Potential Impact of Primary Lithium Produced in Brazil on Global Warming

Abstract

The present study aimed to estimate the contribution of the mining and mineral processing steps of lithium concentrate production in Brazil to the Global Warming Potential (GWP100) using an LCA perspective. No previous national study was identified that quantified national GHG emissions in mining and beneficiation operations for lithium ores. This study is considered original and aims to contribute to filling this gap. The functional unit was 1 ton of lithium carbonate equivalent (LCE) in the mineral concentrate. The contribution to GWP100 was estimated at 1220 kg of CO_2eq per ton of LCE, of which 262 kg originated from foreground processes. In the background processes, the largest contribution was 456 kg of CO_2eq from emissions in the production of ammonium nitrate, used in the manufacture of mining explosives. An analysis of substituting electricity sources in the product system showed a reduction of 22.7% and 14.7% in the estimated global warming impact when using wind or solar power, respectively.

1. Introduction

The present study preliminarily assesses the contribution of lithium mineral concentrate produced in Brazil to global warming by estimating the GHG emissions from the mining and mineral processing steps of its production chain, using a life cycle approach. No national study was identified that quantifies GHG emissions in mining and beneficiation operations for lithium ores. This study is considered original and aims to help fill this gap.

Lithium is a critical mineral, particularly important for the manufacturing of various products that are essential to the so-called energy transition, including batteries for electric vehicles (EVs). Data from the International Energy Agency (IEA) show that demand for EV batteries reached more than 750 GWh in 2023, up 40% relative to 2022, though the annual growth rate slowed slightly compared to 2021–2022. Battery demand for lithium stood at around 140 kt in 2023, 85% of the total lithium demand, and up more than 30% compared to 2022 [1]. Additionally, a significant growth in the world demand for this element is expected in the short and medium term.

Lithium is also intensively used in the production of special glasses and ceramics, lubricants, medicines, and as a source of tritium (Li-6) for use in weapons and nuclear reactors.

These facts, combined with the favorable geological environment for its occurrence in Brazil, particularly in the state of Minas Gerais, suggest a growing incentive for investment in new lithium projects [2,3]. Given the described scenario, there is a strong justification for examining the sustainability of lithium production in Brazil and its applications.

Environmental aspects and impacts of lithium-ion battery manufacturing, for instance, have been the subject of several studies that generally focus primarily on examining the processes that are characteristic of the final steps of the production chain. However, from a systemic perspective, this examination must necessarily begin at the production of lithium mineral concentrates and their chemical compounds and then extend to the finished products, their use, and final disposal. Studies providing detailed estimates of the environmental impacts of the initial operations in this chain, such as mining and mineral processing, have been less frequent [4].

The importance of examining environmental aspects in the initial steps of mineral exploration and lithium concentrate production becomes even more evident when comparing different production chains composed of successive process operations. It is observed that such operations are similar in the final steps of manufacturing [5]. On the other hand, in the initial steps, corresponding to mining and mineral processing, there are significant differences among them, arising from the diversity of the mineral deposits [6,7]. As a consequence, significant variations in the environmental impacts of these production chains can also be expected.

One of the main sources of the mentioned variations is, for example, the ore grade. As is common in mining activities, ore grades tend to decrease over the years. During the early 1900s, Cu grades, for example, were around 1.5% to 4% Cu; however, these have declined substantially to a global average of 0.62% Cu in 2010. Consequently, the energy used in mining and mineral processing tends to increase, leading to greater environmental impacts [8,9,10]. Another global study on copper mines revealed that a 25% decline in ore grade over a decade resulted in a 46% increase in total energy consumption [8].

Lithium compounds, in turn, are typically produced from mineral sources such as brines or pegmatitic rocks of varying grades through different technologies that lead to distinct environmental impacts.

Some authors also point out that inventories of raw materials and emissions of lithium production from brines, for instance, are more common in the literature than those for spodumene from pegmatitic rocks [4], which define Brazil’s mineral resources. The environmental impacts of the latter are strongly dependent on factors such as the geological characteristics of the deposit, the type of mining, the unit operations and equipment used, as well as the volume, treatment, and final disposal of the waste, which are unique to each mining project. In the case of spodumene concentrate production, for example, the variations in the Global Warming Potential (GWP) for the concentration step range between 1.8 kg CO_2eq/kg LCE and 4.9 kg CO_2eq/kg LCE. The GWP of spodumene concentrates exhibits a negative correlation with ore grades and recovery efficiency, as improving these parameters reduces the overall GWP.

