China's Refractories


China's Refractories ›› 2024, Vol. 33 ›› Issue (1): 23-27.DOI: 10.19691/j.cnki.1004-4493.2024.01.005

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Effects of Al2O3-SiO2 Raw Material Types on Properties of Anorthite Based Insulation Refractories

DU Juan1, GUO Huishi2, YANG Jialin2, LI Wenfeng1,*, GUI Yanghai2, ZHAO Zhiqiang2, LIU Yingfan2   

  1. 1 School of Materials Science and Engineering, Henan University of Technology, Zhengzhou 450001, China;
    2 School of Materials and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450051, China
  • Online:2024-03-15 Published:2024-04-07
  • Contact: *e-mail:
  • About author:Du Juan, born in 1995, graduated from Luoyang Institute of Science and Technology with a bachelor's degree in materials science and engineering in 2018. Now she is studying for a master's degree in Henan University of Technology. She mainly engages in the research of refractories and high temperature ceramics.

Abstract: To optimize their Al2O3-SiO2 raw materials, anorthite based insulation refractories were prepared by the in-situ sintering process combined with the foaming method after sintering at 1 350 ℃ for 3 h, using green and pollution-free kaolin, kyanite, andalusite and sillimanite as Al2O3-SiO2 raw materials, respectively, and industrial CaCO3 as the CaO source. Effects of Al2O3-SiO2 raw material types on the physical properties, phase composition and microstructure were investigated. The results are as follows. All samples prepared by different Al2O3-SiO2 raw materials have hexagonal flake anorthite and a small amount of mullite and corundum. Their bulk density and thermal conductivity decrease in the order of using kaolin, andalusite, kyanite and sillimanite as the Al2O3-SiO2 raw material, but their apparent porosity increases. Moreover, in the sample with kaolin, the bonding between anorthite crystals on the pore walls is closer than that of the other samples, which is conducive to increasing the cold crushing strength. The bonding between anorthite crystals on pore walls gradually decreases in the order of using kyanite, andalusite and sillimanite as the Al2O3-SiO2 raw material, thus their cold crushing strength decreases accordingly. In comprehensive consideration, the properties of the sample from kyanite are the optimal. Its apparent porosity, thermal conductivity and cold crushing strength are 84.6%, 0.141 W·m-1·K-1 and 1.89 MPa, respectively.

Key words: anorthite based insulation refractories, Al2O3-SiO2 raw materials, crushing strength, thermal conductivity, microstructure