Interceram - International Ceramic Review

, Volume 67, Supplement 1, pp 32–37 | Cite as

Effect of SiO2 Micropowder on Properties of Calcium Hexaluminate Castables for Coal Catalytic Gasifiers

  • Luo QiongEmail author
  • Gu Huazhi
  • Yu Yalan
  • Huang Ao
  • Zhang Meijie
  • Luo Zhian
Applications and Engineering Furnace Linings


Furnace lining materials for coal catalytic gasifiers should have good high-temperature strength and alkali slag corrosion resistance. Calcium hexaluminate castable is a promising application direction. In this paper, the effect of the addition of SiO2 micropowder on the performance of a calcium hexaluminate castable was evaluated through sintered properties, high-temperature strength, anti-alkali slag performance, and microstructural analysis. The results show a significant increase of grain and matrix bonding strength and a decrease of porosity with SiO2 micropowder addition. The castables with 3 mass-% SiO2 micropowder possessed 14.3 MPa CMOR (Cold Modulus of Rupture) and 107.6 MPa CCS (Cold Crush Strength) after heat treatment at 800 °C for 3 h. The hot flexural strength is 11.8 MPa and the retained residual flexural strength of the castables reached 37.13 % after five thermal shock cycles (water cooling) at 1100 °C. The potassium element in the slag has a very small amount of penetration and aggregation at the interface between the sample and the slag.


calcium hexaluminate castable SiO2 micropowder high-temperature strength alkali slag resistance 


  1. [1]
    Gao, M., Wang, Y., Li Fan: Research progress in calcium catalytic action during coal gasification. Chem. Ind. & Eng. Prog. 9 (2015) 715–719Google Scholar
  2. [2]
    Sharm, A., Takanohash, T.I., Satio. I.: Effect of catalyst addition on gasification reactivity of hyper coal and coal with steam at 775-700 °C. Fuel 87 (2008) 2686–2690CrossRefGoogle Scholar
  3. [3]
    Carlborg, M., Weiland, F., Ma, C. et al.: Exposure of refractory materials during high-temperature gasification of a woody biomass and peat mixture woody biomass and peat mixture. J. Eur. Ceram. Soc. 38 (2018) 777–787CrossRefGoogle Scholar
  4. [4]
    Chen, F.M., Wang, X.J., Wang, X.M. et al.: Transformation of potassium during catalytic gasification of coal and the effect on gasification. J. Fuel Chem. and Technol. 41 (2013) 265–270CrossRefGoogle Scholar
  5. [5]
    Gong, Y., Zhang, Q., Zhu, H.W. et al.: Refractory failure in entrained-flow gasifier: Vision-based macrostructure investigation in a bench-scale OMB gasifier. Appl. Energy 205 (2017) 1091–1099CrossRefGoogle Scholar
  6. [6]
    Xie, J., Gu, H., Duan, H., et al.: Anti-alkali corrosion properties of different refractory raw materials. J. Wuhan Univ. of Sci. & Technol. 37 (2014) [6] 428–431Google Scholar
  7. [7]
    Yu Yalan, Gu Huazhi, Zhang Meijie et al.: Study on corrosion resistance of different refractory raw materials against K2CO3. J. Wuhan Univ. of Sci. & Technol. 40 (2017) [4] 264–268Google Scholar
  8. [8]
    Scudeller, L.A.M., Longo, E., Valela, J.A.: Potassium vapor attack in refractories of the alumina-silica system. J. Am. Ceram. Soc. 73 (1990) [5] 1413–1416CrossRefGoogle Scholar
  9. [9]
    Salomão, R., Ferreira, V.L., de Oliveira, I.R. et al.: Mechanism of pore generation in calcium hexaluminate (CA6) ceramics formed in situ from calcined alumina and calcium carbonate aggregates. J. Eur. Ceram. Soc. 36 (2016) 4225–4235CrossRefGoogle Scholar
  10. [10]
    Chen Chong, Chen Haiyan, Wang Jun: Synthesis, Properties and application of calcium hexaluminate. Bull. Chinese Ceramic Soc. 28 (2009) 201–205Google Scholar
  11. [11]
    Büchel, G., Buhr, A., Gierisch, D.: Alkali and CO resistance of dense calcium hexaluminate Bonite. Proc. 48th Inter. Refractor. Colloq., Aachen, Germany (2005)Google Scholar
  12. [12]
    Xue Haitao, Gu Huazhi, Peng Yuntao et al.: Influences of microsilica on properties of bauxite based low cement castables. Naihuo Cailiao 45 (2011) [5] 338–340Google Scholar
  13. [13]
    Braulio, M.A.L., Brant, P.O C., Bittencourt, L.R.M. et al.: Microsilica or MgO grain size: Which one mostly affects the in situ, spinel refractory castable expansion. Ceram. Int. 35 (2009) [8] 3327–3334CrossRefGoogle Scholar

Copyright information

© Springer Fachmedien Wiesbaden GmbH, part of Springer Nature 2018

Authors and Affiliations

  • Luo Qiong
    • 1
    Email author
  • Gu Huazhi
    • 1
  • Yu Yalan
    • 1
  • Huang Ao
    • 1
  • Zhang Meijie
    • 1
  • Luo Zhian
    • 1
  1. 1.The State Key Laboratory of Refractories and MetallurgyWuhan University of Science and TechnologyWuhanChina

Personalised recommendations