612 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
transport of metal ions in SEP can be faster that in the dif-
fusion of the ions through the diffusion layer, as confirmed
in a detailed study of the uptake of Pb [27]. This effect is
explained by ‘almost instantaneous’ precipitation of the Pb
hydroxycarbonates at the external boundary of the diffu-
sion layer, followed by the slower transport of the precipi-
tates to the electrode surface.
CONCLUSIONS
Batch-type lab scale tests demonstrate that SEP is a prom-
ising method for the direct onsite recovery of dilute valu-
able elements such as Cu, Zn, REE, U, Co, and Ni as a
group from AMD that has a relatively low (10 mg/L) con-
tent of Al and Fe. These results also imply that SEP can
be integrated into a mineral processing circuit to strip dis-
solved valuable and interfering elements off. Further tests
on different types of AMD and mineral processing water
in a continuous type reactor and larger water volumes are
required to verify this conclusion. The elements recovered
as a group can further be purified offsite/offline using a
suite of hydrometallurgical methods including SEP, which
requires further studies.
In the case of high concentrations of Al and Fe, AMD
should be pretreated to drop the concentrations below
10 mg/L. This can be done by chemical precipitation as
in our study or bulk electrochemical precipitation [8]. The
removal of Al from AMD by chemical precipitation signifi-
cantly reduces energy consumption and increases the metal
recovery rate of SEP.
The Cu uptake mechanism in AMD can be either elec-
tro-deposition or SEP depending on the aqueous matrix
and potential, while the Cu uptake rate by SEP is signifi-
cantly higher. Cu can be selectively recovered by electro-
deposition in the first slow step, while Zn, REE, Co, and Ni
can be recovered as a group by SEP in the second fast step.
Even though electro-deposition of Cu at –0.3 V selectively
separates Cu from AMD, this process is 4 times slower than
SEP of Cu in a group with Zn, REE, U, Co, and Ni at
–0.75 V. It is also twice slower than the diffusion-controlled
electro-deposition of Cu in synthetic sulfate solutions.
The co-uptake of Co, Ni, and Mn by SEP at higher pH
depends on the concentrations of the metal cations that
precipitate at lower pH (e.g., Cu, Al).
The main advantage of SEP compared to adsorption
is the fast regenerability (10 min in our study), combined
with a higher adsorption capacity due to the formation of a
bulk phase rather than a strongly adsorbed monolayer.
Overall, these results underscore the potential of SEP
in the valorization and detoxication of mining water.
ACKNOWLEDGMENTS
This was funded by Boliden Minerals, the Department of
Geoscience and Petroleum, NTNU, Norway, and Research
Council of Norway (an INTPART grant #309608). The
authors thank Laurentius Tijhuis for the ICP-MS and
XRD measurements and Stefanie Lode for the SEM/EDS
measurements.
REFERENCES
[1] Regueiro M, Alonso-Jimenez A. Minerals in the future
of Europe. Mineral Economics. 2021 34(2):209–24.
doi: 10.1007/s13563-021-00254-7.
[2] OECD. Global Material Resources Outlook to 2060.
OECD Publishing, Paris 2019.
[3] Can Sener SE, Thomas VM, Hogan DE, Maier RM,
Carbajales-Dale M, Barton MD, et al. Recovery
of Critical Metals from Aqueous Sources. ACS
Sustainable Chem Eng. 2021 9(35):11616–34. doi:
10.1021/acssuschemeng.1c03005.
[4] Costis S, Mueller KK, Coudert L, Neculita CM,
Reynier N, Blais J-F. Recovery potential of rare
earth elements from mining and industrial residues:
A review and cases studies. Journal of Geochemical
Exploration. 2021 221:106699. doi: 10.1016
/j.gexplo.2020.106699.
[5] Chen G, Ye YC, Yao N, Hu NY, Zhang J, Huang Y.
A critical review of prevention, treatment, reuse, and
resource recovery from acid mine drainage. J Cleaner
Prod. 2021 329. doi: 10.1016/j.jclepro.2021.129666.
[6] Tuffnell S: AMD. The global crisis https://www
.globalaquatica.com.au/what-is-amd. Accessed April
29, 2023.
[7] https://wwwmining-technologycom/features/feature-
managing-water-consumption-mining-global-short-
age/.
[8] Brewster ET, Freguia S, Edraki M, Berry L, Ledezma
P. Staged electrochemical treatment guided by model-
ling allows for targeted recovery of metals and rare
earth elements from acid mine drainage. Journal of
Environmental Management. 2020 275:111266.
doi: 10.1016/j.jenvman.2020.111266.
[9] Banks D, Younger PL, Arnesen R-T, Iversen ER,
Banks SB. Mine-water chemistry: the good, the bad
and the ugly. Environ Geol. 1997 32(3):157–74. doi:
10.1007/s002540050204.
