Ferrosilicon is an alloy produced by combining silicon and iron through smelting. The substance was first produced around 1810 by a Swedish chemist and a German physicist, each working independently.

View a second image of a ferrosilicon alloy surface.

The primary use of ferrosilicon is as an alloying agent in the production of steel and cast iron. When ferrosilicon is added before casting steel, the strength, hardness and elasticity of steel greatly improves and its magnetic conductivity increases. By depositing ferrosilicon into iron that is to be cast, the formation of carbide can be prevented, the separation of graphite can be improved, and the basic properties of cast iron are enhanced.

China is currently the largest producer of ferrosilicon and Japan is the largest importer. In response to market demands of the western world, many manufacturers have begun to decrease ferrosilicon production in favor of the more lucrative silicon fabrication. Silicon, though used primarily in the production of aluminum alloys and in chemicals, is vital to the growing semiconductor industry and consumption of the metal is increasing significantly each year.