In 2025,the global rare earth exploration and development sector achieved breakthroughs across multiple fronts.Projects advanced intensively across the Americas,Oceania,Africa,and Europe,with significant growth in res...In 2025,the global rare earth exploration and development sector achieved breakthroughs across multiple fronts.Projects advanced intensively across the Americas,Oceania,Africa,and Europe,with significant growth in resources,continuous emergence of new deposits,and strong impetus injected into the industry by technological innovation and policy support.The global rare earth resource supply pattern was further optimized (Table 1).1.Fruitful results in resource growth and new deposit discoveriesBrazil emerged as a core region for resource growth.The Colossus rare earth deposit saw a 150%increase in resources and announced its first reserve estimate.The Caldeira rare earth deposit’s resource estimate grew by 50%.The combined ore resources in the Caladão rare earth deposit’s Zones A and B reached 5.72×10~8 tonnes,with a total rare earth oxide(TREO) grade of 0.1506%,concurrently hosting 2.29×10~4tonnes of gallium metal resources.展开更多
Rare earth(RE)Y-type zeolite was synthesized in situ by acidic co-hydrolysis route and hydrothermal method.The key process parameters were optimized based on the RE utilization rate.The effect of inducing a rotating p...Rare earth(RE)Y-type zeolite was synthesized in situ by acidic co-hydrolysis route and hydrothermal method.The key process parameters were optimized based on the RE utilization rate.The effect of inducing a rotating packed bed(RPB)in premixing and crystallization on crystallinity and RE utilization rate was further investigated.The results indicate that lanthanide(La)cations are successfully introduced into the sodalite cage of Y-type zeolite.The optimized conditions are that the molar ratio of Si/La is 150,premixing for 5 h,crystallization at 90℃ for 18 h,and calcination at 550℃ for 3.5 h.At this stage,the RE utilization rate reaches 74.5%.Compared with the conventional stirred tank reactor(STR),RPB can effectively shorten the premixing time and crystallization time by 4.3 h and 6 h,improve the crystallinity by 23%and RE utilization rate by 7.5%.The RE utilization rate is more than 80%by RPB,surpassing the effectiveness of using the one-exchange one-calcination process in the traditional liquid ion exchange process.It is expected to provide a reference for the in-situ efficient and green synthesis of RE zeolite.展开更多
Eu^(2+)-doped phosphors show broadband absorption,tunable emission and high quantum efficiency due to the parity-allowed 5d→4f transitions,allowing them to be used in solid-state lighting.To expand their applications...Eu^(2+)-doped phosphors show broadband absorption,tunable emission and high quantum efficiency due to the parity-allowed 5d→4f transitions,allowing them to be used in solid-state lighting.To expand their applications in other fields such as detection and sensing technologies,the Eu^(2+)emission needs to be tuned into the near-infrared region,but it is a big challenge to obtain Eu^(2+)near-infrared region emitters due to the absence of host compounds with extremely large crystal-field splitting.In this work,we chose M_(4)Li(BN_(2))_(3)(M=Ca,Sr,Ba)as a host and realize the near-infrared region emission of Eu^(2+)in it.Among these phosphors,Ba4Li(BN_(2))_(3):Eu^(2+)exhibits the longest emission of 880 nm and the largest full-width at half maximum of 276 nm under 450 nm excitation,while Ca_(4)Li(BN_(2))_(3):Eu^(2+)and Sr_(4)Li(BN_(2))_(3):Eu^(2+)emit at740 and 680 nm,respectively.We observe an interesting phenomenon that the energy shift of emission is linearly related to the radius difference between the alkaline earth cation and the activator Eu^(2+)in this system.展开更多
As an important strategic rare-earth resource,bastnaesite has long been a global research focus.The carbochlorination process,as an efficient and low-cost extraction method,can be applied to treat bastnaesite,achievin...As an important strategic rare-earth resource,bastnaesite has long been a global research focus.The carbochlorination process,as an efficient and low-cost extraction method,can be applied to treat bastnaesite,achieving ideal rare-earth extraction results in just one-step reaction.By using inexpensive chlorine gas as the chlorinating agent,it avoids lengthy procedural steps and the generation of acid-base waste liquids.Based on this,we propose a novel carbochlorination process for bastnaesite involving a fluorine-fixing agent.Thermodynamic data for the carbochlorination process of bastnaesite were calculated using the group contribution method.Thermodynamic feasibility was verified through Gibbs free energy.The effects of different chlorination times,fluorine-fixing agent dosages,chlorine flow rates,and chlorination temperatures on the carbochlorination process of bastnaesite were investigated.Experimental studies showed that under optimal chlorination conditions,a temperature of 800℃,a duration of 60 min,a fluorine-fixing agent dosage of 10%,and a chlorine flow rate of 10 L·min^(−1),the chlorination rates of rare-earth elements,Ca,Ba,and Fe in bastnaesite reached 96%,99%,98%,and 99%,respectively.The reaction mechanism was explored and analyzed based on characterization results such as mineral phase composition,micromorphology and thermogravimetry of water-washed residues under different chlorination conditions.Additionally,kinetic experiments were conducted at varying reaction temperatures and chlorine flow rates,revealing that the carbon-chlorination process is primarily controlled by chemical reactions.展开更多
Rare earth elements are widely used in steel production due to their unique metallurgical properties,which can modify inclusions,improve the cleanliness of molten steel,and optimize steel properties.However,high activ...Rare earth elements are widely used in steel production due to their unique metallurgical properties,which can modify inclusions,improve the cleanliness of molten steel,and optimize steel properties.However,high activity also makes rare earth elements prone to intense chemical reactions with refractories during the smelting process,which can not only accelerate the erosion and failure of refractories,but also reduce the cleanliness of molten steel owing to the formation of secondary inclusions.Therefore,it is essential to understand the interaction mechanisms between rare earth steels and refractories.Herein,the research progress on the interactions between rare earth steels and refractories is systematically reviewed.Based on both laboratory studies and industrial applications,emphasis is placed on the reaction mechanisms and their effects on the stability of refractories and the cleanliness of molten steel.At the same time,the prevention methods are summarized,including the refractory optimization,protective coatings for nozzles,argon blowing,and the application of external electric fields.Furthermore,the applicability and limitations of these methods are analyzed.Finally,future research directions are discussed to address the limitations of current studies,focusing on the development of novel refractories,non-contact control methods,and digitally intelligent process control.展开更多
