XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1267
Also shown in the figure for comparison are the libera-
tion results obtained by grinding. As shown, blunging was
much more efficient than grinding. Work is continuing to
further improve the method of liberating REMs and passiv-
ated IACs from coal.
Conceptual Process Flowsheet
Based on the test results obtained in the present work, a
conceptual flowsheet, as depicted in Figure 8b, may be pro-
posed. A thickener underflow is blunged to liberate REMs
and passivated IACs from the coal matrix in a polyelec-
trolyte solution. The exit stream from the blunger is then
subjected to the two-liquid flotation process i) to obtain
low-ash and low-moisture carbonaceous materials as a
byproduct and ii) to produce a feedstock for activated-IEX
leaching. The material entering the third step will include
both the passivated IACs and REMs. As discussed, NaOH
and a chelating agent are used to overcome the harmful
effects of phosphate passivation. It has also been shown that
the same set of reagents are used to extract REEs from mon-
azite by IEX leaching under relatively mild conditions (Liu
et al., 2022). The product stream exiting the IEX leaching
step is then converted to salable mixed REOs, while the
reject stream is disposed of after appropriate cleanup steps.
ACKNOWLEDGMENT
The authors greatly appreciate the financial support (DE-
FE0029900) from the National Energy Technology Center,
Anthony Zinn and Mary Ann Alvin for helpful discussions,
John Morris and Xu Feng for XPS studies and discussions,
and Rick Honaker for providing low-temperature ash
samples.
Disclaimer: This report was prepared as an account
of work sponsored by an agency of the United States
Government. Neither the United States Government nor
any agency thereof, nor any of their employees, makes any
warranty, express or implied, or assumes any legal liability
or responsibility for the accuracy, completeness, or useful-
ness of any information, apparatus, product, or process
disclosed, or represents that its use would not infringe
privately owned rights. Reference herein to any specific
commercial product, process, or service by trade name,
trademark, manufacturer, or otherwise does not necessarily
constitute or imply its endorsement, recommendation, or
favoring by the United States Government or any agency
thereof. The views and opinions of authors expressed herein
do not necessarily state or reflect those of the United States
Government or any agency thereof.
REFERENCES CITED
Borst, A.M., Smith, M.P., Finch, A.A., Estrade, G.,
Villanova-de-Benavent, C., Nason, P., Marquis, E.,
Horsburgh, N.J., Goodenough, K.M., Xu, C. and
Kynický, J., 2020. Adsorption of rare earth elements
in regolith-hosted clay deposits. Nature communica-
tions, 11(1), p.4386.
Bryan, R.C., Richers, D., Andersen, H.T. and Gray, T.,
2015. Assessment of rare earth elemental contents in
select United States coal basins. United States National
Energy Technology Laboratory.
Cen, P., Bian, X., Liu, Z., Gu, M., Wu, W. and Li, B.,
2021. Extraction of rare earths from bastnaesite con-
centrates: A critical review and perspective for the
future. Minerals Engineering, 171, p.107081.
Dushyantha, N., Batapola, N., Ilankoon, I.M.S.K.,
Rohitha, S., Premasiri, R., Abeysinghe, B.,
Ratnayake, N. and Dissanayake, K., 2020. The story
of rare earth elements (REEs): Occurrences, global dis-
tribution, genesis, geology, mineralogy and global pro-
duction. Ore Geology Reviews, 122, p.103521.
Gaudin, A.M., 1939, Principles of Mineral Processing,
McGraw Hill Book Company, Inc.
Foley, N., Ayuso, R., Hubbard, B., Bern, C. and Shah, A.,
2015. Geochemical and mineralogical character-
istics of REE in Granite-Derived Regolith of the
Southeastern United States. In Mineral resources in a
sustainable world. Proceedings of the 13th Biennial SGA
Meeting (Vol. 2, pp. 725–729).
Foley, N. and Ayuso, R., 2015. REE enrichment in granite-
derived regolith deposits of the Southeastern United
States: Prospective source rocks and accumulation pro-
cesses. Geol. Surv. Pap, 3, pp.131–138.
Krishnamurthy, N. and Gupta, C.K., Extractive metallurgy
of rare earth, Second Edition, CRC Press, New York,
2016.
Huang, K. and Yoon, R.H., 2019. Surface forces in
the thin liquid films (TLFs) of water confined
between n-alkane drops and hydrophobic gold sur-
faces. Langmuir, 35(48), pp.15681–15691.
Huang, K., Strickland, K., Noble, A., Yoon, R.H. and
Basilio, C., 2022. A new method of studying the fun-
damental mechanisms involved in pigment liberation
from recycle papers. TAPPI Journal, 21(10).
Lai, R.W. and Fuerstenau, D.W., 1968. Liquid-liquid
extraction of ultrafine particles. Trans. AIME, 241,
pp.549–556.
