Ferrosilicon (FeSi) stands as a pivotal alloy in steelmaking, meticulously crafted from a blend of iron and silicon. Its primary role lies in steel production, serving as a vital agent for deoxidation and alloy enhancement. By infusing steel with silicon, ferrosilicon fortifies the metal against oxidation at elevated temperatures, augments hardenability, and fosters solid-solution strengthening. Steel and cast-iron alloys stand as the foremost beneficiaries of ferrosilicon’s versatile applications.

The genesis of ferrosilicon traces back to high-purity quartz sand and quartzite, acting as rich sources of silica. These raw materials undergo smelting in blast or submerged electric arc furnaces, culminating in the production of ferrosilicon. The alloy, commonly abbreviated as FeSi, manifests in various grades, with the prevalent FeSi75 constituting 75 wt% silicon. However, the silicon content can span a range from 15 to 90 wt% depending on the intended use.

The pinnacle of ferrosilicon quality is achieved through meticulous manufacturing in electric arc furnaces. Here, silica undergoes reduction with coke in the presence of iron, typically derived from steel scrap or iron ore. The resulting ferrosilicon material often manifests as glossy, metallic-grey lumps or pre-formed briquettes, ensuring versatility in application.

In the realm of steelmaking, ferrosilicon serves a multitude of indispensable functions:

Product performance: Ferrosilicon serves as a convenient medium for introducing silicon into steel, thereby enhancing various properties of the final product.
Slag reduction: Particularly in the production of stainless steels, silicon presence aids in reducing chromium oxides in the melt, thereby facilitating the recovery of metallic chromium.
Deoxidation: Ferrosilicon expedites the removal of oxygen from the melt, preventing the formation of inclusion-forming oxides and safeguarding the retention of desirable elements.
Fuel efficiency: Some steel mills utilize ferrosilicon to introduce heat into the furnace through combustion, thereby reducing energy costs.
Ferrosilicon’s categorization extends to various types tailored to specific application requirements:

Low-carbon ferrosilicon and ultra-low-carbon ferrosilicon: Primarily employed to prevent carbon reintroduction during the manufacturing of stainless steel and electrical steel.
Low-titanium (high-purity) ferrosilicon: Sought after for its ability to mitigate the formation of TiN and TiC inclusions in electrical steel and specialized steels.
Low-aluminum ferrosilicon: Deployed to prevent the formation of hard Al2O3 and Al2O3–CaO inclusions across a diverse range of steel types.
Specialized ferrosilicon: Encompasses a spectrum of bespoke products containing additional alloying elements tailored to specific industrial needs.
Through its multifaceted contributions, ferrosilicon emerges as an indispensable cornerstone of modern steelmaking, imbuing steel with resilience, performance, and adaptability to meet the diverse demands of contemporary industries.