Dimensional control of Macroporous ceramics by in situ CA6 formation

• Grant number: 18/07745-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: December 01, 2018
• End date: February 29, 2020
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Victor Carlos Pandolfelli
• Grantee: Otávio Henrique Borges
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

There is a growing demand for more efficient industrial processes, reducing energy waste. In this context, refractories thermal insulators are widely used since they allow a reduction in the heat transfer rate sustained between the equipment and the environment. As the performance of these insulators has a direct impact on production costs, there is a growing effort for the development of advanced refractory ceramics with adequate thermal properties. Therefore, macroporous refractories are an excellent option because their microstructure interferes with the heat transference. However, the dimensional stability of this type of material is a limiting factor because there is the possibility of densification in service, causing deformations and reduction in efficiency of the insulation coating. Thus, this research project aims at controlling the microstructure of alumina-based macroporous refractories, produced by the direct foaming method, allowing the in situ formation of expansive phase Calcium Hexaluminate (CA6), which can counterbalance the material densification. To do so, different concentrations and types of CaO precursors, such as CaCO3 and calcium aluminate cement, both in powder and in stable aqueous suspension forms (recently developed by our research group) will be tested; in addition to different types of dopants, such as TiO2, Nb2O5 and SiO2.

Scientific publications

(5)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BORGES, O. H.; SANTOS JR, T.; SALVINI, V. R.; PANDOLFELLI, V. C.. Al2O3-CaO macroporous ceramics containing hydrocalumite-like phases. CERAMICS INTERNATIONAL, v. 46, n. 5, p. 5929-5936, APR 1 2020. (18/07745-5)

BORGES, O. H.; SANTOS JUNIOR, T.; OLIVEIRA, R. R. B.; SALVINI, V. R.; PANDOLFELLI, V. C.. Macroporous high-temperature insulators physical properties by in situ CA(6) formation: Does the calcium source matter?. Journal of the European Ceramic Society, v. 40, n. 10, p. 3679-3686, AUG 2020. (18/07745-5)

FINHANA, I. C.; MACHADO, V. V. S.; SANTOS JR, T.; BORGES, O. H.; SALVINI, V. R.; PANDOLFELLI, V. C.. Direct foaming of macroporous ceramics containing colloidal alumina. CERAMICS INTERNATIONAL, v. 47, n. 11, p. 15237-15244, JUN 1 2021. (18/07745-5)

SANTOS JR, T.; MACHADO, V. V. S.; BORGES, O. H.; SALVINI, V. R.; PARR, C.; PANDOLFELLI, V. C.. Calcium aluminate cement aqueous suspensions as binders for Al2O3-based particle stabilised foams. CERAMICS INTERNATIONAL, v. 47, n. 6, p. 8398-8407, MAR 15 2021. (18/07745-5)

BORGES, O. H.; JR, T. SANTOS; SALVINI, V. R.; PANDOLFELLI, V. C.. CA(6)-based macroporous refractory thermal insulators containing mineralizing agents. Journal of the European Ceramic Society, v. 40, n. 15, p. 6141-6148, DEC 2020. (18/07745-5)