For brines, the GWP of brine concentrate varies from 0.3 kg CO_2eq/kg LCE to 2.6 kg CO_2eq/kg LCE, depending on brine quality [5,11].

The type of power matrix used in the mining/industrial project, in turn, has a significant effect on the accounting of greenhouse gases (GHG) emitted during the production of lithium products [7,12]. Thus, mineral production plants of countries where power matrices are based on renewable sources have fewer net atmospheric emissions of GHGs and contribute less to global warming. Indeed, the influence of energy-intensive production steps, such as mining and mineral processing, can be significant in determining the contribution of the mineral product to global warming. The substitution of fossil power sources, such as diesel, for renewable energies in these processes can provide environmental benefits [13].

Recognizing the importance of estimating the environmental impacts associated with the initial steps of the mineral production chain, the present study aimed to estimate, using a life cycle approach, the contribution of lithium produced in Brazil to global warming, focusing on the mining and mineral processing steps.

Lithium mining companies in Brazil produce mineral concentrates of spodumene from lithium-rich pegmatites. There are three main companies that operate in the state of Minas Gerais—MG [14] (Figure 1). The country produced approximately 414,000 tons of lithium mineral concentrate at an average grade of 5.5% Li₂O in 2023 [15], which corresponds to 22,770 t.

The Companhia Brasileira de Lítio—CBL, which was founded in 1985, began its operation as an integrated mining and chemical plant in 1991 [16]. The total resources measured and indicated by the company are 4.5 million tons of lithium-rich pegmatite with 1.4% Li₂O, and the main lithium-bearing minerals are spodumene, amblygonite, lepidolite, and petalite [17,18]. The company operates the Cachoeira mine in the city of Itinga, and its mineral reserves are projected for 20 years [19]. The mining is underground and operates with chambers and pillars [16,17,18].

The mineral processing involves crushing, particle size classification, heavy media separation, optical ore sorting, and X-ray sorting. The capacity of the mineral processing plant is 45,000 tons per year of spodumene concentrate with an average grade of 5.5% Li₂O [16,17,18,20].

AMG Brasil S.A. (Advanced Metallurgical Group—AMG) produces a spodumene concentrate from lithium-rich pegmatites by open-pit mining as a byproduct of its primary operation to produce a tantalum mineral concentrate. Currently, the company also markets products of aluminum, niobium, tin, and feldspar in its Volta Grande mine in the town of Nazareno.

The lithium reserves of AMG are estimated at 20 million tons, with an average grade of 1.06% Li₂O, corresponding to approximately 212,000 tons. In 2019, the lifespan of the mine was estimated at 28 years as to its lithium reserves [21,22,23,24,25,26]. The run-of-mine (ROM) is initially crushed and then sent to concentration spirals, which produce two fractions. The heavy fraction is directed to the tantalum and tin production lines, while the light fraction with 1% Li₂O proceeds to the spodumene concentration plant [26]. This plant is equipped with hydrocyclones, desliming and magnetic separation units, and flotation cells. The grade of the final concentrate is between 5.5% and 6.4% Li₂O. The annual production capacity is 90,000 tons of lithium concentrate for export [22,23,26]. AMG has announced plans to increase its production capacity in Nazareno to 130,000 tons per year, expected to be operational by the end of 2024 [27].

Sigma Lithium S.A. began its operation in 2023 at the Grota do Cirilo site in the towns of Araçuaí, MG, and Itinga, MG. Currently, the company operates an open-pit mine that encompasses the Xuxa Sul and Xuxa Norte pits. The mineral reserve has been estimated at 8.12 million tons at an average grade of 1.52% Li₂O. The lifespan of the project is estimated to be eight years, with a production of 1.45 million tons of ROM per year. The mining operations include stripping, blasting, loading, and transportation [28,29,30].

