3367
Organic Acid Leaching of a Lithium-Bearing Nevada
Sedimentary Claystone
Angela Manka Tita, Emmanuel Atta Mends, Umut Kar, Shokrullah Hussaini, Pengbo Chu
Department of Mining and Metallurgical Engineering
ABSTRACT: Currently, sulfuric acid (H2SO4) is used in the industry for lithium (Li) extraction from claystone,
but this poses issues of selectivity and environmental concerns. This study investigated three organic acids—
citric, oxalic, and tartaric acids—as potential alternatives to H2SO4, for lithium extraction from claystone.
Among the organic acids tested, oxalic acid emerged as the most effective in Li extraction, yielding an extraction
percentage of more than 90% under the conditions: 1 hour, 1M concentration, at 80 °C. These results were
comparable to the performance of H2SO4 under the same conditions, except that oxalic acid had more selectivity
for Li against Mg (Mg) which was the main impurity in this sample. While oxalic acid extracted about 20% Mg,
H2SO4 extracted more than 90%: this was a very important advantage of oxalic acid over H2SO4. The findings
highlight the potential of oxalic acid as a promising alternative to traditional sulfuric acid-based extraction
methods, for innovative and greener Li extraction practices.
Keywords: Lithium, Organic Acids, Oxalic Acid, Magnesium, Dolomite, Sedimentary claystone
INTRODUCTION
The lightest alkali metal with exceptional physical and
chemical properties, Li is the 25th most abundant ele-
ment in the earth’s crust (20 mg/kg) [1, 2]. Li and related
compounds have been widely used in the manufacturing
of polymers, ceramics, glass, lubricating greases, and bat-
teries in recent years [3, 4]. Because Li is a necessary raw
material for the growth of rising industries, it is referred
to as the “new energy metal of the 21st century” [5]. Due
to Li’s necessity as a material for battery manufacturing,
the market for Li has grown explosively in recent years [6,
7]. According to a report by the United States Geological
Survey in 2022, 75% of Li was utilized by the battery sec-
tor in 2021 [8]. Li resources are under tremendous pressure
due to the rapidly growing demand for Li for its numer-
ous applications [9]. The United States and the European
Union have designated Li as one of the critical metal ele-
ments because of its great economic and strategic signifi-
cance [10].
Li resource types are often classified into three groups:
clay, hard rock, and brine types [11, 12]. In 2018, the
proved lithium resource reserves worldwide amounted to
around 41 million tons, with the aforementioned brine-
type, hard rock-type, and sedimentary-type accounting for
roughly 64%, 29%, and 7% of these amounts, respectively
[13]. The utilization of Li-bearing clays and the exploita-
tion of clay-type lithium deposits have drawn increased
attention because of the unequal geographic distribution of
lithium resources [10, 13]. Future sources of lithium have
been discovered as Li-bearing clays [9, 14]. Li-bearing clay
resources are mostly found in Mexico, the US, Serbia, and
the southwest of China and they belong to sedimentary
lithium deposits. Volcanic, carbonate, and Jadarite types
Organic Acid Leaching of a Lithium-Bearing Nevada
Sedimentary Claystone
Angela Manka Tita, Emmanuel Atta Mends, Umut Kar, Shokrullah Hussaini, Pengbo Chu
Department of Mining and Metallurgical Engineering
ABSTRACT: Currently, sulfuric acid (H2SO4) is used in the industry for lithium (Li) extraction from claystone,
but this poses issues of selectivity and environmental concerns. This study investigated three organic acids—
citric, oxalic, and tartaric acids—as potential alternatives to H2SO4, for lithium extraction from claystone.
Among the organic acids tested, oxalic acid emerged as the most effective in Li extraction, yielding an extraction
percentage of more than 90% under the conditions: 1 hour, 1M concentration, at 80 °C. These results were
comparable to the performance of H2SO4 under the same conditions, except that oxalic acid had more selectivity
for Li against Mg (Mg) which was the main impurity in this sample. While oxalic acid extracted about 20% Mg,
H2SO4 extracted more than 90%: this was a very important advantage of oxalic acid over H2SO4. The findings
highlight the potential of oxalic acid as a promising alternative to traditional sulfuric acid-based extraction
methods, for innovative and greener Li extraction practices.
Keywords: Lithium, Organic Acids, Oxalic Acid, Magnesium, Dolomite, Sedimentary claystone
INTRODUCTION
The lightest alkali metal with exceptional physical and
chemical properties, Li is the 25th most abundant ele-
ment in the earth’s crust (20 mg/kg) [1, 2]. Li and related
compounds have been widely used in the manufacturing
of polymers, ceramics, glass, lubricating greases, and bat-
teries in recent years [3, 4]. Because Li is a necessary raw
material for the growth of rising industries, it is referred
to as the “new energy metal of the 21st century” [5]. Due
to Li’s necessity as a material for battery manufacturing,
the market for Li has grown explosively in recent years [6,
7]. According to a report by the United States Geological
Survey in 2022, 75% of Li was utilized by the battery sec-
tor in 2021 [8]. Li resources are under tremendous pressure
due to the rapidly growing demand for Li for its numer-
ous applications [9]. The United States and the European
Union have designated Li as one of the critical metal ele-
ments because of its great economic and strategic signifi-
cance [10].
Li resource types are often classified into three groups:
clay, hard rock, and brine types [11, 12]. In 2018, the
proved lithium resource reserves worldwide amounted to
around 41 million tons, with the aforementioned brine-
type, hard rock-type, and sedimentary-type accounting for
roughly 64%, 29%, and 7% of these amounts, respectively
[13]. The utilization of Li-bearing clays and the exploita-
tion of clay-type lithium deposits have drawn increased
attention because of the unequal geographic distribution of
lithium resources [10, 13]. Future sources of lithium have
been discovered as Li-bearing clays [9, 14]. Li-bearing clay
resources are mostly found in Mexico, the US, Serbia, and
the southwest of China and they belong to sedimentary
lithium deposits. Volcanic, carbonate, and Jadarite types