Phosphorus (P) is an essential nutrient element that is critical for plant growth and ecosystem functionality.The soil P cycle plays multiple roles,such as sustaining plant growth and productivity,regulating nutrient ...Phosphorus (P) is an essential nutrient element that is critical for plant growth and ecosystem functionality.The soil P cycle plays multiple roles,such as sustaining plant growth and productivity,regulating nutrient balance within ecosystems,and enhancing ecosystem adaptability and resilience.This cycle is influenced by factors such as the restoration approach and microbial community dynamics.However,the extent to which the restoration approach alters the P cycle in karst ecosystems and the underlying microbial mechanisms remain poorly understood.The P-cycle multifunctionality index (P-cycle MFI) serves as a comprehensive indicator for evaluating soil P cycle function,and it provides insights into changes in the P cycle between different restoration approaches.To investigate the shifts in soil P-cycle MFI and microbial mechanisms between different restoration approaches,we analyzed soil available P (AP),total P (TP),microbial biomass P (MBP),and the activities of acid phosphatase (ACP) and alkaline phosphatase (ALP).These data were used to calculate the P-cycle MFI by averaging the Z-scores between two restoration approaches(artificial restoration of forest (AF) and natural restoration of forest (NF)) and a control (cropland,CP) at six subtropical karst ecosystem sites in China.We also determined the soil organic carbon (SOC),exchangeable calcium (Ca) and magnesium (Mg),pH,bulk density (BD),microbial biomass C (MBC),and microbial biomass nitrogen (MBN),as well as the community structure,relative abundance,diversity indices,and co-occurrence networks of phoD-harboring bacteria.The results showed that the community structure of phoD-harboring bacteria varied significantly among AF,NF,and CP and across different temperature gradients.These bacteria exhibited increasing complexity and tightness in co-occurrence networks from CP to AF and then to NF,along with the ACP and ALP activities,but not the TP and AP contents.The P-cycle MFI values were significantly higher in NF compared to AF and CP,and the variation was significantly explained by restoration approach,temperature,MBC,MBN,SOC,exchangeable Ca,BD,community structure of phoD-harboring bacteria,and exchangeable Mg.Furthermore,natural restoration had a more substantial impact on the P-cycle MFI than temperature by enhancing SOC,microbial biomass,the complexity and co-occurrence network tightness of the phoD-harboring bacterial community structure,and ACP and ALP activities,but it reduced soil BD.The rare genera of phoD-harboring bacteria significantly influenced the variation of soil P-cycle MFI compared to the dominant genera.This study highlights the importance of rare genera of phoD-harboring bacteria in driving soil P-cycle multifunctionality in karst ecosystems,with natural restoration being more effective than artificial methods for enhancing soil organic matter and microbial community complexity.展开更多
Extracting rare earth elements(REEs)from coal refuse is challenging due to their low co ncentrations and poor leachability.Bioleaching has emerged as a sustainable technology to recover REEs from low-grade materials.I...Extracting rare earth elements(REEs)from coal refuse is challenging due to their low co ncentrations and poor leachability.Bioleaching has emerged as a sustainable technology to recover REEs from low-grade materials.In this study,a ferric sulfate bio acid(BA)with an acidity of~0.2 mol/L H^(+),generated through regulated pyrite bio-oxidation,was used to leach REEs and critical metals(CMs)from coal refuse(ground to<1 mm)after 20-min roasting at 600℃.The influences of solid/liquid(S/L)ratio(100-300 g/L)and leaching temperature(25-95℃)on the leaching performance were examined.The leaching mechanisms were investigated by conducting stepwise precipitation tests and spectroscopic characterization.Results show that raising the leaching temperature to≥65℃accelerated the REE leaching kinetics but causes the loss of light REEs(LREEs)after reaching peak values at 30-60 min.Stage precipitation tests reveal that the loss is due to the incorporation of REEs,especially for LREEs,by gypsum and schwertmannite.The peak total REE(TREE)recovery of the BA leaching reaches 24.9%after 30 min of leaching at75℃with a S/L ratio of 200 g/L.Implementing the three-stage counter-current leaching increases the overall TREE recovery to 31.8%by recovering the REEs incorporated in the Fe and Ca precipitates.Meanwhile,promising recovery values of Li(55.5%),Mn(74.6%),Ni(41.6%),and Co(35.3%)are also achieved.This method provides a sustainable approach to extract REEs and critical metals from coal waste materials with a high treatment capacity.展开更多
Genetic hypoparathyroidism(HP),achondroplasia(ACH),and primary growth hormone deficiency(GHD)are listed as rare diseases in the second List of Rare Diseases in China in 2023.Numerous studies have explored optimal ther...Genetic hypoparathyroidism(HP),achondroplasia(ACH),and primary growth hormone deficiency(GHD)are listed as rare diseases in the second List of Rare Diseases in China in 2023.Numerous studies have explored optimal therapies for certain rare endocrine diseases,and the development of long-acting therapeutic agents has been considered a key strategy for improving treatment outcomes,especially given the challenges associated with daily subcutaneous injections.However,limited attention has been given to the potential of"transient conjugation"(TransCon)technology,a platform designed to convert drugs into prodrug forms,thereby extending their half-lives and reducing dosing frequency,which demonstrates promise as a more convenient treatment option for these conditions.This is the first study to review the research progress of TransCon technology in the treatment of HP,ACH,and GHD,focusing on its pharmacokinetic properties,efficacy,safety,tolerability,and patient-reported outcomes in comparison with conventional therapies,in order to provide a reference for formulation development and clinical management of these rare endocrine diseases.展开更多
Ln@MOFs by anchoring rare metal ions(Ln) into metal-organic frameworks(MOFs) are proved to have great potential in the field of luminescent molecular thermometer.Nevertheless,the current research indicated that the po...Ln@MOFs by anchoring rare metal ions(Ln) into metal-organic frameworks(MOFs) are proved to have great potential in the field of luminescent molecular thermometer.Nevertheless,the current research indicated that the poor structural stability and low sensitivity hindered their application scope.In this work,a new MOF Zn-450 luminescent thermometer with multiple emission fluorescence characteristics was synthesized by the combination of 3,3,5,5-biphenyl tetracarboxylic acid(H_(4)L) and Zn^(2+) ion under solvothermal conditions.Interestingly,a high relative sensitivity of 1.43 % K^(-1) was found within 80-300 K based on Zn-450.Subsequently,two high-sensitivity luminescent Ln@MOFs(Ln = Eu and Tb) were further fabricated by doping rare earth ions into Zn-450 based on the post-synthesis strategy.Among them,the Eu@Zn-450 demonstrates various luminous behaviors while achieving an increased relative sensitivity of 1.63 % K^(-1).In addition,the continuously visible red,pink,and purple luminescent emissions at the same temperature range were observed,suggesting that the Eu@Zn-450 could be utilized as a luminescent colorimetric molecular thermometer.Importantly,this work can present new possibilities for the development of rare earth-doped luminescence and its temperature sensing properties.展开更多
Organic-rich sediments represent vital components of Earth's geochemical cycles, acting both as potential hydrocarbon and coal reservoirs and as unconventional archives for critical metals such as rare earth eleme...Organic-rich sediments represent vital components of Earth's geochemical cycles, acting both as potential hydrocarbon and coal reservoirs and as unconventional archives for critical metals such as rare earth elements(REEs). With the growing emphasis on clean energy technologies, the Cenozoic organic deposits of India have gained renewed significance;however, those from the southern state of Kerala remain understudied. This study investigates lignite and associated carbonaceous sediments from the Cheruvathur and Warkalli Formations using a multi-proxy approach integrating organic petrography,infrared spectroscopy, stable carbon isotopes, and REE geochemistry. The lignite exhibits huminite dominance with Type Ⅲ kerogen, deposited in a wet, mesotropic bog forest swamp under anoxic conditions. The mineral assemblage, dominated by kaolinite, quartz, illite, montmorillonite, feldspar,and pyrite/marcasite, reflects strong chemical alteration in a reducing environment. The δ^(13)C values(-25.1 to-27.3) indicate a C_(3) angiosperm source and deposition in tropical to subtropical swamp settings. REE patterns reveal LREE enrichment in carbonaceous shales and HREE enrichment in lignite,with distinct Ce, Eu, and Gd anomalies associated with provenance and redox conditions. The findings provide new insights into the paleoenvironmental evolution of Kerala's Cenozoic basins and highlight their potential as unconventional REE-bearing resources in the context of the global energy transition.展开更多
