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Repositório Científico do Laboratório Nacional de Energia e Geologia
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Lithium Recovery from Spodumene via Calcium Chloride-Assisted Roasting [Comunicação oral]
Publication . Almeida, Joana; Pedrosa, Fátima; Plancha, Maria João; Gonçalves, Ana; Nogueira, Carlos
ABSTRACT: In 2024, total energy-related CO₂ emissions increased by 0.8% compared with the previous year, reaching a record of 37.8 Gt CO₂. The transportation sector accounts for approximately one-third of global greenhouse gas emissions, where electrification is expected to play a crucial role in mitigation. Electric vehicles (EV) alone avoided 80 Mt of CO₂ emissions during the past year, highlighting the environmental benefits of transitioning to electric mobility (International Energy Agency, 2025). In this context, lithium (Li) is a key element in the global energy transition, primarily due to its use in EV battery components. However, Li is classified as critical raw material in the EU list due to its economic relevance and supply risk (European Commission, 2024). Ensuring that Li production is reliable and sufficient to meet the growing demand for modern technologies is essential for achieving long-term reductions in global CO₂ emissions. Conventional Li recovery from Li-bearing ores relies on metallurgical methods that consume high amounts of energy, with processing temperatures reaching up to 1100 °C, contributing to CO₂ emissions increase. These processes also generate co-products and solid waste, such as silicates and metal sulphates, which require additional purification steps, increasing both complexity and cost. The use of sulfuric acid (H₂SO₄) for ore digestion introduces further challenges, including corrosiveness, the need for frequent equipment maintenance and the release of harmful gases. From an environmental perspective, these operations may contribute to air pollution, acidification and wastewater generation.
Coupling hydrometallurgy and electrochemistry for lithium recovery and compound production [Comunicação oral]
Publication . Almeida, Joana; Pedrosa, Fátima; Plancha, Maria João; Gonçalves, Ana; Nogueira, Carlos
ABSTRACT: Global CO₂ emissions reached 38.11 Gt CO₂ in 2025 (Statista, 2026). The transport sector contributes significantly to these emissions. Therefore, the ongoing energy transition in the European Union (EU) has increased pressure on the resources required for electric vehicle production, particularly critical raw materials used in batteries, such as lithium (Li) (Dong et al., 2026). To reduce the dependence of EU on external suppliers, efforts are being made to decentralize Li production and develop synergies with active industrial processes. In Portugal, it is envisaged the potential implementation of an industrial-scale Li refining facility based on a membrane electrolysis process, feeding LiCl and producing high-purity battery-grade Li compounds. The aim of this work was to produce LiCl from α-spodumene, an important Li-bearing mineral, using more sustainable hydrometallurgical processes. The produced LiCl via extractive metallurgy could then be used in electrolysis processes to maintain chlorine production, that is needed for several commercial applications. By replacing conventional NaCl with LiCl, the process also provides a precursor for other important Li compounds to the energy transition, such as Li₂CO₃ and LiOH. Therefore, hydrometallurgical routes were studied to maximize LiCl recovery from α-spodumene (Li = 3.2%) while minimizing reagent consumption and energy use. A maximum of 91% of Li was recovered, when conventional calcination and H2SO4 digestion was replaced by CaCl2 roasting. This work highlights the potential of integrating hydrometallurgical processes with electrochemical routes to produce diverse Li compounds with lower environmental impacts.
