1692 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
was not selective for either Co or Sm over each other. This
implies that the effectiveness of leaching is rather depen-
dent on the chemical properties of each of the DESs.
RECOMMENDATIONS
• Further work should be done to ascertain why
the leaching of SmCo using Reline, Oxaline, and
EG-TBAC was selective to Co over Sm while
Ethaline showed little difference between Co or Sm
over other leaching conversions.
• Work should be done to have a better understand-
ing of the leaching kinetics in the DESs medium by
increasing time and varying leaching parameters.
• Work should be done to know why Oxaline with a
higher viscosity is shown to be the best reagent for
the leaching of Co with 82% conversion.
• More work should be done by increasing RAM
operating time and varying operating parameters to
improve on recovery efficiency.
REFERENCES
[1] S. Peelman, Z. H. I. Sun, J. Sietsma, and Y. Yang,
“Leaching of Rare Earth Elements: Review of Past
and Present Technologies,” in Rare Earths Industry:
Technological, Economic, and Environmental
Implications, Elsevier Inc., 2015, pp. 319–334. doi:
10.1016/B978-0-12-802328-0.00021-8.
[2] T. Dutta et al., “Global demand for rare earth
resources and strategies for green mining.,” Environ
Res, vol. 150, pp. 182–190, Oct. 2016, doi: 10.1016
/J.ENVRES.2016.05.052.
[3] H. X. Mai et al., “High-quality sodium rare-earth flu-
oride nanocrystals: Controlled synthesis and optical
properties,” J Am Chem Soc, vol. 128, no. 19, pp. 6426–
6436, May 2006, doi: 10.1021/JA060212H/SUPPL
_FILE/JA060212HSI20060414_124908.PDF.
[4] U. States Department of Energy, “Critical Materials
Rare Earths Supply Chain: A Situational White
Paper,” 2020.
[5] G. Inman, I. C. Nlebedim, and D. Prodius,
“Application of Ionic Liquids for the Recycling and
Recovery of Technologically Critical and Valuable
Metals,” Energies, vol. 15, no. 2. MDPI, Jan. 01,
2022. doi: 10.3390/en15020628.
[6] M. Irina et al., “Electrochemical leaching of rare-
earth elements from spent NdFeB magnets,” 2020,
doi: 10.1016/j.hydromet.2020.105264.
[7] J. Z. Wang, Y. C. Tang, and Y. H. Shen, “Leaching
of Sm, Co, Fe, and Cu from Spent SmCo Magnets
Using Organic Acid,” Metals (Basel), vol. 13, no. 2,
Feb. 2023, doi: 10.3390/met13020233.
[8] R. Herrington, “Mining our green future,” doi:
10.1038/s41578-021-00325-9.
[9] N. T. Nassar and S. M. Fortier, “ofr20211045.pdf—
Methodology and Technical Input for the 2021
Review and Revision of the U.S. Critical Minerals
List,” 2021.
[10] S. Prusty, S. Pradhan, and S. Mishra, “Extraction
and separation studies of Nd/Fe and Sm/Co by deep
eutectic solvent containing Aliquat 336 and glycerol,”
Journal of Chemical Technology and Biotechnology, vol.
98, no. 7, pp. 1631–1641, Jul. 2023, doi: 10.1002/
jctb.7381.
[11] M. H. Severson, R. T. Nguyen, J. Ormerod, A.
Palasyuk, and J. Cui, “A preliminary feasibility study
of potential market applications for non-commercial
technology magnets,” Heliyon, vol. 8, no. 12, Dec.
2022, doi: 10.1016/J.HELIYON.2022.E11773.
[12] X. Li, Z. Li, M. Orefice, and K. Binnemans, “Metal
Recovery from Spent Samarium-Cobalt Magnets
Using a Trichloride Ionic Liquid,” ACS Sustain Chem
Eng, vol. 7, no. 2, pp. 2578–2584, Jan. 2019, doi:
10.1021/acssuschemeng.8b05604.
[13] S. Sobekova Foltova, T. Vander Hoogerstraete, D.
Banerjee, and K. Binnemans, “Samarium/cobalt
separation by solvent extraction with undiluted qua-
ternary ammonium ionic liquids,” Sep Purif Technol,
vol. 210, pp. 209–218, Feb. 2019, doi: 10.1016
/j.seppur.2018.07.069.
[14] J. M. D. Coey, “Perspective and Prospects for
Rare Earth Permanent Magnets,” Engineering, vol.
6, no. 2, pp. 119–131, Feb. 2020, doi: 10.1016
/J.ENG.2018.11.034.
[15] C. K. Gupta and N. (Nagaiyar) Krishnamurthy,
Extractive metallurgy of rare earths. CRC Press, 2005.
[16] F. J. Alguacil and J. I. Robla, “Recent Work on the
Recovery of Rare Earths Using Ionic Liquids and
Deep Eutectic Solvents,” Minerals, vol. 13, no.
10. Multidisciplinary Digital Publishing Institute
(MDPI), Oct. 01, 2023. doi: 10.3390/min13101288.
[17] X. Li, Z. Li, M. Orefice, and K. Binnemans, “Metal
Recovery from Spent Samarium-Cobalt Magnets
Using a Trichloride Ionic Liquid,” ACS Sustain Chem
Eng, vol. 7, no. 2, pp. 2578–2584, Jan. 2019, doi:
10.1021/acssuschemeng.8b05604.
[18] H. S. Yoon et al., “The Effect of Grinding and Roasting
Conditions on the Selective Leaching of Nd and Dy
from NdFeB Magnet Scraps,” Metals 2015, Vol. 5,
was not selective for either Co or Sm over each other. This
implies that the effectiveness of leaching is rather depen-
dent on the chemical properties of each of the DESs.
