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Zhang L, Jiao F, Qin W, Wei Q. New Insight into Elastic Mechanical Properties and Anisotropies of Crystal Defect α-Quartz from DFT Calculation. ACS OMEGA 2023; 8:43644-43650. [PMID: 38027338 PMCID: PMC10666211 DOI: 10.1021/acsomega.3c05173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 10/11/2023] [Accepted: 10/13/2023] [Indexed: 12/01/2023]
Abstract
To reveal the cleavage mechanism of α-quartz in the grinding process of nonferrous metal ores, mechanical and charge properties of α-quartz crystals are investigated using the density functional theory. Based on the elastic constant matrix, the bulk and shear moduli were calculated before and after the α-quartz with oxygen atom defects. The results show that the ratios of bulk and shear moduli (B/G) were 0.87 and 0.95, respectively, which indicated that at the same stress level, it was easier to fracture without O-vacancy defects than with O-vacancy defects. The mapping surfaces indicated that the O-vacancy defect increased the bulk-, shear-, and Young's moduli, and Poisson ratio while decreasing the hardness. The anisotropy index (AL and AU) was calculated which illustrated that the O-vacancy can result in an increased anisotropy; meanwhile, the bulk anisotropy index (AB) increased strongly about two times. The anisotropy analysis shows the dominance crystal cleavage of the (011) plane in the shear stress and the dominance crystal cleavage of the (111) plane in the normal stress. The electron localization function α-quartz show that the O-vacancy defect can decrease the Si-Si length from 3.703 to 2.442 Å, which indicated that the O-vacancy formed the new covalent bonds between silicon atoms. Our work provided a systematic approach containing the mechanical, anisotropic, and electronic properties of mineral crystals to explain the cleavage behavior of crystals.
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Affiliation(s)
- Lin Zhang
- School of Minerals Processing
and Bioengineering, Central South University, Changsha 410083, China
| | - Fen Jiao
- School of Minerals Processing
and Bioengineering, Central South University, Changsha 410083, China
| | - Wenqing Qin
- School of Minerals Processing
and Bioengineering, Central South University, Changsha 410083, China
| | - Qian Wei
- School of Minerals Processing
and Bioengineering, Central South University, Changsha 410083, China
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2
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Yang Y, Liu J, Zhu M, Dou S, Ding L. Adsorption of glycine at the anatase TiO 2/water interface: Effects of Ca 2+ ions. J Environ Sci (China) 2023; 128:26-34. [PMID: 36801039 DOI: 10.1016/j.jes.2022.08.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 08/05/2022] [Accepted: 08/10/2022] [Indexed: 06/18/2023]
Abstract
Adsorption reactions of amino acids (AAs) on TiO2 nanoparticles (NPs) play an important role in the available nutrients in soils and sediments. The pH effects on glycine adsorption have been studied, but little is known about its coadsorption with Ca2+ at the molecular level. Combined attenuated total reflectance Fourier transform infrared (ATR-FTIR) flow-cell measurements and density functional theory (DFT) calculations were used to determine the surface complex and corresponding dynamic adsorption/desorption processes. The structures of glycine adsorbed onto TiO2 were closely associated with its dissolved species in the solution phase. The presence of Ca2+ exerted different influences on glycine adsorption within pH 4-11, thus affecting its migration rate in soils and sediments. The mononuclear bidentate complex at pH 4-7, involving the COO- moiety of zwitterionic glycine, remained unchanged in the absence and presence of Ca2+. At pH 11, the mononuclear bidentate complex with deprotonated NH2 can be removed from the TiO2 surface upon coadsorption with Ca2+. The bonding strength of glycine on TiO2 was much weaker than that of the Ca-bridged ternary surface complexation. Glycine adsorption was inhibited at pH 4 but was enhanced at pH 7 and 11.
