Controlling the Thermal Stability of Kyanite-Based Refractory Geopolymers

Area of Science:

• Materials Science
• Ceramics Engineering

Background:

• Refractory composites require high thermal stability.
• Geopolymer composites offer a sustainable alternative.

Purpose of the Study:

• Investigate thermal stability of cold-setting refractory composites.
• Evaluate the effect of kyanite aggregate particle size on thermo-mechanical properties.

Main Methods:

• Studied volumetric shrinkage concerning filler particle size (80-500 µm), temperature (1050-1250 °C), and filler content (70-85 wt.%).
• Utilized thermal analysis and flexural strength testing at 1200 °C.

Main Results:

• Kyanite aggregates significantly improved thermo-mechanical properties.
• Flexural strengths of 40-45 MPa achieved at 1200 °C with varying kyanite particle sizes.
• Sintering at 1200 °C promoted densification and matrix-aggregate bonding without vitrification.

Conclusions:

• Kyanite aggregates are effective for enhancing refractory geopolymer composites.
• These composites exhibit excellent thermal stability, densification, and high strength.
• Kyanite-based composites are promising for environmentally friendly castable refractories.