcher
Tito Trindade
Full professorProjects
Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
acknowledgements
This work was funded by the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) (Grants 2017/18236-1 and 2019/11353-8) , Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) (Grant 88887.571776/2020-00) , Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) (Grants 406193/2018-5 and 308046/2019-6) . Claudia B. Lopes thanks Fundacao para a Ciencia e a Tecnologia (FCT) for her researcher contract (CEECIND/03739/2021) . We also thank the project CICECO - Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC) .