Please wait a minute...
ZJUS-A
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering)  2008, Vol. 9 Issue (11): 1595-1600    DOI: 10.1631/jzus.A0820051
Environmental & Chemical Engineering     
Microstructure of ferrospheres in fly ashes: SEM, EDX and ESEM analysis
Qing-feng XUE, Sheng-gao LU
Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310027, China
Download:     PDF (0 KB)     
Export: BibTeX | EndNote (RIS)      

Abstract  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.

Key words： Fly ash      Ferrosphere      Microstructure      Scanning electron microscopy (SEM)     
Received: 16 January 2008     
CLC:  X752  
  P574  
Service
E-mail this article
Add to my bookshelf
Add to citation manager
E-mail Alert
RSS
Articles by authors
Sheng-gao LU
Qing-feng XUE
Cite this article:

Qing-feng XUE, Sheng-gao LU. Microstructure of ferrospheres in fly ashes: SEM, EDX and ESEM analysis. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2008, 9(11): 1595-1600.

URL:

http://www.zjujournals.com/xueshu/zjus-a/10.1631/jzus.A0820051     OR     http://www.zjujournals.com/xueshu/zjus-a/Y2008/V9/I11/1595

[1] Guo-huan Bao, Yi Chen, Ji-en Ma, You-tong Fang, Liang Meng, Shu-min Zhao, Xin Wang, Jia-bin Liu. Microstructure and properties of cold drawing Cu-2.5% Fe-0.2% Cr and Cu-6% Fe alloys[J]. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2015, 16(8): 622-629.
[2] Xiao-pei Lu, Da-wei Yao, Yi Chen, Li-tian Wang, An-ping Dong, Liang Meng, Jia-bin Liu. Microstructure and hardness of Cu-12% Fe composite at different drawing strains[J]. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2014, 15(2): 149-156.
[3] Yun-sheng Zhang, Wei Sun, Zhi-yong Liu, Shu-dong Chen. One and two dimensional chloride ion diffusion of fly ash concrete under flexural stress[J]. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2011, 12(9): 692-701.
[4] Pei-ming Wang, Xian-ping Liu. Effect of temperature on the hydration process and strength development in blends of Portland cement and activated coal gangue or fly ash[J]. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2011, 12(2): 162-170.
[5] Wu-man Zhang, Heng-jing Ba. Effect of mineral admixtures and repeated loading on chloride migration through concrete[J]. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2010, 11(9): 683-690.
[6] Xing-yi Zhu, Zhi-yi Huang, Zhong-xuan Yang, Wei-qiu Chen. Micromechanics-based analysis for predicting asphalt concrete modulus[J]. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2010, 11(6): 415-424.
[7] Ke Shao, Jian-hua Yan, Xiao-dong Li, Sheng-yong Lu, Mu-xing Fu, Ying-lei Wei. Effects of SO2 and SO3 on the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans by de novo synthesis[J]. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2010, 11(5): 363-369.
[8] Wen-chen Xu, Hao Zhang, De-bin Shan. Promoting the mechanical properties of Ti42Al9V0.3Y alloy by hot extrusion in the α+β phase region[J]. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2010, 11(10): 738-743.
[9] Xue Wang, Liang-fei Zhan, Qian-gang Pan, Zhi-jun Liu, Hong Liu, Yong-shun Tao. Microstructure and creep properties of high Cr resisting weld metal alloyed with Co[J]. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2010, 11(10): 756-760.
[10] Dan Ye, De-chang Jia, Zhi-hua Yang, Zhen-lin Sun, Peng-fei Zhang. Microstructures and mechanical properties of SiBCNAl ceramics produced by mechanical alloying and subsequent hot pressing[J]. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2010, 11(10): 761-765.
[11] Jing-yi Zhang, Feng Ye. Effect of agarose content on microstructures and mechanical properties of porous silicon nitride ceramics produced by gelcasting[J]. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2010, 11(10): 771-775.
[12] Jin-li HU, Jin-dong ZHANG, Liang MENG. Morphology evolution of two-phase Cu-Ag alloys under different conditions[J]. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2009, 10(3): 458-463.
[13] Zhi-yi HUANG, Zhong-xuan YANG, Zhen-yu WANG. Discrete element modeling of sand behavior in a biaxial shear test[J]. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2008, 9(9): 1176-1183.
[14] Da-zuo CAO, Eva SELIC, Jan-Dirk HERBELL. Utilization of fly ash from coal-fired power plants in China[J]. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2008, 9(5): 681-687.
[15] Okan KARAHAN, Harun TANYILDIZI, Cengiz D. ATIS. An artificial neural network approach for prediction of long-term strength properties of steel fiber reinforced concrete containing fly ash[J]. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2008, 9(11): 1514-1523.