MINERALS ENGINEERING
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2026
·
IF 6
Linghui Zhang,Wenbo Li,Shaokai Cheng,Yuying Shao,Xiaolong Zhang
A method for separating bastnaesite and monazite without inhibitor was proposed. • MPT distinctly modifies the surface properties of bastnaesite and monazite. • Bastnaesite and monazite exhibit significantly different flotation behaviors after MPT treatment. • An optimal MPT condition (700 °C for 10 min) was identified for effective separation. • Ce 4+ /Ce 3+ on Ce 7 O 12 surface is chemically adsorbed with –C NOH group of BHA. This study proposes a selective mineral phase transformation (MPT) pretreatment enhanced micro-flotation method. By optimizing the MPT conditions, the selectivity of benzo hydroxamic acid (BHA) toward the MPT products of bastnaesite is improved, enabling efficient separation of bastnaesite and monazite at the source. This approach enables diversion metallurgy and may reduce the environmental pollution caused by high-temperature concentrated sulfuric acid roasting of mixed rare earth concentrates. The results indicate that during the MPT process, an oxidizing thermal pretreatment conducted in air at the optimized condition of 700 °C for 10 min, bastnaesite (CeCO 3 F) was primarily transformed into Ce 7 O 12 , with cracks and pores appearing on particle surfaces and a significantly increased specific surface area compared with the raw ore, whereas monazite (CePO 4 ) exhibited neither significant phase changes nor structural damage. In subsequent micro-flotation experiments with BHA as the collector, the two minerals exhibited distinct flotation behaviors under identical pH conditions. At pH 5.00, the recovery of Ce 7 O 12 was significantly higher than that of CePO 4 . The artificial mixed ore experiments resulted in a Ce 7 O 12 foam product with a REO grade of 70.74 % and a recovery of 96.39 %, and a monazite tank product with a REO grade of 49.46 % and a recovery of 75.52 %. Remarkably, these separations were achieved without the addition of any depressants. Mechanistic analysis revealed that after MPT treatment, more Ce 4+ was exposed on the Ce 7 O 12 surface, which competed with Ce 3+ for adsorption and preferentially underwent chemical adsorption with the oxime group (–C NOH) of BHA to form Ce-O chelate complexes. In contrast, the interaction between CePO 4 and BHA was weak, thereby enabling efficient flotation separation of Ce 7 O 12 and CePO 4 . Download: Download high-res image (289KB) Download: Download full-size image
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高影响因子
LANGMUIR
·
2025
·
IF 3.9
Weiwei Wang,Zhengyao Li,Mingxing Chen,Zuchao Pan,Zhenyu Wang,Zhenyuan Zhou,Chang Zhang,Jiming Zhang,Weiyao Zhu
This study systematically investigates the crystal properties of bastnaesite and the adsorption mechanisms of salicylhydroxamic acid (SHA) and 2-hydroxy-3-naphthyl hydroxamic acid (2-H-3-NHA) onto the bastnaesite (100) surface using density functional theory (DFT) calculations. Computational results indicate that bastnaesite cleavage primarily occurs along Ce–O and Ce–F ionic bonds during dissociation, with the {100} plane identified as the most preferential cleavage direction due to its lowest surface energy. The chemical reactivity and adsorption behaviors of both collectors were thoroughly examined with adsorption energy calculations quantifying their surface affinity. Comparative analysis reveals that 2-H-3-NHA demonstrates significantly greater adsorption stability and chemical reactivity than SHA. This enhanced performance is attributed to the naphthalene ring’s superior steric hindrance effect and the presence of longer carbon chains compared to the benzene ring in SHA. These findings are consistent with results from the pure mineral flotation tests. Collectively, this work provides an atomic-level understanding of hydroxamic acid collector interactions with bastnaesite surfaces, offering valuable guidance for designing high-performance rare earth mineral flotation reagents.
