About this Research Topic
Critical raw materials are crucial for green energy production, but there is a risk of supply interruption in the short and medium term. To achieve a sustainable green energy transition, it is necessary to develop new technologies for extracting these materials from primary sources and explore potential secondary sources. In this context, sustainable mining practices can be implemented, focusing on techniques that have a low carbon footprint and minimal negative environmental impact, promoting a circular economy where all materials, including waste, can be considered as a source of critical minerals.
As society advances and the demand for raw materials for net-zero technologies like photovoltaic panels, electric vehicle batteries, magnets, and LED lamps increases, it becomes crucial to improve the extractive processes. For example, cobalt is essential for Li-ion batteries used in electric vehicles, rare earth elements are widely used in LED lamps, hybrid vehicle batteries, and magnets, and indium and high-purity silicon are used in photovoltaic panels. However, the content of these critical materials in primary sources is declining while their demand is rising. Therefore, promoting a circular economy becomes necessary to increase the supply and mitigate the environmental impacts associated with mineral processing and extractive metallurgy.
Current technologies are focused on traditional technologies from extractive mining. For instance, in hydrometallurgical processing, leaching reaction occurs in acid media using inorganic acids as sulfuric, nitric and hydrochloric acid. Current innovations have demonstrated that the use of organic acids can be advantageous. For instance, a recycling route was proposed in literature using only organic acids for recycling of Li-ion batteries to obtain high-pure Co and Li products. Also, separation and purification steps of leach liquor face several economic and environmental issues regarding the use of solvent extraction and ion exchange resins. On the other hand, ionic liquids and deep eutectic solvents have been shown economic and environmental feasibility. Well-known solvent extraction technique involves steps using organic extractants diluted in flammable and toxic solvents, and upcoming technologies can be used to replace these reagents for non-toxic techniques, or even without reagent addition as for membrane technology. Furthermore, this special issue welcomes outstanding papers aimed at the development of new technologies in the promotion of a circular economy.
Authors are invited to submit contributions on, but not limited to, the following topics:
• Production of critical raw materials by urban mining.
• Greener technologies for critical minerals obtaining.
• Hydro, pyro and biohydrometallurgy to obtain metals from low-grade ores and residues.
• Recovery of metals from tailings, residues, slags and wastes of mineral processing.
• Exploration of low-grade mineral resources.
This Special Issue aims to gather high-quality research that explores the latest advancements in sustainable mining for critical minerals production, with an emphasis on promoting sustainable development and a circular economy within the context of a green energy transition. Novel extraction methods, but not restricted to, are:
• Use of organic acids for extraction of metals – leaching and separation steps using organic acids as citric, DL-malic and oxalic from electronic wastes and mining sources (primary and secondary) to obtain metals as Li, Co, Nb, Ta, Mn, Ag, Au, and Cu.
• Development of new polymeric membranes for separation and purification of critical raw materials – design of membrane materials for separation of metals and organic compounds by nanofiltration, ultrafiltration and electrodialysis. Application of commercial membranes is also considered.
• Separation, purification, and capture of CO2 from industrial processes, including recycling, are also considered – design of new materials, application studies and scale-ups.
The symbiotic relationship between a sustainable green energy transition and the advancement of sustainable mining for critical minerals marks a critical era in the pursuit of environmentally conscious and resource-efficient practices. The integration of renewable energy sources, such as solar and wind power, has significantly reduced carbon emissions, mitigating the impact of climate change. Simultaneously, the emphasis on sustainable mining practices ensures the responsible extraction of critical minerals essential for renewable energy technologies. In addition, urban solid waste can be a source of critical raw materials making them urban mines. This approach not only addresses the growing global demand for clean energy but also mitigates the environmental and social impacts associated with traditional mining. The achievements in this dual transition showcase a commitment to fostering a greener future while minimizing the ecological footprint of the essential processes underpinning the renewable energy revolution.
It exemplifies the outstanding researches corroborating to the development of new materials and processes to overcome current problems in the recovery of critical raw materials, including low grade, high contaminant content and environmental impacts.
As society advances and the demand for raw materials for net-zero technologies like photovoltaic panels, electric vehicle batteries, magnets, and LED lamps increases, it becomes crucial to improve the extractive processes. For example, cobalt is essential for Li-ion batteries used in electric vehicles, rare earth elements are widely used in LED lamps, hybrid vehicle batteries, and magnets, and indium and high-purity silicon are used in photovoltaic panels. However, the content of these critical materials in primary sources is declining while their demand is rising. Therefore, promoting a circular economy becomes necessary to increase the supply and mitigate the environmental impacts associated with mineral processing and extractive metallurgy.
Current technologies are focused on traditional technologies from extractive mining. For instance, in hydrometallurgical processing, leaching reaction occurs in acid media using inorganic acids as sulfuric, nitric and hydrochloric acid. Current innovations have demonstrated that the use of organic acids can be advantageous. For instance, a recycling route was proposed in literature using only organic acids for recycling of Li-ion batteries to obtain high-pure Co and Li products. Also, separation and purification steps of leach liquor face several economic and environmental issues regarding the use of solvent extraction and ion exchange resins. On the other hand, ionic liquids and deep eutectic solvents have been shown economic and environmental feasibility. Well-known solvent extraction technique involves steps using organic extractants diluted in flammable and toxic solvents, and upcoming technologies can be used to replace these reagents for non-toxic techniques, or even without reagent addition as for membrane technology. Furthermore, this special issue welcomes outstanding papers aimed at the development of new technologies in the promotion of a circular economy.
Authors are invited to submit contributions on, but not limited to, the following topics:
• Production of critical raw materials by urban mining.
• Greener technologies for critical minerals obtaining.
• Hydro, pyro and biohydrometallurgy to obtain metals from low-grade ores and residues.
• Recovery of metals from tailings, residues, slags and wastes of mineral processing.
• Exploration of low-grade mineral resources.
This Special Issue aims to gather high-quality research that explores the latest advancements in sustainable mining for critical minerals production, with an emphasis on promoting sustainable development and a circular economy within the context of a green energy transition. Novel extraction methods, but not restricted to, are:
• Use of organic acids for extraction of metals – leaching and separation steps using organic acids as citric, DL-malic and oxalic from electronic wastes and mining sources (primary and secondary) to obtain metals as Li, Co, Nb, Ta, Mn, Ag, Au, and Cu.
• Development of new polymeric membranes for separation and purification of critical raw materials – design of membrane materials for separation of metals and organic compounds by nanofiltration, ultrafiltration and electrodialysis. Application of commercial membranes is also considered.
• Separation, purification, and capture of CO2 from industrial processes, including recycling, are also considered – design of new materials, application studies and scale-ups.
The symbiotic relationship between a sustainable green energy transition and the advancement of sustainable mining for critical minerals marks a critical era in the pursuit of environmentally conscious and resource-efficient practices. The integration of renewable energy sources, such as solar and wind power, has significantly reduced carbon emissions, mitigating the impact of climate change. Simultaneously, the emphasis on sustainable mining practices ensures the responsible extraction of critical minerals essential for renewable energy technologies. In addition, urban solid waste can be a source of critical raw materials making them urban mines. This approach not only addresses the growing global demand for clean energy but also mitigates the environmental and social impacts associated with traditional mining. The achievements in this dual transition showcase a commitment to fostering a greener future while minimizing the ecological footprint of the essential processes underpinning the renewable energy revolution.
It exemplifies the outstanding researches corroborating to the development of new materials and processes to overcome current problems in the recovery of critical raw materials, including low grade, high contaminant content and environmental impacts.
Keywords: urban mining; green process; wasteless mining; critical raw materials
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.