This study explored the impact of sintering time and temperature on the synthesis and formation of high-entropy rare earth oxides(HEOs).By systematically varying the sintering conditions,a series of Lu_(2)Yb_(2)Tm_(2)...This study explored the impact of sintering time and temperature on the synthesis and formation of high-entropy rare earth oxides(HEOs).By systematically varying the sintering conditions,a series of Lu_(2)Yb_(2)Tm_(2)Er_(2)O_(12) samples was synthesized and their structural and chemical properties were analyzed using scanning electron microscopy(SEM)with energy-dispersive X-ray spectroscopy(EDS)elemental mapping,X-ray diffraction(XRD),high-resolution transmission electron microscopy(HRTEM),and X-ray photoelectron spectroscopy(XPS).According to XRD patterns,a single-phase cubic C-type structure is easier to form at higher sintering temperatures(1400-1500℃),with sharper peaks signifying better crystallinity.With longer sintering times improving grain development and homogeneity,SEM research reveals a change in morphology from spherical grains at lower temperatures(1100-1200℃)to blocky grains at higher temperatures(1300-1500℃).HRTEM pictures verified the nanoparticles'strong crystallinity,and at higher temperatures,the lattice fringes widen and become more distinct,indicating better atomic ordering and diffusion.Stable and uniform high-entropy oxide production is indicated by the XPS spectra,which shows uniform elemental distribution and consistent chemical states of the constituent elements with very slight variations in the oxygen peaks.The findings highlight how important the sintering temperature is for reaching the intended high-entropy phase,with higher temperatures promoting improved atomic diffusion and compositional homogeneity.The results open the door for the use of high-entropy rare earth oxides in sophisticated functional materials by offering insightful information on how to best synthesize them.展开更多
Acute presentation of vomiting is a very common presenting complaint in the emergency department(ED).While majority of such complaints can be attributed to benign,self-limiting causes such as gastroenteritis,rarer alt...Acute presentation of vomiting is a very common presenting complaint in the emergency department(ED).While majority of such complaints can be attributed to benign,self-limiting causes such as gastroenteritis,rarer alternative diagnoses should be considered depending on the patient's progress after initial treatment.Here,we present a case of gastric volvulus(GV),a rare but potentially fatal condition that mimics gastroenteritis.展开更多
The healthcare field is fraught with challenges associated with severe class imbalance,wherein such critical conditions like sepsis,cardiac arrest,and drug adverse reactions are rare but have dire clinical consequence...The healthcare field is fraught with challenges associated with severe class imbalance,wherein such critical conditions like sepsis,cardiac arrest,and drug adverse reactions are rare but have dire clinical consequences.This paper presents a new framework,Deep Reinforcement Adaptive Gradient Optimization Network to Mining Rare Events(DRAGON-MINE),to demonstrate how deep reinforcement learning can be used synergistically with adaptive gradient optimization and address the inherent weaknesses of current methods in the prediction of rare health events.The suggested architecture uses a dual-pathway consisting of a reinforcement learning agent to dynamically reweigh samples and an adaptive gradient optimizer to follow novel learning rates.With extensive experiments on the MIMIC-IV and eICU-CRD datasets,DRAGON-MINE consistently outperforms recent state-of-the-art methods for sepsis,cardiac arrest,and adverse drug reaction prediction,achieving AUROC values of 92.3%and 91.6%for sepsis prediction on MIMIC-IV and eICU-CRD,respectively,while consistently outperforming Transformer-,CNN-RNN-,and Fed-Ensemble-based methods across all evaluated tasks and datasets,with particularly strong gains observed in precision-recall performance under severe class imbalance.With its high sensitivity(88.4%)and specificity(90.2%),DRAGON-MINE enables reliable early warning of rare clinical events in critical care settings while minimizing false alarms,supporting safer clinical decision support systems,and demonstrating strong potential for scalable deployment across multi-institutional intensive care environments through federated learning.展开更多
Fine-scale structures can be observed in small field-of-view(FOV)auroral observations,but they are often overlooked because they appear only sporadically in all-sky observations.Such forms are of great interest becaus...Fine-scale structures can be observed in small field-of-view(FOV)auroral observations,but they are often overlooked because they appear only sporadically in all-sky observations.Such forms are of great interest because they may embody specific magnetosphere-ionosphere coupling processes,reveal localized energy deposition pathways,and provide new insights into cross-scale plasma dynamics and instabilities.However,their limited spatial extent,transient occurrence,and scarcity in wide-FOV observations make systematic investigation challenging.Traditional manual analysis struggles to capture these subtle structures within vast all-sky datasets,while automated detection faces severe data imbalance and morphological ambiguity.To address these challenges,we propose a synthetic-to-real progressive learning framework for cross-FOV retrieval of rare auroral forms.A Generative Adversarial Network(GAN)is employed to perform cross-FOV transformation between unpaired small-FOV images containing rare aurora forms and all-sky images(ASI)without such structures,thereby generating large numbers of synthetic ASI with rare auroral morphology.These synthetic samples are used to train an initial detection model,which subsequently undergoes iterative fine-tuning through feedback-guided learning:The model performs inference on new all-sky data,and the progressively accumulated real detections are incorporated into the training set.Experimental results demonstrate that the proposed method achieves over 92%detection accuracy on ASI,enabling high-precision retrieval of small-scale auroral structures across large-scale observations.This framework provides a scalable and effective approach to rediscovering rare auroral phenomena in continuous all-sky monitoring,offering new opportunities for exploring the fine-scale dynamics of the upper atmosphere.展开更多
To inhibit the interfacial(displacement)reaction between Hf and Al elements in the DZ125 superalloy and the Al_(2)O_(3) and SiO_(2) in the Al_(2)O_(3)-based ceramic shell,rare-earth oxides(La_(2)O_(3) and Y_(2)O_(3))w...To inhibit the interfacial(displacement)reaction between Hf and Al elements in the DZ125 superalloy and the Al_(2)O_(3) and SiO_(2) in the Al_(2)O_(3)-based ceramic shell,rare-earth oxides(La_(2)O_(3) and Y_(2)O_(3))were used as dopants into the shell.The effects of dopant types and contents(2 wt%,5 wt%and 8 wt%)on the wettability and interfacial reaction were investigated using the sessile-drop experiment,and the reaction products were analyzed by X-ray diffraction(XRD),a scanning electron microscope(SEM),an electron probe microanalyzer(EPMA)and X-ray photoelectron spectroscopy(XPS),to clarify the mechanism of dopants in the interracial reaction.The results show that increasing the Y_(2)O_(3) doping content(2 wt%-8 wt%)reduces the surface porosity from 22.39%to 13.43%,and decreases the surface roughness from 3.25 to 2.28μm,which enhances the packing density of the shell surface.In the sintering process(1223 K,2 h),both La_(2)O_(3) and Y_(2)O_(3) dopants react with SiO_(2),forming La_(2)Si_(2)O_(7) and Y_(2)SiO_(5) on the shell surface.During the interfacial reaction process(1823 K,40 min),La_(2)Si_(2)O_(7) decomposes and reacts with Al_(2)O_(3) and HfO_(2),resulting in the formation of SiO_(2)·HfO_(2)·La_(2)O_(3) and Al_(2)O_(3)·HfO_(2)·La_(2)O_(3) ternary composite oxides within the reaction products.At 8 wt%La_(2)O_(3) dopant content,the interfacial reaction is exacerbated,resulting in the uneven wettability.Y_(2)SiO_(5) further reacts with Al_(2)O_(3) and SiO_(2) to form SiO_(2)·Al_(2)O_(3)·Y_(2)O_(3) ternary composite oxides,while Y_(2)O_(3) combines with Al_(2)O_(3) to form Al_(5)Y_(3)O_(12)(VAG),which stabilizes the oxides within the shell and inhibits the interfacial reaction,and significantly improves the surface quality of the DZ125 superalloy.As the Y_(2)O_(3) dopant content increases(2 wt%-8 wt%),the wetting angle increases from 97.8°to 110.6°.展开更多
