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.

86-94 0.4-1 0.2-1.5 0.5-2.5 0.4-1.5 1-3 0.5-2 0.1-0.4 0.1-0.5

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:

Product NameLatin NameCode ISICStandard
Powder Micro-silica Micro-Silica Powder 2699412341 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

Other uses:

  • 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.