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Affiliation(s)
- Yanli Yang
- School of Public Health, Cheeloo College of Medicine, Shandong University, China.
| | - Jiaqi Liu
- School of Public Health, Cheeloo College of Medicine, Shandong University, China
| | - Mengyao Zhu
- School of Public Health, Cheeloo College of Medicine, Shandong University, China
| | - Shengping Dou
- School of Public Health, Cheeloo College of Medicine, Shandong University, China
| | - Lei Ding
- Environment Research Institute, Shandong University, Qingdao 266237, China
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3
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Jiang H, Bu J, Bian K, Su J, Wang Z, Sun H, Wang H, Zhang Y, Wang C. Surface change of microplastics in aquatic environment and the removal by froth flotation assisted with cationic and anionic surfactants. WATER RESEARCH 2023; 233:119794. [PMID: 36868113 DOI: 10.1016/j.watres.2023.119794] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 01/29/2023] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Microplastics (MPs) are increasingly released into the environment due to the widespread usage and improper management of plastics. Considerable research efforts have been devoted to the remediation of MPs. Froth flotation has been demonstrated as an effective method to remove MPs in water and sediment. However, there is a lack of knowledge on the regulation of the hydrophobicity/hydrophilicity of MPs surfaces. We found that exposure to the natural environment resulted in the increased hydrophilicity of MPs. The flotation efficiencies of polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), and polyethylene glycol terephthalate (PET) MPs decreased to zero after six months of natural incubation in rivers. According to various characterizations, the hydrophilization mechanism is mainly correlated with surface oxidation and the deposition of clay minerals. Inspired by surface wettability conversion, we applied surfactants (collectors) to enhance MPs hydrophobicity and flotation efficiency. Anionic sodium oleate (NaOL) and cationic dodecyl trimethyl ammonium chloride (DTAC) were used to regulate surface hydrophobicity. The effects of collector concentration, pH, conditioning time, and metal ions on MPs flotation were thoroughly elucidated. Characterizations and adsorption experiments were performed to describe the heterogeneous adsorption of surfactants on MPs surfaces. The interaction between surfactants and MPs was explained through density functional theory (DFT) simulations. The dispersion energy between hydrophobic hydrocarbon chains attracts collectors on the MPs surface, and the collector molecules wrap and laminate to MPs surfaces. Flotation using NaOL exhibited a higher removal efficiency, and NaOL was environmentally friendly. Subsequently, we investigated the activation of Ca2+, Fe3+, and Al3+ to further improve the collecting efficiency of NaOL. Under the optimized conditions, MPs in natural rivers could be removed by froth flotation. This study shows the great promise of froth flotation for the application of MPs removal.
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Affiliation(s)
- Hongru Jiang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, PR China
| | - Jiaqi Bu
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, PR China
| | - Kai Bian
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, PR China
| | - Jiming Su
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, PR China
| | - Zhiyi Wang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, PR China
| | - Han Sun
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, PR China
| | - Hui Wang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, PR China.
| | - Yingshuang Zhang
- School of Chemical Engineering and Technology, Xinjiang University, 830017 Urumqi, Xinjiang, PR China.
| | - Chongqing Wang
- School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, PR China
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4
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Miao Y, Wen S, Zuo Q, Shen Z, Zhang Q, Feng Q. Co-adsorption of NaOL/SHA composite collectors on cassiterite surfaces and its effect on surface hydrophobicity and floatability. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2022.122954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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5
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Nie S, Guo Z, Tian M, Sun W. Selective flotation separation of cassiterite and calcite through using cinnamohydroxamic acid as the collector and Pb2+ as the activator. Colloids Surf A Physicochem Eng Asp 2023. [DOI: 10.1016/j.colsurfa.2023.131262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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6
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Zhang H, Sun W, Chen D, Lin S, Zhang C. Effects of Interfacial Hydroxylation Microstructure on Quartz Flotation by Sodium Oleate. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:2182-2191. [PMID: 36716219 DOI: 10.1021/acs.langmuir.2c02651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Quartz, a common inorganic nonmetallic mineral, is usually removed or purified by beneficiation, normally flotation. Given the strong polarity of the quartz surface, it is easy to hydrate to form a hydroxylation layer, which makes it impossible to float quartz with sodium oleate (OL) used alone. An ideal flotation method for quartz is preactivation with Ca2+, followed by collection with OL. Herein, the effects of surface hydroxylation on the adsorption of the anionic collector OL on the quartz surface before and after Ca2+ activation are systematically investigated by density functional theory (DFT) calculations. The results show that the displacement adsorption of surface hydroxyl substituted by OL- is not feasible in thermodynamics, and the OL- can only bind to the H atoms of the hydroxylated quartz surface via hydrogen bonds, namely, hydrogen binding adsorption. Due to the electrostatic repulsion and steric hindrance effect induced by the surface hydroxylation structure, the adsorption ability of OL- on the quartz surface mediated by hydroxyl bridges is very weak, which is insufficient to realize quartz floating. However, Ca2+ ions are easily adsorbed on the hydroxylated quartz surface, providing favorable active sites for subsequent adsorption of OL-, thus becoming a credible solution for the industrial flotation of the strong hydrophilic mineral quartz. These findings shed some new insights for accurately understanding the flotation mechanism of strongly hydrophilic oxide minerals and are beneficial to promoting the development of mineral flotation fundamentals.
