Interceram - International Ceramic Review

, Volume 66, Issue 7, pp 28–37 | Cite as

Hydratable Alumina-Bonded Suspensions: Evolution of Microstructure and Physical Properties During First Heating

  • R. SalomãoEmail author
  • M. A. Kawamura
  • A. D. V. Souza
  • J. Sakihama
Review Papers


Hydratable alumina (HA) is a calcium-free and high-refractoriness binder for alumina-based suspensions. Although recent studies have improved its dispersion, mixing and drying behaviours, a drawback related to its loss of strength between 250 and 900°C remains unexplored. Pores generated after decomposition of HA curing products are usually an explanation for the effect; however, no experimental result has supported this hypothesis so far. This study investigated the effects of thermal treatment (120–1500°C) upon the microstructure and physical properties of calcined alumina suspensions containing different amounts of HA (10–40 vol.-%). Porosity, compression strength and flexural elastic modulus measurements, thermal linear variation and thermogravimetric analysis were compared with scanning electron microscopy and X-ray diffraction results. The average matrix particle size and amount of HA in the formulation play major roles in the types of curing products that are formed. The strength reduction observed during first heating was not directly associated with the increase in porosity.


hydratable alumina aqueous castable suspensions microstructure evolution porosity 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [1]
    Brown, J.F., Clark D., Elliott, W.W.: The thermal decomposition of the alumina trihydrate gibbsite. J. Chem. Soc. (1953) 84–88Google Scholar
  2. [2]
    Gitzen, W.H.: Alumina as ceramic material. The American Ceramic Society, Westerville (1970)Google Scholar
  3. [3]
    Burtin, P.: Influence of surface area and additives on the thermal stability of transition alumina catalyst supports, II: Kinetic model and interpretation. Appl. Catalysis 34 (1987) [1–2] 239–254CrossRefGoogle Scholar
  4. [4]
    Levin, I., Brandon, D.: Metastable alumina polymorphs: crystal structures and transition sequences. J. Am. Ceram. Soc. 81 (1998) [8] 1995–2012CrossRefGoogle Scholar
  5. [5]
    Musselman, L.L.: Production processes, properties, and applications for aluminum-containing hydroxides. Alumina chemicals: Science and technology handbook (1990) 75–92, ISBN: 978-0-916094-33-1Google Scholar
  6. [6]
    Goodboy, K.P., Downing, J.C.: Production processes, properties, and applications for activated and catalytic aluminas. Alumina chemicals: Science and technology handbook (1990) 93–108, ISBN: 978-0-916094-33-1Google Scholar
  7. [7]
    Zhou, R.S., Snyder, R.L.: Structure and transformation mechanisms of the η, ϒ, and θ transition aluminas. Acta Crystall. Section B: Structural Science 47 (1991) [5] 617–630CrossRefGoogle Scholar
  8. [8]
    Santos, P.S., Santos, H.S., Toledo, S.P: Standard transition aluminas: Electron microscopy studies. Mater. Res. 3 (2000) [4] 104–114CrossRefGoogle Scholar
  9. [9]
    Bhattacharya, I.N., Das, S.C., Mukherjee, P.S., Paul, S., Mitra, P.K.: Thermal decomposition of precipitated fine aluminium trihydroxide, Scand. J. Metal. 33 (2004) [4] 211–219CrossRefGoogle Scholar
  10. [10]
    Coelho, A.C.V., Santos H.S.S., Kiyohara P.K., Marcos K.N.P., Santos P.S.S.: Surface area, crystal morphology and characterization of transition alumina powders from a new gibbsite precursor. Mater. Res. 10 (2007) [2] 183–189CrossRefGoogle Scholar
  11. [11]
    Gan, B.K., Madsen, I.C., Hockridge, J.G.: In situ X-ray diffraction of the transformation of gibbsite to alpha-alumina through calcination: Effect of particle size and heating rate. J. Appl. Crystall. 42 (2009) [4] 697–705CrossRefGoogle Scholar
  12. [12]
    Souza, A.D.V., Arruda, C.C., Fernandes, L., Antunes, M.L.P., Kiyohara, P.K., Salomão, R.: Characterization of aluminum hydroxide (Al(OH)3) for its use as a porogenic agent in castable ceramics. J. Europ. Ceram. Soc. 35 (2015) [2] 803–812CrossRefGoogle Scholar
