Demand For Rare Earth Elements Research Articles

Technoeconomic Analysis of Rare-Earth Metal Recycling Using Efficient Metal Distillation

Recycling has been proposed as a promising potential source of supply to meet some of the US rare-earth demand for use in permanent magnets. The high growth rates of products that make use of rare-earth magnets, particularly wind turbines and electric and hybrid vehicles, show that their stock in use is on the rise and in the near term will become available as scrap feed for recycling. This study presents an overview of magnet recycling technologies and focuses on the technoeconomic analysis of liquid metal leaching and distillation, including the effect of a new continuous gravity-driven multiple effect thermal system (G-METS) metal distillation technology on energy use and overall cost. The G-METS system can potentially reduce the energy consumption of the overall process to 64 kWh/kg, which is about 30% less than metal production from ore and 61–67% less than the process using conventional distillation.

Rare Earth Elements: A brief overview

Recent years have witnessed increasing awareness and interest in rare earth elements (REE). These several, usually unfamiliar elements, are key components of countless products used in our daily lives. Because of their use in many modern technologies, including those important for national security, the demand for REE grows, and so does the production, need to find their new sources and improve the extraction. This article provides an overview of REEs, their availability, production, and uses, and briefly discusses the future of these valuable and critical metals.

Circular economy: A sustainable management strategy for rare earth elements consumption in Australia

Rare earth elements (REEs) are a major constituent of many advanced materials in the information and telecommunication industries, as well as the renewable and energy efficiency sectors. REEs are enablers of speed, performance, durability, and low carbon emissions in these industries. They are required in everyday applications because of their unique chemical and physical properties. Given the rise in environmental concerns and consequent demand for REEs and the limited locations where REEs can be sourced, there is a very high risk of supply disruption.Despite the threat of REE supply risk and its environmental and economic significance, an in-depth examination of the environmental impact and benefits of sustainable consumption of these metals in Australia, as in many other parts of the world, holistically and systematically is lacking, particularly regarding improvement in resource efficiency strategies. Most previous work on REEs has focused either on the politico-economic conflicts over supply and distribution, or the environmental and social impacts of its production and has not holistically examined this problem, as a system.This paper provides a review of REEs' sustainable consumption in Australia. The study highlights Circular Economy (CE) as a scientifically plausible picture of sustainable management strategy to help address the adverse impacts of resource (REEs) shortages while achieving maximum environmental benefits. It provides answers to how sustainable are the current strategies of REEs consumption and how this can be enhanced from a CE perspective. A comprehensive CE framework was developed, followed by an illustrative example of CE as a tool for sustainability management and a practical implementation strategy to close the material loop and improve resource efficiency.

Quantification of Peptide-Bound Particles: A Phage Mimicking Approach via Site-Selective Immobilization on Glass.

The increasing complexity and need of high-tech materials for modern electronics raise the demand for rare earth elements. While recycling rates are still negligible for most elements, geopolitical tensions, circular economy, and the aim for a carbon-neutral society put pressure on conventional supply strategies and emphasize the need for new ideas for recycling. Our research group works on the development of phage surface display (PSD)-derived peptide-based recycling methods for electronic waste. This study focuses on LaPO4:Ce,Tb (LAP), a component of electronic waste from compact energy-saving lamps containing rare earth element-enriched fluorescent powders. While free solution-phase peptides show little to no interaction with the target material, we re-enabled the binding capability by immobilizing them on various glass supports. We shine a spotlight on the transition from phage-bound to free peptides and present the first proof of successful peptide-LAP particle interactions of previously reported PSD-derived sequences. Therefore, we introduce a method to investigate peptide–particle–interactions qualitatively and quantitatively. Additionally, a calibration curve allowed the quantification of peptide-bound particles. Combined with the quantification of the immobilized peptide on the surface, it was possible to calculate a potential dosage of peptides for future recycling processes.

