In the 60s, the dust produced by ferrosilicon factories used to be considered waste. It was further used to cover parks’ grounds and garbage bins’ surfaces. Nowadays, by discovering a variety of uses for this dust (micro-silica), it’s one of the byproducts of ferrosilicon.
Micro-silica is an odorless non-combustible substance stable at environment temperature. Its melting point is 2300 ℃. The following table shows micro-silica’s chemical components. Micro-silica has an amorphous (non-crystalline) structure with spherical particles. Dust particles have average dimensions of around 0.15 micrometer and the dust itself looks like cigarette ash.
Depending on its origin and production process, micro-silica can have different colors. As silica is colorless, micro-silica’s color is determined by other compsitions like carbon or carbon oxide. The micro-silica produced at Ferroall factory is in grey and its ISIC code is as below:
|ASTM C 1240
It should be noted that there is a 300 Kg byproduct of micro-silica per ton of ferrosilicon.
Today micro-silica powder covers a range of uses, some of which are briefly discussed below:
Used in concrete and cement following benefits can be mentioned:
- Increasing the pushing resistance
- Causing more resistance to wear
- Reducing the degree of permeability
- Creating more resistance toward sulfates
- More resistance to corrosion
- Polymer consumptions
- Refractory industries
- In coating and insulating powders
- As auxiliary materials in catalytic protection systems and in chemical industries to absorb the ions selectively
- In producing different types of silicates
All in all, regarding the expansion in ferroalloys’ production and the produced micro-silica dust, other uses are predicted, especially in industries where delicacy and solidity are required.