Ferro-silicon is an atomized alloy, which is formed by combining iron and silicon with a silicon content range of 15% to 90%. Ferro-silicon is a universal "heat-blocker" used in the production of carbon and stainless steels. This additive is used with other ferro-alloys in the deoxidizing process of steel, as well as in the production of silicon itself. Ferro-silicon is used in the production of cast iron, as Ferro-silicon can accelerate graphitization. Ferrosilicon replaces the need for ferro-manganese, spiegeleisen and calcium silicides in the manufacturing process.
Production of Ferrosilicon:
A large portion of the global Ferro-silicon supply is manufactured in China, USA and India. The most basic definition of the Ferro-silicon production process would be that the silica (or sand) is mixed with coke, and then a reduction process takes place in the presence of millscale, scrap or another source of iron. A blast furnace is employed for Ferro-silicon production, but for larger contents of silica, an electric arc furnace is used. Ferro-silicon is usually supplied in bags of particles in pallet boxes or shrink-wrapped on pallets or in steel drums (50kg and dual layer plastic bags or 1000kg packed in drums). The granularity of particles varies from 10 mm to 100mm.
Uses of Ferrosilicon:
There are many practical applications of Ferro-silicon to include carbon steel and stainless steel production, and when using the Pigeon process to produce magnesium from dolomite. Applications in the production of other alloys include the manufacture of silicon steel for electro motors and cores, as well as coatings used during arc welding. One useful by-product of the production processes is silica fume, which is later added to concrete mixes to improve compressive and bonding strength there.
Si : 70 - 75%
Al : 1.5 % Max
C : 0.100%
P : 0.035%
S : 0.035%
Properties of Ferrosilicon
Ferro-silicon has a melting point of 1200°C to 1250°C with a boiling point of 2355°C and Ferro-silicon contains about 2% of calcium and aluminum. Ferro-silicon, as an additive to the production process of ferrous metals, will impart several desirable properties upon the resultant alloy. Some of the primary benefits of adding Ferro-silicon to an alloy is to improve the corrosion resistant properties of the new compound, as well as to add to the high temperature heat-resistance properties of the new alloy, for example, in the production of silicon steel for use in transformer cores.