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BACKGROUND: Prior to soil formation, phosphate liberated by rock weathering is often sequestered into highly insoluble lanthanide phosphate minerals. Dissolution of these minerals releases phosphate and lanthanides to the biosphere. Currently, the microorganisms involved in phosphate mineral dissolution and the role of lanthanides in microbial metabolism are poorly understood. RESULTS: Although there have been many studies of soil microbiology, very little research has investigated microbiomes of weathered rock. Here, we sampled weathered granite and associated soil to identify the zones of lanthanide phosphate mineral solubilisation and genomically define the organisms implicated in lanthanide utilisation. We reconstructed 136 genomes from 11 bacterial phyla and found that gene clusters implicated in lanthanide-based metabolism of methanol (primarily xoxF3 and xoxF5) are surprisingly common in microbial communities in moderately weathered granite. Notably, xoxF3 systems were found in Verrucomicrobia for the first time, and in Acidobacteria, Gemmatimonadetes and Alphaproteobacteria. The xoxF-containing gene clusters are shared by diverse Acidobacteria and Gemmatimonadetes, and include conserved hypothetical proteins and transporters not associated with the few well studied xoxF systems. Given that siderophore-like molecules that strongly bind lanthanides may be required to solubilise lanthanide phosphates, it is notable that candidate metallophore biosynthesis systems were most prevalent in bacteria in moderately weathered rock, especially in Acidobacteria with lanthanide-based systems. CONCLUSIONS: Phosphate mineral dissolution, putative metallophore production and lanthanide utilisation by enzymes involved in methanol oxidation linked to carbonic acid production co-occur in the zone of moderate granite weathering. In combination, these microbial processes likely accelerate the conversion of granitic rock to soil.

This study focuses on examining how the rare-earth cerium incorporation affects the magnetic, dielectric, and mechanical characteristics of Ni 0.5 Mn 0.25 Co 0.25 Ce x Fe 2-x O 4 spinel ferrite nanoparticles. (NMCCF). The nanoferrite Ni 0.5 Mn 0.25 Co 0.25 Ce 0.04 Fe 1.96 O 4 acquires the lowest coercivity of 567 Oe and the highest saturation magnetization of 52.23 emu/g. All the NMCCFx nanoferrites exhibit a microwave frequency range of 9.47–11.55 GHz, suggesting potential applications in longitudinal recording media and microwave absorbance. Moreover, the nanoferrite Ni 0.5 Mn 0.25 Co 0.25 Ce 0.1 Fe 1.9 O 4 demonstrates the highest dielectric value of 1871, with an enhancing ratio of 754 %, excellent conductivity at 3.12 μ(Ω.m)−1 along with a remarkably enhanced percentage of 369 %. Additionally, it shows a loss factor of 2.17, with a notable improvement percentage of 26 % compared to the pure NMCCF0 sample at 50 Hz and room temperature. The elastic moduli (longitudinal, shear, Young, and bulk) of the Ni 0.5 Mn 0.25 Co 0.25 Ce 0.1 Fe 1.9 O 4 nanoferrite increased from 1.21 to 2.77 GPa, 0.25–0.76 GPa, 0.68–1.99 GPa, and 0.87–1.75 GPa, respectively. This study introduces a novel approach to Ni–Mn–Co–Ce spinel nanoferrites, highlighting their magnetic, electrical, and mechanical characteristics, which hold promise for electronic and high-frequency device applications. [ABSTRACT FROM AUTHOR]

Insect farming generates a new type of chitinous waste in the form of dead specimens that have died of natural causes and insect moults (puparia), particularly large amounts of which are generated during the rearing of holometabolous insects. Following the circular economy paradigm, we treated waste in the form of puparia and dead adults of H. illucens as a valuable material, i.e., as sources of chitin, and tested it as a sorbent for cerium, a lanthanide of great industrial importance. For comparison, non-treated, raw insect materials and commercial chitosans were also investigated. Chitin extracted from H. illucens showed an adsorption capacity at the same level as commercially available, marine-source chitin (approximately 6 mg Ce·g−1). However, more interestingly, raw materials exhibited much higher adsorption capacities—dead adults were similar to commercial chitosans (approximately 32 mg Ce·g−1), while puparia demonstrated twice the performance (approximately 60 mg Ce·g−1). This indicates that unprocessed waste can be used as environmentally friendly, cost-effective Ce biosorbents with comparable or even better sorption capacity than chitosans, whose production requires intense chemical processing. [ABSTRACT FROM AUTHOR]

Utilization of actinides and rare earth elements is only possible by separating these metals with high purity. The materials used in separation must have thermal, chemical, mechanical, and radiation resistance. In the present study, separation experiments of actinides and rare earth elements (REEs) were carried out using purified H2SO4 leach liquor. Polyacrylonitrile (PAN)-supported Ti, Zr, and Si oxide nanocomposites were tested for the selective separation of Th, U, Gd, Eu, Sm, Pr, Nd, La, Ce, and Y. The effects of pH, contact time, adsorbent/solution ratio, and temperature on distribution coefficient (KD) and adsorption capacity (Q) were investigated. The synthesized nanocomposites tend to separate the elements into two main groups: Th, U, Gd, Eu and Sm, Pr, Nd, La, Ce. Notably, it was observed that the separation of Th and U from the remaining elements is promising at 15 °C. Additionally, the separation can be further improved depending on the differences in desorption efficiency. [ABSTRACT FROM AUTHOR]

Rare earth elements (REEs) are essential for high-tech and low-carbon economies. Achieving global net-zero emissions by 2050 would require a significant increase in mineral input, including 3–7 times more REEs. At present, there are no direct high-grade ores of heavy REs like terbium. Bastnasite, monazite, and xenotime are the primary sources of terbium, while southern Chinese ion-adsorption clays are the richest commercial sources. To address the scarcity of rare earth resources, countries lacking RE deposits should focus on developing innovative and economically viable recycling techniques for the recovery of REs like terbium from different secondary resources. Spent fluorescent lamp phosphor powder represents a potential secondary resource for terbium recovery, although research efforts have been focused mostly on other REEs than Tb as value-added products. Hydrometallurgical processing is widely employed to extract terbium from different resources. The present review systematically summarizes in detail the major recovery/separation techniques used and critically evaluates the potential of terbium recovery from mineral resources and end-of-life fluorescent phosphor wastes. The advantages and limitations of each of these technologies have been provided. The objective is to foster valuable insights for researchers and the development of economical and promising extraction technologies for the recovery of terbium. [ABSTRACT FROM AUTHOR]