The mineral processing consists of classification, magnetic separation, and heavy media separation. The final products are classified as heavy and mixed concentrates and stockpiled for shipment according to their particle size and composition. The production capacity of the concentrate is 222,000 tons at an average grade of 6% Li₂O [28,29]. The company expects to increase its production capacity to approximately 520,000 tons per year starting in 2025 [31].

In 2023, the government of the state of Minas Gerais launched Lithium Valley Brazil on the NASDAQ stock exchange in New York, an initiative aimed at attracting investments to the lithium production chain in the Jequitinhonha valley [14,32]. In the same year, the working group Vale do Lítio was set up, involving government, industry, and academia, to promote the sustainability of the lithium production chain.

New projects have been developed by companies such as Atlas Lithium, Lithium Ionic, and Latin Resources, which are expected to significantly increase Brazil’s lithium production in the coming years [33,34,35].

Latin Resources is developing lithium projects in Brazil, primarily in Minas Gerais, including the Colina Project (formerly the Salinas Project), which has the potential to become one of the world’s largest hard-rock lithium operations. The company is also exploring additional opportunities in the Jequitinhonha Valley region [34,36].

Lithium Ionic’s main projects include Bandeira, Outro Lado (Itinga), and Baixa Grande (Salinas). The Bandeira Project is the most advanced, with lithium concentrate production expected to begin in the second half of 2026 [35,37].

Atlas Lithium holds multiple lithium mining projects in Brazil, with the Neves Project in Minas Gerais being the most advanced. This project is currently undergoing licensing and construction of a processing plant. Additionally, the company is exploring the lithium district surrounding Salinas, also located in Minas Gerais [33,38].

Based on the current national production capacity and the additional information disclosed by companies, it is estimated that Brazil could surpass the production level of 1 million tons of lithium concentrate by 2026, making the country an important player in the global market (Figure 2).

According to the Brazilian National Mining Agency (ANM), there are still ongoing investments in lithium mineral research in the states of Bahia, Rio Grande do Norte, Paraíba, and Ceará [14,15,39].

2. Materials and Methods

The study was carried out using a life cycle approach. For modeling the product system of lithium production in Brazil, publicly available data of companies that exploit lithium-rich pegmatites were utilized. Additionally, publications of the government of the state of Minas Gerais were used, including environmental licensing documents, as well as papers from technical-scientific events [25,28,40].

As a first approximation to estimate the contribution of lithium production in Brazil to global warming, a life cycle inventory (LCI) was conducted for inputs, outputs, and associated greenhouse gas emissions. This analysis focused on the three companies mentioned above, based on their projected mine and mineral processing plant capacities. The inventory data were calculated using a weighted average of the collected data from each of the three companies, with weighting factors corresponding to the lithium carbonate equivalent (LCE) mass contained in their respective products.

The Global Warming Potential (GWP) is the midpoint characterization factor used by the ReCiPe method to estimate global warming [41]. Thus, this contribution was obtained using the SIMAPRO 9.5 software and the ReCiPe 2016 Midpoint (H) impact assessment method from the greenhouse gas (GHG) emissions inventory and expressed as kg of CO₂ equivalent (CO₂eq)/t of lithium carbonate equivalent (LCE).

GWP is widely used by the Intergovernmental Panel on Climate Change (IPCC) to facilitate the comparison of different greenhouse gases (GHGs). It is a measure of the amount of energy that 1 ton of a GHG will absorb over a specified period compared to 1 ton of carbon dioxide (CO₂). The higher the GWP, the more a particular gas warms the environment relative to CO₂ over the same time frame [42]. The most commonly used time frame is 100 years (GWP100), although other periods can be utilized depending on the objectives of the study.

The functional unit used, as well as the reference flow adopted for the accounting and normalization of inputs and outputs of raw materials and energy, was 1 ton of lithium carbonate equivalent (LCE) in the average mineral concentrate (14.6% LCE or 6% Li₂O). The GHG emissions associated with the production of coproducts were not included in the study.

The boundaries of the study covered the production steps, from the raw materials at their “cradle” to the mineral concentrate delivered at the “factory gate”.

