XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3355
mechanical activation of feed material. From this result, the
mechanical activation is assumed to increase the feed mate-
rial’s reactivity and enable the extraction of valuable metals
under mild conditions.
The crystalline Si, such as quartz, is known to have
very low solubility in acidic media (Rivera et al., 2017).
However, the amorphous Si phase generated by the
mechanical activation process slightly increased the Si
leaching efficiency. The highest leaching efficiency of Si
occurred within 10 minutes of leaching time, and then the
concentration of Si decreased over leaching time as it forms
silica gel (SiO2×H2O) (Figure 3(b)).
CONCLUSION
The mechanical activation process of lepidolite as the pre-
treatment method enables the direct leaching of Li using
diluted sulfuric acid, 20% concentration, under atmo-
sphere pressure and room temperature. In the mechanical
activation stage, the crystallinity decreased from 65.9% to
51.4% for 10 minutes activated and 18.5% for 60 minutes
activated lepidolite. This is assumed to be mainly attributed
to the degree of the dissolution of alkaline metals. From the
leaching result, the mechanical activation enhanced the Li
leaching efficiency by liberating Li from the layered silicate
structure. The Li leaching efficiency gradually improved
from 0.3% for un-activated to 27.2% for 10 minutes acti-
vated, 52.9% for 30 minutes activated, and to 78.4% of
the maximum efficiency for 60 minutes activated lepidolite
at fixed 180 minutes of leaching time and temperature at
25 °C.
ACKNOLWEDGEMENT
This paper was prepared as part of the Lithium Beneficiation
and Chemical Processing of Lithium Minerals proj-
ect funded by the Future Battery Industries Cooperative
Research Centre as part of the Australian Government
Cooperative Research Centres Program.
REFERENCE
Baláž, P., Baláž, M., Bujňáková, Z. Mechanochemistry
in technology: from minerals to nanomaterials and
drugs. Chemical Engineering &Technology. 2014,
37(5), 747–756.
Choubey, P.K., Kim, M., Srivastava, R.R., Lee, J., Lee, J.Y.
2016. Advance review on the exploitation of the prom-
inent energy-storage element: Lithium. Part I: From
mineral and brine resources. Minerals Engineering. 89:
119–137.
Guo, H., Kuang, G., Li, H., Pei, W., and Wang, H. 2021.
Enhanced lithium leaching from lepidolite in con-
tinuous tubular reactor using H2SO4+H2SiF6 as lix-
iviant. Transactions of Nonferrous Metals Society of
China, 31(7): 2165–2173.
Lee, J. 2015. Extraction of Lithium from Lepidolite Using
Mixed Grinding with Sodium Sulfide Followed by
Water Leaching. Minerals, 5(4): 737–743.
Liu, J., Yin, Z., Li, X., Hu, Q., and Liu, W. 2019. Recovery
of valuable metals from lepidolite by atmosphere leach-
ing and kinetics on dissolution of lithium. Transactions
of Nonferrous Metals Society of China, 29(3): 641–649.
Luong, V.T., Kang, D.J., An, J.W., Kim, M.J., and Tran, T.
2013. Factors affecting the extraction of lithium from
lepidolite. Hydrometallurgy, 134–135: 54–61.
Rivera. R.M, Ulenaers, B., Ounoughene, G., Binnemans,
K., and Van Gerven, T. 2017. Behaviour of silica dur-
ing metal recovery from bauxite residue by acidic leach-
ing, in Proceedings of 35th International ICSOBA
Conference, Hamburg, Germany, 2–5 October,
2017, pp. 547–556.
Rodriguez, M., Quiroga, O., and Ruiz, M. del C. 2007.
Kinetic study of ferrocolumbite dissolution in hydro-
fluoric acid medium. Hydrometallurgy, 85(2): 87–94.
Rosales, G.D., Pinna, E.G., Suarez, D.S., and Rodriguez,
M.H. 2017. Recovery Process of Li, Al and Si from
Lepidolite by Leaching with HF. Minerals, 7(3): 36.
Setoudeh, N., Nosrati, A., and Welham, N.J. 2019.
Lithium recovery from mechanically activated mixtures
of lepidolite and sodium sulfate. Mineral Processing and
Extractive Metallurgy, 1–8.
Vieceli, N., Nogueira, C.A., Pereira, M.F.C., Durão, F.O.,
Guimarães, C., and Margarido, F., 2016. Optimization
of Lithium Extraction from Lepidolite by Roasting
Using Sodium and Calcium Sulfates. Mineral Processing
and Extractive Metallurgy Review, 38(1): 62–72.
Vieceli, N., Nogueira, C.A., Pereira, M.F.C., Durão, F.O.,
Guimarães, C., and Margarido, F. 2018. Optimization
of an innovative approach involving mechanical activa-
tion and acid digestion for the extraction of lithium
from lepidolite. International Journal of Minerals,
Metallurgy, and Materials, 25(1): 11–19.
Wang, H., Zhou, A., Guo, H., Meng-hua Lü, and Yu, H.
2020. Kinetics of leaching lithium from lepidolite
using mixture of hydrofluoric and sulfuric acid. Journal
of Central South University, 27(1): 27–36.
Warris, C.J., McCormick, P.G. Mechanochemical pro-
cessing of refractory pyrite. Minerals Engineering.