This paper focuses on improving the electrical properties of 0.4CaBi 2 Nb 2 O 9 -0.6Na 0.5 Bi 2.5 Nb 2 O 9 piezoelectric ceramics through Gd doping. The effect of Gd3+ replacing Ca2+ and Na+ on the 0.4CaBi 2 Nb 2 O 9 -0.6Na 0.5 Bi 2.5 Nb 2 O 9 (0.4CBN-0.6NBN) piezoelectric ceramics was subjected to a comprehensive examination. The introduction of Gd3+ has led to the development of a pseudo-tetragonal phase, enhancing the polarization and strengthening the piezoelectric effect. Among the 0.4CBN-0.6NBN- x Gd (x = 0.00–0.05) ceramic samples, the sample at x = 0.03 that exhibits the best piezoelectric properties demonstrates a high Curie temperature of 849.7 °C, low dielectric loss (tan δ) of 1.295 % (at 550 °C), high DC resistivity (ρ DC) of 1.58 × 108 Ω‧cm (at 500 °C), and a high d 33 value of 17.3 pC/N. Following annealing at 800 °C, its d 33 retains 94.2 % of its initial value. The improved electrical performances indicate that the Gd-doped 0.4CBN-0.6NBN ceramics hold a great deal of promise for high-temperature piezoelectric applications. [ABSTRACT FROM AUTHOR]

The design and synthesis of organic adsorbents for rare earth element (REEs) separation remain significant scientific aspect and industrial endeavor. In a single-pot reaction, acetone and resorcinol in acidic media over a two-day period facilitated the formation of the 2, 4, 4-trimethyl-7, 2′, 4′ trihydroxy flavan (flavan adsorbent). Under acidic conditions, flavan effectively adsorbs REEs (adsorbate), while under alkaline conditions, flavan rapidly dissolves completely. A series of adsorption experiments was conducted to determine the optimal adsorption conditions, including pH variations (1–5), REEs solution concentrations (250–1000 mg/L), adsorption time (5–60 min), and flavan mass (10–100 mg). The maximum adsorption capacity for flavan under optimal conditions was 258 mg g−1. Various analytical instruments were employed for flavan characterization, including Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS), which were essential for analyzing the surface morphology and structural properties of the flavan. Adsorption isotherms suggested that the adsorption of REEs onto the flavan surface followed the Langmuir model, which in turn exhibited a theoretical adsorption capacity of 263.2 mg g−1 better off the Freundlich model. Kinetically, the adsorption of REEs on the flavan is best run in a pseudo-second-order model trajectory, which in turn exhibited an adsorption capacity value of 283 mg g−1. Interference studies revealed that flavan is a selective adsorbent; however, aluminum ions may exert a minor interference effect of 4% (in term of REEs uptake). Other competing elements, including Na, K, Mg, Ba, Mn, Cu, Fe, and Sn, exhibited a minimal decline in flavan uptake for REEs.Highlights: At present rare earth elements (REEs) are in massive demand globally which in turn is crucial for advanced industries. Synthetic flavan (an affordable adsorbent) is setting ambitious findings for REEs separation in a selective implementation. More importantly flavan is an alkaline-soluble adsorbent that is potentially conducive for promoting REEs separation without desorption studies [ABSTRACT FROM AUTHOR]

Rare earth elements (REEs) and cobalt (Co) are listed as critical raw materials because of their importance in global industrial production growth, high supply risk, and economic significance. The recovery of Co and REEs from secondary resources is therefore proposed as a key countermeasure to address this concern. In this study, a straightforward process that integrates acid baking and water leaching is proposed for the recovery of samarium (Sm) and Co from scrap SmCo magnets. Firstly, the chemical composition of SmCo magnets is revealed by ICP-OES and XRF. The Taguchi experimental design technique is employed to optimize nitric acid baking and water leaching. Based on the thermal decomposition behavior of Co, Fe, and Sm, the acid baking temperature is studied for the conversion of metal nitrates, excluding REEs nitrates, into metal oxides. The optimal conditions for acid baking and water leaching are identified, and a reactor for the pilot-scale acid baking process is proposed. The optimum parameters are tested with the proposed reactor. [ABSTRACT FROM AUTHOR]

The research on the source of marine sediments has a vital impact on identifying material sources, transport mechanism, and the evolution of sedimentary environments. Previous studies have shown many outstanding achievements on the source analysis of the South China Sea, but there are still some controversies over the complex source and transport mechanisms of the Zhongjiannan Basin. In this study, we took a gravity core (583cm) from the Zhongjiannan Basin and analyzed the particle size, rare earth elements, and Sr-Nd isotopes of the core sediments to further reveal the source and transport mechanism. The surface sediments in the Zhongjiannan Basinwere relatively stable, with an average particle size ranging from 5.66 to 17.74 mm. The normalized standard curve of chondrite exhibited the depletion of Eu, with LREE dominated in REE. As the depth increased, 87Sr/86Sr ratios showed a gradually increasing trend, while dNd change was relatively complex. On the whole, 87Sr/86Sr ratios (from 0.721537 to 0.725322) and dNd (from -11.561617 to -12.289374) were in a relatively narrow range. Based on the particle size characteristics, we found the geochemical characteristics of sediment largely resulted fromdifferent sediment sources. By comparing rare earth elements and Sr-Nd isotopes, we concluded the sediment of the Zhongjiannan Basin was from mainly terrigenous contribution. In addition, taking into account factors such as terrain, migration distance, and river drainage system, we conclude the sediment were mainly from the Mekong River, the Red River, Taiwan Island, and Hainan Island. The surface current along the northeast direction was the main transportation route for the sediments of the Mekong River. The Guangdong coastal current and the southwest surface current transported sediment from the Red River and Hainan Island to the Zhongjiannan Basin. The surface current and deep-water current in the southwest direction carried sediment from Taiwan Island to the study area, while the Kuroshio also had some impacts on the sediment transportation of Taiwan Island. This study has reinforced the research on provenance in the South China Sea Basin and has an important significance on evolution of sedimentary environments, evolution of ancient oceans. [ABSTRACT FROM AUTHOR]