Beneficiation of Low-Grade Rare Earth Ore from Khalzan Buregtei Deposit (Mongolia) by Magnetic Separation

The global demand for rare earth elements (REEs) is expected to increase significantly because of their importance in renewable energy and clean storage technologies, which are critical for drastic carbon dioxide emission reduction to achieve a carbon-neutral society. REE ore deposits around the world are scarce and those that have been identified but remain unexploited need to be developed to supply future demands. In this study, the Khalzan Buregtei deposit located in western Mongolia was studied with the aim of upgrading low-grade REE ore via magnetic separation techniques. The total REE content in this ore was ~6720 ppm (~3540 ppm light REE (LREE) + ~3180 ppm heavy REE (HREE)) with bastnaesite, pyrochlore, synchysite, and columbite-(Fe) identified as the main REE-bearing minerals. As the particle size fraction decreased from −4.0 + 2.0 mm to −0.5 + 0.1 mm, the recovery by dry high-intensity magnetic separation (DHIMS) increased from 20% to 70% of total rare earth oxide (TREO) while the enrichment ratio reached 2.8 from 1.3. Although effective, gangue minerals such as quartz and aluminosilicates were recovered (~22%) due most likely to insufficient liberation. Meanwhile, the wet high-intensity magnetic separation (WHIMS) could produce a magnetic concentrate with TREO recovery of ~80% and enrichment ratio of 5.5 under the following conditions: particle size fraction, −106 + 75 μm; feed flow rate, 3.2 L/min; magnetic induction, 0.8 T. These results indicate that combining DHIMS and WHIMS to upgrade the low-grade REE ore from the Khalzan Buregtei deposit is an effective approach.

Potential application of graphene oxide and Aspergillus niger spores with high adsorption capacity for recovery of europium from red phosphor, compact fluorescent lamp and simulated radioactive waste

The recovery of rare earth elements (REEs) is a global challenge and the mining of rare earths has serious environmental implications due to the toxic waste released post mining. Hence, the rising demand for rare earths and their far reaching electronic applications necessitates an effective strategy to recover the REEs from more viable sources. In this work, the graphene oxide–Aspergillus niger spores (GO–A. niger spores) blend was utilized for adsorptive recovery of a precious rare earth Eu(III) and the adsorption variables like pH of the medium, adsorbent dosage, sorption kinetics, thermodynamics, and isotherm were optimized for the developed biosorbent. The adsorption process suits the Langmuir isotherm model with a maximum adsorption capacity of 147.3 mg/g. The pseudo–second–order kinetics is a perfect fit to describe the adsorption process. The results obtained through the Van't Hoff plot show negative free energy change (ΔG0) which implies the spontaneity of the adsorption process. The negative standard enthalpy change (ΔH0) values show that the nature of the adsorption process is exothermic. The analytical characterizations including Fourier transform infrared spectroscopy (FTIR), Raman, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), thermal gravimetric analysis (TGA), and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) were employed to study the biosorbent. The features of GO–A. niger spores biosorbent were applied to recover Eu(III) from real samples such as fluorescent lamp phosphor, red phosphor powder, and a simulated radioactive waste solution.

Dissolved Organic Matter Mitigates the Acute Toxicity of Thulium to Hyalella azteca but Ca, Mg and Na Do Not.

The demand for rare earth elements (REEs) is growing and as a result, environmental exposure is a concern. The objective of this research was to evaluate the acute toxicity of Tm to Hyalella azteca and to understand the potential for toxicity modification by dissolved organic matter (DOM) and the cations Ca2+, Mg2+ and Na+. Standard methods were followed for 96h static exposures in a medium with a hardness of 60mg CaCO3/L, pH of 7.3 at 23°C. H. azteca neonates (2-9 d of age) were used and in unmodified media the LC50 concentration was 3.4µM [95% CI 2.9-3.9µM; 573µg/L (482-663)] based on measured dissolved concentrations at the end of the test. Tests done with different concentrations of Ca (0.25, 0.5 and 1.5mM) did not show consistent trends and there was no clear evidence of a protective effect from Ca. Variations in Na (0.26, 0.5 and 1.6mM) resulted in no significant changes in toxicity. Similarly, Mg (0.07, 0.14 and 0.4mM) did not result in significant changes in LC50 values, except for a reduction in toxicity for measured total Tm at the lowest Mg concentration. Our results indicate that Tm toxicity is not influenced by cationic competition (Ca, Na and Mg). Dissolved organic matter (sourced from Luther Marsh ON) offered significant protection against Tm toxicity. Addition of 9mg DOC/L resulted in significantly increased LC50 values. This study contributes toward understanding the toxicity of Tm and the importance of considering dissolved organic matter in estimating the potential for environmental risk of REEs.

