Description

Ferrosilicon, or ferrosilicium, is a ferroalloy an alloy of iron and silicon with between *5 and *0% silicon. It contains a high proportion of iron silicides. Its melting point is about ***0 °C to ***0 °C with a boiling point of ***5 °C. It also contains about 1 to 2% of calcium and aluminium.

Ferrosilicon is produced by reduction of silica or sand with coke in presence of scrap iron, millscale, or other source of iron. Ferrosilicons with silicon content up to about *5% are made in blast furnaces lined with acid fire bricks. Ferrosilicons with higher silicon content are made in electric arc furnaces. An overabundance of silica is used to prevent formation of silicon carbide. Microsilica is a useful byproduct. The usual formulations on the market are ferrosilicons with *5, *5, *5, and *0% of silicon. The remainder is iron, with about 2% of other elements like aluminium and calcium.