A new rare‐earth reduction system is described in which trivalent yttrium and dysprosium react as though present in their unstable divalent oxidation state. This masked divalent reactivity is achieved using the isocarbonyl‐bridged dimers [( Cp2ttt ${{{\rm { Cp}}}_{{\rm { 2}}}^{{\rm { ttt}}}}$ M)(μ‐Fp)]2 (M=Y, 1Y; M=Dy, 1Dy; Cpttt=1,2,4‐C5tBu3H2; Fp=CpFe(CO)2), where the reducing electrons originate from the bridging [Fp]− ligands. The reactivity of 1Y and 1Dy is showcased by reducing the N‐heterocycles 2,2′‐bipyridyl (bipy), phenazine (phnz) and hexaazatrinaphthylene (HAN) to give corresponding mono‐, di‐ and tri‐metallic rare‐earth complexes, respectively, with the heterocyclic ligands present in their singly, doubly and triply reduced forms, respectively. The dynamic magnetic properties of the dysprosium compounds are described. Compound 1Dy is a single‐molecule magnet (SMM) with an appreciable energy barrier of 449(17) cm−1, whereas [( Cp2ttt ${{{\rm { Cp}}}_{{\rm { 2}}}^{{\rm { ttt}}}}$ Dy)2(μ‐phnz)] (3Dy) is not an SMM because of a strong, competing equatorial crystal field. Surprisingly, [( Cp2ttt ${{{\rm { Cp}}}_{{\rm { 2}}}^{{\rm { ttt}}}}$ Dy)3(HAN)] (4Dy) is also not an SMM, the origins of which are traced to the impact of the tert‐butyl substituents on the dysprosium centre and its interaction with the radical [HAN]3− ligand. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusion To evaluate the levels of serum rare earth elements (REEs): lutetium [Lu], praseodymium [Pr], samarium [Sm], dysprosium [Dy], and cerium [Ce] in pregnant women with recurrent pregnancy loss (RPL) and evaluate their relationship with total antioxidant capacity (TAC) and 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG), a marker of DNA damage.A case‐controlled study was conducted on a cohort of 60 female participants, with first‐trimester healthy pregnant women as the control group and pregnant women with a history of consecutive abortions as the recurrent pregnancy loss (RPL) group. Following blood collection, serum concentrations of Lu, Pr, Sm, Dy, and Ce were measured using an inductively coupled plasma mass spectrophotometer (ICP‐MS). Oxidative stress and DNA damage were evaluated through TAC and DNA damage marker (8‐OHdG).Serum levels of Lu, Pr, Sm, Dy, and Ce were higher in women with RPL compared with control (P < 0.001). Intriguingly, a strong significant negative correlation was observed between TAC and REEs (P < 0.05). Lu, Dy, and Ce demonstrated a significant positive correlation with increased DNA damage in the RPL group (P < 0.05). Contrary, there was no evidence of a correlation between 8‐OHdG and Pr and Sm.The study highlights a potential association between Lu, Sm, Dy, and Ce and an increased risk of RPL, highlighting REE‐induced toxicity as a major risk factor for RPL. The outcome of the study is to advance our understanding of the interplay between rare earth elements and RPL, with potential implications for reproductive medicine, environmental health, and the development of preventive strategies for individuals at risk of RPL. [ABSTRACT FROM AUTHOR]

The study aims to synthesize nano CeO2 and Pr2O3 materials to use as fertilizer for cultivation of the Salvia miltiorrhiza Bunge, which is also known as Danshen, an important medicinal plant in many Asian countries. The extraction experiments were also conducted to determine tanshinone IIA contents in the Danshen root to acutely explore effects of the nano‐materials on accumulation of valuable medicine in the plant. The obtained results indicated that nano CeO2 and Pr2O3 applications significantly induced both growth and tanshinone IIA contents of the Danshen. Firstly, the CeO2 application greatly induced side branch and root development of the Danshen rather than the height of the plant, while the Pr2O3 application greatly induced plant height and root growth of the Danshen rather than side branch development. In comparison, the CeO2 effectively induced root growth and tanshinone IIA content in the Danshen rather than the Pr2O3 did. Finally, simultaneous applications of nano Pr2O3 and CeO2 revealed synergic effects to greatly promote the growth of the Danshen. The tanshinone IIA content extracted from the roots of the mixture Pr2O3 and CeO2 exposed Danshen was approximately 0.4318 %, which was higher than those of single CeO2 and Pr2O3 exposed plants. [ABSTRACT FROM AUTHOR]

Coal resources represent an important potential source for the future extraction of rare earth elements (REEs). This study, combining microscopic characterization techniques and experimental analysis, investigates the occurrence characteristics of REEs in coal gangue and the roasting activation mechanisms. The study reveals that phosphate minerals are the primary carriers of REEs, and sequential chemical extraction results further confirm the close association between REEs and phosphate minerals. Roasting at around 600°C facilitates the release of REEs from organic matter and clay minerals like kaolinite, significantly improving leaching efficiency. Under leaching conditions of 20 g/L, 50°C, 0.5 M HCl, and 1000 RPM, the leaching of REEs can reach approximately 80%. However, when the roasting temperature exceeds 1000°C, the formation of mullite leads to mineral surface sintering, reducing the recovery of REEs. This study emphasizes the importance of optimizing roasting conditions and understanding mineral phase changes to maximize REEs recovery, which is crucial for sustainable resource management and environmental remediation. [ABSTRACT FROM AUTHOR]

The rollout of electric vehicles and photovoltaic panels is essential to mitigate climate change. However, they depend on technology‐critical elements (TCEs), which can be harmful to human health and whose use is rapidly expanding, while recycling is lacking. While mining has received substantial attention, in‐use dissipation in urban areas has so far not been assessed, for example, corrosion and abrasion of vehicle components and weather‐related effects affecting thin‐film photovoltaic panels. Therefore, the question arises to which extent TCEs dissipate during use and which potential non‐occupational human health impacts could occur. We assessed the available information on urban in‐use dissipation and human health concerns and conducted exploratory modeling of in‐use technology stocks, in‐ and outflows, and in‐use dissipation of neodymium, dysprosium, lanthanum, praseodymium, cerium, gallium, germanium, and tellurium contained in 21 vehicle and renewable energy technologies, for Vienna, Austria. In prospective scenarios, TCE dynamics in a trend‐continuation vis à vis official city policy plans and a more ambitious transition scenario were then assessed. We find that electrifying the vehicle fleet without demand‐reduction is the main driver of TCE consumption, effectively doubling cumulative end‐of‐life outflows to 3,073 [2,452–3,966] t and cumulative in‐use dissipation to 9.3 [5.2–15.7] t by the year 2060. Sufficiency‐based measures could reduce demand and in‐use dissipation well below levels with continued trends, thus highlighting the need to combine decarbonization with demand‐reducing measures. These results help assess potential future in‐use dissipation dynamics and inform discussions about potential public health hazards associated with exposure to TCEs accumulating in the urban environment. [ABSTRACT FROM AUTHOR]

