Kinetic control of MgO hydration in refractory castables by using carboxylic acids
| Autor: | C. Pagliosa, A.P. Luz, T. dos Santos, J. E. dos Santos, Victor C. Pandolfelli |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science Brucite Magnesium Formic acid Inorganic chemistry Nucleation chemistry.chemical_element 02 engineering and technology engineering.material 021001 nanoscience & nanotechnology 01 natural sciences chemistry.chemical_compound chemistry 0103 physical sciences Materials Chemistry Ceramics and Composites engineering Hydration reaction Hydroxide Reactivity (chemistry) Carboxylate 0210 nano-technology |
| Zdroj: | Journal of the European Ceramic Society. 38:2152-2163 |
| ISSN: | 0955-2219 |
| DOI: | 10.1016/j.jeurceramsoc.2017.11.046 |
| Popis: | Based on a kinetic model that describes the hydration reaction via nucleation and growth mechanisms, formic, acetic or propionic acids were analyzed as hydration site activators on magnesia particles with different reactivity and granulometry used as a main binder source in high-alumina refractory castables. These additives induced the hydroxide generation in MgO suspensions and the hydration degree was proportional to the size of the carboxylate chain. Moreover, a more controlled growth of the brucite crystals could be achieved when formic acid was added to the refractory castables. By adjusting the amount of formic acid in the castable mixtures, large crack-free samples could be prepared, which pointed out the role of this additive to prevent the drawbacks associated with MgO hydration. Therefore, the suitable kinetic control of the nucleation and growth of brucite crystals on the magnesia surface allowed for the development of high-alumina magnesia-bonded castables. |
| Databáze: | OpenAIRE |
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