ACS Earth and Space Chemistry
·
2021
·
IF 3.475
Yang Wu,Xiongxin Dai,Marcus Christl,Hans-Arno Synal,Shan Xing,Shaochun Hou
Plutonium-244 could be the heaviest primordial nuclide existing on earth since the early formation of the solar system. However, the controversial results on the detection of 244Pu in bastnaesite samples require a reassessment. An extremely sensitive analytical method has been developed for the analysis of total 244Pu in completely digested bastnaesite samples by accelerator mass spectrometry. As no true signal of 244Pu was observed, an upper limit for the 244Pu content in the bastnaesite concentrate sample from the Bayan Obo rare-earth deposit (China) was estimated to be 5.4 × 10–19 g/g at 99% confidence level. This result does not agree with the detection of 244Pu at a concentration of 1.0 × 10–18 g/g in bastnaesite reported by Hoffman et al. [Nature1971,234, 132–134] but confirms the latest measurement for an upper limit of 1.5 × 10–19 g 244Pu/g bastnaesite by Lachner et al. [Phys. Rev. C: Nucl. Phys.2012,85, 015801]. Thus, the direct search for primordial 244Pu on earth still remains an open question.
研究领域:
地球化学
·
核物理学
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DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Zhoujie Wang,Houqin Wu,Jie Yang,Zhen Tang,Liping Luo,Kaiqian Shu,Yanbo Xu,Longhua Xu
The inability of rare earth and gangue minerals to be efficiently separated by flotation due to their similar physicochemical properties is a major challenge of the rare earth industry. Bastnaesite is one of the principal sources of light rare earth elements. The use of traditional flotation reagents often poses the problem of poisonous wastewater generation. Therefore, we use xanthan gum (XG) as a non-toxic, biodegradable, and cheap depressant to selectively separate bastnaesite from calcite by flotation and probe the corresponding mechanism. Microflotation experiments/zeta potential measurements conducted with/without XG using sodium oleate as a collector demonstrate that at pH 8, XG decreases the flotation recoveries of calcite and bastnaesite by 85.09 and 22.37%, respectively. Further analysis of adsorption behaviour on the mineral surface and possible reagent-mineral interactions shows that selective mineral separation is due to the preferential interaction of XG with Ca ions on the calcite surface and the suppression of oleate ion adsorption thereon due to the steric hindrance of polymeric XG. Hence with regard to the potential of XG in calcium-bearing mineral separation, XG could be as a new depressant for RE mineral flotation.
研究领域:
矿物学
·
环境科学
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DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2021
·
IF 3.712
Zhao Cao,Zeyu Cheng,Jieliang Wang,Yongdan Cao
Bastnaesite is an important rare earth mineral and is usually beneficiated by flotation . Sodium silicate is commonly used to depress calcium-bearing gangue minerals, however it can also depress bastnaesite when Ca 2+ ions exist in the pulp. In this study, the effect of Ca 2+ ions and sodium silicate individually or in combination on bastnaesite flotation was studied through micro-flotation, zeta potential , fluorescence spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements. Micro-flotation results show that the combination of Ca 2+ ions and sodium silicate depresses bastnaesite more severely due to their synergistic effect. Zeta potential results show that the combination renders the surface potential of bastnaesite negatively shifted more significantly. Fluorescence spectroscopy shows that the combination decreases the surface hydrophobicity of bastnaesite more severely. XPS shows that the combination increases the adsorption of sodium silicate on bastnaesite by forming hydrophilic Ca-SiO 3 precipitate, which causes more serious depression on bastnaesite flotation.
研究领域:
矿物学
·
化学工程
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DOI
高影响因子
MINERALS ENGINEERING
·
2024
·
IF 4.9
Yiwen Hu,Jieliang Wang,Zhao Cao,Xu Wu,Wenda Lu,Weiwei Wang,Wenli Liu
Bastnaesite is an important strategic resource. Since the calcium-bearing gangue minerals in the pulp can dissolve and release Ca 2+ ions, Ca 2+ ions and sodium silicate have a co-depression effect on bastnaesite flotation, which will affect the separation and purification of bastnaesite. In this study, the mechanism of eliminating the co-depression effect using ethylene diamine tetraacetic acid (EDTA) was studied by micro-flotation, bench-scale flotation, zeta potential, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM)–energy spectrometry (EDS), contact angle and DFT calculations measurements. Micro-flotation results show that the addition of EDTA can effectively eliminated the co-depresses effect of Ca 2+ ions and sodium silicate. Bench-scale flotation tests showed that a high-quality rare earth (REE) ore concentrate with higher grade and recovery (62.35 % and 62.08 %, respectively) could be enriched by adding EDTA. Zeta potential results show that the combination of Ca 2+ ions and EDTA than with Ca 2+ ions alone, the surface potential of bastnaesite was significantly negative. XPS shows that EDTA prevented Ca-SiO 3 precipitation between Ca 2+ ions and sodium silicate by complexing Ca 2+ ions, which hindered the adsorption of sodium silicate to bastnaesite. SEM-EDS show that the addition of EDTA between Ca 2+ ions and sodium silicate, Ca 2+ ions had desorbed from the bastnaesite surface. Density functional theory (DFT) calculation showed that the adsorption energy of EDTA and Ca 2+ ions was much smaller than that of sodium silicate and Ca 2+ ions and Ca 2+ ions and mineral surface.
