Grades Of Ferrosilicon

  • FS Metal
  • Jan 14, 2023
  • Blog

Ferrosilicon is a furnace additive widely used in the steel-making and casting process, which can effectively improve the quality of steel and cast iron. Different grades of ferrosilicon are used in different environments. Currently, the main grades of ferrosilicon that are familiar to the public are ferrosilicon 75, ferrosilicon 72, ferrosilicon 65, ferrosilicon 45, etc. Ferrosilicon 75 is used in large quantities, in the process of steelmaking, it can effectively deoxidize the steel, and in the casting process, it can significantly promote the effect of the breeding of iron.

Grades Of Ferrosilicon

Chemical Specifications Of Ferrosilicon

After assaying ferrosilicon, it is rich in Si, and the rest are trace elements such as Fe, Mn, Al, C, P, and S. The silicon in ferrosilicon is mainly derived from quartz stone, which is rich in SiO2. The quartz stone is heated by an electric furnace, melted and then a carbonaceous reducing agent is used to precipitate the Si out of the SiO2 of the quartz stone, resulting in purer Si. Since ferrosilicon has scrap steel and pig iron in its raw materials, Mn, Al, P, and S are added to it after melting at high temperatures, and C is also added to it due to the use of a carbon-reducing agent.

Grading Basis For Ferrosilicon Grades

Ferrosilicon is classified into grades based on its internal Si content. Ferrosilicon with Si greater than 75% will be classified as Ferrosilicon 75, Si: 72% to 75% as Ferrosilicon 72, Si 65% to 72% as Ferrosilicon 65, and Si 45% to 65% as Ferrosilicon 45% grade. It should be noted that different ferrosilicon grades have differences in HS codes, tax rates, methods of use, and applications.

Grades Of Ferrosilicon Chemical Composition (%)
Si Mn Al C P S
FeSi75A 75.0-80.0 ≤0.4 ≤2.0 ≤0.2 ≤0.035 ≤0.02
FeSi75B 73.0-80.0 ≤0.4 ≤2.0 ≤0.2 ≤0.04 ≤0.02
FeSi75C 72.0-75.0 ≤0.5 ≤2.0 ≤0.1 ≤0.04 ≤0.02
FeSi70 72.0   ≤2.0 ≤0.2 ≤0.04 ≤0.02
FeSi65 65.0-72.0 ≤0.6 ≤2.5 —— ≤0.04 ≤0.02

Different Grades Of Ferrosilicon Applications  

Ferrosilicon 75, Ferrosilicon 72, and Ferrosilicon 65 are a kind of furnace additives widely used in the steel-making and casting process. They can effectively reduce the oxygen content in the steel, lower the oxide content in the steel and promote the flow properties of the steel, thus changing the inclusions morphology and making the impurities float on the surface of the steel for easy cleaning by the staff and effectively enhancing the purity of the steel. In casting, these grades of ferrosilicon are rich in silicon, so they can effectively promote the breeding effect in the iron, resulting in a significant increase in the number of eutectic pellets. In the production process of gray cast iron and ductile iron, these grades of ferrosilicon are widely used, and they can reduce the amount of inoculant used and effectively remove the harmful elements in the iron, significantly reducing the tendency of white mouth and honeycomb holes in the castings.

Ferrosilicon 45 is mainly used in the beneficiation process, processing it into powder, using flotation, which can effectively screen aluminum ore and diamond ore, as it contains certain magnetic properties, so it can be recycled and reused after beneficiation, which can effectively reduce the cost of beneficiation.

How To Choose The Right Grade Of Ferrosilicon?

First of all, you need to choose the right grade of ferrosilicon for your needs. You can determine the required ferrosilicon specifications through calculations and use the results to find the right grade of ferrosilicon. Some users do not know much about ferrosilicon, so you can choose a more established ferrosilicon manufacturer and tell them what you are buying for, and they can recommend the right grade of ferrosilicon for you. The advantage of choosing a ferrosilicon manufacturer is that you will be able to purchase quality ferrosilicon more reliably, and you will also receive good after-sales service after payment. We recommend that you request a sample of ferrosilicon from the manufacturer before you buy, try it and test it, and then discuss the purchase once it meets your requirements. The advantage of doing this is that you minimize the risk of buying ferrosilicon. If you do not know where to find a better ferrosilicon manufacturer, we are a manufacturer with 21 years of experience in ferrosilicon production, with a number of ferrosilicon production experience, with an independent R & D laboratory, after years of development, become a larger set of R & D and production in one of the strengths of ferrosilicon manufacturer, to provide users with more perfect pre-sales and after-sales service. If you are interested in our ferrosilicon products or have any questions about ferrosilicon, you can use the form below or send an email to, we will be the first to serve you.