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Affiliation(s)
- Hongliang Zhang
- School of Minerals Processing and Bioengineering, Central South University, Changsha410083, China
| | - Wei Sun
- School of Minerals Processing and Bioengineering, Central South University, Changsha410083, China
| | - Daixiong Chen
- Hunan Provincial Key Laboratory of Complex Copper Lead Zinc Associated Metal Resources Comprehensive Utilization, Hunan Research Institute for Nonferrous Metals, Changsha410100, China
| | - Shangyong Lin
- School of Minerals Processing and Bioengineering, Central South University, Changsha410083, China
| | - Chenyang Zhang
- School of Minerals Processing and Bioengineering, Central South University, Changsha410083, China
- Hunan Provincial Key Laboratory of Complex Copper Lead Zinc Associated Metal Resources Comprehensive Utilization, Hunan Research Institute for Nonferrous Metals, Changsha410100, China
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming650093, China
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7
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Stenina I, Yurova P, Achoh A, Zabolotsky V, Wu L, Yaroslavtsev A. Improvement of Selectivity of RALEX-CM Membranes via Modification by Ceria with a Functionalized Surface. Polymers (Basel) 2023; 15:polym15030647. [PMID: 36771946 PMCID: PMC9919321 DOI: 10.3390/polym15030647] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/23/2023] [Accepted: 01/25/2023] [Indexed: 01/28/2023] Open
Abstract
Ion exchange membranes are widely used for water treatment and ion separation by electrodialysis. One of the ways to increase the efficiency of industrial membranes is their modification with various dopants. To improve the membrane permselectivity, a simple strategy of the membrane surface modification was proposed. Heterogeneous RALEX-CM membranes were surface-modified by ceria with a phosphate-functionalized surface. Despite a decrease in ionic conductivity of the prepared composite membranes, their cation transport numbers slightly increase. Moreover, the modified membranes show a threefold increase in Ca2+/Na+ permselectivity (from 2.1 to 6.1) at low current densities.
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Affiliation(s)
- Irina Stenina
- Kurnakov Institute of General and Inorganic Chemistry RAS, Leninsky Prospect 31, 119991 Moscow, Russia
| | - Polina Yurova
- Kurnakov Institute of General and Inorganic Chemistry RAS, Leninsky Prospect 31, 119991 Moscow, Russia
| | - Aslan Achoh
- Faculty of Chemistry and High Technologies, Kuban State University, 350040 Krasnodar, Russia
| | - Victor Zabolotsky
- Faculty of Chemistry and High Technologies, Kuban State University, 350040 Krasnodar, Russia
| | - Liang Wu
- School of Chemistry and Material Science, University of Science and Technology of China, Hefei 230026, China
| | - Andrey Yaroslavtsev
- Kurnakov Institute of General and Inorganic Chemistry RAS, Leninsky Prospect 31, 119991 Moscow, Russia
- Correspondence:
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8
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Study on the influence of particle size on the flotation separation of kaolinite and quartz. POWDER TECHNOL 2022. [DOI: 10.1016/j.powtec.2022.117747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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9
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Combined inhibitors of Fe3+, Cu2+ or Al3+ and sodium silicate on the flotation of fluorite and quartz. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.128702] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Wang L, Wang G, Ge P, Sun W, Tang H, Hu W. Activation mechanisms of quartz flotation with calcium ions and cationic/anionic mixed collectors under alkalescent conditions. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2021.127771] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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11
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Zhang X, Deng J, Huangfu M, Wang Y, Wu B, Li S, Pang Z, Mei H. Novel insights into the influence of ferric ion as a surface modifier to enhance the floatability of specularite. POWDER TECHNOL 2022. [DOI: 10.1016/j.powtec.2022.117141] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Mweene L, Khanal GP, Nambaje C. Experimental study on the separation of quartz from pyrite using alginate as a selective depressant substantiated by theoretical analysis on intermolecular bonding. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.119251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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13
