Micro Silica
High-Purity Silica Fume (Microsilica)
Supplied from China to the World
For over two decades, Miningsun has been dedicated to supplying premium construction additives to customers across the globe.
Silica Fume (Microsilica) is a by-product of producing silicon metal or ferrosilicon alloys in electric arc furnaces. The ultra-fine amorphous SiO₂ particles are collected and processed into a highly reactive pozzolanic additive used worldwide in high-performance concrete.
Our commitment goes beyond product — we build lasting partnerships founded on trust, transparency, and performance.
≥90% SiO₂ Purity
Consistently high silicon dioxide content verified by third-party laboratory testing on every batch.
Full Documentation
MSDS, COA, and TDS provided with every shipment upon request.
Densified & Undensified
Both grades available to suit your mixing process, transport requirements, and project specifications.
Reliable Lead Times
Established supply chain from verified production facilities in China with consistent on-time delivery.
Building a global legacy in industrial minerals — trusted by partners worldwide since 2003.
Silica Fume consists primarily of amorphous (non-crystalline) silicon dioxide (SiO₂). The individual particles are extremely small — approximately 1/100th the size of a cement particle — making it a very reactive pozzolan that dramatically improves concrete performance.
The quality of silica fume is specified by ASTM C 1240. Miningsun's Silica Fume consistently meets ≥90% SiO₂ content with each batch accompanied by a Certificate of Analysis and independent verification.
Silica Fume's chemical and physical properties make it highly beneficial in concrete — the product of choice for increasing strength and reducing permeability.
- Increased tensile and compressive strength
- Long-term compressive strength development
- Reduced efflorescence
- Improved fiber-matrix bonding in FRC
- Increased sulphate resistance
- Increased chloride resistance
- Reduced water permeability
- Increased abrasion resistance
- Mitigation of alkali–silica reaction (ASR)
- High-rise buildings & bridges
- Marine & offshore structures
- Tunneling & shotcrete
- Refractory castables & industrial floors
- Precast concrete elements
| Parameter | Test Standard | Grade 85 | Grade 90 | Grade 92 |
|---|---|---|---|---|
| SiO₂ Content | GB/T 18736 / ASTM C1240 | ≥ 85% | ≥ 90% | ≥ 92% |
| Specific Surface Area | BET | 15,000 – 25,000 m²/kg | ||
| Average Particle Size | Laser Diffraction | 0.1 – 0.2 μm | ||
| Bulk Density (Densified) | ISO 6274 | 500 – 700 kg/m³ | ||
| Pozzolanic Activity Index | ASTM C1240 | ≥ 95% | ≥ 100% | ≥ 105% |
| Moisture Content | EN 196-2 | ≤ 3% | ||
| Loss on Ignition (LOI) | EN 196-2 | ≤ 10% | ≤ 8% | ≤ 6% |
| Chloride Content | EN 196-2 | ≤ 0.02% | ||
* Values are typical and may vary by batch. Certificates of Analysis available upon request.
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