The approach focused on the operation of the mining units; therefore, downstream steps of the production chain, such as the production of semi-finished or finished lithium products, their uses, and end-of-life and/or recovery/recycling processes, were not included. Additionally, packaging of materials and products, transportation of materials, fuels, and waste, as well as the construction and decommissioning of physical infrastructure, equipment, and vehicles, were also excluded from the study.

The geographic scope of the study was Brazil as a whole, which currently produces about 2.7% of the world’s lithium and holds approximately 1.4% of the world reserves, defined as the amount of lithium that can be economically extracted or produced [43]. The country has proven reserves of 52 million tons of ore, which corresponds to 642 thousand tons of Li₂O [14].

The model of the product system is presented in Figure 3. Its development involved identifying the flows related to the ecosphere and technosphere. As shown in Figure 3, the system boundary is the limit between the modeled process and the remaining technosphere. Additionally, the elementary flows into or out of the process directly from the ecosphere were also inventoried.

The system boundary includes the main steps of Brazilian production in the foreground, encompassing mining and mineral processing. It also considered the auxiliary processes in the background, corresponding to the production of raw materials, fuels, and energy.

Foreground data were obtained separately for each company to develop the life cycle inventory (LCI) and then combined to represent an average operational value based on mass balance.

Background data were selected in the Ecoinvent 3.10 [44] and Agri-footprint 6.0 [45] databases, according to the Brazilian geographical coverage. When specific data were not available, average global datasets from these databases were utilized. Mining and mineral processing were considered as a single elementary process in the product system.

The surface areas of the mining companies were considered for land use, including those for mining, processing, offices, workshops, and preservation areas.

Atmospheric emissions were estimated using the methodology described in the IPCC reports when data were not available in the literature [46,47] and were equivalent to the total emissions due to fuel consumption and the use of explosives.

The following emission factors were considered for diesel combustion [46,47]: CO₂ = 74,100 kg/TJ; CH4 = 4.15 kg/TJ; and N₂O = 28.6 kg/TJ. The calorific value of diesel used was 10,100 kcal/kg, with a density of 840 g/L [48].

Since the companies considered in this study did not publish specific GHG emission factors for explosive detonation in their operations, the study adopted the reference value of 0.17 t CO_2eq per t of explosive [49] for the blasting phase of mining operations. This emission factor was applied to ANFO (ammonium nitrate/fuel oil) explosives, with an assumed composition of 94% ammonium nitrate and 6% diesel oil by mass.

A sensitivity analysis of CO_2eq emissions was carried out regarding the types of power sources of the product system. Three generation scenarios were taken into account. A baseline scenario using the current power mix of the country and two alternative scenarios, with 100% wind or solar (photovoltaic) generation, both selected from the Ecoinvent database, considering the Brazilian geographical coverage.

3. Results and Discussion

The LCI of the main elementary processes for the production of lithium mineral concentrate in Brazil, expressed as LCE, is shown in

Table 1. Life cycle inventory of 1 ton of LCE produced in Brazil.

Output	Value
LCE (t)	1
Inputs from ecosphere
river water (m3)	7.24
well water (m3)	1.64 × 10−3
land use (ha year)	1.39
oxygen (kg)	3.09 × 10−2
Inputs from technosphere
diesel (kg)	6.64 × 101
natural gas (m3)	1.69 × 101
argon (kg)	2.63 × 10−1
lubricating oil (kg)	3.01 × 10−1
ammonium nitrate (kg)	1.71 × 102
diesel (kg)	1.09 × 101
FeSi (t)	1.59 × 10−2
soda ash (kg)	1.33 × 10−2
pallets (units)	2.30 × 10−1
electricity (MWh)	1.30
Air emissions
CO2 (kg)	2.38 × 102
CH4 (kg)	1.16 × 10−2
N2O (kg)	8.03 × 10−2
NOx (kg)	4.21 × 101
particulates (kg)	1.18
SOx (kg)	2.11 × 10−1
hydrocarbons (kg)	1.01
Final waste flows
overburden (t)	6.06 × 102
tailings (t)	2.52 × 101
hazardous waste (kg)	3.60 × 101
non-hazardous waste (kg)	2.89 × 10−1
inert waste (kg)	5.73 × 101
oil waste (t)	3.63 × 10−2
sewage waste (t)	5.04 × 10−2
light bulb waste (kg)	9.19 × 10−3
plastic packaging waste (kg)	3.45 × 10−3
copper waste (kg)	2.30 × 10−3
other metal waste (kg)	3.45 × 10−1

. All inputs and outputs were averages and represent the domestic production capacity. No environmental burden was allocated to coproducts, meaning that 100% of this load was put on to the lithium concentrate.

