Journal of Rare Earths最新文献_第7页

Development of a novel bastnaesite flotation collector: N-hydroxy-3-methoxy-2-naphthalenecarboxamide derived from 2-hydroxy-3-naphthyl hydroxamic acid (H205) 新型氟碳铈矿浮选捕收剂的研制：由2-羟基-3-萘羟肟酸（H205）衍生的n -羟基-3-甲氧基-2-萘甲酰胺

IF 7.2 1区化学 Q1 CHEMISTRY, APPLIED

Journal of Rare Earths

Pub Date : 2026-01-01 Epub Date: 2025-02-25 DOI: 10.1016/j.jre.2025.02.019

Peng Liu , You Zhou , Mengjie Tian , Wei Sun

Bastnaesite flotation typically uses 2-hydroxy-3-naphthyl-hydroxamic acid (H205) as the primary collector. However, the reactivity of the hydroxyl group bonded to the naphthalene ring in H205 also imparts some collecting ability towards fluorite and dolomite. The design of N-hydroxy-3-methoxy-2-naphthalenecarboxamide (HMNC) replaces this hydroxyl group in H205 with a methoxy group. In the flotation separation of bastnaesite from fluorite and dolomite, HMNC collector outperforms H205 in terms of selectivity. Under identical experimental settings, HMNC achieves higher adsorption amounts on bastnaesite surface compared to fluorite and dolomite, providing HMNC with a superior selectivity. Studies on Ce³⁺ and La³⁺ ions dissolution from bastnaesite surface show that after adding HMNC to bastnaesite slurry, dissolved Ce³⁺ and La³⁺ ions re-adsorb onto bastnaesite surface. This suggests that HMNC primarily does not adsorb onto bastnaesite surface as its anion, but in the form of positively charged Ce-HMNC and La-HMNC complexes. Consequently, the presence of HMNC causes positive shifts in the surface zeta potentials of bastnaesite. After HMNC adsorption on bastnaesite surface, the binding energies of the Ce element undergo significant positive shifts. This suggests that HMNC primarily does not adsorb onto bastnaesite surface by donating electrons to the Ce³⁺ ions to form chemical bonds. First-principles calculations reveal that HMNC encounters difficulty adsorbing onto fluorite surface via its N-hydroxyamide group. Additionally, the steric hindrance of the methyl group in HMNC's methoxy group further reduces its collecting ability in fluorite flotation.

氟碳铈矿浮选通常采用2-羟基-3-萘-羟肟酸（H205）作为主要捕收剂。然而，H205中与萘环相连的羟基的反应性也使其对萤石和白云石具有一定的收集能力。设计了n -羟基-3-甲氧基-2-萘甲酰胺（HMNC），用甲氧基取代H205中的羟基。在氟碳石与萤石、白云石的浮选分离中，HMNC捕收剂的选择性优于H205。在相同的实验条件下，HMNC在氟碳石表面的吸附量高于萤石和白云石，具有优越的选择性。对氟碳铈矿表面Ce3+和La3+离子溶解的研究表明，在氟碳铈矿浆料中加入HMNC后，溶解的Ce3+和La3+离子重新吸附到氟碳铈矿表面。这表明HMNC主要不是以阴离子的形式吸附在氟碳醚表面，而是以带正电的Ce-HMNC和La-HMNC配合物的形式吸附在氟碳醚表面。因此，HMNC的存在导致氟碳醚表面zeta电位的正移动。HMNC在氟碳铈表面吸附后，Ce元素的结合能发生了显著的正偏移。这表明HMNC主要不是通过向Ce3+离子提供电子形成化学键而吸附在氟碳铈矿表面的。第一性原理计算表明，HMNC很难通过其n -羟酰胺基团吸附到萤石表面。此外，HMNC的甲氧基中甲基的位阻进一步降低了其在萤石浮选中的收集能力。

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引用次数: 0

A novel thermometric performance of Dy3+ doped phosphor: Fluorescence lifetime of grain boundary-doped MgAlON: Dy3+ transparent ceramics 一种新的Dy3+掺杂荧光粉的测温性能：晶界掺杂MgAlON: Dy3+透明陶瓷的荧光寿命