Recurrent pregnancy loss(RPL)affects 2%-5%of couples attempting to conceive.It is a highly heterogenous condition attributed to several factors including endocrine dysfunction,auto immune disorders,thrombophilia,genet...Recurrent pregnancy loss(RPL)affects 2%-5%of couples attempting to conceive.It is a highly heterogenous condition attributed to several factors including endocrine dysfunction,auto immune disorders,thrombophilia,genetic abnormalities,infectious diseases,uterine anomalies,sperm DNA fragmentation,and epigenetics.Among genetic causes,chromosomal abnormalities are the most frequent etiological factor of early miscarriage,accounting for 50%–60%of first trimester abortions.Numerical or structural chromosomal changes may result in spontaneous miscarriages.These anomalies arise as a result of chromosomal translocation,non-disjunction,or mutations[1].Transmission of parental chromosomal abnormalities may be one of the chances for a recurrence of miscarriage in the first trimester of pregnancy,albeit the cause is unknown[2,3].展开更多
Ion-adsorption rare earth ore(IAREO)is a crucial source of mid-heavy rare earths elements(M-HRE).Reverse osmosis technology is a promising technique for the pre-concentration of the leach solution from in-situ leachin...Ion-adsorption rare earth ore(IAREO)is a crucial source of mid-heavy rare earths elements(M-HRE).Reverse osmosis technology is a promising technique for the pre-concentration of the leach solution from in-situ leaching of IAREO.However,calcium sulfate scaling is inevitably formed in sulfate system,causing decreases in the flux and life time of membrane.Herein,to simulate the precipitation behavior of calcium sulfate in the leach solution of IAREO during reverse osmosis,a series of experiments was conducted in binary and quaternary supersaturated calcium sulfate solution systems.Experimental data show that the concentration of Ca^(2+)decreases with the increase of the concentration of Mg^(2+),and in-creases with the increase of the concentration of RE3+in both binary and quaternary systems.Whereas.the influence of Al^(3+)on the concentration of Ca^(2+)is different.This variation of the Ca^(2+)concentration is explained by thermodynamic analysis.The difference of association concentration for Mg^(2+),Al^(3+)and RE^(3+)with SO_(4)^(2-)in binary or quaternary system is the main reason.Finally,the influence and mechanisms of antiscalant on the precipitation behavior of calcium sulfate are discussed.X-ray diffraction(XRD),Zeta potential and scanning electron microscopy(SEM)analyses reveal that polyacrylic acid(PAA)effectively inhibits the crystal growth of calcium sulfate,and the precipitation time of calcium sulfate is prolonged,indicating that PPA is a potential inhibitor for calcium sulfate scaling during the process of reverse osmosis.展开更多
In order to highlight the achievements of China's rare earth industry over the past year with the support of national policy,and show that technological innovation has promoted the development of new high-quality ...In order to highlight the achievements of China's rare earth industry over the past year with the support of national policy,and show that technological innovation has promoted the development of new high-quality productive forces,expanded the application fields of rare earth elements and accelerated the progress of green and low-carbon transformation.展开更多
Aluminum is the main impurity of the weathered crust elution-deposited rare earth ore(WCED-REO).Efficient leaching of rare earths and low leaching of aluminum are of great importance for the leaching of the WCED-REO.T...Aluminum is the main impurity of the weathered crust elution-deposited rare earth ore(WCED-REO).Efficient leaching of rare earths and low leaching of aluminum are of great importance for the leaching of the WCED-REO.The effects of pH,MgSO_(4) concentration and Al^(3+)concentration of the leaching agent solution on the column leaching behaviors of WCED-REO using magnesium sulfate were investigated.Experimental data show that controlling the MgSO_(4) concentration to 0.15 mol/L,pH of the leaching agent solution to 2,the leaching amount of aluminum from the rare earth ore gradually decreases with the increase of Al^(3+)concentration in the leaching agent solution,indicating that Al^(3+)in the leaching agent solution may act as leaching agent to participate in the ion exchange of RE3+,but the leaching amounts of rare earths change insignificantly as the Al^(3+)concentration is increased.Increasing the MgSO_(4) concentration is beneficial to the leaching of aluminum,and when the Al^(3+)concentration is 0.04 mol/L(Al accumulation),the amount of Al^(3+)leached from the rare earth ore increased gradually with increasing the MgSO_(4) concentration.The pH of the leaching agent solution has a significant influence on the leaching of aluminum in the rare earth ore,and the leaching amount of aluminum from the rare earth ore increases gradually with decreasing the pH.When the Al^(3+)conce ntration is 0.04 mol/L(Al accumulation)and the pH of the leaching agent solution is above 2.0,the aluminum in the leaching agent solution can be back-adsorbed onto the rare earth ore,and the amount of the back-adsorbed Al^(3+)increases with increasing the pH of the leaching agent solution.The injection rate of the leaching agent solution has slight effect on the leaching behavior of rare earths and aluminum.In summary,leaching of Al^(3+)and consumption of MgSO_(4) can be reduced by regulating the accumulation of aluminum,MgSO_(4) concentration and pH.展开更多
State Key Laboratory of Baiyun Obo Rare Earth Resource Researches and Comprehensive Utilization was approved by the Ministry of Science and Technology to be one of the national key laboratories in November 2022.The la...State Key Laboratory of Baiyun Obo Rare Earth Resource Researches and Comprehensive Utilization was approved by the Ministry of Science and Technology to be one of the national key laboratories in November 2022.The laboratory was reconstructed based on former State Key Laboratory of Baiyun Obo Rare Earth Resources Researches and Comprehensive Utilization.展开更多
文摘In 2025,the global rare earth exploration and development sector achieved breakthroughs across multiple fronts.Projects advanced intensively across the Americas,Oceania,Africa,and Europe,with significant growth in resources,continuous emergence of new deposits,and strong impetus injected into the industry by technological innovation and policy support.The global rare earth resource supply pattern was further optimized (Table 1).1.Fruitful results in resource growth and new deposit discoveriesBrazil emerged as a core region for resource growth.The Colossus rare earth deposit saw a 150%increase in resources and announced its first reserve estimate.The Caldeira rare earth deposit’s resource estimate grew by 50%.The combined ore resources in the Caladão rare earth deposit’s Zones A and B reached 5.72×10~8 tonnes,with a total rare earth oxide(TREO) grade of 0.1506%,concurrently hosting 2.29×10~4tonnes of gallium metal resources.
