XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3393
Literature indicates that the intercalation of lithium
into the monoclinic structure of MgX can lead to lithium
losses of 10–0%, which could be a possible reason for the
low extents of lithium dissolution observed in Figure 4 and
Figure 5.
The residual acid concentrations after leaching with
sulphuric acid and organic acid A at the same set of process
conditions, were determined to be similar, on a molar basis.
While magnesium and calcium concentrations in the leach-
ate are very low for organic acid A, relative to sulphuric
acid, a significant amount of acid is still consumed in the
reactions of dolomite and calcite, according to Equation 1
and 2.
CONCLUSIONS
A range of organic acids were screened for the recovery of
lithium from montmorillonite clays, and compared to the
leaching performance of sulphuric acid. Based on the out-
comes of these tests, organic acid A was chosen for leaching
optimisation tests.
Using sulphuric acid, greater than 90% lithium disso-
lution was achieved after 2 hours, with acid concentrations
of at least 1.5 M, temperatures of both 25°C and 60°C,
and 8% solids. A maximum of 82% lithium dissolution
was achieved after 6 hours using organic acid A at 2 M,
40°C and 8% solids. While organic acid A does not have
the advantage of lower acid consumption compared to
sulphuric acid, the significantly lower calcium and magne-
sium concentrations achieved using this organic acid could
potentially simplify downstream processing. Spent organic
acid A could also potentially be regenerated and recycled
back to leaching however, experimental work is required to
determine if this is technically feasible.
Table 3. Metal concentrations for process conditions at which the highest extent of lithium dissolution was achieved for
sulphuric acid and organic acid A, after 6 hours of leaching
Acid type [Acid] (M) Temp. (°C) Solids (%)
Concentration (mg/L)
Al Ca Fe K Li Mg Na
H₂SO₄ 2 60 8 1,090 753 1,310 868 88.7 10,100 1,950
OA-A 2 40 8 919 190 1,210 328 69.1 1,930 1,590
Table 4. Metal concentrations for process conditions at which the highest lithium concentrations were achieved for sulphuric
acid and organic acid A, after 6 hours of leaching
Acid type [Acid] (M) Temp. (°C) Solids (%)
Concentration (mg/L)
Al Ca Fe K Li Mg Na
H₂SO₄ 2 60 12 1,480 641 1,760 1,100 129 17,800 3,000
OA-A 1.5 60 12 1,713 68 2,120 1,100 108 1,850 2,440
REFERENCES
Al-Ani, T., and Sarapää, O. 2008. Clay and clay mineral-
ogy: Physical-chemical properties and industrial uses.
Report. Espoo: Geological Survey of Finland.
Brindley, G.W., and Brown, G. 1984. Crystal structures of
clay minerals and their x-ray identification. London:
Mineralogical Society. p. 169–175.
Ehsani, R., Fourie, L., Hutson, A., Peldiak, D., Spiering, R.,
Young, J., and Armstrong, K. 2018. Technical Report
on the Pre-Feasibility Study for the Thacker Pass Project,
Humboldt County. Report. British Columbia: Advisian.
Fayram, T.S., Lane, T.A., and Brown, J.J. 2020. Prefeasibility
Study Clayton Valley Lithium Project, Esmeralda County.
Nevada: Continental Metallurgical Services and Global
Resource Engineering.
Garcia-Romero, E., Lorenzo, A., Garcia-Vicente, A.,
Morales, J., Garcia-Rivas, J., and Suarez, M. 2021. On
the structural formula of smectites: A review and new
data on the influence of exchangeable cations. Journal of
Applied Crystallography 54:251–262.
Graham, K. 2019. Structure &Reactivity in Organic,
Biological and Inorganic Chemistry: Network Solids -
Aluminosilicates. https://chem.libretexts.org. Accessed
August 2022.
Grant, A. 2019. The Sedimentary Lithium Opportunity.
Report. San Francisco: Jade Cove Partners.
Grant, A., and Goodenough, K. 2021. Is There Enough
Lithium to Make All the Batteries? Report. San Francisco:
Jade Cove Partners.
Hawkstone Mining Ltd. 2019. Big Sandy Lithium Project.
https://www.hawkstonemining.com. Accessed August
2022.
Li, H., Eksteen, J., and Kuang, G. 2019. Recovery of lith-
ium from mineral resources: State-of-the-art and per-
spectives – A review. Hydrometallurgy 189:105129.