Bottlenecks in Lithium Recovery: From Spodumene Processing to Sustainable Battery Recycling [Comunicação oral]
Publication . Almeida, Joana; Pedrosa, Fátima; Plancha, Maria João; Neiva Correia, Maria Joana; Nogueira, Carlos
ABSTRACT: Several mineralogical and process-related bottlenecks limit the efficiency and sustainability of Li extraction from spodumene, an important Li-bearing mineral. In its natural form, spodumene occurs as α-spodumene, a highly stable and refractory phase with low chemical reactivity. To aid effective Li extraction, it must first be converted into the more reactive β-spodumene through calcination at temperatures above 1000 °C [1]. This high-temperature treatment results in significant energy consumption and represents one of the major economic and environmental constraints of conventional spodumene processing. Following thermal activation, Li is extracted through acid roasting with H₂SO₄, which converts Li into soluble Li sulphate [2]. This method is widely used industrially and involves large quantities of corrosive reagents, generating acidic effluents, and producing waste residues that require proper management. The recycling of Li-ion batteries presents additional bottlenecks in the recovery of critical raw materials. Examples include complex and evolving cathode chemistry, difficulties in safe handling and dismantling, operational costs and economies of scale, and inefficient recovery. Although metals such as cobalt (Co), nickel (Ni), manganese (Mg) and Li can be recovered through hydrometallurgical or pyrometallurgical processes, other battery components remain challenging to recover, such as graphite, which accounts for about 12–21 wt% of batteries [3]. High energy and reagent consumption, as well as inefficient recovery or lack of purity of the metals (Li, Ni, Co, Mn), are limiting the circularity of battery materials. To address these challenges, alternative approaches were investigated to reduce energy consumption and reagent use in spodumene processing. Mechanical activation (high energy milling) has been studied to induce structural disorder in α-spodumene, potentially lowering the temperature required for the follow α-to-β phase transformation. Other strategies include the use of CaCl₂ roasting to produce LiCl, as an alternative to H₂SO₄, reducing the dependence on strong acids. Additionally, leaching processes at or near room temperature are being explored to minimize thermal requirements. In battery recycling, process integration and flexibility, through correct design of hydrometallurgy flows and operations, is being pursued. These aim to reduce energy demand, minimize waste generation, and improve the sustainability of Li supply chains.
Leaching Approaches for Lithium Recovery from Spodumene [Comunicação oral]
Publication . Almeida, Joana; Pedrosa, Fátima; Plancha, Maria João; Gonçalves, Ana; Nogueira, Carlos
ABSTRACT: Lithium, a critical raw material, is essential for the electrification of vehicles due to its pivotal role in battery production, thereby contributing to the decarbonisation of the transport sector. The growing environmental and supplychain challenges associated with primary metal extraction have increased the need for alternative resources and sustainable processing methods. This study investigates the leaching behaviour of lithium from calcined spodumene, a lithium-bearing mineral, with the aim of optimising recovery under more environmentally friendly conditions. The research focuses on the assessment of the influence of key operational parameters on lithium solubilisation by water leaching, such as temperature, liquid-to-solid ratio, and reaction time. By varying these factors, the study aims to assess the conditions that maximise lithium yield while minimising resource consumption and environmental impact. The results demonstrate that almost complete lithium recovery was achieved at room temperature (24 °C), with liquid-to-solid ratios of 2–3.5 L/kg and leaching durations of 30–60 minutes, indicating that additional heating, excessive solvent, or prolonged contact time offers minimal improvement. These findings provide a route to improve resource use while lowering the carbon footprint of lithium production.
Lithium Role in the Clean Energy Transition: Challenges and Prospects
Publication . Almeida, Joana; Pedrosa, Fátima; Plancha, Maria João; Gonçalves, Ana; Nogueira, Carlos
ABSTRACT: Global decarbonization strategies depend on the large-scale electrification of the transport sector, mainly supported by lithium-ion battery technologies. Lithium’s role in assisting low-carbon mobility has driven a fast rise in demand. This has intensified concerns regarding resource scarcity and supply chain vulnerabilities, particularly in the European Union, which remains heavily dependent on imports. The restricted availability of lithium and other critical raw materials, compounded by geopolitical tensions, poses a risk to the resilience of the clean energy transition. In this sense, the adoption of circular economy principles has emerged, emphasizing material recovery, recycling, and resource efficiency. This review provides a comprehensive analysis of lithium relevance in the energy transition, with a focus on resource trends, recovery technologies, and battery production. A systematic understanding of these trends and challenges is needed to guide future developments and ensure a secure, sustainable, and circular lithium value chain that supports the transition to clean energy systems.