基金supported by the NationalKey Research and Development Program of China(2023YFA1507701)National Natural Science Foundation of China(U22B6011,22288102)“Announcement and Challenge”Science and Technology Project of Xinjiang Uygur Autonomous Region(XJKJTJBGS-2023).
文摘Rare earth(RE)Y-type zeolite was synthesized in situ by acidic co-hydrolysis route and hydrothermal method.The key process parameters were optimized based on the RE utilization rate.The effect of inducing a rotating packed bed(RPB)in premixing and crystallization on crystallinity and RE utilization rate was further investigated.The results indicate that lanthanide(La)cations are successfully introduced into the sodalite cage of Y-type zeolite.The optimized conditions are that the molar ratio of Si/La is 150,premixing for 5 h,crystallization at 90℃ for 18 h,and calcination at 550℃ for 3.5 h.At this stage,the RE utilization rate reaches 74.5%.Compared with the conventional stirred tank reactor(STR),RPB can effectively shorten the premixing time and crystallization time by 4.3 h and 6 h,improve the crystallinity by 23%and RE utilization rate by 7.5%.The RE utilization rate is more than 80%by RPB,surpassing the effectiveness of using the one-exchange one-calcination process in the traditional liquid ion exchange process.It is expected to provide a reference for the in-situ efficient and green synthesis of RE zeolite.
基金Project supported by the National Key Research and Development Program(2022YFE0108800)。
文摘Eu^(2+)-doped phosphors show broadband absorption,tunable emission and high quantum efficiency due to the parity-allowed 5d→4f transitions,allowing them to be used in solid-state lighting.To expand their applications in other fields such as detection and sensing technologies,the Eu^(2+)emission needs to be tuned into the near-infrared region,but it is a big challenge to obtain Eu^(2+)near-infrared region emitters due to the absence of host compounds with extremely large crystal-field splitting.In this work,we chose M_(4)Li(BN_(2))_(3)(M=Ca,Sr,Ba)as a host and realize the near-infrared region emission of Eu^(2+)in it.Among these phosphors,Ba4Li(BN_(2))_(3):Eu^(2+)exhibits the longest emission of 880 nm and the largest full-width at half maximum of 276 nm under 450 nm excitation,while Ca_(4)Li(BN_(2))_(3):Eu^(2+)and Sr_(4)Li(BN_(2))_(3):Eu^(2+)emit at740 and 680 nm,respectively.We observe an interesting phenomenon that the energy shift of emission is linearly related to the radius difference between the alkaline earth cation and the activator Eu^(2+)in this system.
基金supported by the National Natural Science Foundation of China(ZX20230386)the 2023 Special Project for High-Industrial Base Reconstruction Quality Development of the Manufacturing Industry(2023ZY01019-11)the sixth batch of top talent support funds(QNBJ-2022-04).
文摘As an important strategic rare-earth resource,bastnaesite has long been a global research focus.The carbochlorination process,as an efficient and low-cost extraction method,can be applied to treat bastnaesite,achieving ideal rare-earth extraction results in just one-step reaction.By using inexpensive chlorine gas as the chlorinating agent,it avoids lengthy procedural steps and the generation of acid-base waste liquids.Based on this,we propose a novel carbochlorination process for bastnaesite involving a fluorine-fixing agent.Thermodynamic data for the carbochlorination process of bastnaesite were calculated using the group contribution method.Thermodynamic feasibility was verified through Gibbs free energy.The effects of different chlorination times,fluorine-fixing agent dosages,chlorine flow rates,and chlorination temperatures on the carbochlorination process of bastnaesite were investigated.Experimental studies showed that under optimal chlorination conditions,a temperature of 800℃,a duration of 60 min,a fluorine-fixing agent dosage of 10%,and a chlorine flow rate of 10 L·min^(−1),the chlorination rates of rare-earth elements,Ca,Ba,and Fe in bastnaesite reached 96%,99%,98%,and 99%,respectively.The reaction mechanism was explored and analyzed based on characterization results such as mineral phase composition,micromorphology and thermogravimetry of water-washed residues under different chlorination conditions.Additionally,kinetic experiments were conducted at varying reaction temperatures and chlorine flow rates,revealing that the carbon-chlorination process is primarily controlled by chemical reactions.
基金supported by the National Natural Science Foundation of China(Nos.52450003,52025041,U2341267,and 52174294).
文摘Rare earth elements are widely used in steel production due to their unique metallurgical properties,which can modify inclusions,improve the cleanliness of molten steel,and optimize steel properties.However,high activity also makes rare earth elements prone to intense chemical reactions with refractories during the smelting process,which can not only accelerate the erosion and failure of refractories,but also reduce the cleanliness of molten steel owing to the formation of secondary inclusions.Therefore,it is essential to understand the interaction mechanisms between rare earth steels and refractories.Herein,the research progress on the interactions between rare earth steels and refractories is systematically reviewed.Based on both laboratory studies and industrial applications,emphasis is placed on the reaction mechanisms and their effects on the stability of refractories and the cleanliness of molten steel.At the same time,the prevention methods are summarized,including the refractory optimization,protective coatings for nozzles,argon blowing,and the application of external electric fields.Furthermore,the applicability and limitations of these methods are analyzed.Finally,future research directions are discussed to address the limitations of current studies,focusing on the development of novel refractories,non-contact control methods,and digitally intelligent process control.