Figure 4 shows the Sankey diagram of the global warming contribution of the production of 1 ton of LCE in lithium concentrate in Brazil.

The numbers inside each process block of the diagram represent the contribution to global warming, in kilograms of CO_2eq, accumulated upstream and added to the respective process. The thickness of the lines connecting the blocks is proportional to these contributions.

Figure 5 shows the percentage of contribution of each elementary process.

The contribution of 1 ton of LCE contained in the mineral concentrate to global warming was estimated at 1220 kg of CO_2eq, of which 262 kg (21.5%) is considered a direct contribution from the foreground, mainly resulting from emissions of fuel consumption in drilling/blasting equipment used in the mining, motor vehicles for transport within the mine, and from the use of explosives.

The electrification of mining operations can be an alternative for reducing GHG emissions. The motivations for adopting the electrification of vehicle fleets and equipment are related not only to the reduction in emissions but also to mitigating the exposure of the workers to gases and particulate emissions from fossil fuel use. Additionally, fleet electrification can minimize the demand on ventilation systems in underground mines and promote a reduction in power use, noise, and ambient temperature [50,51].

A challenge for electrification in mining is the development of a robust electrical infrastructure. Reliable energy storage and distribution systems are essential, especially in remote locations. Advances in grid technologies enable the integration of renewable energy sources even in these areas, further enhancing the sustainability of mining operations.

Despite investments and advances in new technologies, progress in the electrification of mines still depends on several factors. Among them is the price of essential minerals for batteries, including lithium itself [52,53].

In the background processes, the largest contribution was 456 kg of CO_2eq, equivalent to 37.4%, originating from emissions from the manufacture of explosives (ammonium nitrate) used in the mining of lithium ore.

Indeed, the significant contribution of ammonium nitrate-based explosives to global warming is also observed in other studies that report the production of explosives as a major source of CO_2eq emissions in the background [54]. GHG emissions from ammonium nitrate are responsible for more than 90% of the contribution to global warming in the production of explosives. This is primarily due to the use of ammonia and nitric acid [55]. More efficient production is crucial to reduce this contribution [56]. One example is ammonium nitrate produced from ammonia made with green hydrogen (obtained by the electrolysis of water), which is a low-carbon process [57,58].

The second largest contribution to global warming is due to power generation, accounting for 290 kg of CO_2eq/t of LCE in the mineral concentrate (23.8%).

Power generation significantly impacts GHG emissions in mineral production processes. As ore grades decline and global demand for metals increases, GHG emissions from primary ore production processes are expected to rise [59,60]. Consequently, mining companies are increasingly pursuing sustainable energy supply alternatives, including wind and photovoltaic sources. These renewable energy solutions have been successfully implemented in mining projects globally, demonstrating favorable economic, social, and environmental outcomes [13].

Figure 6 shows a brief examination of the effect of a change in the mix of the power sources on the total CO_2eq emissions of the product system. The vertical bars represent the contribution to global warming associated with the production of 1 ton of LCE in Brazil, expressed in tons of CO_2eq. The analysis focused on wind and solar energy sources, utilizing national datasets from the Ecoinvent database. In both cases, a reduction in total emissions from the product system was observed compared to the emissions associated with the exclusive use of the current Brazilian power generation.

If the product system operates using 100% wind energy, it is possible to achieve a reduction of approximately 22.7% in the contribution to global warming. Conversely, using exclusively a solar source would result in a reduction of 14.7%.