IF 7.2 1区化学 Q1 CHEMISTRY, APPLIED

Journal of Rare Earths

Pub Date : 2026-01-01 Epub Date: 2025-02-15 DOI: 10.1016/j.jre.2025.02.002

Zhengyang Jing , Bowen Chen , Hao Wang , Pan Gao , Guangsheng Tu , Bingtian Tu , Weimin Wang , Zhengyi Fu

The energy transfer (ET) between f–f transition is achieved by rare earth ions (RE³⁺) doped grain boundaries of transparent ceramics, which enhances the fluorescence thermometry performance and enables multiple fluorescence thermometry modes of transparent ceramics. In this work, MgAlON:Dy³⁺ transparent ceramics were prepared and segregation of Dy³⁺ in grain boundaries was realized. With excellent absolute and relative sensitivities (2.447 μs/K and 2.09%/K), the fluorescence lifetime (FL) signals of MgAlON:Dy³⁺ exceeds most of RE³⁺ doped phosphors. The ET between closely segregated Dy³⁺ in grain boundaries modifies the distribution of electron on ⁴I_15/2 level, and induces temperature-dependent FL to the phosphors. This work reveals the influence of grain boundary segregation on ET between Dy³⁺ for improving the fluorescence thermometry performance of phosphors.

稀土离子（RE3+）掺杂透明陶瓷晶界实现了f-f跃迁之间的能量转移（ET），增强了透明陶瓷的荧光测温性能，实现了透明陶瓷的多种荧光测温模式。本文制备了MgAlON:Dy3+透明陶瓷，实现了Dy3+在晶界的偏析。MgAlON:Dy3+的绝对灵敏度和相对灵敏度分别为2.447 μs/K和2.09%/K，其荧光寿命（FL）信号超过了大多数RE3+掺杂的荧光粉。晶界上紧密分离的Dy3+之间的ET改变了4I15/2能级上的电子分布，诱导了荧光粉的温度依赖性FL。本工作揭示了晶界偏析对Dy3+间ET的影响，以改善荧光粉的荧光测温性能。

引用次数: 0

Microstructural modification of Sm2Co17-type magnets by addition of TiO2 powder to enhance mechanical properties 添加TiO2粉末改性sm2co17型磁体的微观结构以提高其力学性能

IF 7.2 1区化学 Q1 CHEMISTRY, APPLIED

Journal of Rare Earths

Pub Date : 2026-01-01 Epub Date: 2025-01-18 DOI: 10.1016/j.jre.2025.01.012

Lei Wang , Hao Wang , Qiangfeng Li , Chao Wang , Meng Zheng , Yifei Bi , Boxi Zhang , Hang Zhao , Youhao Liu , Yikun Fang , Xiaofei Yi , Wei Li

The mechanical properties of Sm₂Co₁₇ magnets are improved by introducing oxide powders. However, there is a trade-off between the mechanical and magnetic properties. It is important to explore an oxide powder that effectively improves the mechanical properties while avoiding more introduced nonmagnetic elements. TiO₂ is a candidate because it is more reducible than Sm₂O₃ and Ti in it is in +4 valence state. In this work, a small amount (0.08 wt%–0.38 wt%) of fine TiO₂ powers (average powder size is ∼0.2 μm) were introduced into the magnets. The fracture mechanism of TiO₂-added magnets is still brittle cleavage fracture. With TiO₂ addition of 0.08 wt%, the maximum energy product (BH)_max of the magnet is more than 218 kJ/m³, and the coercivity H_cj is larger than 2290 kA/m. More impressively, the maximum flexural strength of the magnets is improved by 37% compared to the original magnet. The introduced TiO₂ is reduced by Sm in the magnet to form Ti and Sm₂O₃ at sintering. Ti is uniformly distributed in the matrix. The newly-formed Sm₂O₃ particles and the ones from the unavoidable oxidation during the preparation process are mainly distributed on the grain boundaries. The particles refine the grains by the Zener pinning effect. Thus, the flexural strength of magnet is improved. Furthermore, with the TiO₂ addition up to 0.38 wt%, the mean grain size decreases by about 36.9%. However, the flexural strength is not further improved significantly. The evolution of the flexural strength is expected to be associated with the larger cellular structure sizes and the increased number of Sm₂O₃ aggregation zones. The results provide a new perspective and inspiration for enhancing the mechanical properties of Sm₂Co₁₇-type magnets.