Also shown in the figure for comparison are the libera-
tion results obtained by grinding. As shown, blunging was
much more efficient than grinding. Work is continuing to
further improve the method of liberating REMs and passiv-
ated IACs from coal.
Conceptual Process Flowsheet
Based on the test results obtained in the present work, a
conceptual flowsheet, as depicted in Figure 8b, may be pro-
posed. A thickener underflow is blunged to liberate REMs
and passivated IACs from the coal matrix in a polyelec-
trolyte solution. The exit stream from the blunger is then
subjected to the two-liquid flotation process i) to obtain
low-ash and low-moisture carbonaceous materials as a
byproduct and ii) to produce a feedstock for activated-IEX
leaching. The material entering the third step will include
both the passivated IACs and REMs. As discussed, NaOH
and a chelating agent are used to overcome the harmful
effects of phosphate passivation. It has also been shown that
the same set of reagents are used to extract REEs from mon-
azite by IEX leaching under relatively mild conditions (Liu
et al., 2022). The product stream exiting the IEX leaching
step is then converted to salable mixed REOs, while the
reject stream is disposed of after appropriate cleanup steps.
ACKNOWLEDGMENT
The authors greatly appreciate the financial support (DE-
FE0029900) from the National Energy Technology Center,
Anthony Zinn and Mary Ann Alvin for helpful discussions,
John Morris and Xu Feng for XPS studies and discussions,
and Rick Honaker for providing low-temperature ash
samples.
Disclaimer: This report was prepared as an account
of work sponsored by an agency of the United States
Government. Neither the United States Government nor
any agency thereof, nor any of their employees, makes any
warranty, express or implied, or assumes any legal liability
or responsibility for the accuracy, completeness, or useful-
ness of any information, apparatus, product, or process
disclosed, or represents that its use would not infringe
privately owned rights. Reference herein to any specific
commercial product, process, or service by trade name,
trademark, manufacturer, or otherwise does not necessarily
constitute or imply its endorsement, recommendation, or
favoring by the United States Government or any agency
thereof. The views and opinions of authors expressed herein
do not necessarily state or reflect those of the United States
Government or any agency thereof.
REFERENCES CITED
Borst, A.M., Smith, M.P., Finch, A.A., Estrade, G.,
Villanova-de-Benavent, C., Nason, P., Marquis, E.,
Horsburgh, N.J., Goodenough, K.M., Xu, C. and
Kynický, J., 2020. Adsorption of rare earth elements
in regolith-hosted clay deposits. Nature communica-
tions, 11(1), p.4386.
Bryan, R.C., Richers, D., Andersen, H.T. and Gray, T.,
2015. Assessment of rare earth elemental contents in
select United States coal basins. United States National
Energy Technology Laboratory.
Cen, P., Bian, X., Liu, Z., Gu, M., Wu, W. and Li, B.,
2021. Extraction of rare earths from bastnaesite con-
centrates: A critical review and perspective for the
future. Minerals Engineering, 171, p.107081.
Dushyantha, N., Batapola, N., Ilankoon, I.M.S.K.,
Rohitha, S., Premasiri, R., Abeysinghe, B.,
Ratnayake, N. and Dissanayake, K., 2020. The story
of rare earth elements (REEs): Occurrences, global dis-
tribution, genesis, geology, mineralogy and global pro-
duction. Ore Geology Reviews, 122, p.103521.
Gaudin, A.M., 1939, Principles of Mineral Processing,
McGraw Hill Book Company, Inc.
Foley, N., Ayuso, R., Hubbard, B., Bern, C. and Shah, A.,
2015. Geochemical and mineralogical character-
istics of REE in Granite-Derived Regolith of the
Southeastern United States. In Mineral resources in a
sustainable world. Proceedings of the 13th Biennial SGA
Meeting (Vol. 2, pp. 725–729).
Foley, N. and Ayuso, R., 2015. REE enrichment in granite-
derived regolith deposits of the Southeastern United
States: Prospective source rocks and accumulation pro-
cesses. Geol. Surv. Pap, 3, pp.131–138.
Krishnamurthy, N. and Gupta, C.K., Extractive metallurgy
of rare earth, Second Edition, CRC Press, New York,
2016.
Huang, K. and Yoon, R.H., 2019. Surface forces in
the thin liquid films (TLFs) of water confined
between n-alkane drops and hydrophobic gold sur-
faces. Langmuir, 35(48), pp.15681–15691.
Huang, K., Strickland, K., Noble, A., Yoon, R.H. and
Basilio, C., 2022. A new method of studying the fun-
damental mechanisms involved in pigment liberation
from recycle papers. TAPPI Journal, 21(10).
Lai, R.W. and Fuerstenau, D.W., 1968. Liquid-liquid
extraction of ultrafine particles. Trans. AIME, 241,
pp.549–556.