The rare earth elements (REEs) are critical resources for many clean energy technologies, but are difficult to obtain in their elementally pure forms because of their nearly identical chemical properties. Here, an analogue of macropa, G‐macropa, was synthesized and employed for an aqueous precipitation‐based separation of Nd3+ and Dy3+. G‐macropa maintains the same thermodynamic preference for the large REEs as macropa, but shows smaller thermodynamic stability constants. Molecular dynamics studies demonstrate that the binding affinity differences of these chelators for Nd3+ and Dy3+ is a consequence of the presence or absence of an inner‐sphere water molecule, which alters the donor strength of the macrocyclic ethers. Leveraging the small REE affinity of G‐macropa, we demonstrate that within aqueous solutions of Nd3+, Dy3+, and G‐macropa, the addition of HCO3− selectively precipitates Dy2(CO3)3, leaving the Nd3+−G‐macropa complex in solution. With this method, remarkably high separation factors of 841 and 741 are achieved for 50 : 50 and 75 : 25 mixtures. Further studies involving Nd3+:Dy3+ ratios of 95 : 5 in authentic magnet waste also afford an efficient separation as well. Lastly, G‐macropa is recovered via crystallization with HCl and used for subsequent extractions, demonstrating its good recyclability. [ABSTRACT FROM AUTHOR]

Rare earth elements (REEs) are considered vital raw materials for the economy and are on the European Union's list of critical raw materials (CRMs). Europe is mainly dependent on REE imports. This dependence could be reduced if locally available primary or secondary resources would be processed. In Poland, there are, for instance, over 5 million metric tons of phosphogypsum (PG), a fine powdery byproduct from the fertilizer industry, available near the former Wizów Chemical Plant near Bolesławiec. This material that is considered a waste in Poland contains significant amounts of REEs that could theoretically be recovered and contribute to Europe's economy. This work is the first systematic analysis of REE leaching studies with sulfuric acid and PG from Wizów. Process parameters such as temperature, particle size, concentration of the leaching solution, and the addition of oxidant and reductant agents were tested to determine the most efficient process. Ultimately, a leaching efficiency of 99% was obtained. Lanthanum exhibited the highest leaching efficiency at almost 100%, followed by Yttrium, Neodymium, Terbium, and Dysprosium. The results of the laboratory experiments are promising and suggest that larger pilot or commercial experiments can be performed next. [ABSTRACT FROM AUTHOR]

Samarium hydrogen iodate Sm(IO3)3·HIO3 was successfully synthesized by the unconventional low-temperature solution-melt method, its structure was determined by X-ray diffraction analysis of single crystals. This compound crystallizes in the monoclinic space group P21/c with lattice parameters: a = 10.4637(6) Å, b = 7.4629(5) Å, c = 14.0174(13) Å, β = 110.53(0), Z = 6. In the studied structure, samarium atoms are surrounded by 8 oxygen atoms in a polyhedron in the form of a distorted square antiprism. The iodate groups are linked through common oxygen atoms of the SmO8 antiprism into a three-dimensional framework. The compound was characterized by X-ray diffraction, IR and NQR spectroscopy and EDX analysis. [ABSTRACT FROM AUTHOR]

Density functional theory (DFT) was used to study the structural, electronic, magnetic, and optical properties of the rare-earth-based ternary chalcogenide GdCuX2 (X = S, Se, and Te). DFT calculations were performed using the Tran-Blaha modified Becke-Johnson (TB-mBJ) generalized gradient approximation (GGA), generalized gradient approximation with Hubbard U (GGA + U), and spin orbit coupling (GGA + U + SOC) potentials. In structural properties, we computed the ground state energy, with equilibrium volume, and lattice parameters for GdCuS2, GdCuSe2, and GdCuTe2 compounds. The structural properties show that the GdCuS2, GdCuSe2 and GdCuTe2 compounds have stable structures at the Wycoff position. The electronic properties were calculated in terms of the density of states (DOS) and electronic band diagram. Electronic properties confirm the semiconductor nature of GdCuS2, GdCuSe2, and GdCuTe2 compounds using TB-mBJ, GGA, and GGA + U potentials. However, the GdCuTe2 compound displays a metallic nature when using the GGA + U + SOC potential. Magnetic properties in terms of spin polarization magnetic moments of GdCuS2, GdCuSe2 and GdCuTe2 compounds. With magnetic optimisation, we made a graph of the energy vs. volume curve to show that ferromagnetic [FM] is more stable than antiferromagnetic [AFM] and nonmagnetic [NM]. The GdCuS2, GdCuSe2 and GdCuTe2 compounds show a good ferromagnetic nature. The optical properties of the compounds in terms of dielectric functions, refractive indices, and absorption coefficients. In the visible and infrared ranges, the optical properties reveal an upstate semiconductor nature and a downstate metallic nature. In the higher energy range, the maximum absorption is observed in the optical properties. [ABSTRACT FROM AUTHOR]

Archaeological bone chemical composition is modified post-mortem by diagenesis processes, and over decades, several authors have proposed different protocols to avoid post-depositional contamination that can carry to misleading interpretations about the lifestyle and origin of ancient populations. In this work, a methodological approach based on rare earth elements analysis was developed to determine diagenetic alterations on femurs, humeri, and skull surfaces, and internal layers from thirteen individuals exhumed during fieldwork in the Fatih Sultan Mehmet Mosque at Rozafa Castle (Shkodër, Albania). Major, minor, and trace elements, including rare earth elements, were measured employing spectrometric techniques, and the obtained data were statistically processed by principal component analysis and one-way ANOVA to select the best preserved bones. The results show that in general, the internal parts of bones, especially skulls, suffered post-depositional chemical contamination. Finally, to show the effectiveness of the proposed approach, a diet reconstruction employing log(Sr/Ca) and Zn/Ca was tested, obtaining results that are in line with the literature describing a diet based on a mixed economy, mostly agricultural products with low protein intakes. [ABSTRACT FROM AUTHOR]