通过引入氧化物粉末，提高了Sm2Co17磁体的力学性能。然而，在机械性能和磁性之间有一个权衡。探索一种既能有效提高机械性能，又能避免引入更多非磁性元素的氧化物粉末是很重要的。TiO2是一个候选材料，因为它比Sm2O3更容易还原，而且其中的Ti处于+4价态。在这项工作中，将少量（0.08 wt% -0.38 wt%）的细TiO2粉末（平均粉末尺寸为~ 0.2 μm）引入磁体中。添加tio2磁体的断裂机制仍然是脆性解理断裂。TiO2添加量为0.08 wt%时，磁体的最大能积（BH）max大于218 kJ/m3，矫顽力Hcj大于2290 kA/m。更令人印象深刻的是，磁铁的最大弯曲强度比原来的磁铁提高了37%。引入的TiO2在磁体中被Sm还原，烧结形成Ti和Sm2O3。Ti在矩阵中均匀分布。新形成的Sm2O3颗粒和制备过程中不可避免的氧化形成的Sm2O3颗粒主要分布在晶界上。颗粒通过齐纳钉钉效应使颗粒细化。从而提高了磁体的抗弯强度。当TiO2添加量达到0.38 wt%时，平均晶粒尺寸减小约36.9%。然而，抗弯强度没有进一步显著提高。抗折强度的演变与更大的细胞结构尺寸和Sm2O3聚集区数量的增加有关。研究结果为提高sm2co17型磁体的力学性能提供了新的视角和启示。

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引用次数: 0

Electrochemical properties and degradation mechanism of A5B19-type La-Y-Mg-Ni-Al-based hydrogen storage alloy a5b19型la - y - mg - ni - al基储氢合金的电化学性能及降解机理

IF 7.2 1区化学 Q1 CHEMISTRY, APPLIED

Journal of Rare Earths

Pub Date : 2026-01-01 Epub Date: 2024-12-30 DOI: 10.1016/j.jre.2024.12.022

Qing Wang , Hao Wang , Yuan Li , Shiru Guo , Lu Zhang , Wenfeng Wang , Shumin Han

Excellent activation and high capacity qualify the A₅B₁₉-type RE–Mg–Ni-based hydrogen storage alloy as anode material for nickel/metal hydride batteries. Its cycling stability, however, is insufficient to satisfy industrial standards. Herein, phase transformation was studied in a consecutive temperature-rising process, and a Pr₅Co₁₉-type La–Y–Mg–Ni–Al-based alloy was achieved at 1030 °C. The subsequent electrochemical measurements show that the multiphase alloy with more phase interfaces has strikingly high-rate discharge ability performance and low temperature performance. At a discharge current density of 2160 mA/g, the discharge capacity is still 68.3% of the fully-discharged capacity, and the discharge capacity maintains up to 240.5 mAh/g at −40 °C. Otherwise, the single-phase Pr₅Co₁₉-type alloy has superior cycling performance. After 200 cycles of charge and discharge, the capacity retention rate is as high as 80.2%. Structural evolution analysis reveals the degradation mechanism of single-phase Pr₅Co₁₉-type alloy, and it is found that the mismatch between [AB₅]-1 and [AB₅]-2 subunits may be the main factor causing capacity degradation. This work provides new insight into understanding the degradation of Pr₅Co₁₉-type superlattice alloys.

a5b19型re - mg - ni基储氢合金具有优异的活化性能和高容量，是镍/金属氢化物电池的负极材料。然而，其循环稳定性不足以满足工业标准。在连续升温过程中研究相变，在1030℃下获得pr5co19型la - y - mg - ni - al基合金。随后的电化学测试表明，具有较多相界面的多相合金具有显著的高倍率放电性能和低温性能。在放电电流密度为2160 mA/g时，放电容量仍为完全放电容量的68.3%，在−40℃下，放电容量保持在240.5 mAh/g。此外，单相pr5co19型合金具有较好的循环性能。经过200次充放电循环，容量保持率高达80.2%。结构演化分析揭示了单相pr5co19型合金的退化机理，发现[AB5]-1与[AB5]-2亚基的失配可能是导致容量退化的主要因素。这项工作为理解pr5co19型超晶格合金的降解提供了新的见解。

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引用次数: 0

Excellent enhanced photocatalytic degradation of methyl orange and methylene blue by Gd-substituted LaMn0.9Zn0.1O3 gd取代LaMn0.9Zn0.1O3对甲基橙和亚甲基蓝的光催化降解效果有极好的增强作用