Many factors related to ore processing can influence the Global Warming Potential in lithium production. In Australia, for instance, the world’s largest lithium producer from pegmatites, the Greenbushes (Talison Lithium) and Mt. Cattlin (Arcadium Lithium) mining projects both operate open-pit mines from hard rock, although they have different processing plants according to the geometallurgical properties of the ore. The concentration is carried out by heavy media at Mt. Cattlin and by flotation at Greenbushes, and lithium mineral concentrates with grades between 5.7% and 6.5% of Li₂O are attained [7], similar to those produced in Brazil.

In Greenbushes, the contribution of lithium products to global warming is 26,000 kg of CO_2eq/t of LCE, a value significantly higher than the estimate of the present study, primarily due to diesel consumption for power generation. In Mt. Cattlin, this contribution is approximately 5000 kg of CO_2eq/t of LCE. The largest share in this case occurs in the mining step, accounting for approximately 69% of global warming [7].

In other mining operations in Australia, Canada, and Finland that produce lithium concentrates (spodumene), GHG emissions ranging from 760 to 3400 kg of CO_2eq/t LCE were reported. In Australia, emissions related to diesel consumption for power generation were again identified as the primary contributors to global warming [61].

Exploitation of lithium ores of different grades also affects differently the contribution to global warming. Results reveal that this contribution is inversely proportional to the lithium grade in the ore. The literature quotes values from 2000 to 8000 kg of CO_2eq/t of LCE [5,62].

These findings highlight the significant variability in contributions from the mining and mineral processing steps to the global warming associated with lithium mineral products. This variability, as evidenced, is primarily due to the characteristics of each deposit, the production processes employed, and the power sources used.

Brazil, which has one of the cleanest energy matrices in the world, holds advantages regarding the contribution of electricity generation to global warming. Additionally, studies reveal that decarbonizing mining operations, for instance, through self-generation of wind or solar energy, is a key factor in increasing the sustainability of the mineral sector [63].

Finally, in order to compare the global warming results obtained in this study with those from other sources, a dataset was selected from the Ecoinvent database (market for spodumene—GLO). This dataset was constructed from publicly available data on lithium concentrate production and complemented by technical data of other mineral goods [4,6,7]. The result obtained for global warming was 1078 kg CO_2eq/t of LCE, which is lower than the reported in the various studies reviewed and also lower than the value calculated in this work.

Finally, it must be mentioned that direct comparison of the GWP values obtained in this study with those from previously mentioned references has inherent limitations. Each life cycle inventory differs in terms of completeness (system boundaries), representativeness (technical and geographical scope), data reliability (source quality and uncertainty), temporal relevance (year of data collection), and time horizon consideration (for impact assessment). However, these GWP data reported may be used as preliminary reference data.

4. Conclusions

The study estimated the contribution of a lithium mineral concentrate from lithium-bearing pegmatites in Brazil to global warming, and the results were expressed as lithium carbonate equivalent—LCE. This estimate was carried out using a life cycle approach, which covered the steps of lithium ore processing from mining to the gate of the mineral processing plant. Based on this approach, a product system was proposed, and a life cycle inventory was carried out to account for inputs and outputs of raw material, materials, and energy using data publicly available from companies operating in the country.

The contribution of the production of 1 ton of LCE contained in the lithium mineral concentrate to global warming was estimated at 1220 kg of CO_2eq, of which 262 kg are due to fuel emissions from equipment used in the mining step. The largest contribution in the background processes was 456 kg of CO_2eq, or about 37.4%, from the production of explosives. The second largest contribution, 290 kg of CO_2eq/t of LCE (23.8%), is related to power generation.

A comparison with other studies showed a wide variability in the global warming estimates associated with lithium mineral concentrates. This variability is mainly due to the characteristics of each deposit, the types of production processes, and the power source used. The latter aspect plays a significant role and may provide competitive advantages for Brazil in terms of sustainability, as the country has an energy matrix considered cleaner compared to other countries with significant mineral production.

Additionally, this study indicated that adopting 100% wind or solar energy sources, instead of the Brazilian energy mix, could lead to a reduction in the Global Warming Potential associated with mining and mineral processing operations by up to approximately 23% and 15%, respectively.

Several other projects are expected to increase lithium production in the country and with the prospect of this production occurring sustainably, the present study gathered information that might be useful as a starting point for a future assessment of the global warming associated with the lithium produced in Brazil in the coming years.