Silica Fume

## Why buyers start here Silica fume is one of the most cost-effective pozzolanic materials available for high-performance concrete and refractory applications. Its ultrafine particle size (average 0.1–0.5 μm) fills voids between cement particles, producing denser, stronger, and more durable concrete. ## Key specifications to verify | Property | Typical Range | Why It Matters | |----------|--------------|----------------| | SiO₂ content | 85%–98% | Higher purity means stronger pozzolanic reactivity | | Bulk density (undensified) | 200–350 kg/m³ | Affects transport cost and handling | | Bulk density (densified) | 500–700 kg/m³ | Easier storage and lower shipping volume | | Loss on ignition (LOI) | 1%–6% | Indicates carbon and moisture content | | Average particle size | 0.1–0.5 μm | Determines reactivity and mixing behavior | ## Densified vs undensified forms **Undensified silica fume** is collected directly from furnace exhaust gases. It has very low bulk density, which makes it expensive to transport but easy to disperse in mixes. **Densified silica fume** is processed by compressing the undensified powder into small agglomerates. This increases bulk density by 2–3×, reducing shipping costs. However, it requires longer mixing times to break down agglomerates fully. ## Common applications - **High-performance concrete**: Bridges, marine structures, high-rise buildings - **Refractory castables**: Steel, glass, and ceramic kiln linings - **Oil well cementing**: Thermal wells and corrosive environments - **Shotcrete and gunite**: Tunnel linings, slope stabilization - **Rubber and polymer fillers**: Enhanced mechanical properties ## What to clarify before inquiry Share the target application, required SiO₂ content range, preferred form (densified or undensified), expected monthly volume, and any specific LOI or carbon content limits.