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Aarab I, Derqaoui M, El Amari K, Yaacoubi A, Abidi A, Etahiri A, Baçaoui A. Influence of surface dissolution on reagents’ adsorption on low-grade phosphate ore and its flotation selectivity. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.127700] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Surface characteristics and flotation behaviours of specularite as influenced by lead ion modification. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.119384] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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Gao J, Sun W, Lyu F. Understanding the activation mechanism of Ca2+ ion in sodium oleate flotation of spodumene: A new perspective. Chem Eng Sci 2021. [DOI: 10.1016/j.ces.2021.116742] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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16
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Selective adsorption of Na2ATP as an eco-friendly depressant on the calcite surface for effective flotation separation of cassiterite from calcite. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.126899] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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17
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Hou Y, Sobhy A. New Insights on Sodium Oleate Adsorption on Quartz for Iron Direct Flotation under Weak-Acidic Condition. TENSIDE SURFACT DET 2021. [DOI: 10.1515/tsd-2020-2342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
To study the sodium oleate (NaOL) adsorption on quartz and its effect on flotation under weak-acidic conditions, the adsorption characteristics of NaOL on the surface of quartz were determined at pH = 6.5 by Fourier transform infrared spectroscopy (FTIR). The solution chemical calculation results show that NaOL exists as oleic acid (HOL) under weakly acidic conditions. The existence form and charge distribution of quartz and HOL were analyzed by Molecular Dynamics Simulation (MDS) using Materials Studio (MS) software, and the results showed that HOL is prone to the (101) and (100) surfaces of quartz under weak-acidic conditions by hydrogen bonding. The flotation verification test with NaOL as a collector was also performed under weak-acidic conditions. The flotation test led to a partial flotation of quartz into the froth products, reducing the grade of hematite direct flotation concentrate, which is consistent with industrial production.
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Affiliation(s)
- Ying Hou
- School of Mining Engineering, University of Science and Technology Liaoning , Anshan 114051 , China
| | - Ahmed Sobhy
- School of Resources and Environmental Engineering, Shandong University of Technology , Zibo , 255049 , China
- Minerals Technology Department, Central Metallurgical R&D Institute , Helwan , Cairo, 11421 , Egypt
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18
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The Flotation Separation of Magnesite and Limonite Using an Amine Collector. ADSORPT SCI TECHNOL 2021. [DOI: 10.1155/2021/5534274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
In order to reduce the iron impurities in magnesite ore and improve the purity of magnesium products, the difference in floatability between magnesite and limonite has been studied by using mixtures with a collecting agent—KD (cationic amine collectors, containing soluble components). Sodium hexametaphosphate, pH, sodium silicate, and sodium carboxymethyl cellulose were used as regulators. Adsorption mechanisms of the reagents on minerals were analyzed by a zeta potential analyzer and infrared spectroscopy. Sodium silicate increased the floatability of both minerals at 11.6. All the three regulators reduced the zeta potential of both minerals, while KD increased the zeta potential of magnesite and decreased the zeta potential of limonite. All the three regulators were likely chemically adsorbed on the surface of both minerals; KD has electrostatic adsorption on the surface of the minerals.
