Ferrosilicon is an alloy consisting of iron and silicon. Its raw materials are coke, steel scraps and quartz (silica), which are smelted in an electric furnace. The silicon content of ferrosilicon ranges from 10 to 90 %.
Ferrosilicon can be classified according to the size that determines its shape: it can be divided into lump ferrosilicon, ferrosilicon briquettes and pulverised ferrosilicon powder.
Ferrosilicon, often abbreviated as FeSi, is an iron–silicon alloy that also contains smaller proportions of other elements. The most popular grade of ferrosilicon contains 75 wt% silicon (designated 'FeSi75'), but the amount can range from 15–90 wt% depending on the intended application.
The highest-quality ferrosilicon is manufactured in an electric arc furnace through the reduction of silica with coke in the presence of iron (typically derived from steel scrap or iron ore). The resulting product is typically in the form of shiny, metallic-grey lumps, though it is also available as pre-formed briquettes.