(Invited) Electrochemical Extraction of Rare Earth Elements from Coal-by Products

Rare earth elements (REEs) are a group of 15 lanthanide elements plus Scandium and Yttrium with similar properties. REEs are strategically important as they are used in numerous technologies and applications. As the demand for REE has increased the search for their alternative resources becomes crucial [1]. Regarding this, coal and coal by-products have attracted much attention in recent years as a potential source for rare earth elements [2].Botte and members of her research group has been working on the development of advanced electrochemical cells for the extraction of rare earth elements from coal and coal-by products [3, 4]. In this presentation, we will discuss the progress on this process, RRE extraction efficiency and preliminary economic analysis.References Franus, W., M.g.M. Wiatros-Motyka, and M. Wdowin, Coal fly ash as a resource for rare earth elements.Environmental Science and Pollution Research. 22(12): p. 9464-9474. Dai, S., I.T. Graham, and C.R. Ward, A review of anomalous rare earth elements and yttrium in coal. International journal of coal geology. 159: p. 82-95. Jin, X. and G.G. Botte, Feasibility of hydrogen production from coal electrolysis at intermediate temperatures.Journal of Power Sources, 2007. 171(2): p. 826-834. Jin, X. and G.G. Botte, Understanding the kinetics of coal electrolysis at intermediate temperatures. Journal of Power Sources. 195(15): p. 4935-4942.

Analysis of Unstable Supply and Demand of Rare Earths from Korea to China and Countermeasures against Regulations: Based on Quad-system Subscriptions

Purpose – This study investigates the impact of regulations over Rare earth that recently China had carried out agianst USA. This discussion examines the definition of essential strategic resources called rare earths, China’s precedent of declaring resource weaponization, and its influence. Furthermore, it analyzes the possibility of China’s rare earth export regulations in trade between South Korea and China, and also suggests Korea’s countermeasures to them, focusing on joining the QUAD system. Furthurmore, POSCO Group, which is pushing for ‘E-Autopos’, a next-generation electric vehicle platform, will be analyzed as a concrete example to discuss the impact on not only the Korean electric vehicle industry but also automakers doing business with POSCO Group. Design/Methodology/Approach – To this end, we used d ata f rom China’s rare earth production, actual cases of damage suffered by POSCO at the time of the restriction on rare earth imports from Japan and the United States. Findings – The quad system is a U.S.-centered security talks planned since the Trump administration and is preparing for China’s exclusive exercise of rare earth hegemony. Moreover we discuss about the high probability that China’s export regulations would be imposed on Korea, considering the domestic economy, which is highly dependent on the Chinese economy. As a result , we insist it is essential for Korea to join the QUAD in preparation for existing rare earth-related risks. In order to elaborate its discussion, we will also link up with the domestic electric vehicle industry, which is essential to have rare earths. To this end, POSCO Group, which is pushing for ‘E-Autopos’,a next-generation electric vehicle platform, will be analyzed as a concrete example to discuss the impact on not only the Korean electric vehicle industry but also automakers doing business with POSCO Group. Research Implications – Through this analysis process, we will analyze the impact of China’s rare earth export regulations on the Korean economy, approach and develop the phenomenon on Korea in terms of resource factors, and present solutions.