IF 7.2 1区化学 Q1 CHEMISTRY, APPLIED

Journal of Rare Earths

Pub Date : 2026-01-01 Epub Date: 2025-05-07 DOI: 10.1016/j.jre.2025.04.017

Maryam Naghavi, Ahmad Gholizadeh

Lanthanum manganite (LMO) is a promising and efficient photocatalyst for the degradation of azo dyes. La_1–xGd_xMn_0.9Zn_0.1O₃ (x = 0.0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3) nanoparticles were synthesized using a sol–gel citrate-nitrate method. The samples were analyzed using X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, Raman spectroscopy, Fourier-transform infrared spectroscopy, and UV–visible spectroscopy. The synergistic effects of Gd and Zn substitution are shown to induce a structural phase transition (Pbnm I to Pbnm II), reduce particle size, and optimize the bandgap, significantly enhancing photocatalytic performance. The photocatalytic performance of La_1–xGd_xMn_0.9Zn_0.1O₃ nanoparticles was investigated by evaluating the effects of catalyst dose, pH, and irradiation time on the degradation of methyl orange (MO) and methylene blue (MB) solutions. Results indicate that La_0.8Gd_0.2Mn_0.9Zn_0.1O₃ sample exhibits higher photocatalytic activity compared to initial LMO for the 97% and 80% degradation of MO and MB under sunlight irradiation, respectively. A possible mechanism for the photocatalytic activity of the samples is critically discussed. Stability tests demonstrate a slight decrease in the photocatalytic efficiency of La_0.8Gd_0.2Mn_0.9Zn_0.1O₃ after six cycles, indicating its potential for long-term applications.

锰酸镧（LMO）是一种很有前途的降解偶氮染料的高效光催化剂。采用柠檬酸盐-硝酸盐溶胶-凝胶法制备了La1-xGdxMn0.9Zn0.1O3 （x = 0.0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3）纳米粒子。采用x射线衍射、场发射扫描电镜、能量色散x射线光谱、拉曼光谱、傅里叶变换红外光谱和紫外可见光谱对样品进行了分析。Gd和Zn取代的协同效应诱导了结构相变（Pbnm I到Pbnm II），减小了粒径，优化了带隙，显著提高了光催化性能。考察了La1-xGdxMn0.9Zn0.1O3纳米粒子的光催化性能，考察了催化剂剂量、pH和照射时间对甲基橙（MO）和亚甲基蓝（MB）溶液降解的影响。结果表明，与初始LMO相比，La0.8Gd0.2Mn0.9Zn0.1O3样品在日光照射下对MO和MB的降解率分别为97%和80%，表现出更高的光催化活性。讨论了样品光催化活性的可能机制。稳定性测试表明，经过6次循环后，La0.8Gd0.2Mn0.9Zn0.1O3的光催化效率略有下降，表明其具有长期应用的潜力。

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引用次数: 0

Promotional effect of cerium and niobium doping on Cu/TiO2 catalyst for diethylamine catalytic degradation 铈和铌掺杂对Cu/TiO2催化剂催化降解二乙胺的促进作用

IF 7.2 1区化学 Q1 CHEMISTRY, APPLIED

Journal of Rare Earths

Pub Date : 2026-01-01 Epub Date: 2024-12-27 DOI: 10.1016/j.jre.2024.12.018

Xiaoqiang Wang , Ling Zhou , Yue Liu , Zhongbiao Wu

In this study, the promotional effect of Ce and Nb doping on Cu/TiO₂ catalyst for diethylamine catalytic degradation was investigated. The activity tests reveal that the Ce and Nb modification can facilitate the rising of mineralization rate and N₂ selectivity during diethylamine degradation, achieving over 90% mineralization rate at 250–450 °C, along with N₂ selectivity exceeding 80% within 300–400 °C. Characterization results show that the co-addition of Ce and Nb induces strong interactions with Cu species and increases surface Brønsted acid sites. Crucially, the enhanced redox capability derived from interactions guarantees good catalytic activity and mineralization rate. Additionally, the increased Brønsted acidity from Nb doping can suppress the formation of NCO(a) species, resulting in less generation of NO_x from NCO(a) oxidation. Moreover, the enhanced Brønsted acidity can promote the internal SCR reaction, which also reduces the NO_x emission. This work could offer valuable insights for designing catalysts with superior catalytic performance for amine-like volatile organic compounds (VOCs) degradation.

