3368 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
are the three categories into which one of the categoriza-
tion techniques separated clay-type lithium resources [15].
Volcanic, carbonate, and Jadarite types are the three catego-
ries into which one of the classification techniques sepa-
rates clay-type lithium resources. Volcanic eruptions, which
are primarily found in Kings Valley, Sonora, and Hector,
produce the volcanic clay-type lithium deposits. Brine and
hydrothermal solution leach the lithium from the ash fol-
lowing the volcanic eruption. After a considerable amount
of time, some leached lithium elements are enriched in clay
in crater lake deposits, which eventually forms volcanic
clay lithium resources. Illite and smectite minerals, which
contain lithium in their crystal structure, are the primary
lithium-bearing minerals in volcanic clay type lithium
resources. The volcanic clay type lithium deposit has a high
concentration of SiO2 and Mg in addition to lithium these
concentrations are typically greater than 50% and 10%,
respectively [10, 16].
The sulfuric acid method has been utilized extensively
in the extraction of lithium from ore [17]. Nevertheless,
it has drawbacks, including excessive leaching reagent use,
severe equipment corrosion from powerful acids, and sig-
nificant environmental damage from leaching residue [15].
As a result, it is necessary to reduce the usage of these chem-
icals and switch to safer (greener) alternatives [18, 19]. One
potential substitute for inorganic acids is organic acids,
which are also biologically degradable leachates [20, 21]. In
the hydrometallurgy processes, organic acids play a vital role
as more ecologically friendly leaching reagents [22]. They
offer several benefits over inorganic acids. Organic acids
are environmentally friendly and highly effective leaching
reagents that can selectively leach metals while also prevent-
ing secondary contamination, delaying equipment corro-
sion, and posing less risk to operators [23, 24]. In addition,
organic acids usually have chelating or complexing proper-
ties, generating more efficient recovery efficiency [25]. The
price of reagents may be an issue because organic acids are
more expensive than inorganic acids, which could raise the
operating costs of industrial installations, besides that the
reactions during the process are slower than in the case of
experiments where the leaching agents were inorganic acids
[26]. However, organic acids used in leaching operations
can be recycled and the waste generated from the leaching
step would be easily managed [27] as an example, Chen et
al. (2015) recovered both citric acid and waste materials by
using oxalic and phosphoric acid [28].
So far, organic acids have not yet been employed in the
leaching of Li-bearing sedimentary claystone. However, Yu
Xie et al. used oxalic acid to recover Li from a coal-based Li
ore, which is a sedimentary type of ore but not a claystone,
where they obtained an 89% leaching rate and were able to
recycle the oxalic acid and reuse it in the system [29]. Also,
organic acids have been used extensively in the leaching of
iron ores, spent Li-ion batteries, lead and zinc ores, tailings,
phosphate ores, nickel ores, etc [30, 31].
The primary aim of this article is to systematically eval-
uate and compare the extraction performances of Li from
claystone, using various organic acids in comparison with
traditional inorganic acids, since this type of research has
not been previously performed on Li-bearing claystone.
By meticulously examining the efficiency, selectivity, and
environmental implications associated with these distinct
leaching agents, this research endeavors to provide a com-
prehensive understanding of the nuanced intricacies in Li
extraction processes from clay resources. Through a rigorous
comparative analysis, the article aims to shed light on the
advantages and challenges posed by organic acids, known
for their biodegradability and environmental friendliness,
in contrast to conventional inorganic acids. This study
aspires to contribute valuable insights to the scientific com-
munity, facilitating informed decision-making in the pur-
suit of sustainable and efficient Li extraction methods from
clay-type resources.
EXPERIMENTAL SECTION
Materials and Characterization Methods
Li-bearing claystone samples from the Nevada region were
utilized for the leaching experiments. Prior to the experi-
ments, the samples were pulverized, and representative
samples were taken by passing the samples through a rotary
splitter (Sepor 48” Rotary Sample Splitter), and further
splitting by a Humboldt riffle-type splitter (Model H-3987
of 0.66’’ Max Material Size). Sulfuric acid and organic acids
including citric, tartaric, and oxalic acid were used in the
study, and they were analytically pure reagents, purchased
from ThermoFisher Scientific ™. The particle size distribu-
tion was obtained from a particle size analyzer. Inductively
coupled plasma atomic emission spectroscopy (ICP-OES)
was employed for elemental analysis. It was used to assess
the levels of Li and other ions present in solution samples
obtained through the aqua regia acid digestion of samples
from the feed material [32, 33]. Also, X-ray diffraction
(XRD) with Cu Kα radiation was employed to deter-
mine the mineral constituents of the Li claystone samples.
Organic Acid Vs Sulfuric Acid Recoveries and Leaching
Method
The leaching experiments were conducted in a
GYROMAX ™ 929 water bath (Figure 1), where 10 g of
are the three categories into which one of the categoriza-
tion techniques separated clay-type lithium resources [15].