Material consumption and environmental impact of wind turbines in the USA and globally

Wind power is one of the fastest-growing energy in the world. Its contribution to global electricity generation should increase from 5 to 30% in 2050. With the increasing number of wind farms, we need to ensure that we will have enough material to meet the expected global capacity growth without creating new environmental issues. In this work, we estimated the material demand for wind turbines in the USA and the rest of the world and compared those values with the expected production until 2050. Based on the annual capacity installation, we quantified the carbon footprint and cumulative energy demand associated with the material production. Cement demand in 2032-2036 could be twice as much as the current amount used for wind turbines and pipeline construction in the USA. Compared to 2018, the USA steel demand in 2033 will increase by 511% (from 853 to 5215 kt). Rare earth elements (REEs) demand in the USA will increase by 254%-815% in 2033 (from 0.33 to 1.16-3 kt) compared to 2018. In the rest of the world, REEs demand will be 38% of the Chinese production in 2050. In 2050, the carbon footprint for materials required for wind turbines globally will be 9.3 times lower than the CO2 emitted currently from coal power plants in the USA. It is important to evaluate the potential impact of large-scale deployment of wind energy to avoid as much as possible creating new issues related to material scarcity, which could increase the carbon footprint of future electricity production.

Mining value from waste: Scandium and rare earth elements selective recovery from coal fly ash leach solutions

Global demand for rare earth elements (REEs) has been on the rise due to recent rapid technological advancements. Even though most REEs are mainly recovered from rich ores and mineral deposits, recovery of REEs from secondary sources has attracted attention. However, low metal concentration, complex matrices and high levels of other impurities in mine wastes and tailings have remained the toughest challenges to overcome. The presence of low amount of valuable metals such as Sc requires utilization of very selective separation techniques such as ion exchange. A series of ion exchange resins (chelating, solvent impregnated and strongly acidic) were studied in the recovery of Sc from synthetic and actual pregnant leach solutions obtained from acid-leaching of coal fly ash. To the best of our knowledge, this paper exhibits the first attempt in selective recovery (from other REEs as well as major Fe and Al contaminations) of Sc in coal fly ash using ion exchange separation technique. With maximum capacity of ∼24 mg Sc/g resin, Sc was adsorbed quickly on phosphorus containing Lewatit® VP OC 1026 and TP 272 resins even in the presence of high levels of potentially interfering Fe3+ and Al3+ ions. Full elution of the adsorbed REEs from VP OC 1026 was achieved with 5 M H2SO4, with only minor Sc removal. While elution of Sc from these chelating resins has been reported to be challenging, Sc could be eluted almost completely with 2 M NH4F. Recovery of REEs with 5 M H2SO4 from TP 272 resulted in co-elution of only 7% of the adsorbed Sc while the rest could be eluted efficiently with 6 M HNO3.

Leaching of Rare Earth Elements (REEs) from lake sediments around Eppawala phosphate deposit, Sri Lanka: A secondary source for REEs

Rare earth elements (REEs) are widely employed in a spectrum of high-tech applications. Since primary REE resources are limited, secondary REE sources will be crucial to reduce future supply chain gap between REE demand and supply, which is currently about 3000 t per year. In this context, lake sediments around Eppawala Phosphate Deposit (EPD) in Sri Lanka could be considered as a potential secondary REE source since a man-made water canal running across the EPD transports REE-rich materials to the lake sediments. The average total REE (ΣREE) concentration of the downstream surface lake sediments was 804 mg/kg. The REEs were present in lake sediments as 3 fractions, namely, ion-adsorbed, colloidal, and mineral bound fractions. Ion-adsorbed fraction was assessed using less expensive, easy, and environmentally friendly ion-exchangeable leaching by a solution of (NH4)2SO4 under optimum conditions. Experimental results revealed that 34% of ΣREE was leached as ion-adsorbed fraction. In addition, the maximum leachable REE content (i.e. ion-adsorbed and colloidal fractions) was determined as 78% of ΣREE through HCl leaching under optimum conditions. Therefore, acid leaching was proven to be the best leaching process and the results in this preliminary study could be useful to assess low-grade geological resources, especially sediments and soils around major phosphate deposits with similar geological settings.

