(1) Ferrosilicon is used as a deoxidizer and alloying agent in the steelmaking industry. To obtain steel with acceptable chemical composition and ensure its quality, deoxidation is necessary in the final stage of steelmaking. Silicon and oxygen have a strong chemical affinity, making ferrosilicon a powerful deoxidizer used for precipitation and diffusion deoxidation. Adding a certain amount of silicon to steel significantly improves its strength, hardness, and elasticity. Therefore, ferrosilicon is also used as an alloying agent in the smelting of structural steel (containing 0.40-1.75% silicon), tool steel (containing 0.30-1.8% Si), spring steel (containing 0.40-2.8% Si), and transformer silicon steel (containing 2.81-4.8% silicon).
(2) Ferrosilicon is used as an inoculant and spheroidizing agent in the cast iron industry. Cast iron is an important metallic material in modern industry. It is cheaper than steel, easier to melt and smelt, and has excellent casting properties and much better shock resistance than steel. In particular, ductile iron has mechanical properties that reach or approach those of steel. Adding a certain amount of ferrosilicon to cast iron can prevent the formation of carbides in the iron and promote the precipitation and spheroidization of graphite. Therefore, in the production of ductile iron, ferrosilicon is an important inoculant (helping to precipitate graphite) and spheroidizing agent.
(3) Used as a reducing agent in ferroalloy production. Not only is there a strong chemical affinity between silicon and oxygen, but high-silicon ferrosilicon also has a very low carbon content. Therefore, high-silicon ferrosilicon (or silicon alloy) is a commonly used reducing agent in the production of low-carbon ferroalloys in the ferroalloy industry.
(4) 75# ferrosilicon is often used in the high-temperature smelting process of magnesium metal in the Pidgeon process to displace magnesium from CaO.MgO. Ferrosilicon powder is used as a reducing agent to produce magnesium metal through a reduction reaction under vacuum and high temperature . Approximately 1.04 to 1.1 tons of ferrosilicon are consumed for every ton of magnesium metal produced [12], playing a significant role in magnesium metal production.
(5) Other uses. Finely ground or atomized ferrosilicon powder can be used as a suspended phase in the mineral processing industry. In the electrode manufacturing industry, it can be used as a coating for electrodes, where ferrosilicon powder acts as a deoxidizer to improve welding quality . High-silicon ferrosilicon can be used in the chemical industry to manufacture products such as silicone. In addition, ferrosilicon powder is also used in powder metallurgy, surface treatment and other fields.
Among these applications, the steelmaking industry, casting industry and ferroalloy industry are the largest users of ferrosilicon. They consume more than 90% of ferrosilicon in total. Among the various grades of ferrosilicon, 75% ferrosilicon is the most widely used. In the steelmaking industry, about 3-5 kg of 75% ferrosilicon is consumed for every 1 ton of steel produced. Ferrosilicon grades and chemical composition
