BK90 undensified micro silica powder is the original collected powder without densification treatment. Its ultra-fine particle size and large specific surface area provide superior micro-filling. It is mainly used in ultra-low-cement refractory castables, high-grade special mortar and premium concrete where the finest particle filling is required.
Technical Specifications
| Product model | BK90-U |
|---|---|
| SiO₂ | ≥ 90.0% |
| Loss on ignition | ≤ 3.0% |
| Moisture | ≤ 1.5% |
| Water demand | ≤ 118% |
| Specific surface area | ≥ 18,000 m²/kg |
| Activity index | ≥ 112% |
| Bulk density | 150–350 kg/m³ |
| Standard | GB/T 27690-2023 |
| pH value | — |
| Packing | 25 kg bag or 1,000 kg jumbo bag |
Product Strengths
- Excellent micro-gap filling
- High activity and large surface area
- Ideal for ultra-low-cement castables
- Original physical state
Target Applications
- Ultra-low-cement castables
- Refractory precast blocks
- High-performance mortar
- Formula trials and research
Quality Assurance
- Particle size and activity are inspected per lot.
- COA test report supplied with cargo.
- Dust-proof handling guidance provided.
Frequently Asked Questions
Why does undensified powder create more dust?
Very low bulk density and fine particles increase airborne dust, so closed handling is recommended.
When should I choose undensified silica fume?
Use it when maximum fine-particle filling is more important than handling density.