Geochemical behavior and fractionation characteristics of rare earth elements (REEs) in riverine water profiles and sentinel Clam (Corbicula fluminea) across watershed scales: Insights for REEs monitoring

The increasing global demand for rare earth elements (REEs) has led to their recognition as emerging contaminants; however, the effect that biota have on the cycling of these elements at the watershed scale is not currently well understood. In this study, water samples and field freshwater clams Corbicula fluminea were concurrently collected along watershed gradients, and concentration profiles of 14 naturally occurring REEs were measured in operationally defined water fractions and soft tissues of the freshwater clams. Moreover, Post Archean Australian Shale (PAAS) normalized REE patterns, fractionation indices, and anomalous values were determined to further extract characteristic features. As a result, both the water and biological samples had variable REE compositions, with higher concentrations of light REEs (LREEs) than middle REEs (MREEs) and heavy REEs (HREEs), while decreasing concentrations were generally observed as filter pore size decreased, implying that large colloidal and particulate fractions were important carriers of REEs. The spatial distribution patterns of REEs revealed a clear site effect among profiles, with variability more pronounced among watersheds and with peaks in sites from a small watershed near the hotspots of the mining area, and then exhibited a decreasing trend with distance from there. Meanwhile, significant bioaccumulation of REEs was observed potentially reflecting different degrees of contamination gradients among the watersheds. The PAAS-normalized distribution patterns tended to be slightly enriched in MREEs, producing a peculiar “roof-shaped” feature and characteristic fractionation. Remarkably, bio-concentration factors (BCFs) highlighted the importance of large colloidal and particulate phases in assessing biologically available REEs for filter-feeding species. Collectively, our study strongly favored that accumulation patterns and fractionation characteristics of REEs in C. fluminea can serve as a reliable indicator of geochemical behavior, providing a promising biomonitoring tool to quantitatively denote different degrees of REE contamination and assess possible impacts in mining watersheds.

Phosphate Polymer Nanogel for Selective and Efficient Rare Earth Element Recovery.

Demand for rare earth elements (REEs) is increasing, and REE production from ores is energy-intensive. Recovering REEs from waste streams can provide a more sustainable approach to help meet REE demand but requires materials with high selectivity and capacity for REEs due to the low concentration of REEs and high competing ion concentrations. Here, we developed a phosphate polymer nanogel (PPN) to selectively recover REEs from low REE content waste streams, including leached fly ash. A high phosphorus content (16.2 wt % P as phosphate groups) in the PPN provides an abundance of coordination sites for REE binding. In model solutions, the distribution coefficient (Kd) for all REEs ranged from 1.3 × 105 to 3.1 × 105 mL g-1 at pH = 7, and the sorption capacity (qm) for Nd, Gd, and Ho were ∼300 mg g-1. The PPN was selective toward REEs, outcompeting cations (Ca, Mg, Fe, Al) at up to 1000-fold excess concentration. The PPN had a Kd of ∼105-106 mL g-1 for lanthanides in coal fly ash leachate (pH = 5), orders of magnitude higher than the Kd of major competing ions (∼103-104 mL g-1). REEs were recovered from the PPN using 3.5% HNO3, and the material remained effective over three sorption-elution cycles. The high REE capacity and selectivity and good durability in a real waste stream matrix suggest its potential to recover REEs from a broad range of secondary REE stocks.