研究领域:
矿物加工工程
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计算材料学
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表面科学
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资源与环境科学
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冶金物理化学
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PubMed
高影响因子
Mineral Processing and Extractive Metallurgy Review
·
2023
·
IF 5
Xu Wu,Yiwen Hu,Sultan Ahmed Khoso,Zhao Cao
The large loss of fine-grained bastnaesite has become an increasingly important issue restricting the development of rare earth ore flotation industry. To solve this issue, a new collector mixture that combines octyl hydroxamic acid (OHA) and octyl phenol ethoxylation (OP10, the number of ethylene oxide groups is 10) is proposed to be used to improve the flotation of bastnaesite. The flotation adsorption mechanism of OHA/OP10 on bastnaesite was investigated by a series of experimental and analytical tests. The results showed that when the molar ratio of OHA/OP10 was 3:1, the OHA/OP10 combination significantly improved the recovery of −74 + 38 μm and −15 μm bastnaesite compared with only OHA. Optical microscopy revealed that mixed OHA/OP10 had a beneficial effect on fine-grained bastnaesite aggregation. In addition, the results of the zeta potential test, fluorescence spectrum analysis, and XPS analysis showed that OHA and OP10 were co-adsorbed on the surface of bastnaesite.
研究领域:
矿物加工工程
·
化学工程与技术
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高影响因子
JOURNAL OF RARE EARTHS
·
2026
·
IF 9.6
Yifan Wang,Yongsheng Sun,Qiang Zhang,Peng Gao,Jie Liu,Yuexin Han,Wenbo Li
The discovery of flotation collectors remains constrained by limited experimental data and continued reliance on empirical modification of known molecular structures. An AI-guided de novo molecular design framework was developed using only 36 reference collector structures and six bastnaesite-fluorite separation experiments. The framework integrates mechanism-informed molecular generation, structural filtering, small-data prediction, and uncertainty-aware ranking. Candidate structures were generated and screened computationally, and 4-( N , N -dipropylamino)benzohydroxamic acid (DPABHA) was selected for synthesis and experimental validation. The framework generates 121 candidate collectors, of which 90 satisfy the predefined screening criteria, and DPABHA ranks seventh among the retained candidates. Under the optimized mixed-mineral flotation conditions of pH=8.0 and a DPABHA dosage of 2.0 × 10 −5 mol/L, DPABHA achieves a bastnaesite recovery of 92.43%, limits fluorite recovery to 14.75%, and produces a concentrate with a rare-earth oxide (REO) grade of 61.59 wt%. Interfacial analyses and theoretical calculations consistently show preferential adsorption and stronger hydrophobic modification of DPABHA on bastnaesite than on fluorite. These findings demonstrate that mechanism-informed small-data learning provides a practical route for de novo flotation collector discovery under severe data scarcity.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Mingyang Liu,Dan Zou,Donghai Yu,Shaoji Xiang,Yuefeng Deng,Ji Chen,Jichang Xiao
Cyanex923 (a mixture of four trialkyl (hexyl and octyl) phosphine oxides) has been extensively employed in the recovery of cerium (Ce(IV)) and fluorine (F), as well as the separation over thorium (Th(IV)) from bastnaesite. However, rigorous production conditions and involvement of highly toxic raw materials (PH 3 ) have been critical problems to be solved during the synthesis of Cyanex923. Meanwhile, its extraction performance remains to be improved. Therefore, we attempted to adjust the feed ratio to increase the proportion of short carbon chain components, successfully synthesized a novel extractant (P113, a mixture of four trialkyl (hexyl and octyl) phosphine oxides) with contents of each component different from Cyanex923 using an environmentally benign method. The comparison with Cyanex923 revealed obvious improvement of P113 in terms of extraction efficiency, selectivity and saturation capacity. The extraction efficiency and saturation capacity of Ce(IV) were increased by 10% and 10 g L -1 , respectively. Separation factor of Ce(IV)/Th(IV) was increased from 16 to 27 at 2 mol L -1 H 2 SO 4 . Furthermore, P113 presented excellent regenerability. The superiority of P113 was theoretically explored using the density functional theory (DFT) and polarizable continuum model (PCM), and the results indicated that THPO (trihexyl phosphine oxide) had lower extraction phase transfer energy than TOPO (trioctyl phosphine oxide) from aqueous phase to organic phase. The comprehensive evaluation of P113 demonstrated the feasibility employed in the recovery of Ce(IV)-F and the separation of Th(IV) from bastnaesite, which advanced industrial application of the novel extractant, and held significant value for the utilization of resources and environmental protection.