Volcanic, carbonate, and Jadarite types are the three catego-
ries into which one of the classification techniques sepa-
rates clay-type lithium resources. Volcanic eruptions, which
are primarily found in Kings Valley, Sonora, and Hector,
produce the volcanic clay-type lithium deposits. Brine and
hydrothermal solution leach the lithium from the ash fol-
lowing the volcanic eruption. After a considerable amount
of time, some leached lithium elements are enriched in clay
in crater lake deposits, which eventually forms volcanic
clay lithium resources. Illite and smectite minerals, which
contain lithium in their crystal structure, are the primary
lithium-bearing minerals in volcanic clay type lithium
resources. The volcanic clay type lithium deposit has a high
concentration of SiO2 and Mg in addition to lithium these
concentrations are typically greater than 50% and 10%,
respectively [10, 16].
The sulfuric acid method has been utilized extensively
in the extraction of lithium from ore [17]. Nevertheless,
it has drawbacks, including excessive leaching reagent use,
severe equipment corrosion from powerful acids, and sig-
nificant environmental damage from leaching residue [15].
As a result, it is necessary to reduce the usage of these chem-
icals and switch to safer (greener) alternatives [18, 19]. One
potential substitute for inorganic acids is organic acids,
which are also biologically degradable leachates [20, 21]. In
the hydrometallurgy processes, organic acids play a vital role
as more ecologically friendly leaching reagents [22]. They
offer several benefits over inorganic acids. Organic acids
are environmentally friendly and highly effective leaching
reagents that can selectively leach metals while also prevent-
ing secondary contamination, delaying equipment corro-
sion, and posing less risk to operators [23, 24]. In addition,
organic acids usually have chelating or complexing proper-
ties, generating more efficient recovery efficiency [25]. The
price of reagents may be an issue because organic acids are
more expensive than inorganic acids, which could raise the
operating costs of industrial installations, besides that the
reactions during the process are slower than in the case of
experiments where the leaching agents were inorganic acids
[26]. However, organic acids used in leaching operations
can be recycled and the waste generated from the leaching
step would be easily managed [27] as an example, Chen et
al. (2015) recovered both citric acid and waste materials by
using oxalic and phosphoric acid [28].
So far, organic acids have not yet been employed in the
leaching of Li-bearing sedimentary claystone. However, Yu
Xie et al. used oxalic acid to recover Li from a coal-based Li
ore, which is a sedimentary type of ore but not a claystone,
where they obtained an 89% leaching rate and were able to
recycle the oxalic acid and reuse it in the system [29]. Also,
organic acids have been used extensively in the leaching of
iron ores, spent Li-ion batteries, lead and zinc ores, tailings,
phosphate ores, nickel ores, etc [30, 31].
The primary aim of this article is to systematically eval-
uate and compare the extraction performances of Li from
claystone, using various organic acids in comparison with
traditional inorganic acids, since this type of research has
not been previously performed on Li-bearing claystone.
By meticulously examining the efficiency, selectivity, and
environmental implications associated with these distinct
leaching agents, this research endeavors to provide a com-
prehensive understanding of the nuanced intricacies in Li
extraction processes from clay resources. Through a rigorous
comparative analysis, the article aims to shed light on the
advantages and challenges posed by organic acids, known
for their biodegradability and environmental friendliness,
in contrast to conventional inorganic acids. This study
aspires to contribute valuable insights to the scientific com-
munity, facilitating informed decision-making in the pur-
suit of sustainable and efficient Li extraction methods from
clay-type resources.
EXPERIMENTAL SECTION
Materials and Characterization Methods
Li-bearing claystone samples from the Nevada region were
utilized for the leaching experiments. Prior to the experi-
ments, the samples were pulverized, and representative
samples were taken by passing the samples through a rotary
splitter (Sepor 48” Rotary Sample Splitter), and further
splitting by a Humboldt riffle-type splitter (Model H-3987
of 0.66’’ Max Material Size). Sulfuric acid and organic acids
including citric, tartaric, and oxalic acid were used in the
study, and they were analytically pure reagents, purchased
from ThermoFisher Scientific ™. The particle size distribu-
tion was obtained from a particle size analyzer. Inductively
coupled plasma atomic emission spectroscopy (ICP-OES)
was employed for elemental analysis. It was used to assess
the levels of Li and other ions present in solution samples
obtained through the aqua regia acid digestion of samples
from the feed material [32, 33]. Also, X-ray diffraction
(XRD) with Cu Kα radiation was employed to deter-
mine the mineral constituents of the Li claystone samples.
Organic Acid Vs Sulfuric Acid Recoveries and Leaching
Method
The leaching experiments were conducted in a
GYROMAX ™ 929 water bath (Figure 1), where 10 g of