1. As deoxidizer and alloy agent in steelmaking industry, in order to obtain steel with qualified chemical composition and ensure the quality of steel, deoxidization must be carried out in the last stage of steelmaking. The chemical affinity between silicon and oxygen is very great, so ferrosilicon is a strong deoxidizer in steelmaking for precipitation and diffusion deoxidization. Adding a certain amount of silicon to the steel can significantly improve the strength, hardness and elasticity of the steel. Ferrosilicon is also used as an alloy agent. At the same time, it is an effective new technology to improve the quality of steel, reduce the cost and save the iron. It is specially suitable for continuous casting steel deoxidization requirements. Practice has proved that ferrosilicon not only meets the deoxidization requirements of steelmaking, but also has desulfurization performance and has significant specific strength, strong penetration and other advantages. In addition, ferrosilicon powder is often used as the heating agent of ingot cap to improve the quality and recovery of ingot in the steelmaking, because it can give off a lot of heat at high temperature.
2. As inoculant and spheroidizing agent in cast iron industry. Cast iron is an important metal material in modern industry. It is cheaper than steel and easy to be melted and smelted. Ductile iron, in particular, has mechanical properties equal to or close to those of steel. Adding a certain amount of ferrosilicon to cast iron can prevent the formation of carbides in iron and promote the precipitation and spheroidization of graphite.
3. As reducing agent in ferroalloy production. Not only the chemical affinity between silicon and oxygen is very great, but also the carbon content of high silicon ferrosilicon is very low. Therefore, high silicon ferrosilicon (or silicon alloy) is a common reducing agent in the production of low carbon ferroalloy in the ferroalloy industry.
4. In magnesium smelting by the peijiang process, ferrosilicon is often used to replace the magnesium in CaO.MgO during the high-temperature smelting of magnesium. For every ton of magnesium produced, about 1.2 tons of ferrosilicon will be consumed, which plays a great role in the production of magnesium.
5. Other uses. Pulverized or atomized ferrosilicon powder can be used as a suspended phase in the mineral processing industry. It can be used as coating for welding rod in welding rod manufacture. High silicon ferrosilicon is used in the chemical industry to make products such as silicone.
Among these uses, steelmaking, foundry and ferroalloy industries are the largest users of ferrosilicon. They consume more than 90 percent of ferrosilicon. Among various grades of ferrosilicon, the most widely used is 75% ferrosilicon. In the steelmaking industry, approximately 3-5kg75% ferrosilicon is consumed for each 1t of steel produced.