研究领域:
化学工程
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环境科学
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材料科学
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高影响因子
MINERALS ENGINEERING
·
2026
·
IF 6
Yonglun Wang,Wengang Liu,Wenbao Liu,Zongxu Li,Ruiqi Ge,Qing Jia
Hydroxyl positional isomerism significantly regulates the flotation selectivity of cinnamohydroxamic acid. • Ortho substitution induces steric hindrance and conformational constraint, reducing non-selective adsorption on Ca minerals. • DFT results reveal steric–electronic coupling as the key mechanism governing selective metal ion recognition. The molecular structure of hydroxamic acid collectors strongly affects their flotation selectivity for rare earth minerals. In this study, two hydroxyl positional isomers, p-hydroxycinnamohydroxamic acid (pHCHA) and o-hydroxycinnamohydroxamic acid (oHCHA), were synthesized and used for the flotation separation of bastnaesite from calcium-bearing gangue minerals. Single-mineral flotation, artificial mixed-mineral flotation, adsorption amount measurements, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and quantum chemical calculations were combined to clarify the effect of hydroxyl substitution position on collector adsorption and flotation behavior. Both pHCHA and oHCHA showed effective collecting ability toward bastnaesite, with recoveries of 84.33 % and 82.46 %, respectively. However, oHCHA exhibited much lower recoveries for fluorite and calcite, decreasing to 49.33 % and 10.86 %, respectively, indicating improved relative selectivity. Adsorption amount measurements showed that oHCHA retained appreciable adsorption on bastnaesite but adsorbed less on fluorite and calcite than pHCHA. XPS and AFM results further confirmed that oHCHA produced weaker surface interaction and lower surface coverage on calcium-bearing minerals. Quantum chemical calculations revealed that ortho -hydroxyl substitution changed the electronic distribution and molecular conformation near the active region, reducing its accessibility during interaction with calcium-bearing mineral surfaces. These results indicate that hydroxyl positional isomerism regulates collector selectivity mainly by weakening non-selective adsorption on fluorite and calcite while maintaining effective adsorption on bastnaesite. Download: Download high-res image (191KB) Download: Download full-size image
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高影响因子
APPLIED SURFACE SCIENCE
·
2026
·
IF 6.6
Yonglun Wang,Wengang Liu,Wenbao Liu,Ruiqi Ge,Qing Jia
First combined application of DFT calculations and RDKit-based analysis for the structure–activity relationship study of BHA derivatives in bastnaesite flotation. • 3OMeBHA achieves 49.06% selectivity index, outperforming BHA and industrial H205 in mixed-ore tests. • Selectivity governed by ΔE (R = − 0.90); gangue adsorption correlated with I min (0.92) and V max (0.87). The limited selectivity of benzohydroxamic acid (BHA) between rare-earth and calcium-bearing minerals remains a challenge due to their similar surface active sites. In this study, a series of BHA derivatives were synthesized via substituent modification to optimize their electronic and spatial configurations. Among these, the meta -methoxy derivative (3OMeBHA) exhibited superior selectivity, achieving a selectivity index of 49.06% and outperforming the industrial collector H205 in actual ore tests. Integrating flotation experiments with RDKit-based molecular descriptors and density functional theory (DFT), we elucidated the structure–activity relationships. Correlation analysis revealed that calcite recovery is primarily governed by the minimum average local ionization energy and maximum electrostatic potential, while the selectivity index strongly correlates with the energy gap. DFT results indicate that 3OMeBHA’s higher-lying highest occupied molecular orbital (HOMO) and delocalized orbitals promote specific coordination with Ce 3+ on bastnaesite while suppressing non-selective interactions with Ca 2+ on gangue minerals. This work provides a high-performance collector for bastnaesite flotation and clarifies the electronic mechanisms of substituent effects on mineral-collector interactions. Download: Download high-res image (202KB) Download: Download full-size image
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高影响因子
Minerals
·
2024
·Vol. 14
·期 9
·870
·
IF 2.2
Jieliang Wang,Wenda Lu,Zhao Cao,Xu Wu,Peng Wang,Xiaoping Wang,Wenli Liu
