Extraction Of Metals Research Articles

Influence of Pseudomonas aeruginosa-based biopolymer on mitigating soil erosion and heavy metal dispersion

Extreme weather phenomena caused by climate change have exacerbated soil erosion and the subsequent dispersion of pollutants. Pseudomonas aeruginosa is known to contribute to the remediation of polluted water and reduce the geochemical mobility of heavy metals in contaminated soil. However, studies on the influence of biopolymers produced by soil microbes and P. aeruginosa on physical soil properties and soil erosion are limited. We aimed to investigate the influence of soil microbes on the mitigation of soil erosion and geochemical dispersion of heavy metals using a naturally occurring microbial substance, P. aeruginosa-based biopolymer (PBB). The PBB comprised carboxyl, hydroxyl, and amine surface functional groups; consequently, the biopolymer effectively sequestered Cd (maximum sorption capacity qm = 45.7 mg/g), Cu (qm = 26.7 mg/g), Pb (qm = 64.9 mg/g), and Zn (qm = 26.1 mg/g) in the solution. The PBB amendment of the soil improved the physical properties associated with soil erosion, increasing soil aggregation stability and shear strength by 41.6 % and 36.8 %, respectively. The extraction of heavy metals from soil via synthetic precipitate leaching decreased by 54.2 % following the PBB amendment, and a negative correlation was observed between soil aggregate stability and heavy metal extraction, indicating that this microbial substance could immobilize pollutants by adsorbing cationic metal ions and inhibiting water-induced disaggregation. In the soil erosion experiments, soil loss and heavy metal extraction decreased by 70.9 % and 43.8 %, respectively, following the PBB amendment. These aggregation and sorption effects of the PBB underscore the potential of soil microbes to mitigate soil erosion and immobilize the geochemical dispersion of heavy metals, thereby contributing to the conservation of soil and water quality in areas surrounding contaminated slopes and heavy metal-contaminated areas, such as cut slopes, agricultural fields, mine dumps, and dams.

Extraction of Platinum Group Metals from the Acidic Leaching Solutions of Secondary Resources by Hydrometallurgical Methods: A Review

Extraction of Platinum Group Metals from the Acidic Leaching Solutions of Secondary Resources by Hydrometallurgical Methods: A Review

Crystallization of Cathode Active Material Precursors from Tartaric Acid Solution.

In this study L-(+)-tartaric acid was used to extract metals from either pure cathode material (NMC111) or black mass from spent lithium-ion batteries. The leaching efficiencies of Li, Co, Ni, and Mn from NMC111 are > 87% at 70 °C, with an initial solid to liquid ratio of 17, and > 72.4±1.0% from black mass under corresponding conditions. The metals tend to form mixed phases in antisolvent crystallization and seeding has a minimal effect on the final solid composition. Impurities influence both crystal nucleation and growth. By controlling the antisolvent addition rate crystal growth can be promoted. The theoretical dielectric constant of the solution is shown to correlate excellently to the recovery efficiency across different antisolvents, where a value <52 results in over 95% total transition metal recovery efficiency. The correlation can be a powerful tool for quantitative prediction of optimal solvent composition for effective antisolvent crystallization.

Review of Heavy Metal Removal from Soil: Methods and Technologies

Soil health is vital for ecosystem functioning, agriculture, and human well-being, yet heavy metal contamination poses significant risks to environmental and public health. This review examines various methods for removing heavy metals from contaminated soils, focusing on physical, chemical, and biological remediation techniques. Sources of contamination, including industrial activities, mining, and improper waste disposal, are discussed, alongside the environmental and health impacts of heavy metals like lead, cadmium, and mercury. Physical techniques such as soil washing and excavation effectively reduce contamination but generate secondary waste and incur high costs. Chemical methods, including soil stabilization and chemical leaching, immobilize or extract metals but may risk recontamination. Biological approaches like phytoremediation and bioremediation leverage natural processes for eco-friendly remediation, though they often require longer timescales for significant results. Emerging technologies, such as nanotechnology and biochar application, show promise for enhancing remediation efficacy. However, challenges remain, including economic constraints, regulatory inconsistencies, and the need for sustainable, long-term solutions. Future directions include integrating various remediation techniques, developing eco-friendly technologies, and emphasizing long-term monitoring to ensure the effectiveness of remediation efforts. This comprehensive overview aims to inform future research and policy development to address heavy metal contamination sustainably.

