Ferrosilicon Applications

1. Ferrosilicon is used in steel factories and foundries as source of silicon. It is also used in all types of carbon, low alloy and high alloy steels for deoxidizing purposes and is used in production of ferroalloys using Silicothermite process as well.
2. Silicon is used as alloying element in production of electrical steels that are used in transformer cores and electrical motors.
3. Ferrosilicon is used as silicon donor for up to 3% in production of gray and ductile iron.
4. Ferrosilicon is the base material for the production of ferrosilicon magnesium and foundry inoculants.
5. Used as a part of the composition of electrode coatings in arc welding

The addition of silica dust to concrete remains inert initially. However once the water and cement in the concrete begin to react (hydrating), two chemicals are produced:

1. Calcium silicate hydrate (CSH), which is responsible for the strength of concrete
2. Calcium hydroxide (CH) or free lime, which is a byproduct of the reaction

Calcium hydroxide fills the gaps between calcium silicate crystals and in low-grade cements is responsible for being leached out.

The Pozzolanic reaction between silica fume and free lime produces more calcium silicate hydrate which adds to the compressive strength of the concrete as well as compaction and impermeability.

• The word Pozzolanic originates from an old town in Italy called Pozzuoli where ancient Romans produced mortars for construction by combining volcanic ash with lime stone.
  Volcanic ash had a similar composition to silica fume which its combination with lime stone produces calcium silicate hydrate which is the bonding material of cement therefore after thousands of years these ancient buildings are still standing.