Industrial Chemicals
Micro Silica
Ultrafine, highly amorphous silica with a very large surface area — used for densification, pozzolanic reactivity and early strength in oilfield cementing.
Overview
Densified & undensified grades, sourced from ferrosilicon production.
414 Solutions offers a range of densified and undensified micro silica derived as a byproduct of ferrosilicon production. In oilfield cementing applications, micro silica is used mainly as a densification, pozzolan and reactivity product to attain high and early cementing strength.
Strength retrogression matters in oil well cementing: hydration products formed when cement is exposed to high temperatures (>110°C / 230°F) cause a decline in cement strength and pore diameter at elevated temperatures. This is addressed by reacting micro silica with calcium hydroxide to form a calcium silicate bond, which reduces permeability and improves zonal isolation in the concrete pore structure.
Typical Properties
| Physical state | Ultrafine powder |
|---|---|
| Color | Dark to light gray |
| SiO₂ | 92% min |
| Fe₂O₃ | 1% max |
| Carbon | ≤2% |
| Loss on ignition | ≤3% |
| Moisture | ≤1% |
| Solubility (water) | Insoluble |
| Melting point | Approx. 1230°C |
| Specific gravity | 2.2 – 2.3 |
| Bulk density | 500 – 680 kg/m³ |
| Particle size | Approx. 0.3 μm |
Dosage
Typically 1% – 5% cement replacement.
Depending on the concrete mix design, micro silica is usually used to replace cement by weight from 1% to 5%, depending on several project-specific factors.
Specifications
Benefits in Concrete
Why it's specified.
Advantages
Packaging
Available in three formats.
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