研究领域:
矿物学
·
浮选化学
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DOI
高影响因子
Surfaces and Interfaces
·
2025
·
IF 6.3
Donghui Wang,Zhoujie Wang,Yan Wang,Chang Liu,Guohuan Li,Zhimin Ma,Kai Xue,Jia Tian,Longhua Xu
The surface characteristics of bastnaesite and barite are highly similar, leading to comparable reagent interactions during flotation processes. Conventional collectors often demonstrate limited selectivity and suboptimal collection efficiency, which negatively impact flotation outcomes. Effective mineral separation requires highly selective and efficient collectors. This study presents the synthesis and initial application of lauryl hydroxamic acid (LHA) as a new collector for the flotation of bastnaesite. LHA exhibited remarkable selectivity and collecting efficiency in the flotation separation of bastnaesite from barite. The synergistic application of LHA and carboxymethyl cellulose (CMC) as depressants enabled effective separation. This resulted in a recovery difference of up to 66.5 % between the two minerals. Spectroscopic analysis revealed that LHA interacts with Ce sites on bastnaesite surfaces through N and O atoms in its hydroxamate groups. Pre-adsorption of CMC was found to prevent LHA adsorption on barite without affecting its adsorption on bastnaesite. LHA adsorbs through the synergistic effect of electrostatic interaction and chemisorption. Comparative analysis indicated that LHA’s hydroxamate group possesses lower non-bonded tension than traditional octyl hydroxamic acid (OHA), enhancing its chelate-forming capability. Density Functional Theory calculations identified hydroxamate groups as LHA’s primary active sites, with O and N atoms playing critical roles. This research systematically investigates the potential of LHA for bastnaesite-barite separation and elucidates its adsorption mechanism. The findings not only advance theoretical understanding of selective flotation control but also provide molecular design guidelines for novel collector development.
研究领域:
矿物加工工程
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表面化学
·
理论计算
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DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2025
·
IF 7.2
Yanxu Wang,Siyuan Yang,Qianqian Wang,Bo Chen,Shenxu Bao,Wenbo Li,Cheng Liu
The efficient flotation separation of rare earth elements (REEs) from gangue minerals is crucial in mineral processing. This study synthesized a quaternary ammonium salt ionic liquid collector, tetrabutylammonium salicylhydroxamate (T-S), and investigated its performance in separating bastnaesite and fluorite. T-S was synthesized from salicylhydroxamic acid (SHA) and tetrabutylammonium chloride (TBAC), and its molecular structure was characterized using Fourier transform infrared (FTIR) spectroscopy. Microflotation tests indicate that T-S outperforms SHA and TBAC in both collecting ability and selectivity for bastnaesite. Adsorption, zeta potential, and infrared spectroscopy measurements reveal that T-S exhibits stronger adsorption on bastnaesite compared to SHA and TBAC. X-ray photoelectron spectroscopy (XPS) and molecular dynamics simulations (MDS) results confirm that chemical adsorption occurs between Ce on the bastnaesite surface and the –C(=O)NHOH groups of T-S. Moreover, the interaction between T-S and the bastnaesite surface is stronger than that with the fluorite surface. This work provides valuable insights for designing ionic liquid collectors for the flotation separation of bastnaesite and fluorite.
研究领域:
矿物加工工程
·
材料化学
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产品关联
DOI
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2026
·Vol. 36
·期 6
·1875-1890
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IF 5.5
Qiang ZHANG,Yong-sheng SUN,Zhao CAO,Peng GAO,Wen-bo LI
The effect of oxidation roasting on the surface characteristics and flotation behavior of bastnaesite was investigated. Oxidation roasting experiments were performed at various temperatures, time, and O 2 concentrations. The results indicated that increasing the temperature promoted the thermal decomposition of bastnaesite, resulting in the formation of Ce 7 O 12 , RE 2 O 3 , and REF 3 as the main phases. Furthermore, oxidation roasting induced the formation of long, narrow, and nearly parallel cracks within the particles, increasing the porosity and facilitating partial particle fragmentation. During flotation, the concentration of dissolved rare earth ions increased significantly, and surface hydrolysis led to the formation of rare earth hydroxyl compounds. The complete decomposition of bastnaesite increased the required collector dosage to achieve a recovery above 85.00%. This increase might be attributed to the enhanced particle wettability, the altered adsorption mechanism of the collector, and the deeper penetration of the collector into the porous structure.