Recycling Li-Ion Batteries via the Re-Synthesis Route: Improving the Process Sustainability by Using Lithium Iron Phosphate (LFP) Scraps as Reducing Agents in the Leaching Operation

The development of hydrometallurgical recycling processes for lithium-ion batteries is challenged by the heterogeneity of the electrode powders recovered from end-of-life batteries via physical methods. These electrode materials, known as black mass, vary in composition, containing differing amounts of nickel, manganese, and cobalt (NMC), as well as other chemicals, such as lithium iron phosphate (LFP). This study presents the results of the hydrometallurgical treatment of mixed NMC and LFP black masses aimed at creating flexible recycling processes. This approach leverages the reducing power of LFP to optimize the leach liquor composition for re-synthesizing NMC precursors. In particular, the leaching conditions were optimized based on the LFP content in the solid feed to maximize the extraction of key metals (Ni, Mn, Co, and Li). The leaching solid residue, graphite, was treated and characterized as a secondary raw material for new anode preparation. Iron phosphate was recovered by increasing the pH of the leach liquor, and the NMC precursors were obtained via coprecipitation. This process achieved a recycling rate of 51%, based on the black mass input and the mass of recovered elements in the output products. Additionally, substituting LFP scraps as the reducing agent in place of H2O2 reduced the recycling process’s environmental impact by avoiding 1.7 tons of CO2-equivalent emissions per ton of NMC black mass.

Development of Software for Hydrometallurgical Calculation of Metal Extraction

Hydrometallurgy plays a critical role in the metallurgical industry by providing an efficient method for extracting metals from ores and secondary materials using aqueous solutions. This approach is particularly advantageous for processing low-grade and complex ores, as well as secondary resources that cannot be effectively processed by traditional pyrometallurgical methods. The objective of this study is to develop specialized software to automate and optimize the calculations necessary for metal extraction in hydrometallurgical processes. The software integrates a complete computational framework for automating the various stages of the hydrometallurgical process, including ore composition initialization, total element mass calculations, and the determination of metal concentrations in both metal products (matte) and by-products (slag). The methodology involves the design and implementation of a web-based application using Django for the user interface and MySQL for robust data storage. The computational module, written in Python, automates the mathematical operations required to simulate complex chemical reactions and metal extraction processes. This module supports real-time processing and ensures accurate calculations for each stage of metal extraction, including leaching, extraction, re-extraction, sorption, and electrolysis. The software also features detailed tables and dynamic graphs that allow users to analyze the distribution of valuable metals and assess the influence of key operational parameters on extraction efficiency. The results show that the developed software successfully manages large datasets, enhances the precision of hydrometallurgical calculations, and minimizes the risk of human error. The implementation of the software leads to significant improvements in the economic efficiency of production by optimizing metal recovery rates and reducing operational costs. Additionally, it supports comprehensive process control by providing actionable insights into each stage of extraction, thus improving the quality of the final metal product. Overall, the software represents a significant technological advancement in the field, offering a scalable solution for industries aiming to streamline hydrometallurgical processes.

Thiourea-functionalized magnetic coffee residue for adsorption and magnetic solid-phase extraction of selected toxic metals in water

Herein, a recyclable thiourea-modified magnetic coffee residue was prepared, characterized, and investigated for Cd(II) and Pb(II) adsorption and magnetic solid-phase extraction in aqueous solutions. Optimal conditions of the adsorption parameters were found to be initial Cd(II) and Pb(II) concentrations of 4 and 20 mg/L, respectively, sample solution pH of 7, adsorbent amount of 50 mg, agitation rate of 150 rpm, and adsorption period of 30 min. The adsorption isotherm and kinetics aligned well with the Langmuir and the pseudo-second-order models, respectively. The modified magnetic coffee residue demonstrated a high uptake potential (mg/g), 8.9 for Cd(II) and 40 for Pb(II). The results indicate that chemosorption is the rate-limiting and that temperature influences the process. The elution procedure was performed by 5 mL 0.5 M thiourea in 2 % HCl and the developed magnetic solid-phase extraction technique presented excellent linearity (R2 ≥0.998), sensitivity (LOD (µg/L), 0.18 and 0.93 respectively for Cd(II) and Pb(II)), and precision (%RSD, ≤2.7 %). Compared to the reported techniques, the method is highly effective, environmentally friendly, and easily accessible. It also demonstrated good potential (%R, 92.5–99.0 %) when applied to real-world water samples. In conclusion, the developed techniques are recommended for the adsorption and magnetic solid-phase extraction of toxic metals in water systems.

A Planetary Boundary for Mineral, Metal, and Fossil Resource Extraction Rates: How Much Primary Materials Can a Circular Economy Extract?