Theoretical Investigation on Rare Earth Elements of Y, Nd and La Atoms’ Adsorption on the Kaolinite (001) and (001¯) Surfaces

With the growing demand of rare earth elements, the recovery of rare earth elements is a major issue for researchers in related fields. Adsorption technology is one of the most effective and popular recovery methods. Therefore, the adsorption mechanism of Yttrium (Y), Neodymium (Nd), and Lanthanum (La) atoms on the kaolinite (001) and (001¯) surfaces was examined by density functional theory (DFT). The most stable adsorption sites on the kaolinite (001) surface for Y atoms was the bridge site, and the hollow site was the most favorable adsorption site for Nd and La atoms with high adsorption energy. However, the adsorption energies of kaolinite (001¯) surface sites for Y, Nd, and La atoms were much lower than the (001) surface sites, indicating that the adsorption capability of the hydroxylated (001) surface is stronger. The effects of coverage on adsorption position, energy, and structures were entirely investigated on top, bridge, and hollow sites of the kaolinite (001) surface from 0.11 to 1.0 monolayers (ML). The adsorption energy of Y, Nd, and La atoms on three kinds of sites increased with increasing of the coverage implied the stronger capability of surface adsorption. The recovery capability of kaolinite for the rare earth atoms was in the order of La > Nd > Y. The changes in the atomic structure, charge density, and electron density of states for Y, Nd, and La/kaolinite (001) before and after adsorption were also analyzed in depth.

Analytical Capabilities of EDXRF for Determination of Rare Earth Elements

Rare earth elements (REE) are present in the lanthanide range and are widely used in high-tech and clean technology applications that are predicted to grow significantly in the coming decades. Therefore, there will be a high demand for REE in the future that will impact the needs for development of sensitive and selective methods for determination of REEs such as X-Ray Fluorescence (XRF). Reliability of REEs analysis results depend on analytical capability of XRF instrument’s performance. Analytical capability shows the ability of the instrument to perform sample analysis with high accuracy and precision and proven by validation so that the results obtained are reliable. The aim of this study is to assess the analytical capability of XRF for REEs analysis in samples particularly Lanthanum (La), Cerium (Ce), Neodymium (Nd), Samarium (Sm) and Yttrium (Y), by performing method validation of energy dispersive x-ray spectrometers (ED-XRF). Four measurement conditions that covered the selected elements were defined. Accuracy, precision and detection limits determination were performed by measuring the CRM In House Monazite Sand. The yield of the selected element corresponds to its certified value, with a %recovery between 95.99 to 103.1%. The %RSD values ranging from 0.59 to 5.19%. The detection limits (LLD) of ED-XRF ranged from 8.78 to 67.4 ppm. The results showed the good analytical capability of ED-XRF method for REEs analysis.

Selective Leaching of Rare Earth Elements from Ion-Adsorption Rare Earth Tailings: A Synergy between CeO2 Reduction and Fe/Mn Stabilization.

The increasing demand for rare earth elements (REEs) motivates the development of novel strategies for cost-effective REE recovery from secondary sources, especially rare earth tailings. The biggest challenges in recovering REEs from ion-adsorption rare earth tailings are incomplete extraction of cerium (Ce) and the coleaching of iron (Fe) and manganese (Mn). Here, a synergistic process between reduction and stabilization was proposed by innovatively using elemental sulfur (S) as reductant for converting insoluble CeO2 into soluble Ce2(SO4)3 and transforming Fe and Mn oxides into inert FeFe2O4 and MnFe2O4 spinel minerals. After the calcination at 400 °C, 97.0% of Ce can be dissolved using a diluted sulfuric acid, along with only 3.67% of Fe and 23.3% of Mn leached out. Thermodynamic analysis reveals that CeO2 was indirectly reduced by the intermediates MnSO4 and FeS in the system. Density functional theory calculations indicated that Fe(II) and Mn(II) shared similar outer electron arrangements and coordination environments, favoring Mn(II) over Ce(III) as a replacement for Fe(II) in the FeO6 octahedral structure of FeFe2O4. Further investigation on the leaching process suggested that 0.5 mol L-1 H2SO4 is sufficient for the recovery of REEs (97.0%). This research provides a promising strategy to selectively recover REEs from mining tailings or secondary sources via controlling the mineral phase transformation.