[10] Bakalarz A, Duchnowska M, Luszczkiewicz A. The
effect of process water salinity on flotation of cop-
per ore from Lubin mining region (SW Poland). E3S
Web Conf. 2017 18:01007.
transport of metal ions in SEP can be faster that in the dif-
fusion of the ions through the diffusion layer, as confirmed
in a detailed study of the uptake of Pb [27]. This effect is
explained by ‘almost instantaneous’ precipitation of the Pb
hydroxycarbonates at the external boundary of the diffu-
sion layer, followed by the slower transport of the precipi-
tates to the electrode surface.
CONCLUSIONS
Batch-type lab scale tests demonstrate that SEP is a prom-
ising method for the direct onsite recovery of dilute valu-
able elements such as Cu, Zn, REE, U, Co, and Ni as a
group from AMD that has a relatively low (10 mg/L) con-
tent of Al and Fe. These results also imply that SEP can
be integrated into a mineral processing circuit to strip dis-
solved valuable and interfering elements off. Further tests
on different types of AMD and mineral processing water
in a continuous type reactor and larger water volumes are
required to verify this conclusion. The elements recovered
as a group can further be purified offsite/offline using a
suite of hydrometallurgical methods including SEP, which
requires further studies.
In the case of high concentrations of Al and Fe, AMD
should be pretreated to drop the concentrations below
10 mg/L. This can be done by chemical precipitation as
in our study or bulk electrochemical precipitation [8]. The
removal of Al from AMD by chemical precipitation signifi-
cantly reduces energy consumption and increases the metal
recovery rate of SEP.
The Cu uptake mechanism in AMD can be either elec-
tro-deposition or SEP depending on the aqueous matrix
and potential, while the Cu uptake rate by SEP is signifi-
cantly higher. Cu can be selectively recovered by electro-
deposition in the first slow step, while Zn, REE, Co, and Ni
can be recovered as a group by SEP in the second fast step.
Even though electro-deposition of Cu at –0.3 V selectively
separates Cu from AMD, this process is 4 times slower than
SEP of Cu in a group with Zn, REE, U, Co, and Ni at
–0.75 V. It is also twice slower than the diffusion-controlled
electro-deposition of Cu in synthetic sulfate solutions.
The co-uptake of Co, Ni, and Mn by SEP at higher pH
depends on the concentrations of the metal cations that
precipitate at lower pH (e.g., Cu, Al).
The main advantage of SEP compared to adsorption
is the fast regenerability (10 min in our study), combined
with a higher adsorption capacity due to the formation of a
bulk phase rather than a strongly adsorbed monolayer.
Overall, these results underscore the potential of SEP
in the valorization and detoxication of mining water.
ACKNOWLEDGMENTS
This was funded by Boliden Minerals, the Department of
Geoscience and Petroleum, NTNU, Norway, and Research
Council of Norway (an INTPART grant #309608). The
authors thank Laurentius Tijhuis for the ICP-MS and
XRD measurements and Stefanie Lode for the SEM/EDS
measurements.
REFERENCES
[1] Regueiro M, Alonso-Jimenez A. Minerals in the future
of Europe. Mineral Economics. 2021 34(2):209–24.
doi: 10.1007/s13563-021-00254-7.
[2] OECD. Global Material Resources Outlook to 2060.
OECD Publishing, Paris 2019.
[3] Can Sener SE, Thomas VM, Hogan DE, Maier RM,
Carbajales-Dale M, Barton MD, et al. Recovery
of Critical Metals from Aqueous Sources. ACS
Sustainable Chem Eng. 2021 9(35):11616–34. doi:
10.1021/acssuschemeng.1c03005.
[4] Costis S, Mueller KK, Coudert L, Neculita CM,
Reynier N, Blais J-F. Recovery potential of rare
earth elements from mining and industrial residues:
A review and cases studies. Journal of Geochemical
Exploration. 2021 221:106699. doi: 10.1016
/j.gexplo.2020.106699.
[5] Chen G, Ye YC, Yao N, Hu NY, Zhang J, Huang Y.
A critical review of prevention, treatment, reuse, and
resource recovery from acid mine drainage. J Cleaner
Prod. 2021 329. doi: 10.1016/j.jclepro.2021.129666.
[6] Tuffnell S: AMD. The global crisis https://www
.globalaquatica.com.au/what-is-amd. Accessed April
29, 2023.
[7] https://wwwmining-technologycom/features/feature-
managing-water-consumption-mining-global-short-
age/.
[8] Brewster ET, Freguia S, Edraki M, Berry L, Ledezma
P. Staged electrochemical treatment guided by model-
ling allows for targeted recovery of metals and rare
earth elements from acid mine drainage. Journal of
Environmental Management. 2020 275:111266.
doi: 10.1016/j.jenvman.2020.111266.
[9] Banks D, Younger PL, Arnesen R-T, Iversen ER,
Banks SB. Mine-water chemistry: the good, the bad
and the ugly. Environ Geol. 1997 32(3):157–74. doi:
10.1007/s002540050204.
[10] Bakalarz A, Duchnowska M, Luszczkiewicz A. The
effect of process water salinity on flotation of cop-
per ore from Lubin mining region (SW Poland). E3S
Web Conf. 2017 18:01007.