Resource consumption is expected to further increase in the next decades. A circular economy could decrease the environmental impact of this resource consumption by minimizing the primary raw materials consumption and minimizing emissions that render materials inaccessible for further use. However, such a circular economy will still have primary raw material inflows, due to population growth, stock expansion, energy transition, and inevitable dissipation. The potential magnitude of such primary raw material inflows in a circular economy remains unclear. To address this uncertainty, the planetary boundary framework, which defines absolute limits on resource and emission flows, could be utilized. Although this framework incorporates aspects of biomass, water, and land use, mineral, metal, and fossil resources are not included. This study provides a principle for a planetary boundary for these three resources, based on the net accessibility rate and an allocated share of the accessible resource stock in the ecosphere. Inter- and intragenerational equality are crucial for determining this allocated share and for quantifying a sustainable rate of resource extraction in (an economy transitioning toward) a circular economy. Next steps to operationalize this principle provide further guidance to determine the safe operating space for mineral, metal, and fossil resource extraction.

The imaginaries of the city of Norilsk, from the Soviet industrial utopia to the contemporary nickel legend

Norilsk is a polar city in Russia, located to the South of the Taimyr Peninsula in the Arctic Circle. The city’s surroundings are rich in unique deposits of polymetallic ores, and life in the city is organised around metal extraction. This is a reason why Norilsk is an interesting object for analysis of the social representation of the city’s image. Social representation is a fairly new socio-philosophical concept. By the word ‘representation’ we mean perceptions that are formed on the basis of reality. In the case of Norilsk, it is the result of all perceptions of the city and its environment. The study is based on contemporary documentary films, geographical, historical and journalistic documents. The analysis of perceptions of Norilsk allows us to understand the reasons for ideological debates around the history of Russia, such as discussions about memorials to victims of political repressions. Statements about Norilsk are contradictory. Negative statements are related to negative perceptions of the city, while positive statements are related to the residents’ love for their city. The analysis of representations related to the architecture of Norilsk allows us to identify gaps in the official discourse about the foundation of the city and explore its historical background. The study has revealed that the Soviet architectural heritage is well-preserved and documented, while statements about buildings associated with the Gulag are relegated to a marginalised space. Consideration of external and local representations of Norilsk allows us to understand the process of rewriting the history of the city.

A key feedback loop: building electricity infrastructure and electrifying metals production.

Energy infrastructure requires metals, and metals production requires energy. A transparent, physical model of the metals-energy system is presented to explore under what conditions this dependence constrains or accelerates the transition to a net-zero economy. While the mineral (as high as 340 Mt yr-1 iron ore, 210 Mt yr-1 limestone, 250 Mt yr-1 bauxite and 5.5 Gt yr-1 copper ore in the 2040-2050 decade, assuming no improvements) and total energy (up to 22 EJ yr-1) requirements for building low-carbon energy infrastructure are significant, it compares favourably with the current extraction and energy use supporting the fossil fuel system (15 Gt yr-1 fossil minerals and ~38 EJ yr-1). There are levers to significantly reduce material use and associated impacts over time. The metals industry can play a key reinforcing role in the transition by adapting to the increasing supply of renewable electricity. Specifically, direct electrolysis can extract metal from ore close to the thermodynamic limit, to make efficient use of low-C electricity. The unique features of emerging technologies for iron extraction, molten oxide electrolysis and molten sulphide electrolysis are considered in this evolving system. Electrification enables elegant separations and provides a pathway to build out infrastructure while reducing environmental impacts, though material efficiency measures will still be crucial to meet 2050 carbon budgets.This article is part of the discussion meeting issue 'Sustainable metals: science and systems'.

Sustainable extraction and recycling of non-ferrous metals: a review from a European perspective.

This review article provides a comprehensive examination of sustainable extraction and recycling methods for non-ferrous metals, which are critical to a wide range of industries including electronics, construction and renewable energy. Focusing on metals such as aluminium, copper and silicon, the study highlights the importance of recycling in conserving resources and minimizing environmental impact. It discusses the challenges posed by material diversity in recycling processes and the advances in recycling technologies that have emerged in response. Special emphasis is placed on the importance of a circular economy in maintaining a sustainable balance between consumption and conservation of metal resources. Through detailed analysis, it advocates innovative recycling practices and improved design for recyclability and highlights the role of policy, industry and consumer behaviour in achieving sustainability goals. The findings contribute to the discourse on strategic self-sufficiency in Europe through recycling, providing insights into how to improve efficiency and manage the complexity of the global material cycle. This work calls for a collaborative effort towards sustainable metallurgy and underlines the critical need for advances in recycling infrastructure and technology to ensure the long-term availability and environmental stewardship of non-ferrous metals.This article is part of the discussion meeting issue 'Sustainable metals: science and systems'.