The extraction of rare earth elements (REEs) from mineral resources is of significant global importance due to their critical role in modern technologies. This study focuses on the leaching behavior of artificial cerium and lanthanum phosphates using nitric, sulfuric, and hydrochloric acids under varying conditions of acid concentration and temperature. Our experiments demonstrated that the maximum extraction efficiency of lanthanum and cerium was achieved with nitric acid solutions at concentrations of 12.5 mol/dm3, with 85.0% and 79.1% extraction efficiency, respectively. The leaching mechanism involved the protonation of phosphate anions, which disrupted the phosphate matrix, facilitating the dissolution of lanthanum and cerium into solution. Sulfuric acid, although less effective at room temperature, proved to be the most thermodynamically favorable leaching agent at higher temperatures due to the formation of stable sulfate complexes. Additionally, hydrochloric acid displayed high selectivity for cerium extraction, although its applicability is limited by complexation and environmental concerns. This study offers new insights into optimizing REE recovery from phosphates, demonstrating the advantages of sulfuric acid for industrial-scale leaching processes due to its economic and thermodynamic benefits. The novelty of this work lies in its systematic comparison of the three acids' effects on REE extraction, providing a comprehensive framework for selecting optimal leaching agents based on specific operational conditions. [ABSTRACT FROM AUTHOR]

In this study, the recovery of rare earth elements (REEs) from red mud (bauxite residue) was explored through a combination of citric acid leaching and sulfation roasting–water leaching processes, introducing an innovative approach to the field. The research uniquely investigates the influence of citric acid on the leaching behavior of REEs and impurities in both untreated red mud and red mud subjected to sulfation roasting, providing a direct comparison of these methodologies. A novel aspect of this study is the evaluation of solvent extraction efficiency using DEHPA, highlighting the selective recovery of REEs over impurities from both citric acid and water-leaching solutions. Furthermore, a comprehensive phase analysis using X-ray diffraction (XRD) was conducted to track the transformations of minerals during the sulfation roasting process, an original contribution to the literature. The findings revealed that over 85% of REEs and major elements such as Fe, Al, Ca, and Ti dissolved in water after sulfation at 105 °C, while iron and titanium dissolution significantly decreased following roasting at 725 °C. Importantly, terbium, neodymium, and gadolinium extraction efficiencies were notably affected by roasting temperature. Citric acid leaching results demonstrated that the direct leaching of red mud leads to higher leaching efficiency than leaching it after the roasting process. Solvent extraction demonstrated lower terbium and neodymium recovery from citric acid solutions compared to water leaching solution. Finally, stripping experiments illustrated that 6M H2SO4 solution is capable of stripping more than 80% of rare earth elements, except terbium. [ABSTRACT FROM AUTHOR]

Rare earth elements (REEs) hold significant industrial, scientific, and modern technological worth. This study focused on detecting and quantifying REEs in various geological ore samples. These samples were collected from different REE-bearing locations recommended by geological experts. The analysis was conducted using laser-induced breakdown spectroscopy (LIBS) and laser ablation time-of-flight mass spectrometry (LA-TOF-MS). In this work, LIBS methodology was employed using three different configurations: standard LIBS, LIBS with an applied magnetic field, and LIBS with both an applied magnetic field and target sample heating within an optimal temperature range. Elements from the REE group, specifically lanthanum (La), cerium (Ce), and neodymium (Nd), were identified and quantified. To detect, quantify, and validate the results from LIBS and LA-TOF-MS, we utilized an array of analytical techniques—Energy-Dispersive X-ray Spectroscopy (EDX), Energy-Dispersive X-ray Fluorescence Spectrometer (ED-XRF), and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Interestingly, the quantitative results for REEs (La, Ce, and Nd) in the ore samples obtained using the LIBS technique with various configurations were found to be in agreement with those from LA-TOF-MS, EDX, XRF, and ICP-OES. In addition, LIBS enables detailed microchemical imaging, allowing the map of the spatial distribution of elements within the mineral–ore matrix. The high-resolution microscale elemental mapping of REEs was accomplished using the emission lines Ce (II) at 446.0 nm, La (II) at 492.1 nm, and Nd (II) at 388.8 nm. By integrating multiple analytical techniques, our study enabled the construction of a complete elemental distribution map, providing new insights into the geochemical processes and mineral composition of rare earth ores, while advancing geochemistry and contributing valuable data for rare earth resource exploration. [ABSTRACT FROM AUTHOR]

Yongxin Gold Deposit is located in the southern part of Duobaoshan Cu-Mo-Au metallogenic belt. To understand the genesis of the deposit and provide exploration insights, a study was conducted on the rare earth elements, micro-elements, and isotopic composition of gold-bearing pyrite. The results indicate that the chemical composition of pyrite shows enrichment in light REEs and depletion in heavy REEs, with a right-sloping REE distribution pattern. The pyrite is enriched in high-field-strength elements such as U, Th, Zr, and Hf, and depleted in large-ion lithophile elements like Ba and Sr. Ratios such as w(Hf)/w(Sm), w(Nb)/w(La), and w(Th)/w(La) suggest that the ore-forming fluid contained more Cl than F. A negative Eu anomaly and the absence of a Ce anomaly indicate that the ore-forming fluid formed under reducing conditions. Ratios like w(Y)/w(Ho), w(Zr)/w(Hf), and w(Nb)/w(Ta) suggest that the mineralization process did not involve external hydrothermal fluids, nor did metasomatism occur, with the ore-forming fluid closely related to both mantle and crustal sources. The sulfur isotopic characteristics indicate that the ore-forming materials originated from deeper sources. Genetic indicators such as w(Co)/w(Ni) and w(Fe)/w(S＋As) suggest that the deposit is of a meso-epithermal volcanic hydrothermal origin. Based on the magmatic origin, tectonic setting, diagenesis-mineralization age, metallogenic process, geochemical characteristics, and the main features of representative gold deposits in the region, it is concluded that Yongxin Gold Deposit belongs to a porphyry metallogenic system, forming during the Early Cretaceous as a meso-epithermal, relatively Cl-rich, weakly reducing gold deposit. [ABSTRACT FROM AUTHOR]