1997, 10(10), 1119–1125.
mechanical activation of feed material. From this result, the
mechanical activation is assumed to increase the feed mate-
rial’s reactivity and enable the extraction of valuable metals
under mild conditions.
The crystalline Si, such as quartz, is known to have
very low solubility in acidic media (Rivera et al., 2017).
However, the amorphous Si phase generated by the
mechanical activation process slightly increased the Si
leaching efficiency. The highest leaching efficiency of Si
occurred within 10 minutes of leaching time, and then the
concentration of Si decreased over leaching time as it forms
silica gel (SiO2×H2O) (Figure 3(b)).
CONCLUSION
The mechanical activation process of lepidolite as the pre-
treatment method enables the direct leaching of Li using
diluted sulfuric acid, 20% concentration, under atmo-
sphere pressure and room temperature. In the mechanical
activation stage, the crystallinity decreased from 65.9% to
51.4% for 10 minutes activated and 18.5% for 60 minutes
activated lepidolite. This is assumed to be mainly attributed
to the degree of the dissolution of alkaline metals. From the
leaching result, the mechanical activation enhanced the Li
leaching efficiency by liberating Li from the layered silicate
structure. The Li leaching efficiency gradually improved
from 0.3% for un-activated to 27.2% for 10 minutes acti-
vated, 52.9% for 30 minutes activated, and to 78.4% of
the maximum efficiency for 60 minutes activated lepidolite
at fixed 180 minutes of leaching time and temperature at
25 °C.
ACKNOLWEDGEMENT
This paper was prepared as part of the Lithium Beneficiation
and Chemical Processing of Lithium Minerals proj-
ect funded by the Future Battery Industries Cooperative
Research Centre as part of the Australian Government
Cooperative Research Centres Program.
REFERENCE
Baláž, P., Baláž, M., Bujňáková, Z. Mechanochemistry
in technology: from minerals to nanomaterials and
drugs. Chemical Engineering &Technology. 2014,
37(5), 747–756.
Choubey, P.K., Kim, M., Srivastava, R.R., Lee, J., Lee, J.Y.
2016. Advance review on the exploitation of the prom-
inent energy-storage element: Lithium. Part I: From
mineral and brine resources. Minerals Engineering. 89:
119–137.
Guo, H., Kuang, G., Li, H., Pei, W., and Wang, H. 2021.
Enhanced lithium leaching from lepidolite in con-
tinuous tubular reactor using H2SO4+H2SiF6 as lix-
iviant. Transactions of Nonferrous Metals Society of
China, 31(7): 2165–2173.
Lee, J. 2015. Extraction of Lithium from Lepidolite Using
Mixed Grinding with Sodium Sulfide Followed by
Water Leaching. Minerals, 5(4): 737–743.
Liu, J., Yin, Z., Li, X., Hu, Q., and Liu, W. 2019. Recovery
of valuable metals from lepidolite by atmosphere leach-
ing and kinetics on dissolution of lithium. Transactions
of Nonferrous Metals Society of China, 29(3): 641–649.
Luong, V.T., Kang, D.J., An, J.W., Kim, M.J., and Tran, T.
2013. Factors affecting the extraction of lithium from
lepidolite. Hydrometallurgy, 134–135: 54–61.
Rivera. R.M, Ulenaers, B., Ounoughene, G., Binnemans,
K., and Van Gerven, T. 2017. Behaviour of silica dur-
ing metal recovery from bauxite residue by acidic leach-
ing, in Proceedings of 35th International ICSOBA
Conference, Hamburg, Germany, 2–5 October,
2017, pp. 547–556.
Rodriguez, M., Quiroga, O., and Ruiz, M. del C. 2007.
Kinetic study of ferrocolumbite dissolution in hydro-
fluoric acid medium. Hydrometallurgy, 85(2): 87–94.
Rosales, G.D., Pinna, E.G., Suarez, D.S., and Rodriguez,
M.H. 2017. Recovery Process of Li, Al and Si from
Lepidolite by Leaching with HF. Minerals, 7(3): 36.
Setoudeh, N., Nosrati, A., and Welham, N.J. 2019.
Lithium recovery from mechanically activated mixtures
of lepidolite and sodium sulfate. Mineral Processing and
Extractive Metallurgy, 1–8.
Vieceli, N., Nogueira, C.A., Pereira, M.F.C., Durão, F.O.,
Guimarães, C., and Margarido, F., 2016. Optimization
of Lithium Extraction from Lepidolite by Roasting
Using Sodium and Calcium Sulfates. Mineral Processing
and Extractive Metallurgy Review, 38(1): 62–72.
Vieceli, N., Nogueira, C.A., Pereira, M.F.C., Durão, F.O.,
Guimarães, C., and Margarido, F. 2018. Optimization
of an innovative approach involving mechanical activa-
tion and acid digestion for the extraction of lithium
from lepidolite. International Journal of Minerals,
Metallurgy, and Materials, 25(1): 11–19.
Wang, H., Zhou, A., Guo, H., Meng-hua Lü, and Yu, H.
2020. Kinetics of leaching lithium from lepidolite
using mixture of hydrofluoric and sulfuric acid. Journal
of Central South University, 27(1): 27–36.
Warris, C.J., McCormick, P.G. Mechanochemical pro-
cessing of refractory pyrite. Minerals Engineering.
1997, 10(10), 1119–1125.