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Received: 2008-01-16

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Journal of Zhejiang University SCIENCE A 2008 Vol.9 No.11 P.1595~1600


Microstructure of ferrospheres in fly ashes: SEM, EDX and ESEM analysis

Author(s):  Qing-feng XUE, Sheng-gao LU

Affiliation(s):  Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310027, China

Corresponding email(s):   lusg@zju.edu.cn

Key Words:  Fly ash, Ferrosphere, Microstructure, Scanning electron microscopy (SEM)

Qing-feng XUE, Sheng-gao LU. Microstructure of ferrospheres in fly ashes: SEM, EDX and ESEM analysis[J]. Journal of Zhejiang University Science A, 2008, 9(11): 1595~1600.

@article{title="Microstructure of ferrospheres in fly ashes: SEM, EDX and ESEM analysis",
author="Qing-feng XUE, Sheng-gao LU",
journal="Journal of Zhejiang University Science A",
publisher="Zhejiang University Press & Springer",

%0 Journal Article
%T Microstructure of ferrospheres in fly ashes: SEM, EDX and ESEM analysis
%A Qing-feng XUE
%A Sheng-gao LU
%J Journal of Zhejiang University SCIENCE A
%V 9
%N 11
%P 1595~1600
%@ 1673-565X
%D 2008
%I Zhejiang University Press & Springer
%DOI 10.1631/jzus.A0820051

T1 - Microstructure of ferrospheres in fly ashes: SEM, EDX and ESEM analysis
A1 - Qing-feng XUE
A1 - Sheng-gao LU
J0 - Journal of Zhejiang University Science A
VL - 9
IS - 11
SP - 1595
EP - 1600
%@ 1673-565X
Y1 - 2008
PB - Zhejiang University Press & Springer
ER -
DOI - 10.1631/jzus.A0820051

ferrospheres in fly ashes from a coal-fired power plant were extracted by a magnetic separation technique and their microstructure was studied by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and environmental scanning electron microscopy (ESEM). ferrospheres in fly ashes show significant iron enrichment compared to their respective fly ashes. Iron oxides in ferrospheres mainly occur as minerals magnetite (Fe3O4) and hematite (α-Fe2O3), which are derived mainly from the decomposition and oxidation of iron-bearing minerals in coal during combustion. EDX data indicate that ferrospheres also contain Si, S, Al and Ca resulting from quartz, mullite, anhydrite and amorphous materials. A large percentage of ferrospheres are commonly 5~50 μm in size. The microstructure of ferrospheres includes smooth, polygonal, dendritic, granular and molten drop characteristics. SEM coupled with EDX provided fast and accurate results of the microstructure and chemical composition of ferrospheres, and helped us to assess environmental issues related to the disposal and utilization of fly ashes.

Darkslateblue:Affiliate; Royal Blue:Author; Turquoise:Article


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