Ferrosilicon is an alloy composed of iron and silicon, serving as a widely used key auxiliary material in the metallurgical industry.
I. Fundamental Properties
It appears as grayish-black lumps with a smooth cross-section and metallic luster, exhibiting hardness and brittleness.
With a melting point of approximately 1300-1400°C, it possesses strong reducing properties and excellent alloying effects.
Common grades are classified by silicon content, such as 75# (72%-80% Si), 80# (78%-85% Si), and 90# (85%-92% Si).
II. Core Value
Ferrosilicon efficiently removes oxygen and sulfur impurities from molten steel while enhancing the strength, hardness, and wear resistance of metallic materials, earning it the nickname "industrial vitamin" for steel production.
It is produced from raw materials like silica stone and iron concentrate (or scrap steel) through high-temperature smelting in electric arc furnaces. The process is mature and widely applied at scale.
III. Ferrosilicon Production Raw Materials
Silicon Source: Silica stone is the core raw material supplying silicon, requiring SiO₂ content ≥97% with low impurities (aluminum, calcium, magnesium, etc.).
Iron Source Raw Materials: Iron ore concentrate or scrap steel supplies iron, which combines with silicon to form the alloy.
Reducing Agent: Carbon materials primarily reduce silicon from quartzite at high temperatures. Common combinations include coke (fixed carbon ≥85%) + charcoal (enhances reaction activity).
Fluorspar: Added in small quantities (1%-3% of total raw materials) as a flux to lower slag melting point, improve slag fluidity, and facilitate slag removal.
Lime: Added as needed to adjust slag alkalinity, reduce silicon volatilization losses, and enhance recovery rates.