A non-isothermal kinetic study on the extraction of metals from spent lithium iron phosphate batteries using the NH2SO3H roasting process

A non-isothermal kinetic study on the extraction of metals from spent lithium iron phosphate batteries using the NH2SO3H roasting process

Decoupling of sulfation reactions to enhance zinc extraction from electric arc furnace dust: Unveiling the significance of O2 activation and mechanistic insights

Electric arc furnace dust (EAFD) is a hazardous solid waste generated during steelmaking, boasting significant concentrations of zinc and iron. Currently, a large amount of EAFD is disposed of in landfills, causing severe environmental pollution and resource wastage. To address this issue, the sulfation roasting followed by water leaching process was proposed, offering efficient zinc extraction, iron separation, low cost, and environmental friendliness advantages. This study presented a novel experimental design that decoupled the sulfation process for EAFD into gas–solid and solid–solid processes to uncover the sulfation mechanisms. During these processes, Zn-bearing phases were successfully converted into zinc sulfate (ZnSO4), while Fe-bearing phases transformed into iron oxide (Fe2O3). The resulting compounds were then separated using a water leaching process, achieving a high zinc extraction rate of 97.21% and a low iron residue of 0.61%, respectively, for the gas–solid sulfation process, and 98.76% and 0.81% for the solid–solid sulfation process. Comprehensive characterizations, in situ diffusion Fourier transform infrared spectroscopy (DRIFTS) experiments, and density functional theory (DFT) calculations provide a deeper understanding of the sulfation restructuring mechanisms in gas–solid and solid–solid roasting processes, highlighting the significant role of O2 activation. In the solid–solid sulfation process, Fe2(SO4)3, derived from the oxidation of FeSO4 by O2, was identified as the predominant compound responsible for sulfation. In the gas–solid sulfation process, sulfite species (SO32-) played a critical role as intermediates, eventually transforming into sulfate species (SO42-) with the assistance of O2. Moreover, adsorbed SO2 underwent oxidation and activation by adsorbed O2, forming the sulfate functional group. Migration of this functional group to the adjacent Zn atom through a transition state, established a Zn-SO4 bond, disrupting the Zn-O bond on ZnFe2O4 and completing the sulfation of ZnFe2O4. This study provides a fresh perspective on the application of sulfation roasting for the extraction of valuable metals, contributing to resource sustainability and effective management of zinc-bearing resources.

Experimental and molecular insights into ionic liquid-based recovery of valuable metals from spent lithium-ion batteries

A new type of collaborative extractants consisting of the ionic liquid (IL) 1-aminoprooyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)imide, ([APMIM][Tf2N]) and Cyanex 923 (C923) is first applied for selective extraction of valuable metals from spent lithium-ion batteries (LIBs). The one-stage extraction efficiencies of Co2+, Ni2+ and Mn2+ are up to 99.87 %, 97.74 %, 99.98 %, respectively, at the optimal conditions, and the high-purity Li+ was enriched at the raffinate. It is found that the extraction process follows the so-called “cation exchange mechanism”, and the molecular-level mechanism is revealed via quantum chemical (QC) calculations. The findings show that C923 plays the role of coordinating with metal ions, the cation of IL exchanges metal ions from the aqueous to organic phases, and the anion [Tf2N]- of IL can stabilize the complex species of metal ion-[Tf2N]--C923 in organic phase. This work provides new insights for the design of novel IL-based extractants for the recycling of spent LIBs.

Selective Growth of Nb-Fe-B Intermetallic Compounds for the Direct Separation of Rare Earths Based on Manipulating Liquation

Since the primary goal of industrialization has changed to carbon neutrality, the importance of rare earths (REs) has increased due to their criticality in green industries. The attainment of sustainable resources via green production processes is necessary due to the increasing need for REs. Liquid metal extraction is regarded as a leading technology for supporting the sustainability of resources based on the selective reactivity between REs and extractants. However, this process requires multiple stages, including pretreatment, extraction and separation, which are considered bottlenecks in industrialization. In this work, reverse selectivity is applied instead of conventional liquid metal extraction (c-LME) for the direct separation of REs in a single stage. Niobium (Nb) is selected because of its thermodynamic properties for enhancing the selectivity of the reactions between the extractant and other elements, excluding REs. The process is thermodynamically designed for liquation systems, and it reflects the interactions between the extractant and magnets. The solidification behavior based on the selective growth of phases without REs is shown with variations in the composition and cooling rate to confirm the kinetics. The composition prevents the formation of RE-Fe intermetallic compounds, and excess Nb is considered a bottleneck for separating REs. In addition, the cooling rate influences the agglomeration of RE as a layer. Because of the manipulation of the liquation, 92.89% of the REs are successfully separated in the form of accumulated layers. This effective process for the direct separation of REs is verified through thermodynamic and experimental assessments. Overall, this investigation can provide new guidelines for the construction of a circular economy after improving the energy efficiency of this system in future research.