The surface properties of bastnaesite and parisite are similar to their associated gangue mineral, fluorite, which makes the flotation separation of these two rare earth minerals from fluorite one of the industry’s most significant challenges. This study systematically investigates the inhibitory effects and mechanisms of sodium silicate (SS) on bastnaesite, parisite, and fluorite in an octyl hydroxamic acid (OHA) collector system through flotation experiments, various modern analytical methods, and DFT simulations. The flotation test results indicate that the inhibition effects of SS on the three minerals are in the order: fluorite > parisite > bastnaesite. Detection and analysis results indicate that SS forms hydrophilic complexes with Ca atoms on the surfaces of fluorite and parisite, enhancing surface hydrophilicity and inhibiting OHA adsorption, but its impact on bastnaesite is relatively minor. DFT simulation results show that OHA forms covalent bonds with metal ions on mineral surfaces, favoring five-membered hydroxamic-(O-O)-Ce/Ca complexes, and reacts more strongly with Ce atoms than Ca atoms. SS primarily forms covalent bonds with metal atoms on mineral surfaces via the SiO(OH)3−component, and OHA and SS compete for adsorption on the mineral surfaces. OHA has a stronger affinity for bastnaesite, whereas SS shows the highest affinity for fluorite, followed by parisite, and the weakest affinity for bastnaesite.
研究领域:
矿物加工工程
·
计算化学
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高影响因子
MINERALS ENGINEERING
·
2023
·
IF 4.8
Yan Wang,Donghui Wang,Longhua Xu,Kai Xue,Xi Zhang,Xinzhang Shi,Chang Liu,Jinping Meng
Hydroxamic acid collectors display excellent selectivity but poor collecting ability in bastnaesite flotation . Improving the collecting capacity of hydroxamic acid collector appropriately become an effective method to enhance the performance of flotation reagents. A novel oleate hydroxamic acid (OLHA) as a collector was synthesized and applied to bastnaesite flotation in this work. The structure of OLHA was characterized by Fourier transform infrared spectrometry (FTIR) and nuclear magnetic resonance spectroscopy (NMR). The single mineral and artificial mixed minerals flotation experiments results show that OLHA achieved efficient flotation separation of bastnaesite and barite when odium hexametaphosphate (SHMP) was used as depressant. The contact angle, zeta potential, FTIR and X-ray Photoelectron Spectroscopy (XPS) measurements were performed to investigate the adsorption mechanism of OLHA. The contact angle results show that OLHA significantly improved the surface hydrophobicity of bastnaesite. Zeta potential and FTIR results show that in the presence of SHMP, OLHA selectively adsorbs to the surface of bastnaesite. Over all, OLHA adsorbs on the surface of bastnaesite through chemically adsorption, and strengthen the hydrophobicity of bastnaesite surface. Therefore, OLHA is a promising collector for bastnaesite flotation.
研究领域:
矿物加工工程
·
化学工程
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Jieliang Wang,Xianbo Fang,Zhao Cao,Wenqiang Zhu,Jianguo Cui,Qizheng Qin,Peng Wang,Aiqing Wang,Burdonov Alexander Evgenievich
In this study, ultrasonic treatment was introduced to improve the activation of octyl hydroxamic acid (OHA) as a collector, enhancing the flotation of bastnaesite. The mechanism of OHA activation by ultrasonic treatment and its role in strengthening adsorption of octyl hydroxamic acid on bastnaesite surface were investigated via flotation experiments combined with solution chemistry calculations, conductivity tests, bubble-particle wrap angle (BPWA), atomic force microscopy (AFM), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), and molecular dynamics simulations (MDS). Solution chemistry calculations and conductivity measurements indicated that ultrasonic treatment enhanced the dissociation of OHA molecules significantly, generating more active OHA − anions and thereby improving OHA activation. The increased BPWA confirm enhanced the adhesion of bastnaesite to bubbles following OHA adsorption. AFM and SEM-EDS analysis showed that the adsorption amount of OHA on the surface of bastnaesite increased after ultrasonic treatment. XPS analysis demonstrated that the chemical adsorption of ultrasonic-treated OHA on the bastnaesite surface is enhanced, which improves the hydrophobicity and flotation performance of bastnaesite. This also confirmed that ultrasonic-treated OHA produced more active OHA − anions. MD simulations indicated that as the proportion of OHA − increased, the adsorption and spreading ability of OHA collector clusters on the bastnaesite surface were enhanced, repelling water molecules from the bastnaesite surface. Consequently, the hydrophobicity of the bastnaesite surface increased, further strengthening its flotation performance.