  13. [13]
    Hong, Y.: ρ-Alumina bonded castable refractories. Taikabutsu Overseas 9 (1988) [1] 35–38Google Scholar
  14. [14]
    Ma, W., Brown, P.W.: Mechanisms of reaction of hydratable aluminas. J. Am. Ceram. Soc. 82 (1999) [2] 453–456CrossRefGoogle Scholar
  15. [15]
    Mista, W., Wrzyszcz, J.: Rehydration of transition aluminas obtained by flash calcination of gibbsite. Thermochimica Acta 331 (1999) [1] 67–72CrossRefGoogle Scholar
  16. [16]
    Vaidya, S.D., Thakkar, N.V.: Effect of temperature, pH and ageing time on hydration of rho alumina by studying phase composition and surface properties of transition alumina obtained after thermal dehydration. Mater. Letters 51 (2001) [4] 295–300CrossRefGoogle Scholar
  17. [17]
    Vaidya, S.D., Thakkar, N.V.: Study of phase transformation during hydration of rho alumina by combined loss of ignition and X-ray diffraction technique. J. Phys. and Chem. Solids 62 (2001) [5] 977–986CrossRefGoogle Scholar
  18. [18]
    Salomão, R., Ismael, M.R., Pandolfelli, V.C.: Hydraulic binders for refractory castables: Mixing, curing and drying. CFI 84 (2007) [9] 103–108Google Scholar
  19. [19]
    Nagaoka, T., Duran, C., Isobe, T., Hotta, Y., Watari, K.: Hydraulic alumina binder for extrusion of alumina ceramics. J. Am. Ceram. Soc. 90 (2007) [12] 3998–4001Google Scholar
  20. [20]
    Souza, A.D.V., Salomão, R.: Evaluation of the porogenic behavior of aluminum hydroxide particles of different size distribution in castable high-alumina structures. J. Europ. Ceram. Soc. 36 (2016) [3] 885–897CrossRefGoogle Scholar
  21. [21]
    Pinto, U.A., Visconte, L.L.Y., Gallo J.B.: Flame retardancy in thermoplastic polyurethane elastomers with mica and aluminum trihydrate. Polymer degradation and Stability 69 (2000) [3] 257–260CrossRefGoogle Scholar
  22. [22]
    Santos, P.S., Coelho, A.C.V., Santos, H.S.S., Kiyohara, P.K.: Hydrothermal synthesis of well-crystallized boehmite crystals of various shapes. Mater. Res. 12 (2009) [4] 437–445.CrossRefGoogle Scholar
  23. [23]
    Rebouillat, L., Rigadu, M.: Andalusite-based high alumina castables. J. Am. Ceram. Soc. 85 (2002) [2] 373–378CrossRefGoogle Scholar
  24. [24]
    Ismael, M.R., Salomão, R., Pandolfelli, V.C.: Refractory castables based on colloidal silica and hydratable alumina. Am. Ceram. Soc. Bull. 86 (2007) [9] 58–61Google Scholar
  25. [25]
    Zhang, J., Jia, Q., Yan, S., Zhang, S., Liu, X.: Microstructure and properties of hydratable alumina bonded bauxite-andalusite based castable. Ceram. Inter. 42 (2016) [1] 310–316CrossRefGoogle Scholar
  26. [26]
    Ye, G., Troczynski, T.: Hydration of hydratable alumina in the presence of various forms of MgO. Ceram. Inter. 32 (2006) [3] 257–262CrossRefGoogle Scholar
  27. [27]
    Ahari, K.G., Sharp, J.H., Lee, W.E.: Hydration of refractory oxides in castable bond systems, I: Alumina, magnesia, and alumina-magnesia mixtures. J. Europ. Ceram. Soc. 22 (2002) [4] 495–503CrossRefGoogle Scholar
  28. [28]
    Oliveira, I.R., Pandolfelli, V.C.: Castable matrix, additives, and their role on hydraulic binder hydration. Ceram. Inter. 35 (2009) [4] 1453–1460CrossRefGoogle Scholar
  29. [29]
    Salomão, R., Pandolfelli, V.C.: The role of hydraulic binders on magnesia containing refractory castables: Calcium aluminate cement and hydratable alumina. Ceram. Inter. 35 (2009) [8] 3117–3124CrossRefGoogle Scholar
  30. [30]
    Braulio, M.A.L., Bittencourt, L.R.M., Pandolfelli, V.C.: Selection of binders for in situ spinel refractory castables. J. Europ. Ceram. Soc. 29 (2009) [13] 2727–2735CrossRefGoogle Scholar
  31. [31]
    Oliveira, I.R., Pandolfelli, V.C.: Does a tiny amount of dispersant make any change to refractory castable properties? Ceram. Inter. 36 (2010) [1] 79–85CrossRefGoogle Scholar
  32. [32]
