Oil Column Method for Magnetic Microspheres with Core-Shell Structure

Abstract:

Spherical alumina catalysts have been widely used in fluidized bed and slurry-bed or catalyst carrier due to their excellent pore structure, large surface area, good physical strength and resistance to acids and stability. Magnetic microspheres of γ-Fe₂O₃ @ Al₂O₃ with core-shell structure were obtained by γ-Fe₂O₃ magnetic core coating with aluminum sol. After aging, drying and calcinations process, microspheres with certain hardness and magnetic properties can be obtained. During the preparation of core-shell structure microspheres, effect of both the content of aluminum sol, hexamethylenetetramine(HMT), magnetic core γ-Fe₂O₃ and process parameters of shaping time, aging temperature, calcination temperature on the properties of the spherical carrier was investigated. The optimum properties of microsphere carrier for hardness of 36.32 N/mm, specific surface area of 89.016 m²/g, pore volume of 0.874 cm³/g and average pore diameter 18.51 nm were synthesized, respectively.

• Periodical: Materials Science Forum (Volumes 743-744)
• Pages: 677-680
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.743-744.677
• Online since: January 2013
• Authors: Lian Qing Yu, Kai Tuo Dong, Qian Qian Zhi, Ming Jiang Cai
• Keywords: Magnetic Carrier, Oil Column Method, Spherical Alumina, γ-Fe₂O₃ Magnetic Core

References

[1] A. Barrera, K. Muramatsu, T. Viveros, et al., Influence of the type of sepiolite on the modification of the pore-size distribution in γ-Al2O3 support, Applied Clay Science, 42 (2009) 415-421.

DOI: 10.1016/j.clay.2008.04.009

[2] J.C. Li, L. Xiang, F. Xu, Z.W. Wang, F. Wei. Effect of hydrothermal treatment on the acidity distribution of γ-Al2O3 support, Applied Surface Science, 253 (2006) 766-770.

[3] M. Darbandi, R. Thomann, T. Nann, Single Quantum Dots in Silica Spheres by Microemulsion Synthesis, Chem. Mater., 17 (2005) 5720-5725.

DOI: 10.1021/cm051467h

[4] L.Q. Yu, J. Zhang, S.Q. Hu, Z.D. Han, M. Yan, Production for high thermal stability NdFeB magnets, J. Magn. Magn. Mater., 320 (2008) 1427-1430.

DOI: 10.1016/j.jmmm.2007.11.022

[5] L.Q. Yu, C.C. Huang, Effect of Zr on High Properties Consistency of NdFeB Magnets, Rare Metal Materials and Engineering, 38 (2009) 465-467.

[6] L.Q. Yu, X.L. Zhong, Y.P. Zhang, Y.G. Yan, Production and Corrosion Resistance of NdFeBZr Magnets with an Improved Response to Thermal Variations during Sintering, Journal of Magnetism and Magnetic Materials, 323 (2011) 1152-1155.

DOI: 10.1016/j.jmmm.2010.12.029

[7] L.Q. Yu, M. Yan, J. M. Wu, W. Luo, X.G. Cui, H.G. Ying, On the cooling rate of strip cast alloys for sintered NdFeB magnets, Physica B. 393 (2007) 1-5.

DOI: 10.1016/j.physb.2006.11.042

[8] Q.T. Fu, T.T. He, L.Q. Yu, Preparation and properties of magnetic alumina microspheres with a gamma-Fe2O3/SiO2 core and Al2O3 shell, Journal of Natrual Gas Chemistry, 20 (2011) 72-76.

DOI: 10.1016/s1003-9953(10)60155-7

[9] X.G. Luo, L.N. Zhang, Creation of regenerated cellulose microspheres with diameter ranging from micron to millimeter for chromatography applications, Journal of Chromatography A, 1217 (2010) 5922-5929.

DOI: 10.1016/j.chroma.2010.07.026

[10] V. Horvath, B. Lorantfy, B. Toth, et al., Preparation of terbutylazine imprinted polymer microspheres using viscous polymerization solvents, Journal of Separation Science, 32 (2009) 3347-3358.

DOI: 10.1002/jssc.200900230