Separation and enrichment of Cd and Pb from food and water samples based on a graphene oxide-decorated poly 2-diethylaminoethyl methacrylate nanocomposite by dispersive micro-solid phase extraction (d-μ-SPE)

In this study, a graphene oxide combined with poly(2-diethylaminoethyl methacrylate) (GO@PDEAEMA) nanocomposite was synthesized for the separation and enrichment of Cd and Pb from food and water samples using the dispersive micro-solid phase extraction (d-μ-SPE) technique. The GO@PDEAEMA nanocomposite was synthesized using surface-initiated atom transfer radical polymerization (SI-ATRP) and characterized using various analytical techniques, such as FTIR, FE-SEM, TGA, BET, and XRD. The optimal experimental conditions were pH 8, 0.5 M HNO₃ as eluent, 5 mg of sorbent, and adsorption/desorption times of 0.5 and 1 min, respectively, with a recovery range of 89–101 %. The suggested method showed low limits of detection (LOD) and quantification (LOQ) of 0.11 μg L−1 and 0.37 μg L−1 for Cd and 0.28 μg L−1 and 0.93 μg L−1 for Pb, respectively. The optimal procedure was successfully applied to real water and food samples. The study demonstrates the possibility of using GO@PDEAEMA nanocomposite as an effective sorbent for toxic metal extraction.

Metal Extraction from Commercial Black Mass of Spent Lithium-Ion Batteries Using Food-Waste-Derived Lixiviants through a Biological Process

Metal Extraction from Commercial Black Mass of Spent Lithium-Ion Batteries Using Food-Waste-Derived Lixiviants through a Biological Process

Analyzing the lifecycle of solar panels including raw material sourcing, manufacturing, and end-of-life disposal

The lifecycle of photovoltaic systems, encompassing the procurement of raw materials, manufacturing processes, and eventual disposal at the end of their operational lifespan, presents considerable ecological challenges notwithstanding their contribution to the enhancement of renewable energy sources. This research offers an exhaustive examination of the ecological ramifications associated with each phase of the lifecycle of photovoltaic systems. The extraction of essential materials, including silicon, silver, and rare earth metals, necessitates energy-demanding processes and leads to resource depletion, while the manufacturing phase is associated with the emission of greenhouse gases and resource consumption, particularly in the fabrication of crystalline silicon panels. The disposal at the end of life is becoming increasingly significant, as retired panels accumulate, and existing recycling technologies provide minimal recovery of valuable materials. Despite the substantial reduction in greenhouse gas emissions attributable to solar panels throughout their operational lifespan, there is a pressing need for enhancements in material efficiency, manufacturing methodologies, and recycling frameworks to mitigate their lifecycle repercussions. The investigation underscores the imperative for sustainable methodologies, circular economy paradigms, and policy measures to guarantee the enduring environmental sustainability of solar energy.

Strategies for Hydrocarbon Removal and Bioleaching-Driven Metal Recovery from Oil Sand Tailings

Oil sand tailings from bitumen extraction contain various contaminants, including polycyclic aromatic hydrocarbons, BTEX, and naphthenic acids, which can leak into surrounding environments, threatening aquatic ecosystems and human health. These tailings also contribute to environmental issues such as habitat disruption and greenhouse gas emissions. Despite these challenges, oil sand tailings hold significant potential for waste-to-resource recovery as they contain valuable minerals like rare earth elements (REEs), titanium, nickel, and vanadium. Traditional metal extraction methods are environmentally damaging, requiring high energy inputs and generating dust and harmful emissions. Furthermore, the coating of hydrocarbons on mineral surfaces presents an additional challenge, as it can inhibit the efficiency of metal extraction processes by blocking access to the minerals. This highlights the need for alternative, eco-friendly approaches. Bioleaching, which uses microorganisms to extract metals, emerges as a sustainable solution to unlock the valuable metals within oil sand tailings. This review discusses the minerals found in oil sand tailings, the challenges associated with their extraction, methods from hydrocarbon removal from minerals, and bioleaching as a potential metal recovery method.

Synergistic Utilization of Basic Oxygen Furnace Slag and Coal Gangue: Modified Slag and Metal Extraction

Synergistic Utilization of Basic Oxygen Furnace Slag and Coal Gangue: Modified Slag and Metal Extraction