Novel microporous MgO-based high-temperature thermal insulator

Author(s)

Salomao, Rafael ; Fernandes, Leandro ; Simao, Luiz Carlos

• Document type: Journal article
• Source: OPEN CERAMICS; v. 16, p. 10-pg., 2023-09-04.

Abstract

This paper addresses the development of a novel microporous MgO-based (MPMB) thermal insulator whose temperature-resistant microporous structure was engineered for the introduction of controlled packing flaws amongst their highly asymmetric and porous particles during compacting by uniaxial pressing. Hard-burnt MgO, dolomite, and TiO2 particles were dry-mixed with expanded aluminum phyllosilicate and fibers before being sprayed with a colloidal silica dispersion. The mixture was uniaxially pressed as 400 x 100 x 20 mm boards and dried at 120 degrees C. Samples were thermally treated at different temperatures (120-1100 degrees C) for the evaluation of their physical properties (compression strength, rigidity, permanent dimensional thermal variation, solid density, total porosity, pore diameter distribution, and thermal conductivity), crystalline phases, and microstructure. The microporous microstructure generated during pressing was not significantly affected by thermal treatments up to 1100 degrees C and the samples' thermal conductivity, total porosity, and compression strength varied between 0.20 and 0.14 W (m K)-1, 54-56%, and 29-15 MPa in the 200-1000 degrees C temperature range. (AU)

• FAPESP's process: 18/19773-3 - Microporous castable refractories in the Al2O3-MgO-CaO system for thermal insulation above 1200ºC
• Grantee: Rafael Salomão
• Support Opportunities: Scholarships abroad - Research
• FAPESP's process: 22/03655-7 - Reducing energy losses in industrial processes with high-efficiency thermal insulation of microporous castable calcium silicate produced from elements of biomass: eggshells and rice husk ash
• Grantee: Rafael Salomão
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Regular Program Grants