基金supported by the National Key Research and Development Program of China (2022YFF1300705)the Key Research and Development Project of Guangxi,China (Guike AB24010051)+1 种基金the National Natural Science Foundation of China (42261011,32271730 and U20A2011)the Central Public Welfare Research Institutes,Chinese Academy of Geological Sciences (2023020)。
文摘Phosphorus (P) is an essential nutrient element that is critical for plant growth and ecosystem functionality.The soil P cycle plays multiple roles,such as sustaining plant growth and productivity,regulating nutrient balance within ecosystems,and enhancing ecosystem adaptability and resilience.This cycle is influenced by factors such as the restoration approach and microbial community dynamics.However,the extent to which the restoration approach alters the P cycle in karst ecosystems and the underlying microbial mechanisms remain poorly understood.The P-cycle multifunctionality index (P-cycle MFI) serves as a comprehensive indicator for evaluating soil P cycle function,and it provides insights into changes in the P cycle between different restoration approaches.To investigate the shifts in soil P-cycle MFI and microbial mechanisms between different restoration approaches,we analyzed soil available P (AP),total P (TP),microbial biomass P (MBP),and the activities of acid phosphatase (ACP) and alkaline phosphatase (ALP).These data were used to calculate the P-cycle MFI by averaging the Z-scores between two restoration approaches(artificial restoration of forest (AF) and natural restoration of forest (NF)) and a control (cropland,CP) at six subtropical karst ecosystem sites in China.We also determined the soil organic carbon (SOC),exchangeable calcium (Ca) and magnesium (Mg),pH,bulk density (BD),microbial biomass C (MBC),and microbial biomass nitrogen (MBN),as well as the community structure,relative abundance,diversity indices,and co-occurrence networks of phoD-harboring bacteria.The results showed that the community structure of phoD-harboring bacteria varied significantly among AF,NF,and CP and across different temperature gradients.These bacteria exhibited increasing complexity and tightness in co-occurrence networks from CP to AF and then to NF,along with the ACP and ALP activities,but not the TP and AP contents.The P-cycle MFI values were significantly higher in NF compared to AF and CP,and the variation was significantly explained by restoration approach,temperature,MBC,MBN,SOC,exchangeable Ca,BD,community structure of phoD-harboring bacteria,and exchangeable Mg.Furthermore,natural restoration had a more substantial impact on the P-cycle MFI than temperature by enhancing SOC,microbial biomass,the complexity and co-occurrence network tightness of the phoD-harboring bacterial community structure,and ACP and ALP activities,but it reduced soil BD.The rare genera of phoD-harboring bacteria significantly influenced the variation of soil P-cycle MFI compared to the dominant genera.This study highlights the importance of rare genera of phoD-harboring bacteria in driving soil P-cycle multifunctionality in karst ecosystems,with natural restoration being more effective than artificial methods for enhancing soil organic matter and microbial community complexity.
文摘Extracting rare earth elements(REEs)from coal refuse is challenging due to their low co ncentrations and poor leachability.Bioleaching has emerged as a sustainable technology to recover REEs from low-grade materials.In this study,a ferric sulfate bio acid(BA)with an acidity of~0.2 mol/L H^(+),generated through regulated pyrite bio-oxidation,was used to leach REEs and critical metals(CMs)from coal refuse(ground to<1 mm)after 20-min roasting at 600℃.The influences of solid/liquid(S/L)ratio(100-300 g/L)and leaching temperature(25-95℃)on the leaching performance were examined.The leaching mechanisms were investigated by conducting stepwise precipitation tests and spectroscopic characterization.Results show that raising the leaching temperature to≥65℃accelerated the REE leaching kinetics but causes the loss of light REEs(LREEs)after reaching peak values at 30-60 min.Stage precipitation tests reveal that the loss is due to the incorporation of REEs,especially for LREEs,by gypsum and schwertmannite.The peak total REE(TREE)recovery of the BA leaching reaches 24.9%after 30 min of leaching at75℃with a S/L ratio of 200 g/L.Implementing the three-stage counter-current leaching increases the overall TREE recovery to 31.8%by recovering the REEs incorporated in the Fe and Ca precipitates.Meanwhile,promising recovery values of Li(55.5%),Mn(74.6%),Ni(41.6%),and Co(35.3%)are also achieved.This method provides a sustainable approach to extract REEs and critical metals from coal waste materials with a high treatment capacity.
文摘Genetic hypoparathyroidism(HP),achondroplasia(ACH),and primary growth hormone deficiency(GHD)are listed as rare diseases in the second List of Rare Diseases in China in 2023.Numerous studies have explored optimal therapies for certain rare endocrine diseases,and the development of long-acting therapeutic agents has been considered a key strategy for improving treatment outcomes,especially given the challenges associated with daily subcutaneous injections.However,limited attention has been given to the potential of"transient conjugation"(TransCon)technology,a platform designed to convert drugs into prodrug forms,thereby extending their half-lives and reducing dosing frequency,which demonstrates promise as a more convenient treatment option for these conditions.This is the first study to review the research progress of TransCon technology in the treatment of HP,ACH,and GHD,focusing on its pharmacokinetic properties,efficacy,safety,tolerability,and patient-reported outcomes in comparison with conventional therapies,in order to provide a reference for formulation development and clinical management of these rare endocrine diseases.
基金supported by the National Natural Science Foundation of China (No.21801111)the Training Plan for Young Core Teachers in Higher Education of Henan Province (No.2021GGJS131)+1 种基金Natural Science Foundation of Henan Province (No.232300421232)the Heluo Young Talent Lifting Project (No.2023HLTJ02)。
文摘Ln@MOFs by anchoring rare metal ions(Ln) into metal-organic frameworks(MOFs) are proved to have great potential in the field of luminescent molecular thermometer.Nevertheless,the current research indicated that the poor structural stability and low sensitivity hindered their application scope.In this work,a new MOF Zn-450 luminescent thermometer with multiple emission fluorescence characteristics was synthesized by the combination of 3,3,5,5-biphenyl tetracarboxylic acid(H_(4)L) and Zn^(2+) ion under solvothermal conditions.Interestingly,a high relative sensitivity of 1.43 % K^(-1) was found within 80-300 K based on Zn-450.Subsequently,two high-sensitivity luminescent Ln@MOFs(Ln = Eu and Tb) were further fabricated by doping rare earth ions into Zn-450 based on the post-synthesis strategy.Among them,the Eu@Zn-450 demonstrates various luminous behaviors while achieving an increased relative sensitivity of 1.63 % K^(-1).In addition,the continuously visible red,pink,and purple luminescent emissions at the same temperature range were observed,suggesting that the Eu@Zn-450 could be utilized as a luminescent colorimetric molecular thermometer.Importantly,this work can present new possibilities for the development of rare earth-doped luminescence and its temperature sensing properties.