本研究考察了Ce和Nb掺杂对Cu/TiO2催化剂对二乙胺催化降解的促进作用。活性测试表明，Ce和Nb改性有利于二乙胺降解过程中矿化率和N2选择性的提高，在250 ~ 450℃时矿化率达到90%以上，在300 ~ 400℃时N2选择性超过80%。表征结果表明，Ce和Nb的共加成诱导了与Cu的强相互作用，增加了表面Brønsted酸位。至关重要的是，相互作用增强的氧化还原能力保证了良好的催化活性和矿化率。此外，Nb掺杂增加的Brønsted酸性可以抑制NCO(a)的形成，导致NCO(a)氧化产生的NOx减少。此外，Brønsted酸性的增强可以促进内部SCR反应，从而减少NOx的排放。该研究为设计具有优异催化性能的胺类挥发性有机化合物（VOCs）降解催化剂提供了有价值的见解。

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引用次数: 0

Magnetocaloric effect of Ce(La)In2 alloys near hydrogen condensation point 氢凝点附近Ce(La)In2合金的磁热效应

IF 7.2 1区化学 Q1 CHEMISTRY, APPLIED

Journal of Rare Earths

Pub Date : 2026-01-01 Epub Date: 2025-03-12 DOI: 10.1016/j.jre.2025.03.010

Luis M. Moreno-Ramírez , Daniel P. Rojas , José I. Espeso , Jesús Rodríguez Fernández , Victorino Franco

Gas liquefiers allow efficient transport and storage of gases, key for the development of new energy vectors such as hydrogen fuel. In this sense, magnetic liquefiers based on the magnetocaloric effect are an energy-saving and sustainable alternative to current systems based on the Joule-Thomson expansion. Here, we report the magnetocaloric effect of light rare-earth-based Ce(La)In₂ alloys near the hydrogen condensation point. They exhibit a first-order ferromagnetic to paramagnetic phase transition with reduced thermal hysteresis (0.05 K) and moderate criticality compared to their heavy rare-earth-based counterparts. Both isothermal entropy change, and adiabatic entropy change have been indirectly determined from heat capacity measurements. A previously developed method based on low-temperature truncation of heat capacity data was applied for those calculations, accounting for

\sim

8% underestimation of the maximum values as well as possible misinterpretations of the results in the paramagnetic range. The parent CeIn₂ alloy shows an isothermal entropy change of 9.5 J/(kg·K) and an adiabatic temperature change of 2.8 K for a magnetic field change of 5 T. The substitution of Ce by La leads to a slight decrease of the transition temperature in the explored range together with a significant reduction of the magnetocaloric magnitudes: about −1.0 J/(kg·K) and about −0.2 K per atom fraction of La for the isothermal entropy and adiabatic temperature changes for 5 T, respectively.

气体液化器可以有效地运输和储存气体，这是开发氢燃料等新能源载体的关键。从这个意义上说，基于磁热效应的磁液化器是当前基于焦耳-汤姆逊展开的系统的节能和可持续替代方案。本文报道了轻稀土基Ce(La)In2合金在氢凝点附近的磁热效应。与重质稀土相比，它们表现出一级铁磁到顺磁的相变，热滞后降低（0.05 K），临界程度中等。等温熵变和绝热熵变都是由热容测量间接确定的。先前开发的一种基于低温截断热容数据的方法被应用于这些计算，导致对最大值的低估约8%，以及对顺磁范围内结果的可能误解。父CeIn2合金显示了等温熵变9.5 J /(公斤·K)和2.8 K的绝热温度变化的磁场变化5 T . Ce的替换拉导致轻微下降的转变温度一起探索范围显著减少的磁致热的大小:关于−1.0 J /(公斤·K)和−0.2 K /原子分数拉的等温熵和绝热温度变化5 T,分别。

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引用次数: 0

Magnetic phase transition and magnetocaloric properties in ErB2C compound ErB2C化合物的磁相变和磁热学性质