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高影响因子
Minerals
·
2020
·Vol. 10
·期 3
·282
·
IF 2.38
Wenliang Xiong,Jie Deng,Kaile Zhao,Weiqing Wang,Yanhong Wang,Dezhou Wei
The flotation of bastnaesite, as a major mineral source of rare earth elements, attracting much attention in the mineral processing field, is challenging owing to the natural flotability of calcium-bearing minerals. To promote the application of flotation, we systematically investigated the flotation behavior of bastnaesite, barite, and calcite, with salicylhydroxamic acid (SHA) as the collector through micro-flotation experiments, zeta-potential measurements, Fourier transform infrared (FT-IR) analyses, X-ray photoelectron spectroscopy (XPS) analyses, and solution chemistry analyses. Micro-flotation experiments confirm that the flotability of bastnaesite is high at pH 6.5–8.5, while calcite floats at pH 8.0–9.5, and barite has little flotation response. The results of FT-IR, XPS, and zeta-potential measurements indicate that there is chemical adsorption of SHA on the bastnaesite surface, and physical adsorption also occurs. However, as for barite and calcite, there is only physical adsorption of SHA on the surfaces. The solution chemistry results show that SHA anions can interact with RE3+, REOH2+, and RE(OH)2+on bastnaesite surfaces in aqueous suspensions, resulting in bastnaesite flotation.Keywords:bastnaesite;barite;calcite;salicylhydroxamic acid;flotation
研究领域:
矿物加工工程
·
化学工程
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DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2026
·
IF 9.6
Jingyang Shi,Xianbo Fang,Jieliang Wang,Zhao Cao,Jing Lv,Yongdan Cao,Xiaoping Wang,Na Luo,Fang Zhou,Aiqing Wang,Burdonov Alexander Evgenievich
In rare earth flotation, the separation of bastnaesite and parisite from fluorite is challenging by the similarity of their surface properties and solubility. This study utilized carboxymethyl chitosan (CTS) as a green organic inhibitor for the flotation separation of bastnaesite and parisite from fluorite. The inhibitory effect and mechanism of CTS on fluorite were studied through flotation tests and modern detection methods. The flotation tests results indicate that CTS can effectively inhibit fluorite under the conditions: CTS concentration of 20 mg/L, octyl hydroxamic acid (OHA) concentration of 1×10 –4 mol/L, and at pH 9.8, whereas it only slightly affects the flotation recovery of bastnaesite and parisite. The mechanism analysis results indicate that CTS selectively adsorbs on fluorite surface and reduces the contact angle from 27.25° to 20.38°, while significantly delaying the adhesion process of bubbles on the fluorite surface and reducing its ultimate adhesion angle. CTS undergoes strong chemical adsorption on the surface of fluorite, hindering the subsequent adsorption of OHA, but has weak adsorption on the rare earth minerals. CTS chelates with Ca 2+ on the fluorite surface through its –COO – molecule, forming a hydrophilic Ca(COOR) adsorption cover on the fluorite surface to increase its steric hindrance and inhibit fluorite flotation. Therefore, CTS can be used as a green, environmentally friendly, and highly selective inhibitor to achieve efficient flotation separation of bastnaesite and parisite from fluorite.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2026
·
IF 6.7
Xinglu He,Yan Zhou,Xiangxin Xue,He Yang,Jianxing Liu,Gongjin Cheng
Bastnaesite is an important rare-earth mineral and a key precursor for functional materials. Controllable hydrothermal synthesis enables the preparation of composition-defined bastnaesite for investigating their thermal decomposition and roasting behavior. In this work, bastnaesite with different rare-earth compositions were synthesized hydrothermally from RECl 3 , NaF, and Na 2 CO 3 at 100̃140 °C for 12̃72 h. Single-rare-earth bastnaesite samples containing Ce, La, Pr, and Nd were successfully prepared under optimized fluorine-containing conditions. In the cerium-containing system, CeF 3 and CeO 2 appeared under overly acidic or alkaline conditions, whereas chloride was more favorable than nitrate for bastnaesite formation because it suppressed Ce(III) oxidation. Rare-earth composition strongly affected the decomposition behavior. Increasing Ce content lowered the onset decomposition temperature from 418.9 °C for La-bastnaesite to 298.4 °C for Ce-bastnaesite, with further decreases in air. Under N 2 , Ce-bastnaesite underwent multistep decomposition involving decarbonation, formation of CeO 2 − x and CeF 3 , and subsequent generation of cerium oxyfluoride phases, whereas La-, Pr-, and Nd-based bastnaesite was largely insensitive to atmosphere and was converted mainly into the corresponding REOF phases in nitrogen. These results provide reference for understanding the roasting behavior and thermal-treatment window of bastnaesite.