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20
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Gong G, Liu J, Han Y, Zhu Y. Experimental and density functional theory studies of the effects and mechanisms of Cu2+ on flotation separation of cassiterite from fluorite. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.114907] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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21
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Selective separation of hematite from quartz with sodium oleate collector and calcium lignosulphonate depressant. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.114502] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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22
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Lv L, Wang X, Ren H, Liu J, Zhu Y. Depressing behaviors and mechanism of an eco-friendly depressant on flotation separation of cassiterite and fluorite. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.114898] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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23
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Selective adsorption of a new depressant Na2ATP on dolomite: Implications for effective separation of magnesite from dolomite via froth flotation. Sep Purif Technol 2020. [DOI: 10.1016/j.seppur.2020.117278] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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24
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Enhanced biosorption of Cr(VI) from synthetic wastewater using algal-bacterial aerobic granular sludge: Batch experiments, kinetics and mechanisms. Sep Purif Technol 2020. [DOI: 10.1016/j.seppur.2020.117323] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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25
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26
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Zeng G, Ou L, Zhang W, Zhu Y. Effects of Sodium Alginate on the Flotation Separation of Molybdenite From Chalcopyrite Using Kerosene as Collector. Front Chem 2020; 8:242. [PMID: 32411654 PMCID: PMC7199513 DOI: 10.3389/fchem.2020.00242] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 03/13/2020] [Indexed: 01/27/2023] Open
Abstract
In this paper, the effect of sodium alginate (SA) on the flotation separation of molybdenite (MoS2) from chalcopyrite using kerosene as collector was systematically investigated. The results of single-mineral micro-flotation tests indicated that SA exhibited strong depression on chalcopyrite flotation while it imposed no impact on the floatability of molybdenite. However, in the chalcopyrite–molybdenite mixed-mineral flotation system, the presence of chalcopyrite significantly increased the depressing effect of SA on molybdenite flotation, leading to a considerable reduction in the flotation selectivity. The negative impact of chalcopyrite on the performance of SA in molybdenite flotation was eliminated by adding a certain dosage of kerosene prior to SA. A concentrate containing 53.43% of molybdenum (Mo) was obtained at 76.90% of recovery using 19 mg/L kerosene and 40 mg/L SA at pH 5.4. Zeta potential measurements indicated that the adsorption of SA on chalcopyrite surfaces was stronger than that on molybdenite surfaces, which agreed with the single-mineral flotation test results. The adsorption of SA on chalcopyrite was further confirmed to be chemisorption by Fourier-transform infrared spectroscopy (FTIR) spectra analyses. When Cu2+ appeared in solution, the flotation of molybdenite was strongly depressed by SA. Mechanism analyses indicated that more active sites were generated on molybdenite surfaces after the addition of Cu2+, thus promoting the adsorption of SA.
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Affiliation(s)
- Guangsheng Zeng
- College of Chemistry and Chemical Engineering, Central South University, Changsha, China
| | - Leming Ou
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China
| | - Wencai Zhang
- Department of Mining and Minerals Engineering, Virginia Polytechnic and State University, Blacksburg, VA, United States
| | - Yuteng Zhu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China
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27
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Liu W, Liu W, Zhao Q, Shen Y, Wang X, Wang B, Peng X. Design and flotation performance of a novel hydroxy polyamine surfactant based on hematite reverse flotation desilication system. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2019.112428] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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28
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Zeng X, Du Z, Ding X, Jiang W. Characterization of the direct interaction between apple condensed tannins and cholesterol in vitro. Food Chem 2019; 309:125762. [PMID: 31670123 DOI: 10.1016/j.foodchem.2019.125762] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 10/17/2019] [Accepted: 10/20/2019] [Indexed: 11/15/2022]
Abstract
To provide the scientific evidences for a possible new hypocholesterolemic mechanism of apple condensed tannins (ACT), the direct interaction of ACT with cholesterol (CH) was investigated in the present study. Our results suggested that the quenching of ACT fluorescence by CH was carried out according to a static mechanism, while the interaction between ACT and CH in vitro was a spontaneous process. ACT were capable of binding with CH directly, and the CH-binding capacity (35.9-43.9%) of ACT remarkably enhanced with the increase of ACT concentration (0.5-2.0 mg proanthocyanidin B2 equivalent/mL). Besides, spectroscopic methods and morphological analysis were used to characterize the ACT-CH coprecipitates, the findings indicated that ACT were able to precipitate CH via ionic interactions, hydrophobic interactions and intermolecular hydrogen bonds rather than covalent bonds. In conclusion, the direct interaction of ACT with CH might play a role in their CH-lowering effects in humans and animals.
