Ferro Silicon

(Fe Si) Atomic Numbers 26,14

Ferro Silicon is formed by combining iron and silicon with a usual silicon content of over 70% for steel application. This additive is used with other ferro alloys in the deoxidising 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 graphitisation. Ferro Silicon replaces the need for ferro manganese, spiegeleisen and calcium silicides in the manufacturing process.

Properties of Ferro Silicon

Ferro Silicon has a melting point of 1200C to 1250C with a boiling point of 2355C and Ferro Silicon contains about 2% of calcium and aluminium. 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.

Standard Material %
Si 74-78%
AI 1.5% max
C 0.2% max
P 0.03% max
S 0.03% max

Material is available sized as follows:

  • 10-50 mm
  • 10-80 mm
  • 3-10 mm
  • 0-3 mm

Production of Ferro Silicon

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 Ferro Silicon

There are many practical applications of Ferro Silicon to include carbon steel and stainless steel production, and when using the Pidgeon 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.

Ferro Silicon Market

Since the start of 2009, the Ferro Silicon market has dropped across the board, and especially noted is the drop in the Chinese market. Most consider the drop there a serious slump that is outside predictable trends. Reasons for the slump is as follows:

1) EU anti-dumping impacting demand,

2) both Japan and South Korea imported a large quantity of FeSi before an export tariff rate increase, and

3) adequate amounts are currently stockpiled.

The China Ferro Silicon market remains weak due to governmental policy changes, where despite considerable mill profits, many mills are closing due to the strong competition from overseas.