文摘Organic-rich sediments represent vital components of Earth's geochemical cycles, acting both as potential hydrocarbon and coal reservoirs and as unconventional archives for critical metals such as rare earth elements(REEs). With the growing emphasis on clean energy technologies, the Cenozoic organic deposits of India have gained renewed significance;however, those from the southern state of Kerala remain understudied. This study investigates lignite and associated carbonaceous sediments from the Cheruvathur and Warkalli Formations using a multi-proxy approach integrating organic petrography,infrared spectroscopy, stable carbon isotopes, and REE geochemistry. The lignite exhibits huminite dominance with Type Ⅲ kerogen, deposited in a wet, mesotropic bog forest swamp under anoxic conditions. The mineral assemblage, dominated by kaolinite, quartz, illite, montmorillonite, feldspar,and pyrite/marcasite, reflects strong chemical alteration in a reducing environment. The δ^(13)C values(-25.1 to-27.3) indicate a C_(3) angiosperm source and deposition in tropical to subtropical swamp settings. REE patterns reveal LREE enrichment in carbonaceous shales and HREE enrichment in lignite,with distinct Ce, Eu, and Gd anomalies associated with provenance and redox conditions. The findings provide new insights into the paleoenvironmental evolution of Kerala's Cenozoic basins and highlight their potential as unconventional REE-bearing resources in the context of the global energy transition.
基金Project supported by Natural Science Foundation of Zhejiang Province(LD21E080001)Zhejiang Provincial Ten Thousand Talent Program(ZJWR0302055)。
文摘This study explored the impact of sintering time and temperature on the synthesis and formation of high-entropy rare earth oxides(HEOs).By systematically varying the sintering conditions,a series of Lu_(2)Yb_(2)Tm_(2)Er_(2)O_(12) samples was synthesized and their structural and chemical properties were analyzed using scanning electron microscopy(SEM)with energy-dispersive X-ray spectroscopy(EDS)elemental mapping,X-ray diffraction(XRD),high-resolution transmission electron microscopy(HRTEM),and X-ray photoelectron spectroscopy(XPS).According to XRD patterns,a single-phase cubic C-type structure is easier to form at higher sintering temperatures(1400-1500℃),with sharper peaks signifying better crystallinity.With longer sintering times improving grain development and homogeneity,SEM research reveals a change in morphology from spherical grains at lower temperatures(1100-1200℃)to blocky grains at higher temperatures(1300-1500℃).HRTEM pictures verified the nanoparticles'strong crystallinity,and at higher temperatures,the lattice fringes widen and become more distinct,indicating better atomic ordering and diffusion.Stable and uniform high-entropy oxide production is indicated by the XPS spectra,which shows uniform elemental distribution and consistent chemical states of the constituent elements with very slight variations in the oxygen peaks.The findings highlight how important the sintering temperature is for reaching the intended high-entropy phase,with higher temperatures promoting improved atomic diffusion and compositional homogeneity.The results open the door for the use of high-entropy rare earth oxides in sophisticated functional materials by offering insightful information on how to best synthesize them.
文摘Acute presentation of vomiting is a very common presenting complaint in the emergency department(ED).While majority of such complaints can be attributed to benign,self-limiting causes such as gastroenteritis,rarer alternative diagnoses should be considered depending on the patient's progress after initial treatment.Here,we present a case of gastric volvulus(GV),a rare but potentially fatal condition that mimics gastroenteritis.
文摘The healthcare field is fraught with challenges associated with severe class imbalance,wherein such critical conditions like sepsis,cardiac arrest,and drug adverse reactions are rare but have dire clinical consequences.This paper presents a new framework,Deep Reinforcement Adaptive Gradient Optimization Network to Mining Rare Events(DRAGON-MINE),to demonstrate how deep reinforcement learning can be used synergistically with adaptive gradient optimization and address the inherent weaknesses of current methods in the prediction of rare health events.The suggested architecture uses a dual-pathway consisting of a reinforcement learning agent to dynamically reweigh samples and an adaptive gradient optimizer to follow novel learning rates.With extensive experiments on the MIMIC-IV and eICU-CRD datasets,DRAGON-MINE consistently outperforms recent state-of-the-art methods for sepsis,cardiac arrest,and adverse drug reaction prediction,achieving AUROC values of 92.3%and 91.6%for sepsis prediction on MIMIC-IV and eICU-CRD,respectively,while consistently outperforming Transformer-,CNN-RNN-,and Fed-Ensemble-based methods across all evaluated tasks and datasets,with particularly strong gains observed in precision-recall performance under severe class imbalance.With its high sensitivity(88.4%)and specificity(90.2%),DRAGON-MINE enables reliable early warning of rare clinical events in critical care settings while minimizing false alarms,supporting safer clinical decision support systems,and demonstrating strong potential for scalable deployment across multi-institutional intensive care environments through federated learning.
基金supported by the National Natural Science Foundation of China(Grant no.41874173).
文摘Fine-scale structures can be observed in small field-of-view(FOV)auroral observations,but they are often overlooked because they appear only sporadically in all-sky observations.Such forms are of great interest because they may embody specific magnetosphere-ionosphere coupling processes,reveal localized energy deposition pathways,and provide new insights into cross-scale plasma dynamics and instabilities.However,their limited spatial extent,transient occurrence,and scarcity in wide-FOV observations make systematic investigation challenging.Traditional manual analysis struggles to capture these subtle structures within vast all-sky datasets,while automated detection faces severe data imbalance and morphological ambiguity.To address these challenges,we propose a synthetic-to-real progressive learning framework for cross-FOV retrieval of rare auroral forms.A Generative Adversarial Network(GAN)is employed to perform cross-FOV transformation between unpaired small-FOV images containing rare aurora forms and all-sky images(ASI)without such structures,thereby generating large numbers of synthetic ASI with rare auroral morphology.These synthetic samples are used to train an initial detection model,which subsequently undergoes iterative fine-tuning through feedback-guided learning:The model performs inference on new all-sky data,and the progressively accumulated real detections are incorporated into the training set.Experimental results demonstrate that the proposed method achieves over 92%detection accuracy on ASI,enabling high-precision retrieval of small-scale auroral structures across large-scale observations.This framework provides a scalable and effective approach to rediscovering rare auroral phenomena in continuous all-sky monitoring,offering new opportunities for exploring the fine-scale dynamics of the upper atmosphere.