The eastern Wehai area, bordered by the Mishan Fault, is an important polymetallic mineralization zone in the Jiaodong region. It hosts a series of copper molybdenum, lead zinc, and gold silver polymetallic mineral deposits related to the late Yanshanian Mesozoic intermediate-acidic intrusive magmatic activity. This study investigates the geochemical characteristics, metallogenic age, and ore genesis of the Kuangbei skarn-type copper deposit, a typical deposit in the area. Testing results of rare earth elements (REEs) and micro-elements suggest that the intrusive activities of Weideshan Period magmatic rocks provided both the metallogenic materials and the hydrothermal conditions essential for the deposit formation. Research on stable isotopes of S and Pb indicates a multi-source origin of the ore-bearing hydrothermal fluids. Zircon U-Pb dating reveals that the formation age of Kuangbei Copper Deposit, approximately 116. 6 Ma, is close to the diagenetic age of Weideshan Period magmatic rocks. This deposit is a Mesozoic contact metasomatic (skarn) type copper deposit. [ABSTRACT FROM AUTHOR]

Electronic waste (e-waste) contains valuable rare earth elements (REEs) essential for various high-tech applications, making their recovery crucial for sustainable resource management. This review provides an overview of the occurrence of REEs in e-waste and discusses both conventional and emerging green technologies for their recovery. Conventional methods include physical separation, hydrometallurgy, and pyrometallurgy, while innovative approaches such as bioleaching, supercritical fluid extraction, ionic liquid extraction, and lanmodulin-derived peptides offer improved environmental sustainability and efficiency. The article presents case studies on the extraction of REEs from waste permanent magnets and fluorescent powders, highlighting the specific processes involved. Future research should focus on developing eco-friendly leaching agents, separation materials, and process optimization to enhance the overall sustainability and efficiency of REE recovery from e-waste, addressing both resource recovery and environmental concerns effectively. [ABSTRACT FROM AUTHOR]

Recent policy initiatives in the United States and beyond have called for decreasing reliance on China for rare earth elements and related downstream products, such as neodymium iron boron (NdFeB) magnets. Among these initiatives, recycling of rare earth elements and NdFeB magnets from electronic waste (e-waste) has emerged as an approach to reduce both import dependence on China and the environmental impacts of mining and refining these products. This paper highlights several methods for recycling NdFeB magnets from e-waste and assesses potential impacts on supply chains and the environment from the commercial adoption of these recycling techniques. [ABSTRACT FROM AUTHOR]

Rare earth elements (REEs), comprising seventeen metallic elements, including lanthanides, scandium, and yttrium, are indispensable for modern technological industries due to their unique properties. However, their supply is critically risky for the European Union, with 95% of global production concentrated in China, Brazil, Vietnam, Russia, India, and Australia. This mini-review examines the adsorption of REEs onto pyrolytic carbon-based materials as a sustainable recovery method from secondary raw materials. The review covers different types of carbon-based adsorbents used in several research works, such as activated carbon, chars, and biochar, and discusses their adsorption mechanisms and influencing factors. Comparative analyses of adsorption capacities highlight the significance of surface area and functionalization in enhancing adsorption efficiency. Despite promising results, the variability in adsorption performance due to experimental conditions and the scarcity of real-world application studies are noticed. This review underscores the need for further research using real e-waste leachates to validate the practical applicability of pyrolytic carbon-based adsorbents for REEs' recovery, aiming for an economically and environmentally sustainable solution. [ABSTRACT FROM AUTHOR]

In this work, AZ31 and AZ31-1 wt.% RE (RE = Nd, Dy, Nd+Dy) alloys were prepared by conventional casting. The effect of single and co-addition of rare earth (RE) on the microstructure, mechanical properties and corrosion behavior of as-cast AZ31 magnesium alloys were investigated at ambient temperature, and after heat treatment at 400 °C for 1 h. The addition of 1 wt.% RE (RE = Nd, Dy, Nd+Dy) preferentially formed the Al2RE phase and completely suppressed the formation of the intermetallic β-Mg17Al12 phase. An excellent ultimate tensile strength (UTS)/ductility combination of 209 MPa/21% and 192 MPa/17% with an adequate yield strength (YS) of 90 MPa was observed for AZ31+Nd sample in as-cast and annealed states, respectively. The work-hardening rate of the AZ31 alloy containing Nd and Dy increased significantly after annealing compared to those of the as-cast state. Fracture analysis indicated that the additive RE did not obviously change the fracture mechanism of the Mg alloy. All specimens exhibit a hybrid fracture with cleavages and dimples. The weight loss test showed that the corrosion resistance of the AZ31 Mg alloy was improved with added RE as it interacts with Al to form Al-RE phase, which upgraded the corrosion resistance of the alloys. The co-addition of RE (RE = Nd+Dy) was proven to enhance corrosion resistance, and also stabilized the corrosion rate. In brief, the co-addition of Nd and Dy significantly improved the corrosion resistance of the AZ31 magnesium alloys than the counterpart of the mechanical properties. [ABSTRACT FROM AUTHOR]

Background: Gallstone disease poses a global threat to human health and is strongly linked to environmental factors. However, there is currently no data on the presence of rare earth elements (REEs) in human gallstones. This paper investigates the concentration and distribution of REEs in gallstones for the first time, aiming to explore the environmental implications on human health. Methods: A total of 25 gallstone samples were collected in Shanghai and the content of REEs was measured by Inductively coupled plasma-Mass Spectrometry (ICP-MS) to explore the distribution of REEs in gallstones. Results: The concentration of REEs in gallstones ranged from 4.89 to 190.8 ng/g (mean 39.21). In most of the gallstone analyses, REEs have been detected and generally attributed to environmental exposure or food contamination. The Y/Ho ratio of gallstones was lower than that of continental rocks, similar to that in the blood, indicating limited fractionation during fluid transport processes in the gallbladder. Conclusions: The upper continental crust (UCC)-normalized REEs pattern in gallstones showed depletion of light REEs, while most showed enrichment of heavy REEs. Positive Gd anomalies were found in most samples, while few samples suggested anthropogenic influence. Whether exogenous inputs or in vivo biofractionation lead to changes in REEs fractionated patterns require further analyses. [ABSTRACT FROM AUTHOR]

Rare earth elements are an essential critical raw material in the development of modern technologies and are highly sensitive to both supply chain disruptions and market turbulence. The presented study examines the characteristics of fuel, fly ash, and bottom ash from lignite combustion in power plant units. Also, we attempted to determine the amount of amorphous glass in the ashes and whether and to what extent the glass from the ash samples is bound to REY. The suitability of the ash was assessed as an alternative source of REY. The fuel and ash samples were acquired from power plants in Poland. The tests determined the fuel quality parameters, including the chemical and phase composition, of amorphous glass using ICP-MS and XRD methods, respectively. The study showed that all ash samples dissolved in 4% HF were enriched in REY. The efficiency of REY enrichment varied, and its presence in the residue samples was found to be in similar proportions compared to the raw sample. All ash residue samples were enriched in critical elements. The obtained values of the Coutl prospective coefficient allowed for the classification of some of the analyzed ashes and their residues after dissolution in 4% HF as prospective REY raw materials. [ABSTRACT FROM AUTHOR]