RECOMMENDATIONS
• Further work should be done to ascertain why
the leaching of SmCo using Reline, Oxaline, and
EG-TBAC was selective to Co over Sm while
Ethaline showed little difference between Co or Sm
over other leaching conversions.
• Work should be done to have a better understand-
ing of the leaching kinetics in the DESs medium by
increasing time and varying leaching parameters.
• Work should be done to know why Oxaline with a
higher viscosity is shown to be the best reagent for
the leaching of Co with 82% conversion.
• More work should be done by increasing RAM
operating time and varying operating parameters to
improve on recovery efficiency.
REFERENCES
[1] S. Peelman, Z. H. I. Sun, J. Sietsma, and Y. Yang,
“Leaching of Rare Earth Elements: Review of Past
and Present Technologies,” in Rare Earths Industry:
Technological, Economic, and Environmental
Implications, Elsevier Inc., 2015, pp. 319–334. doi:
10.1016/B978-0-12-802328-0.00021-8.
[2] T. Dutta et al., “Global demand for rare earth
resources and strategies for green mining.,” Environ
Res, vol. 150, pp. 182–190, Oct. 2016, doi: 10.1016
/J.ENVRES.2016.05.052.
[3] H. X. Mai et al., “High-quality sodium rare-earth flu-
oride nanocrystals: Controlled synthesis and optical
properties,” J Am Chem Soc, vol. 128, no. 19, pp. 6426–
6436, May 2006, doi: 10.1021/JA060212H/SUPPL
_FILE/JA060212HSI20060414_124908.PDF.
[4] U. States Department of Energy, “Critical Materials
Rare Earths Supply Chain: A Situational White
Paper,” 2020.
[5] G. Inman, I. C. Nlebedim, and D. Prodius,
“Application of Ionic Liquids for the Recycling and
Recovery of Technologically Critical and Valuable
Metals,” Energies, vol. 15, no. 2. MDPI, Jan. 01,
2022. doi: 10.3390/en15020628.
[6] M. Irina et al., “Electrochemical leaching of rare-
earth elements from spent NdFeB magnets,” 2020,
doi: 10.1016/j.hydromet.2020.105264.
[7] J. Z. Wang, Y. C. Tang, and Y. H. Shen, “Leaching
of Sm, Co, Fe, and Cu from Spent SmCo Magnets
Using Organic Acid,” Metals (Basel), vol. 13, no. 2,
Feb. 2023, doi: 10.3390/met13020233.
[8] R. Herrington, “Mining our green future,” doi:
10.1038/s41578-021-00325-9.
[9] N. T. Nassar and S. M. Fortier, “ofr20211045.pdf—
Methodology and Technical Input for the 2021
Review and Revision of the U.S. Critical Minerals
List,” 2021.
[10] S. Prusty, S. Pradhan, and S. Mishra, “Extraction
and separation studies of Nd/Fe and Sm/Co by deep
eutectic solvent containing Aliquat 336 and glycerol,”
Journal of Chemical Technology and Biotechnology, vol.
98, no. 7, pp. 1631–1641, Jul. 2023, doi: 10.1002/
jctb.7381.
[11] M. H. Severson, R. T. Nguyen, J. Ormerod, A.
Palasyuk, and J. Cui, “A preliminary feasibility study
of potential market applications for non-commercial
technology magnets,” Heliyon, vol. 8, no. 12, Dec.
2022, doi: 10.1016/J.HELIYON.2022.E11773.
[12] X. Li, Z. Li, M. Orefice, and K. Binnemans, “Metal
Recovery from Spent Samarium-Cobalt Magnets
Using a Trichloride Ionic Liquid,” ACS Sustain Chem
Eng, vol. 7, no. 2, pp. 2578–2584, Jan. 2019, doi:
10.1021/acssuschemeng.8b05604.
[13] S. Sobekova Foltova, T. Vander Hoogerstraete, D.
Banerjee, and K. Binnemans, “Samarium/cobalt
separation by solvent extraction with undiluted qua-
ternary ammonium ionic liquids,” Sep Purif Technol,
vol. 210, pp. 209–218, Feb. 2019, doi: 10.1016
/j.seppur.2018.07.069.
[14] J. M. D. Coey, “Perspective and Prospects for
Rare Earth Permanent Magnets,” Engineering, vol.
6, no. 2, pp. 119–131, Feb. 2020, doi: 10.1016
/J.ENG.2018.11.034.
[15] C. K. Gupta and N. (Nagaiyar) Krishnamurthy,
Extractive metallurgy of rare earths. CRC Press, 2005.
[16] F. J. Alguacil and J. I. Robla, “Recent Work on the
Recovery of Rare Earths Using Ionic Liquids and
Deep Eutectic Solvents,” Minerals, vol. 13, no.
10. Multidisciplinary Digital Publishing Institute
(MDPI), Oct. 01, 2023. doi: 10.3390/min13101288.
[17] X. Li, Z. Li, M. Orefice, and K. Binnemans, “Metal
Recovery from Spent Samarium-Cobalt Magnets
Using a Trichloride Ionic Liquid,” ACS Sustain Chem
Eng, vol. 7, no. 2, pp. 2578–2584, Jan. 2019, doi:
10.1021/acssuschemeng.8b05604.
[18] H. S. Yoon et al., “The Effect of Grinding and Roasting
Conditions on the Selective Leaching of Nd and Dy
from NdFeB Magnet Scraps,” Metals 2015, Vol. 5,