基金Project supported by the National Natural Science Foundation of China(52374292)the China Baowu Low Carbon Metallurgy Innovation Foundation(BWLCF202309)the Natural Science Foundation of Changsha(KQ2208271)。
文摘To inhibit the interfacial(displacement)reaction between Hf and Al elements in the DZ125 superalloy and the Al_(2)O_(3) and SiO_(2) in the Al_(2)O_(3)-based ceramic shell,rare-earth oxides(La_(2)O_(3) and Y_(2)O_(3))were used as dopants into the shell.The effects of dopant types and contents(2 wt%,5 wt%and 8 wt%)on the wettability and interfacial reaction were investigated using the sessile-drop experiment,and the reaction products were analyzed by X-ray diffraction(XRD),a scanning electron microscope(SEM),an electron probe microanalyzer(EPMA)and X-ray photoelectron spectroscopy(XPS),to clarify the mechanism of dopants in the interracial reaction.The results show that increasing the Y_(2)O_(3) doping content(2 wt%-8 wt%)reduces the surface porosity from 22.39%to 13.43%,and decreases the surface roughness from 3.25 to 2.28μm,which enhances the packing density of the shell surface.In the sintering process(1223 K,2 h),both La_(2)O_(3) and Y_(2)O_(3) dopants react with SiO_(2),forming La_(2)Si_(2)O_(7) and Y_(2)SiO_(5) on the shell surface.During the interfacial reaction process(1823 K,40 min),La_(2)Si_(2)O_(7) decomposes and reacts with Al_(2)O_(3) and HfO_(2),resulting in the formation of SiO_(2)·HfO_(2)·La_(2)O_(3) and Al_(2)O_(3)·HfO_(2)·La_(2)O_(3) ternary composite oxides within the reaction products.At 8 wt%La_(2)O_(3) dopant content,the interfacial reaction is exacerbated,resulting in the uneven wettability.Y_(2)SiO_(5) further reacts with Al_(2)O_(3) and SiO_(2) to form SiO_(2)·Al_(2)O_(3)·Y_(2)O_(3) ternary composite oxides,while Y_(2)O_(3) combines with Al_(2)O_(3) to form Al_(5)Y_(3)O_(12)(VAG),which stabilizes the oxides within the shell and inhibits the interfacial reaction,and significantly improves the surface quality of the DZ125 superalloy.As the Y_(2)O_(3) dopant content increases(2 wt%-8 wt%),the wetting angle increases from 97.8°to 110.6°.
文摘Recurrent pregnancy loss(RPL)affects 2%-5%of couples attempting to conceive.It is a highly heterogenous condition attributed to several factors including endocrine dysfunction,auto immune disorders,thrombophilia,genetic abnormalities,infectious diseases,uterine anomalies,sperm DNA fragmentation,and epigenetics.Among genetic causes,chromosomal abnormalities are the most frequent etiological factor of early miscarriage,accounting for 50%–60%of first trimester abortions.Numerical or structural chromosomal changes may result in spontaneous miscarriages.These anomalies arise as a result of chromosomal translocation,non-disjunction,or mutations[1].Transmission of parental chromosomal abnormalities may be one of the chances for a recurrence of miscarriage in the first trimester of pregnancy,albeit the cause is unknown[2,3].
基金the Major Research Plan of the National Natural Science Foundation of China(91962211)the Key Research and Development Program of Guangxi Province(Guike-AB22080056)+1 种基金the Beijing Nova Program(20230484379)the Major Program of Qingyuan Innovation Laboratory(00122004)。
文摘Ion-adsorption rare earth ore(IAREO)is a crucial source of mid-heavy rare earths elements(M-HRE).Reverse osmosis technology is a promising technique for the pre-concentration of the leach solution from in-situ leaching of IAREO.However,calcium sulfate scaling is inevitably formed in sulfate system,causing decreases in the flux and life time of membrane.Herein,to simulate the precipitation behavior of calcium sulfate in the leach solution of IAREO during reverse osmosis,a series of experiments was conducted in binary and quaternary supersaturated calcium sulfate solution systems.Experimental data show that the concentration of Ca^(2+)decreases with the increase of the concentration of Mg^(2+),and in-creases with the increase of the concentration of RE3+in both binary and quaternary systems.Whereas.the influence of Al^(3+)on the concentration of Ca^(2+)is different.This variation of the Ca^(2+)concentration is explained by thermodynamic analysis.The difference of association concentration for Mg^(2+),Al^(3+)and RE^(3+)with SO_(4)^(2-)in binary or quaternary system is the main reason.Finally,the influence and mechanisms of antiscalant on the precipitation behavior of calcium sulfate are discussed.X-ray diffraction(XRD),Zeta potential and scanning electron microscopy(SEM)analyses reveal that polyacrylic acid(PAA)effectively inhibits the crystal growth of calcium sulfate,and the precipitation time of calcium sulfate is prolonged,indicating that PPA is a potential inhibitor for calcium sulfate scaling during the process of reverse osmosis.
文摘In order to highlight the achievements of China's rare earth industry over the past year with the support of national policy,and show that technological innovation has promoted the development of new high-quality productive forces,expanded the application fields of rare earth elements and accelerated the progress of green and low-carbon transformation.
基金Project supported by the Major Research Plan of the National Natural Science Foundation of China(91962211)the National Key Research and Development Program of China(2021YFC2902202)the Key Research and Development Program of Guangxi Province(Guike-AB22080056)。
文摘Aluminum is the main impurity of the weathered crust elution-deposited rare earth ore(WCED-REO).Efficient leaching of rare earths and low leaching of aluminum are of great importance for the leaching of the WCED-REO.The effects of pH,MgSO_(4) concentration and Al^(3+)concentration of the leaching agent solution on the column leaching behaviors of WCED-REO using magnesium sulfate were investigated.Experimental data show that controlling the MgSO_(4) concentration to 0.15 mol/L,pH of the leaching agent solution to 2,the leaching amount of aluminum from the rare earth ore gradually decreases with the increase of Al^(3+)concentration in the leaching agent solution,indicating that Al^(3+)in the leaching agent solution may act as leaching agent to participate in the ion exchange of RE3+,but the leaching amounts of rare earths change insignificantly as the Al^(3+)concentration is increased.Increasing the MgSO_(4) concentration is beneficial to the leaching of aluminum,and when the Al^(3+)concentration is 0.04 mol/L(Al accumulation),the amount of Al^(3+)leached from the rare earth ore increased gradually with increasing the MgSO_(4) concentration.The pH of the leaching agent solution has a significant influence on the leaching of aluminum in the rare earth ore,and the leaching amount of aluminum from the rare earth ore increases gradually with decreasing the pH.When the Al^(3+)conce ntration is 0.04 mol/L(Al accumulation)and the pH of the leaching agent solution is above 2.0,the aluminum in the leaching agent solution can be back-adsorbed onto the rare earth ore,and the amount of the back-adsorbed Al^(3+)increases with increasing the pH of the leaching agent solution.The injection rate of the leaching agent solution has slight effect on the leaching behavior of rare earths and aluminum.In summary,leaching of Al^(3+)and consumption of MgSO_(4) can be reduced by regulating the accumulation of aluminum,MgSO_(4) concentration and pH.
文摘State Key Laboratory of Baiyun Obo Rare Earth Resource Researches and Comprehensive Utilization was approved by the Ministry of Science and Technology to be one of the national key laboratories in November 2022.The laboratory was reconstructed based on former State Key Laboratory of Baiyun Obo Rare Earth Resources Researches and Comprehensive Utilization.