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高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2026
·
IF 3.5
Qiang Zhang,Lina Wu,Yongsheng Sun,Peng Gao,Yuexin Han
Bastnaesite significantly accelerates hydrogen reduction of hematite. • Iron recovery increased from 82.93% to 99.96% with bastnaesite at 475°C. • Ce redox pairs and oxygen vacancies enhance hematite reduction kinetics. • Natural rare earth additives enable efficient, low-carbon iron ore processing. Hydrogen reduction of hematite followed by magnetic separation is a promising low-carbon route for iron ore beneficiation, but its relatively high reduction temperature limits practical application. Here, naturally occurring bastnaesite (RECO 3 F) was used as a low-cost promoter to enable low-temperature hydrogen reduction of hematite. Its effects were compared with those of rare-earth oxyfluoride (REOF), the main decomposition product of bastnaesite, and synthetic CeO 2 . Thermodynamic calculations, isothermal kinetic analysis, magnetic separation experiments, and comprehensive characterizations were integrated to elucidate the reduction behavior and promotion mechanism. Bastnaesite lowered the apparent activation energy from 48.93 to 45.58 kJ·mol -1 , while the reduction process remained governed by a diffusion-controlled shrinking-core mechanism. After the addition of bastnaesite, the iron recovery increased from 82.93% to 99.96% (mass), and the total iron grade improved from 69.52% to 70.08% (mass) at temperature of 475°C. The enhanced reduction was attributed to the combined effects of Ce(III)/Ce(IV) redox cycling, oxygen vacancy formation, improved gas diffusion, and in situ CO generation via the water-gas shift reaction using CO 2 released during bastnaesite decomposition. Bastnaesite also suppressed the over-reduction of magnetite to weakly magnetic wüstite above 550°C, thereby preserving magnetic separation efficiency. These findings demonstrate that natural bastnaesite can serve as an effective promoter for energy-efficient hydrogen-based iron recovery. Download: Download high-res image (190KB) Download: Download full-size image
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高影响因子
JOURNAL OF RARE EARTHS
·
2025
·
IF 7.2
Xuan Wang,Wei Sun,Jing Zhao,Haisheng Han
Nitrilotrimethylene phosphonic acid (nitrilotri, ATMP) enables effective flotation separation of fluorite from bastnaesite through selective surface modification. A multi-technique investigation including micro-flotation tests, zeta potential measurements, contact angle analysis, adsorption studies, Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) characterization, and quantum chemical calculations can elucidate the inhibition mechanism. Single-mineral and synthetic mixed-ore flotation experiments demonstrate ATMP's selective inhibition toward bastnaesite, achieving >70% fluorite recovery with <12% bastnaesite recovery at optimal dosage (40 g/t). Mechanistic studies reveal that ATMP preferentially chemisorbs at Ce 3+ active sites on bastnaesite surfaces through dual mechanisms: Firstly, nitrilotri undergoes chemisorption with Ce active sites on the bastnaesite surface, forming Ce-PO(OH) 2 complexes that exhibit strong adsorption on the mineral surface. Secondly, the three phosphonate groups of nitrilotri are arranged in a triangular configuration with an interatomic distance of 0.7512 nm, which spatially aligns with the Ce sites (0.7186 nm interatomic spacing) on bastnaesite. Each nitrilotri molecule chemisorbs with three Ce sites, yielding an adsorption energy of −294.624 kJ/mol, being indicative of a thermodynamically favorable interaction. This site-specific adsorption generates a hydrophilic Ce–phosphonate interface that destabilizes collector (NaOL) adsorption, reducing bastnaesite surface hydrophobicity by 42.78% (contact angle decreases from 65.23° to 22.45°). Conversely, nitrilotri exhibits limited interaction with fluorite due to geometric mismatch at Ca 2+ sites, allowing NaOL-dominated hydrophobization to persist. The fundamental understanding of ligand-receptor complementarity presented here provides a promising strategy for rare earth/fluorite separation in industrial beneficiation circuits.
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高影响因子
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