Hot Corrosion Resistance of Aluminosilicate Refractories – Comparative Tests in the Secondary Combustion Chamber of a Hazardous Waste Incinerator

Adrian Villalba Weinberg1, Dominique Goeuriot2, Cyrille Varona3, Xavier Chaucherie4, Jacques Poirier5

1 BONY SA – Produits Réfractaires, 42001 Saint­Étienne/France
2 LGF CNRS UMR 5307, MINES Saint­Étienne, 42023 Saint­Étienne/France
3 BONY SA – Produits Réfractaires, 42001 Saint­Étienne/France
4 SARPI­VEOLIA, 78520 Limay/France
5 CEMHTI CNRS UPR 3079, Université d’Orléans, 45071 Orléans/France

Revision 15.01.2018, 21.01.2018

Volume 10, Issue 2, Pages 57 - 62


This paper presents the alkali and sulphur vapour corrosion resistance of aluminosilicate refractories under industrial conditions. Aluminosilicate refractory samples with Al2O3 contents ranging 42 – 90 mass­% were exposed for 8 months to the corrosive atmosphere in the secondary combustion chamber (gas temperature approx. 950 °C) of a hazardous waste incineration facility. After the exposure, the samples were analysed in the laboratory regarding porosity and mineralogical changes. The test results show that degradation is caused by hot corrosion, specifcally by condensed thenardite (Na2SO4). Free silica, largely accessible in freclay bricks, is the frst phase that reacts with thenardite. The reaction generates liquid natrosilite (Na2Si2O5). This low melting phase leads to deformation and creep of hotter brick parts. In a next step, natrosilite reacts with mullite forming albite (NaAlSi3O8). Simultaneously, thenardite reacts directly with mullite forming nosean (Na8Al6Si6O28S). In order to better withstand the hot corrosion mechanism, refractories should contain as little silica as possible.


alkali attack, sulphur, mullite, hazardous waste incinerator


[1] Jacobson, N.S.; Smialek, J.L.; Fox, D.S.: Molten salt corrosion of ceramics. In: Corrosion of modelling proceedings of the NATO advanced research workshop on corrosion of advanced ceramics. Tübingen, Germany, 30. August–3. September 1993, Springer Netherlands 1994, 205–222 [2] Jacobson, N.S.: Corrosion of silicon­based ceramics in combustion environments. J. Amer. Ceram. Soc. 76 (1993) [1] 3–28 [3] Jacobson, N.S.: Sodium sulfate: deposition and dissolution of silica. Oxid. Met. 31 (1989) [1] 91–103 [4] Jacobson, N.S.; Lee, K.N.; Yoshio, T.: Corrosion of mullite by molten salts. J. Amer. Ceram. Soc. 79 (1996) [8] 2161–2167 [5] Opila, E.J.; Jacobson, N.S.: Oxidation and corrosion of ceramics. In: Ceramics science and technology, vol. 4: Applications, R. Riedel and I.­W. Chen, Eds. Weinheim 2013, 1–93 [6] Villalba Weinberg, A.; et al.: Corrosion of Al2O3–SiO2 refractories by sodium and sulphur vapours: A case study on hazardous waste incinerators. Ceram. Int. 43 (2017) 5743–5750 [7] DIN EN 993­1, Method of test for dense shaped refractory products. Determination of bulk density, apparent porosity and true porosity, 1995 [9] Fryburg, G.C.; et al.: Formation of Na2SO4 and K2SO4 in fames doped with sulphur and alkali chlorides and carbonates. In: Symp. on High Temp. Metal Halide Chem., Atlanta 1977 [10] Gow, K.V.: Reaction of vaporized sodium sulfate with aluminous refractories. J. Amer. Ceram. Soc. 34 (1951) [11] 343–347 [11] Kohl, F.J.; et al.: Theoretical and experimental studies of the deposition of Na2SO4 from seeded combustion gases. J. Electrochem. Soc. 126 (1979) [6]1054–1061 [12] Lawson, M.G.; et al.: Hot corrosion of silica. J. Amer. Ceram. Soc. 73 (1990) [4] 989–995 [13] Nickel, K.G.; Quirmbach, P.; Pötschke, J.: Shreir’s Corrosion, Chapter 1.26: High temperature corrosion of ceramics and refractory materials. Ed. T.J.A. Richardson, Amsterdam 2010, 668–690 [14] Zaitsev, A.; et al.: Thermodynamic properties and phase equilibria in the Na2O–SiO2 system. PCCP 1 (1999) [8] 1899–1907


Göller Verlag GmbH