Fire-resistant and thermal

insulation materials

In fireproofing and thermal insulation, silica fume serves as a high-quality additive, significantly improving materials' refractoriness, high-temperature strength, and thermal insulation properties.

Rheology Modifier and Low-Temperature Binder:

· Microsphere Effect and Lubrication: The ultra-fine spherical particles of silica fume act like "ball bearings" in refractory castables, reducing the mixing water requirement by 25-35% for the same flow level. Lower water content directly translates to higher dried strength, lower porosity, and better high-temperature performance.

· Silica Fume Condensation Bonding: During ambient curing, silanol groups form on the surface of silica fume particles, creating a cohesive bond through hydrogen bonding and van der Waals forces, providing sufficient green strength for demolding.

Phase Transformation and Structural Strengthening at High Temperatures:

· At temperatures above 1100°C, silica fume reacts with components like Al₂O₃ in the material via solid-state reactions, generating high-temperature stable phases such as Mullite (3Al₂O₃·2SiO₂). The interlocking network of mullite crystals significantly enhances the material's hot strength, creep resistance, and thermal shock stability (resistance to rapid heating and cooling).