IF 7.2 1区化学 Q1 CHEMISTRY, APPLIED

Journal of Rare Earths

Pub Date : 2026-01-01 Epub Date: 2025-09-30 DOI: 10.1016/j.jre.2025.09.044

Yingzhe Na, Zhaoxing Wang, Zhe Kong, Yang Xie, Yikun Zhang

The rare-earth (RE)-based materials have been extensively investigated recently regarding their magnetocaloric (MC) responses which are aimed to develop suitable candidate materials for low-temperature magnetic refrigeration (MR) applications. We herein fabricated an erbium-based magnetic boride carbide, namely the ErB₂C compound, by arc-melting method and unveiled its low-temperature MC and magnetic phase transition (MPT) properties, through experimental determination and theoretical calculation. The ErB₂C compound is confirmed to crystallize in a tetragonal YB₂C-type orthorhombic structure (space group P42/mbc, No. 135) and exhibit two successive low-temperature MPT around 3.9 and 17.0 K, respectively. Large low-temperature conventional and inverse MC responses in ErB₂C compound are observed. The determined conventional MC parameters for ErB₂C compound mainly including temperature-averaged entropy change/maximum magnetic entropy and refrigerant capacity (field variation of 0–7 T) reach 15.3/15.9 J/(kg·K) and 284.4 J/kg, respectively, which are comparable to some recently reported RE-based materials with notable MC responses around 20 K, making the ErB₂C compound maybe considerable for low-temperature MR applications.

近年来，人们对稀土基材料的磁热响应进行了广泛的研究，旨在开发适合低温磁制冷（MR）应用的候选材料。本文采用电弧熔炼法制备了铒基磁硼化物化合物ErB2C，并通过实验测定和理论计算揭示了其低温MC和磁相变（MPT）性能。结果表明，该化合物以yb2c型四方正交晶型结构（空间群P42/mbc， No. 135）结晶，在3.9 K和17.0 K左右分别表现出两个连续的低温MPT。在低温条件下，观察到ErB2C化合物的常规和逆MC响应。测定的ErB2C化合物的常规MC参数主要包括温度平均熵变/最大磁熵和制冷剂容量（0-7 T的场变化）分别达到15.3/15.9 J/（kg·K）和284.4 J/kg，这与最近报道的一些在20 K左右具有显著MC响应的re基材料相当，这使得ErB2C化合物可能具有相当的低温MR应用价值。

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引用次数: 0

A novel process for precipitation of rare earths using carboxylic acid compounds 用羧酸化合物沉淀稀土的新工艺

IF 7.2 1区化学 Q1 CHEMISTRY, APPLIED

Journal of Rare Earths

Pub Date : 2026-01-01 Epub Date: 2025-01-23 DOI: 10.1016/j.jre.2025.01.014

Yuhe Ran , Ru'an Chi , Zhenyue Zhang , Yuting Shi , Wendou Chen , Fei Long , Hanjun Wu

Weathered rare earth ores are an important strategic mineral resource in China, and they are the primary source of medium and heavy rare earths (MHRE). The efficient recovery of MHRE is of great significance from an industrial standpoint. In this study, fulvic acid (FA) was employed as a precipitant to investigate the precipitation of rare earth (RE). The results indicate that the precipitation rates (w) of RE range from 89.69 wt% to 99.86 wt% with the pH of 9, the molar ratio of 2, and the temperature of 40 °C, except for Lu³⁺, the w reaches 97.33 wt% with the pH of 9, the molar ratio of 3, and the temperature of 25 °C. The w of RE in the ammonium acetate rare earth leaching solution ranges from 95.99 wt% to 98.54 wt%, with the MH/L of the rare earth distribution after precipitation increasing from 0.77 to 0.80. The use of FA as a precipitant is demonstrated to yield effective precipitation of RE, particularly those of MHRE. FA complexes with RE³⁺, where deprotonation of COO^– increases the surface electron density of oxygen atoms, creating additional active sites for electron-deficient RE³⁺. The mechanism provides a theoretical basis for using carboxylic acid compounds as new precipitants. Further, a novel technology for FA complexation precipitation of RE from lignite extract is proposed.

