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Lu X, Yang J, Ning XA, Shih K, Wang F, Chao Y. Formation of lead ferrites for immobilizing hazardous lead into iron-rich ceramic matrix. CHEMOSPHERE 2019; 214:239-249. [PMID: 30265931 DOI: 10.1016/j.chemosphere.2018.09.121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 09/14/2018] [Accepted: 09/19/2018] [Indexed: 06/08/2023]
Abstract
A strategy of immobilizing lead in the framework of ferrite-ceramic matrix, to reduce its environmental hazard was explored in this study. The mechanisms of incorporating lead into lead ferrites (δ-phase (2PbO·Fe2O3), γ-phase (PbO·(2-2.5)Fe2O3) and β-phase (PbO·(5-6)Fe2O3)) was revealed by observing the phase transformation in the products. The δ-phase was dominantly formed at low temperature of 700-800 °C at Pb/Fe of 1/1-1/3. The significant growth of γ-phase was observed at 750-850 °C and Pb/Fe of 1/4-1/7. The β-phase substantially formed at 900-1000 °C with Pb/Fe of 1/7-1/12. The transformation of δ-phase to γ-phase and/or β-phase indicated the destruction of δ-phase unit and reconstruction of γ-phase and β-phase units during sintering process. However, the transformation of γ-phase into β-phase suggested a structure conversion process, local structural changes arose as a consequence of the addition of Fe2O3. When comparing the leaching ability of δ-, γ- and β-phase, the results showed the superiority of β-phase for lead immobilization over the longer leaching period.
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Affiliation(s)
- Xingwen Lu
- School of Environmental Science and Engineering, and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou, 510275, China
| | - Jiani Yang
- School of Environmental Science and Engineering, and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Xun-An Ning
- School of Environmental Science and Engineering, and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Kaimin Shih
- Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Fei Wang
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China; Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
| | - Yuanqing Chao
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou, 510275, China
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Asiri S, Güner S, Demir A, Yildiz A, Manikandan A, Baykal A. Synthesis and Magnetic Characterization of Cu Substituted Barium Hexaferrites. J Inorg Organomet Polym Mater 2017. [DOI: 10.1007/s10904-017-0735-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Lu X, Ning XA, Lee PH, Shih K, Wang F, Zeng EY. Transformation of hazardous lead into lead ferrite ceramics: Crystal structures and their role in lead leaching. JOURNAL OF HAZARDOUS MATERIALS 2017; 336:139-145. [PMID: 28494301 DOI: 10.1016/j.jhazmat.2017.04.061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 04/24/2017] [Accepted: 04/26/2017] [Indexed: 06/07/2023]
Abstract
This study quantitatively determined the transformation of lead into lead ferrite ceramics and examined the influence of structural defects in lead ferrites (i.e. Pb2Fe2O5, PbFe4O7 and PbFe12O19) on lead leaching. Mechanisms of metal incorporation were examined from quantifying the phase compositions of lead ferrites in the products of sintering lead oxide with hematite. At low-temperature of 700°C, Pb was preferentially incorporated into the Pb2Fe2O5 crystals, and the incorporation efficiency ranged from 25.7 to 97.5% depending on different Pb/Fe molar ratios. By increasing temperatures to 750-850°C, Pb2Fe2O5 was subsequently reacted with hematite for the formation of PbFe4O7 and PbFe12O19 in Pb/Fe of 1/4 and 1/12 systems. PbFe12O19 was found to be the high-temperature (1000°C) stable phase for incorporating lead, and the incorporation efficiency ranged from 28.6 to 92.1% by different Pb/Fe molar ratios. Leaching tests demonstrated that PbFe12O19 was more resistant to acid attack than Pb2Fe2O5 and PbFe4O7. The crystal structural defects in Pb2Fe2O5 and PbFe4O7 were determined to be the factors influencing their intrinsic phase durability. On the other hand, PbFe12O19 was relatively free of structural defects and was found to be the preferred stabilization product to reduce the environmental hazard posed by lead.
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Affiliation(s)
- Xingwen Lu
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region, China
| | - Xun-An Ning
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Po-Heng Lee
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region, China
| | - Kaimin Shih
- Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region, China
| | - Fei Wang
- Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region, China; School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China.
| | - Eddy Y Zeng
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China
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Tan G, Wang W, Li W, Liu L. Multiferroic and magnetoelectric properties of La0.1Ba0.9Fe12O19 ceramics. CHINESE SCIENCE BULLETIN-CHINESE 2014. [DOI: 10.1007/s11434-014-0466-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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