Surface water and sediment rare earth elements (REEs) concentrations can reflect the impact of human activities on aquatic ecosystems. Variations in formation time may result in changes in the geochemical characteristics of REEs in the water‒sediment system of coal mining subsidence lakes. However, our understanding of this phenomenon is limited. The spatial distribution, coexistence patterns, and fractionation characteristics of REEs were investigated in coal mining subsidence lakes with different subsidence times in the Huainan coalfield in eastern China. The results indicate that REEs concentrations in lake water are relatively low. Both compartments are enriched in light rare earth elements (LREEs), and the degree of enrichment increases with time, which can be attributed to the combined influences of natural processes and human activities. Under alkaline water conditions in the study area, LREEs are preferentially removed from the aqueous phase, leading to their enrichment in sediments. The anomalous behavior of Ce is associated with the oxidative environment under alkaline conditions, whereas the Eu anomaly is influenced primarily by the dissolution of feldspar minerals. Agricultural activities result in significant inputs of light rare earth elements (La) to farmlands each year through the application of rare earth fertilizers. These elements are ultimately released into coal mining subsidence lakes, resulting in noticeable anomalies of La in the majority of lakes within the study area. These findings indicate that the lakes in the subsidence area are strongly affected by agricultural activities. The difference between lakes with different numbers of sinking years is reflected mainly in the degree of enrichment of LREEs, and the older the lake is, the greater the degree of enrichment of LREEs. These research results provide a scientific basis for the treatment and protection of the water environment in coal mining subsidence lakes influenced by anthropogenic activities. Through this series of studies, we will improve our understanding of the behavior of REEs in the aquatic environment under the influence of human activities and to provide support for sustainable mineral resource development and environmental protection policy formulation. [ABSTRACT FROM AUTHOR]

The renewable energy industry is heavily reliant on rare earth elements, underscoring the need to develop resources and production. The objective of this work was to estimate coal ash resources and potential for extraction of rare earth elements using data for the US. Data on spatiotemporal variability in coal ash resources and disposition were compiled from various federal databases and rare earth elements levels in ash were compiled from the literature. Results show that ~ 52 gigatons (Gt) of coal were produced in the US (1950–2021). Power plants account for most of the coal use, particularly since 1980. Coal ash (5.3 Gt) represents a mean of 10% of coal by weight, ranging from 6% for subbituminous to 14% for lignite. About 70% of coal ash is potentially accessible for rare earth element extraction (1985–2021) and was disposed in landfills and ponds with the remaining coal ash used onsite or sold. Median values of total rare earth elements are much higher in ashes derived from the Appalachian Basin (median 431 mg/kg) than in the Illinois (282 mg/kg) or Powder River basins (264 mg/kg). Considering the market value of rare earth oxides, potentially accessible ash volumes, and percent rare earth element extraction (30% Appalachian and Illinois Basins; 70% Powder River Basin) results in an estimated $8.4 billion value. This study provides fundamental information on accessible coal ash resources in the US, linkages to coal sources, and preliminary estimates of rare earth element levels for future development within the US. [ABSTRACT FROM AUTHOR]

Background: Rare-earth sulfide nanoparticles (NPs) could harness the optical and magnetic features of rare-earth ions for applications in nanotechnology. However, reports of their synthesis are scarce and typically require high temperatures and long synthesis times. Results: Here we present a biosynthesis of terbium sulfide (TbS) NPs using microorganisms, identifying conditions that allow Escherichia coli to extracellularly produce TbS NPs in aqueous media at 37 °C by controlling cellular sulfur metabolism to produce a high concentration of sulfide ions. Electron microscopy revealed ultrasmall spherical NPs with a mean diameter of 4.1 ± 1.3 nm. Electron diffraction indicated a high degree of crystallinity, while elemental mapping confirmed colocalization of terbium and sulfur. The NPs exhibit characteristic absorbance and luminescence of terbium, with downshifting quantum yield (QY) reaching 28.3% and an emission lifetime of ~ 2 ms. Conclusions: This high QY and long emission lifetime is unusual in a neat rare-earth compound; it is typically associated with rare-earth ions doped into another crystalline lattice to avoid non-radiative cross relaxation. This suggests a reduced role of nonradiative processes in these terbium-based NPs. This is, to our knowledge, the first report revealing the advantage of biosynthesis over chemical synthesis for Rare Earth Element (REE) based NPs, opening routes to new REE-based nanocrystals. [ABSTRACT FROM AUTHOR]

AbstractA new ion-pairing HPLC method has been developed for the analytical separation of rare earth elements (REEs), utilizing the unique “diad-effect” of the lanthanides. A chemometric approach was used to optimize the separation process, examining the impact of mobile phase pH and ion-pairing reagent concentration on resolution and elution time. A triple gradient elution program was proposed, involving changes in the pH of the mobile phase from 3.5 to 4.5, the ion-pairing reagent concentration from 25 mM to 0.05 M, and the mobile phase complexing additive (hydroxyisobutyric acid) concentration from 0.05 M to 0.5 M. With the proposed method, all REEs, including pairs that are typically difficult to separate (Pr–Nd, Eu–Gd, and Dy–Y), were effectively separated in less than eight minutes. The method validation conducted following ICH guidelines showed accurate results, with an accuracy of 99–108% across a concentration range of 50–150% of the target concentration for REEs. It also exhibited good linearity (0.9998–0.9992) across a concentration range of 5–15 µg/mL for REEs and a detection limit of 0.27–0.98 µg/mL for the various species. The proposed HPLC method proved reliable and successfully separated a commercial sample of yttrium-group oxides. [ABSTRACT FROM AUTHOR]

A simple method was developed for the determination of REEs, Zr, Hf, Th and U in ultramafic rocks by inductively coupled plasma‐mass spectrometry with a combination of RE and UTEVA extraction resins for their separation and pre‐concentration. Ultramafic rocks were digested with HNO3‐HF‐HClO4 and finally turned into 11 mol l−1 HCl solutions together with H3BO3 to remove insoluble fluorides. The removal of matrix elements was achieved during the loading procedure. Following this, REEs on RE resin, and Zr, Hf, Th and U on UTEVA resin were eluted with 10 ml of 0.24 mol l−1 HCl, with recoveries better than 94.4%. This method was validated using reference materials JP‐1, DTS‐2B, OKUM, UB‐N, MUH‐1 and DZΣ‐2, and the measurement results for target analytes were comparable to literature values, indicating its applicability to the determination of REEs, Zr, Hf, Th and U at ultra‐trace level in ultramafic rocks. [ABSTRACT FROM AUTHOR]