风化稀土矿是中国重要的战略性矿产资源，是中、重稀土的主要来源。从工业角度来看，高效回收MHRE具有重要意义。本研究以黄腐酸（FA）为沉淀剂，研究稀土（RE）的沉淀。结果表明：当pH = 9，摩尔比为2，温度为40℃时，RE的析出率w在89.69 ~ 99.86 wt%之间，除Lu3+外，在pH = 9，摩尔比为3，温度为25℃时，RE的析出率w达到97.33 wt%。乙酸铵稀土浸出液中稀土的w在95.99 ~ 98.54 wt%之间，沉淀后稀土分布的MH/L从0.77增加到0.80。使用FA作为沉淀剂已被证明可以有效地沉淀RE，特别是MHRE。FA与RE3+配合物，其中COO -的去质子化增加了氧原子的表面电子密度，为缺电子的RE3+创造了额外的活性位点。该机理为羧酸类化合物作为新型沉淀剂提供了理论依据。在此基础上，提出了褐煤萃取物中稀土的FA络合沉淀新工艺。

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引用次数: 0

Dissolution and mechanism of bastnaesite mediated by Acidithiobacillus ferrooxidans 氧化亚铁硫杆菌介导氟碳铈矿的溶解及其机制

IF 7.2 1区化学 Q1 CHEMISTRY, APPLIED

Journal of Rare Earths

Pub Date : 2026-01-01 Epub Date: 2025-03-25 DOI: 10.1016/j.jre.2025.03.025

Yujian Liang , Zuotan Huang , Qiudong Xiao , Xuan Guan , Xinman Xu , Hongmin Jiang , Yijian Zhong , Zhihong Tu

Current industrial extraction of rare earth elements (REEs) from bastnaesite involves energy-intensive and costly processes like roasting and acid leaching, which generate significant amounts of hazardous waste. This study explored Acidithiobacillus ferrooxidans (A. ferrooxidans)-mediated bastnaesite dissolution, focusing on influencing factors and the dissolution mechanism. Notably, A. ferrooxidans is primarily contributed by oxidizing pyrite to release H⁺ and Fe³⁺, which subsequently promotes the dissolution of cerium (Ce) and lanthanum (La) from bastnaesite. In particular, Fe³⁺ forming [FeF₅]²⁻ with F⁻ is crucial for bastnaesite dissolution. Furthermore, the particle size of bastnaesite can significantly affect the dissolution rate. When the particle size is 75 μm, after 30 d of leaching, the concentrations of La and Ce are 9.48 and 12.78 mg/L respectively, which is approximately threefold higher than that of the bastnaesite with a particle size of 750 μm. Dialysis experiments indicate no direct physical dissolution by A. ferrooxidans. Additionally, adsorption studies reveal no significant specific affinity for La and Ce by A. ferrooxidans cell or jarosite, suggesting that REEs remain ionic in the leachate. Utilizing A. ferrooxidans to oxidize pyrite tailings for continuous H⁺ and Fe³⁺ production enhances bastnaesite dissolution and REEs leaching, promoting tailings recycling and reducing leaching agent costs. This study provides insights into bastnaesite bioleaching for La and Ce recovery, while also sheds light on the biogeochemical implications of acidophilic microorganism-mediated bastnaesite weathering.

目前从氟碳铈矿中提取稀土元素的工业过程涉及诸如焙烧和酸浸等能源密集型和昂贵的过程，这些过程会产生大量有害废物。本研究探讨了Acidithiobacillus ferrooxidans （A. ferrooxidans）介导的氟碳醚溶解，重点探讨了影响因素和溶解机制。值得注意的是，a.f erooxidans主要是通过氧化黄铁矿释放H+和Fe3+，从而促进铈（Ce）和镧（La）从氟碳铈矿中溶解。特别是，Fe3+与F−形成[FeF5]2−对于氟碳铈矿的溶解至关重要。氟碳铈矿的粒径对溶解速率有显著影响。当粒径为75 μm时，浸出30 d后，La和Ce的浓度分别为9.48和12.78 mg/L，比粒径为750 μm的氟碳铈矿高出约3倍。透析实验表明氧化亚铁杆菌没有直接的物理溶解作用。此外，吸附研究显示a.f erferrooxidans细胞或黄钾铁矾对La和Ce没有明显的特异性亲和力，这表明稀土元素在渗滤液中保持离子状态。利用A. ferrooxidans氧化黄铁矿尾矿连续生产H+和Fe3+，促进了氟碳铈矿的溶解和稀土的浸出，促进了尾矿的回收利用，降低了浸出剂成本。本研究为氟碳铈矿的生物淋滤恢复提供了新的思路，同时也揭示了嗜酸微生物介导的氟碳铈矿风化的生物地球化学意义。

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引用次数: 0