Abstract
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.
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Gao, M., Wang, Y., Li Fan: Research progress in calcium catalytic action during coal gasification. Chem. Ind. & Eng. Prog. 9 (2015) 715–719
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) 2686–2690
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) 777–787
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) 265–270
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) 1091–1099
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] 428–431
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] 264–268
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] 1413–1416
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) 4225–4235
Chen Chong, Chen Haiyan, Wang Jun: Synthesis, Properties and application of calcium hexaluminate. Bull. Chinese Ceramic Soc. 28 (2009) 201–205
Büchel, G., Buhr, A., Gierisch, D.: Alkali and CO resistance of dense calcium hexaluminate Bonite. Proc. 48th Inter. Refractor. Colloq., Aachen, Germany (2005)
Xue Haitao, Gu Huazhi, Peng Yuntao et al.: Influences of microsilica on properties of bauxite based low cement castables. Naihuo Cailiao 45 (2011) [5] 338–340
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] 3327–3334
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Qiong, L., Huazhi, G., Yalan, Y. et al. Effect of SiO2 Micropowder on Properties of Calcium Hexaluminate Castables for Coal Catalytic Gasifiers. Interceram. - Int. Ceram. Rev. 67 (Suppl 1), 32–37 (2018). https://doi.org/10.1007/s42411-018-0044-x
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DOI: https://doi.org/10.1007/s42411-018-0044-x