The Na3Nd(BO3)2-NdBO3 phase diagram was investigated by the solid-state synthesis and DSC methods. Na3Nd(BO3)2, Na3Nd2(BO3)3 and NdBO3 were grown by spontaneous crystallization from the Na2O-B2O3-NaF flux. Typical Nd3+ luminescence of 4F3/2 → 4I9/2 and 4F3/2 → 4I11/2 electron transitions at 875 nm and 1054 nm were registered. Maximum integral intensity of the luminescence was observed for Na3Nd2(BO3)3 crystals, more than twice that of NdBO3, Na3Nd(BO3)2. [ABSTRACT FROM AUTHOR]

Lanthanum (La(III)) is one of the high-demand rare earth elements with applications in various products. However, La(III) in mining waste streams and electronic waste also poses environmental and health concerns. Therefore, the recovery of La(III) in the waste is needed. In the present study, the adsorption of La(III) with Dowex 50W-X8, Amberchrom50WX4, Amberlyst 15, and Amberchrom 50WX2 was evaluated using a shaker water bath. Dowex 50W-X8 was found to be the best adsorbent and was used to investigate the effect of the shaker speed (RPM = 50–150), adsorbent dosage (1.0–4.0 g), pH (2.0–7.0), and temperature (20–40 °C) on adsorption. La(III) adsorption was found to increase with the shaker speed, as expected. On the other hand, the adsorption capacity decreased with the adsorbent amount. Also, the highest La(III) adsorption was observed at pH = 6.0. La(III) percentage removal did not vary significantly with a temperature from 20 °C to 40 °C. However, the first-order kinetic rate constant decreased moderately with increases in temperature. The adsorption of La(III) by Dowex 50-X8 followed the Freundlich isotherm model better than the Langmuir model. In addition, the adsorption kinetics were represented well by the pseudo-first-order kinetic model. Moreover, enthalpy and Gibbs free energy changes were found to be negative, indicating an exothermic and thermodynamically favorable adsorption process. [ABSTRACT FROM AUTHOR]

Laboratory flotation tests carried out using an ore sample containing Rare Earth Elements (REEs) present as monazite and bastnaesite show that the flotation of monazite is slower and yielded lower recovery than that of bastnaesite. Results show that when studying the performances of a concentration process for an REE ore, it is essential to not look only at the behavior of the individual REEs but to convert elemental assays into mineral assays to obtain the mineral's actual response to the concentration process. The results of the laboratory flotation tests are used to calibrate a flotation simulator applied to study different circuit configurations for the concentration of the REE minerals. Indeed, it is shown that for the studied ore, two cleaning stages of a rougher concentrate are sufficient to produce a concentrate with a Total Rare Earth Oxide (TREO) grade above 40%, which is acceptable for the subsequent hydrometallurgical process. The simulation also shows that it may be feasible, if required for the hydrometallurgy step, to separate bastnaesite and monazite by taking advantage of the different flotation kinetics of the two minerals. [ABSTRACT FROM AUTHOR]

The aim of the research was to assess the potential of bottom ash from Polish coal-fired power plants as an alternative source of rare earth elements (REY). The potential of these ashes was compared with fly ash from the same coal combustion cycle. The phase and chemical composition, as well as REY, were determined using: X-ray diffraction and inductively coupled plasma mass spectrometry. The tested ashes were classified as inert-low pozzolanic and inert-medium pozzolanic, as well as sialic and ferrosialic, with enrichment in detrital material. The phase and chemical composition of bottom ash was similar to fly ash from the same fuel combustion cycle. The REY content in the ash was 199–286 ppm and was lower than the average for global deposits, and the threshold value was considered profitable for recovery from coal. Bottom ash's importance as a potential source of REY will increase by recovering these metals from separated amorphous glass and mullite and grains rich in Al, Mg, K, and P. The industrial value of bottom ash as an alternative source of REY was similar to fly ash from the same fuel combustion cycle. [ABSTRACT FROM AUTHOR]

As the 21st century advances, the demand for rare earth elements (REEs) is rising, necessitating more robust exploration methods. Our research group is using hyperspectral remote sensing as a tool for mapping REEs. Unique spectral features of bastnaesite mineral, has proven effective for detection of REE with both spaceborne and airborne data. In our study, we collected hyperspectral data using a Senop hyperspectral camera in field and a SPECIM hyperspectral camera in the laboratory settings. Data gathered from California's Mountain Pass district revealed bastnaesite-rich zones and provided detailed insights into bastnaesite distribution within rocks. Further analysis identified specific bastnaesite-rich rock grains. Our results indicated higher concentrations of bastnaesite in carbonatite rocks compared to alkaline igneous rocks. Additionally, rocks from the Sulphide Queen mine showed richer bastnaesite concentrations than those from the Birthday shonkinite stock. Results were validated with thin-section studies and geochemical data, confirming the reliability across different hyperspectral data modalities. This study demonstrates the potential of drone-based hyperspectral technology in augmenting conventional mineral mapping methods and aiding the mining industry in making informed decisions about mining REEs efficiently and effectively. [ABSTRACT FROM AUTHOR]

Rare earth elements (REEs) comprises of a uniform group of lanthanides and scandium (Sc) and yttrium (Y) finding their key importance in agriculture sectors, electronic and defense industries, and renewable energy production. The immense application of REEs as plant growth promoters has led to their undesirable accumulation in the soil system raising concerns for REE pollution as upcoming stresses. This review mainly addresses the chemistry of REEs, uptake and distribution and their biphasic responses in plant systems and possible plausible techniques that could mitigate/alleviate REE contamination. It extends beyond the present understanding of the biphasic impacts of rare earth elements (REEs) on physio-biochemical attributes. It not only provides landmarks for further exploration of the interrelated phytohormonal and molecular biphasic nature but also introduces novel approaches aimed at mitigating their toxicities. By delving into innovative strategies such as recycling, substitution, and phytohormone-assisted mitigation, the review expands upon existing knowledge of REEs whilst also offering pathways to tackle the challenges associated with REE utilization. [ABSTRACT FROM AUTHOR]