Literature indicates that the intercalation of lithium
into the monoclinic structure of MgX can lead to lithium
losses of 10–0%, which could be a possible reason for the
low extents of lithium dissolution observed in Figure 4 and
Figure 5.
The residual acid concentrations after leaching with
sulphuric acid and organic acid A at the same set of process
conditions, were determined to be similar, on a molar basis.
While magnesium and calcium concentrations in the leach-
ate are very low for organic acid A, relative to sulphuric
acid, a significant amount of acid is still consumed in the
reactions of dolomite and calcite, according to Equation 1
and 2.
CONCLUSIONS
A range of organic acids were screened for the recovery of
lithium from montmorillonite clays, and compared to the
leaching performance of sulphuric acid. Based on the out-
comes of these tests, organic acid A was chosen for leaching
optimisation tests.
Using sulphuric acid, greater than 90% lithium disso-
lution was achieved after 2 hours, with acid concentrations
of at least 1.5 M, temperatures of both 25°C and 60°C,
and 8% solids. A maximum of 82% lithium dissolution
was achieved after 6 hours using organic acid A at 2 M,
40°C and 8% solids. While organic acid A does not have
the advantage of lower acid consumption compared to
sulphuric acid, the significantly lower calcium and magne-
sium concentrations achieved using this organic acid could
potentially simplify downstream processing. Spent organic
acid A could also potentially be regenerated and recycled
back to leaching however, experimental work is required to
determine if this is technically feasible.
Table 3. Metal concentrations for process conditions at which the highest extent of lithium dissolution was achieved for
sulphuric acid and organic acid A, after 6 hours of leaching
Acid type [Acid] (M) Temp. (°C) Solids (%)
Concentration (mg/L)
Al Ca Fe K Li Mg Na
H₂SO₄ 2 60 8 1,090 753 1,310 868 88.7 10,100 1,950
OA-A 2 40 8 919 190 1,210 328 69.1 1,930 1,590
Table 4. Metal concentrations for process conditions at which the highest lithium concentrations were achieved for sulphuric
acid and organic acid A, after 6 hours of leaching
Acid type [Acid] (M) Temp. (°C) Solids (%)
Concentration (mg/L)
Al Ca Fe K Li Mg Na
H₂SO₄ 2 60 12 1,480 641 1,760 1,100 129 17,800 3,000
OA-A 1.5 60 12 1,713 68 2,120 1,100 108 1,850 2,440
REFERENCES
Al-Ani, T., and Sarapää, O. 2008. Clay and clay mineral-
ogy: Physical-chemical properties and industrial uses.
Report. Espoo: Geological Survey of Finland.
Brindley, G.W., and Brown, G. 1984. Crystal structures of
clay minerals and their x-ray identification. London:
Mineralogical Society. p. 169–175.
Ehsani, R., Fourie, L., Hutson, A., Peldiak, D., Spiering, R.,
Young, J., and Armstrong, K. 2018. Technical Report
on the Pre-Feasibility Study for the Thacker Pass Project,
Humboldt County. Report. British Columbia: Advisian.
Fayram, T.S., Lane, T.A., and Brown, J.J. 2020. Prefeasibility
Study Clayton Valley Lithium Project, Esmeralda County.
Nevada: Continental Metallurgical Services and Global
Resource Engineering.
Garcia-Romero, E., Lorenzo, A., Garcia-Vicente, A.,
Morales, J., Garcia-Rivas, J., and Suarez, M. 2021. On
the structural formula of smectites: A review and new
data on the influence of exchangeable cations. Journal of
Applied Crystallography 54:251–262.
Graham, K. 2019. Structure &Reactivity in Organic,
Biological and Inorganic Chemistry: Network Solids -
Aluminosilicates. https://chem.libretexts.org. Accessed
August 2022.
Grant, A. 2019. The Sedimentary Lithium Opportunity.
Report. San Francisco: Jade Cove Partners.
Grant, A., and Goodenough, K. 2021. Is There Enough
Lithium to Make All the Batteries? Report. San Francisco:
Jade Cove Partners.
Hawkstone Mining Ltd. 2019. Big Sandy Lithium Project.
https://www.hawkstonemining.com. Accessed August
2022.
Li, H., Eksteen, J., and Kuang, G. 2019. Recovery of lith-
ium from mineral resources: State-of-the-art and per-
spectives – A review. Hydrometallurgy 189:105129.