Since silicon and oxygen easily combine to form silica, ferrosilicon is often used as a deoxidizer in steelmaking. At the same time, since SiO2 releases a large amount of heat when it is generated, it is also beneficial to increase the temperature of molten steel while deoxidizing. At the same time, ferrosilicon can also be used as an alloying element additive and is widely used in low-alloy structural steel, spring steel, bearing steel, heat-resistant steel and electrical silicon steel. Ferrosilicon is often used as a reducing agent in ferroalloy production and chemical industry.
(1) Used as deoxidizer and alloying agent in the steelmaking industry. In order to obtain steel with qualified chemical composition and ensure the quality of steel, deoxidation must be carried out during the steelmaking stage. The chemical affinity between silicon and oxygen is very large, so ferrosilicon is a strong deoxidizer for steelmaking and is used for precipitation and diffusion deoxidation. . Adding a certain amount of silicon to steel can significantly improve the strength, hardness and elasticity of the steel. Therefore, it is widely used in smelting structural steel (containing 0.40-1.75% silicon), tool steel (containing SiO.30-1.8%), spring steel ( Ferrosilicon is also used as an alloying agent when it comes to silicon steel for transformers (containing 2.81-4.8% silicon). At the same time, improving the shape of inclusions and reducing the content of gas elements in molten steel is an effective new technology to improve steel quality, reduce costs, and save iron. It is especially suitable for the deoxidation requirements of continuous casting molten steel. Practice has proved that ferrosilicon not only meets the deoxidation requirements of steelmaking, but also has desulfurization performance and has the advantages of large specific gravity and strong penetrating power.
In addition, in the steelmaking industry, ferrosilicon powder can release a large amount of heat when burned at high temperatures and is often used as a heating agent for steel ingot caps to improve the quality and recovery rate of steel ingots.
(2) Used as inoculant and spheroidizing agent in the cast iron industry. Cast iron is an important metal material in modern industry. It is cheaper than steel, easy to melt and smelt, has excellent casting properties and is much better than steel in earthquake resistance. In particular, the mechanical properties of ductile iron reach or are close to 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 reducing agent in ferroalloy production. Not only is the chemical affinity between silicon and oxygen very high, but the carbon content of high-silicon ferrosilicon is very low. Therefore, high-silicon ferrosilicon (or silicon alloy) is a commonly used reducing agent in the ferroalloy industry when producing low-carbon ferroalloys.
(4) 75# ferrosilicon is often used in the high-temperature smelting process of metallic magnesium in the Pidgeon process to replace the magnesium in CaO.MgO. About 1.2 tons of ferrosilicon are consumed for every ton of metallic magnesium produced. It plays a big role in the production of magnesium metal.
(5) Use in other aspects. Ground or atomized ferrosilicon powder can be used as a suspended phase in the mineral processing industry. It can be used as a coating for welding rods in the welding rod manufacturing industry. High-silicon ferrosilicon is used in the chemical industry to make products such as silicone.
Among these uses, the steelmaking industry, foundry industry and ferroalloy industry are users of ferrosilicon. Together they consume more than 90% of ferrosilicon. Among various brands of ferrosilicon, 75% ferrosilicon is currently widely used. In the steelmaking industry, approximately 3-5kg of 75% ferrosilicon is consumed for each ton of steel produced.