研究领域:
矿物加工工程
·
表面化学
·
浮选化学
·
计算材料科学
·
资源与环境科学
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2026
·
IF 5.4
Ruiqi Ge,Wenbao Liu,Haiyan Feng,Xinglong Xu,Yonglun Wang,Sikai Zhao,Wengang Liu,Yanbai Shen
The efficient flotation separation of bastnaesite from chemically similar calcium-bearing gangue minerals, such as fluorite and calcite, remains a formidable challenge. In this study, N-phosphonomethyl-N-carboxymethyl sulfamic acid (CPMS), a multi-group synergistic depressant, was designed and synthesized for selective bastnaesite flotation. Single mineral flotation tests showed that CPMS strongly depressed fluorite and calcite over pH 7–11 while maintaining bastnaesite recovery above 90%. In the artificial ternary system, a concentrate containing 23.21% Ce was obtained at pH 9.12 with a Ce recovery of 91.25%. Contact angle and zeta potential analyses revealed that CPMS preferentially altered the wettability and electrokinetic response of fluorite and calcite. XPS results supported the involvement of phosphonate and carboxylate groups in interactions with surface Ca sites, whereas the sulfonate group was inferred to contribute mainly to interfacial hydration. DFT calculations predicted much more negative adsorption energies for CPMS on fluorite and calcite than on bastnaesite. Electronic structure analysis further indicated predominantly covalent P-O-Ca interactions and mainly electrostatic C-O-Ca interactions. These results support CPMS as a selective depressant for bastnaesite systems and provide a functional-group design strategy for calcium-bearing gangue depression. Download: Download high-res image (225KB) Download: Download full-size image
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高影响因子
Journal of Environmental Chemical Engineering
·
2026
·Vol. 14
·期 1
·120898
·
IF 7.2
Jing Wang,Guangxi Wang,Xiaoyan Ji,Zhiwen Chang,Yu Wang,Wenguang Chen,Leilei Zhang,Shuwen An,Yi Gu,Jun Liu
The mining, processing, and refining of rare-earth ores generate Th-rich radioactive wastewater, making its effective treatment critical for environmental protection and public health. In this study, mesoporous MoX 2 -α-ZrP (X = S, Se) composite powders were synthesized for Th(IV) adsorption from aqueous solutions. Under the conditions of [Th(IV)] initial = 50 ± 2 mg·L −1 , pH initial = 3, temperature = 298 K, and a contact time = 1440 min, the larger pore volume and pore width of the composites, compared with α-ZrP, enhanced the adsorption capacity ( q e ) of MoSe 2 -α-ZrP and MoS 2 -α-ZrP to 146.3 ± 7.4 mg·g −1 and 143.7 ± 2.5 mg·g −1 , respectively. Higher pH, [Th(IV)] initial, and temperature further enhanced Th(IV) adsorption. Notably, MoX 2 -α-ZrP removed Th(IV) from simulated leaching solution of monazite or bastnaesite and selectively adsorbed Th(IV) in the presence of co-existing ions. Thermodynamic and kinetic analyses confirmed a spontaneous, endothermic, and homogeneous chemisorption behavior. The Thomas and Yoon-Nelson models accurately described dynamic column Th(IV) adsorption, and increases in adsorbent mass, together with decreases in influent Th(IV) concentration, and reduced flow rate extended both breakthrough and saturation times. Mechanistic studies revealed Th(IV) coordination with oxygen-containing groups, ion exchange with -OH, and electrostatic interaction with phosphate groups. Results from our study can help explore the adsorption behaviors and mechanisms of Th(IV) on potential MoX 2 (X = O, S, Se)-based or α-ZrP-based materials for treating Th-rich radioactive wastewater.
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高影响因子
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