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Affiliation(s)
- Xiangquan Zeng
- College of Food Science and Nutritional Engineering, China Agricultural University, P.O. Box 111, Qinghua Donglu No. 17, Beijing 100083, PR China.
| | - Zhenjiao Du
- College of Food Science and Nutritional Engineering, China Agricultural University, P.O. Box 111, Qinghua Donglu No. 17, Beijing 100083, PR China.
| | - Xiaomeng Ding
- College of Food Science and Nutritional Engineering, China Agricultural University, P.O. Box 111, Qinghua Donglu No. 17, Beijing 100083, PR China.
| | - Weibo Jiang
- College of Food Science and Nutritional Engineering, China Agricultural University, P.O. Box 111, Qinghua Donglu No. 17, Beijing 100083, PR China.
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29
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Zhang Z, Cao Y, Ma Z, Liao Y. Impact of calcium and gypsum on separation of scheelite from fluorite using sodium silicate as depressant. Sep Purif Technol 2019. [DOI: 10.1016/j.seppur.2019.01.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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30
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Liu W, Li W, Han J, Wu D, Li Z, Gu K, Qin W. Preparation of calcium stannate from lead refining slag by alkaline leaching-purification-causticization process. Sep Purif Technol 2019. [DOI: 10.1016/j.seppur.2018.11.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Feng Q, Wen S, Zhao W, Chen H. Interaction mechanism of magnesium ions with cassiterite and quartz surfaces and its response to flotation separation. Sep Purif Technol 2018. [DOI: 10.1016/j.seppur.2018.06.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Effect of Al (III) Ions on the Separation of Cassiterite and Clinochlore Through Reverse Flotation. MINERALS 2018. [DOI: 10.3390/min8080347] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Most hydrophobic clay minerals, such as clinochlore, are known to cause problems in the recovery of cassiterite. In this study, a new reagent scheme, i.e., sodium oleate (NaOL) as a collector and Al (III) ions as a depressant, for reverse flotation separation of cassiterite and clinochlore was investigated. The flotation performance and interaction mechanism were studied by microflotation tests, adsorption tests, contact angle measurements, and X-ray photoelectron spectroscopy (XPS) analysis. Results of single mineral flotation experiments showed that NaOL had a different flotation performance on cassiterite and clinochlore, and the addition of Al (III) ions could selectively inhibit the floatability of cassiterite. Reverse flotation tests performed on mixed minerals indicated that the separation of cassiterite and clinochlore could be achieved in the presence of NaOL and Al (III) ions. Adsorption experiments demonstrated that Al (III) ions hindered the adsorption of NaOL on cassiterite surfaces but exerted little influence on the adsorption of NaOL on clinochlore surfaces. Results of contact angle measurements indicated that Al (III) ions could impede the hydrophobization process of cassiterite in NaOL solution. XPS results showed that aluminum species were adsorbed onto the cassiterite surfaces through the interaction with O sites.
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Selective Flotation of Cassiterite from Calcite with Salicylhydroxamic Acid Collector and Carboxymethyl Cellulose Depressant. MINERALS 2018. [DOI: 10.3390/min8080316] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cassiterite is the most common and important tin-bearing mineral, and calcite, a primary gangue mineral is generally found in tin deposit. The flotation separation of cassiterite from calcite remains a challenge due to their similar response to traditional reagents. In cassiterite flotation, sodium oleate (NaOL) and sodium silicate (SS) have been widely used as a collector and a depressant, respectively. However, the low selectivity of NaOL and the large amount of SS required (which leads to serious problems in wastewater treatment) remain a difficult issue. In this study, a novel reagent scheme using lead nitrate as the activator, salicylhydroxamic acid (SHA) as the collector and carboxymethyl cellulose as the depressant was employed to improve the separation selectivity of cassiterite from calcite. Results of the flotation experiment using this new reagent scheme showed that compared with the previously reported scheme using benzohydroxamic acid (BHA) as the collector, the separation of cassiterite from calcite exhibited a higher selectivity and selectivity index (SI). The mechanism of the selective separation was investigated by zeta potential measurements, Fourier transform infrared and X-ray photoelectron spectroscopy analysis.
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