Nanoengineering cellulose for the selective removal of neodymium: Towards sustainable rare earth element recovery

Rare earth elements (REE) have exceedingly become critical in advanced industries. Despite the high demand for REE, the world is still experiencing a shortage in ready-to-exploit resources, environmentally friendly processing, and reliable recovery strategies, rendering sustainable REE removal an immediate and unmet environmental, industrial, and economical challenge worldwide. We nanoengineered cellulose, the most abundant biopolymer in the world, to develop a sustainable bio-based technology named anionic hairy nanocellulose (AHNC) for the high-capacity and selective removal of neodymium ions (Nd3+), one of the most widely used REE, from aqueous media. AHNC comprises fully solubilized dicarboxylated cellulose (DCC) chains and cellulose nanocrystals (CNC) decorated with DCC (hairs) bearing a charge density that is about one order of magnitude higher than conventional CNC. The unique colloidal properties of AHNC, particularly the polyanionic hairs, enable the removal of ~ 264 ± 14 mg of Nd3+ per gram of the nanoadsorbent within seconds, which, to the best of our knowledge, place this advanced material among the adsorbents with the highest removal capacity at the shortest contact time. We investigated the roles of ionic strength, pH, and competing iron species on the performance of AHNC. Besides Nd3+ removal at high initial Nd3+ concentrations (C0 > 150 ppm) wherein AHNC is fully neutralized and precipitated, we show, for the first time, that at C0 ≤ 100 ppm wherein AHNC maintains its partial colloidal stability, Nd3+ removal can be enhanced via complementary calcium ion-mediated colloidal bridging. Together, our colloidal engineering approach combined with the biorenewability of cellulose and an ambient, low-cost unit operation, renders AHNC a promising sustainable nanotechnology for the removal of Nd3+ from industrial wastewater, mining tails, e-waste, and NdFeB permanent magnet leachates.

Toward the Circular Economy of Rare Earth Elements: A Review of Abundance, Extraction, Applications, and Environmental Impacts.

Rare earth elements (REEs) are increasingly critical to the high-technology and low-carbon economy. With a shift to sustainable socioeconomic development that aims to be less fossil fuel dependent, global demand for REEs continues to rise, despite their uncertain supply chain and high environmental impact of production. Here, we review recent research on REEs, including global reserve assessment, REE-based applications, major REE production pathways, environmental impacts, and the potential to leverage circular economies within the REE industry. The main objective of this review is to provide an overall socioeconomic and environmental perspective of the REE industry with a central focus on environmental impacts of various REE-related activities. The literature reveals significant interest in extracting REEs from secondary materials(e.g., tailings, bauxite residues, coal combustion ash) and electronic wastes. However, some of these REE recovery processes are not yet economically profitable and environmental-friendly. Continued technological advancements and increasing demands for REEs may entice countries with recently discovered REE reserves to break the current monopolistic REE supply chain. Furthermore, the sustainability of REE usage may also depend on consumer awareness of environmental and human health impacts associated with end-of-life electronics that contain REEs. On the other hand, REEs may show promise in sustainable agriculture and environmental applications. Nevertheless, further research on REE ecotoxicological impacts is required to establish environmental regulations that protect the environment and human health.

Strategic evaluations and mining process optimization towards a strong global REE supply chain

Rare earth elements (REE) have turned from an inconspicuous group of raw materials to critical commodities in the last decade. The insatiable and continuously growing demand for rare earths combined with their small and opaque market has resulted in a global exploration boom that has led to the delineation of extensive resources on every continent. Nevertheless, the special boundary conditions that govern the REE industry require second thoughts and careful evaluations when it comes to the potential exploitation of such resources. Past mistakes, with respect to environmental impacts and uncertain investments, have resulted in an overall uncertainty whether the mining and beneficiation of rare earth elements can be a viable industry in a free market context. This paper attempts to record the erroneous practices of the past and use them as guidelines to strengthen the global REE supply-chain. Moreover, the paper focuses on the assessments that need to be made in order to optimize the mining process and reinforce the growth prospects of the market. An overall assessment tool for the mineability of rare earth deposits is also used to consolidate these evaluations and answer the question, if REE mining can be sustainable.