    Ribeiro, C., Innocentini, M.D.M., Pandolfelli, V.C.: Permeability behavior during drying of refractory castables based on calcium-free alumina binders. J. Am. Ceram. Soc. 84 (2001) [1] 248–250CrossRefGoogle Scholar
  33. [33]
    Innocentini, M.D.M., Pardo, A.R.F., Pandolfelli, V.C., Menegazzo, B.A., Bittencourt, L.R.M., Rettore, R.P.: Permeability of high-alumina refractory based on various hydraulic binders. J. Am. Ceram. Soc. 85 (2002) [6] 1517–1521CrossRefGoogle Scholar
  34. [34]
    Salomão, R., Cardoso, F.A., Innocentini, M.D.M., Pandolfelli, V.C., Bittencourt, L.R.M.: Effect of polymeric fibers on refractory castables permeability. Am. Ceram. Soc. Bul. 82 (2003) [4] 51–56Google Scholar
  35. [35]
    Cardoso, F.A., Innocentini, M.D.M., Miranda, M.F.S., Valenzuela, F.A.O., Pandolfelli, V.C.: Drying behavior of hydratable alumina-bonded refractory castables. J. Europ. Ceram. Soc. 24 (2004) [5] 797–802CrossRefGoogle Scholar
  36. [36]
    Salomão, R., Pandolfelli, V.C.: Magnesia sinter hydration-dehydration behavior in refractory castables. Ceram. Inter. 34 (2008) [8] 1829–1834.CrossRefGoogle Scholar
  37. [37]
    Luz, A.P., Neto A.S., Santos, T., Medeiros, J., Pandolfelli, V.C.: Mullite-based refractory castable engineering for the petrochemical industry. Ceram. Inter. 39 (2013) [8] 9063–9070CrossRefGoogle Scholar
  38. [38]
    Souza, A.D.V., Sousa, L.L., Fernandes, L., Cardoso, P.H.L., Salomão, R.: Al2O3-Al(OH)3-Based castable porous structures. J. Europ. Ceram. Soc. 35 (2015) [6] 1943–1954CrossRefGoogle Scholar
  39. [39]
    Salomão, R., Souza, A.D.V., Cardoso, P.H.L.: A comparison of Al(OH)3 and Mg(OH)2 as inorganic porogenic agents for alumina. InterCeram: Inter. Ceram. Rev. 64 (2015) [4] 193–194Google Scholar
  40. [40]
    Salomão, R., Villas-Boas, M.O.C., Pandolfelli, V.C.: Porous alumina-spinel ceramics for high temperature applications. Ceram. Inter. 37 (2011) [7] 1393–1399CrossRefGoogle Scholar
  41. [41]
    Innocentini, M.D.M., Miranda, M.F.S., Cardoso, F.A., Pandolfelli, V.C.: Vaporization processes and pressure builtup during dewatering of dense refractory castables. J. Am. Ceram. Soc. 86 (2003) [9] 1500–1503CrossRefGoogle Scholar
  42. [42]
    Sousa, L.L., Souza, A.D.V., Fernandes, L., Arantes, V.L., Salomão, R.: Development of densification-resistant castable porous structures from in situ mullite. Ceram. Inter. 41 (2015) [8] 9443–9454CrossRefGoogle Scholar
  43. [43]
    Sousa, L.L., Salomão, R., Arantes, V.L.: Development and characterization of porous moldable refractory structures of the alumina-mullite-quartz system. Ceram. Inter. 43 (2017) [1B] 1362–1370CrossRefGoogle Scholar
  44. [44]
    Deng, Z.Y., Fukasawa, T., Ando, M.: High-surface-area alumina ceramics fabricated by the decomposition of Al(OH)3. J. Am. Ceram. Soc. 84 (2001) [3] 485–491CrossRefGoogle Scholar
  45. [45]
    Kwon, S., Messing, G.L.: Sintering of mixtures of seeded boehmite and ultrafine alpha-alumina. J. Am. Ceram. Soc. 83 (2000) [1] 82–88CrossRefGoogle Scholar
  46. [46]
    Deng, Y., Fukasawa, T., Ando, M.: Microstructure and mechanical properties of porous alumina ceramics fabricated by the decomposition of aluminum hydroxide. J. Am. Ceram. Soc. 84 (2001) [11] 2638–2644CrossRefGoogle Scholar
  47. [47]
    Oliveira, I.R., Leite, V.M.C., Lima, M.P.V.P., Salomão, R.: Production of porous ceramic material using different sources of alumina and calcia. Revista Matéria 20 (2015) [3] 739–746CrossRefGoogle Scholar
  48. [48]
    Salomão, R., Fernandes, L.: Porous co-continuous mullite structures obtained from sintered aluminum hydroxide and synthetic amorphous silica. J. Europ. Ceram. Soc. 37 (2017) [8] 2849–2856CrossRefGoogle Scholar

Copyright information

© Springer Fachmedien Wiesbaden GmbH, part of Springer Nature 2017

Authors and Affiliations

  • R. Salomão
    • 1
    Email author
  • M. A. Kawamura
    • 1
  • A. D. V. Souza
    • 1
  • J. Sakihama
    • 1
  1. 1.Materials Engineering Depart., São Carlos School of EngineeringUniversity of São PauloSão CarlosBrazil

Personalised recommendations