various grades of ferrosilicon and the effect of carbon on FeSi
Common grades of ferrosilicon
1. Ferrosilicon 75. Generally, silicon iron containing silicon 75. Low carbon, phosphorus and sulfur content,
2. Ferrosilicon 72. Typically ferrosilicon containing silicon 72. Carbon, sulfur and phosphorus are moderate.
3. Ferrosilicon 65. Ferrosilicon containing silicon 65. The carbon, sulfur and phosphorus contents are relatively high.
Among the various grades of ferrosilicon, the most widely used is 75% ferrosilicon. In the steelmaking industry, about 3-5 kg of 75% ferrosilicon is consumed for every 1 t of steel produced.The physical and chemical properties of ferrosilicon>>
The steelmaking industry, the foundry industry and the ferroalloy industry are the largest users of ferrosilicon. They consume more than 90% of ferrosilicon.
1. The role of ferrosilicon in steelmaking.
Used as a deoxidizer and alloying agent in the steel industry.
In order to obtain a chemically qualified steel and to ensure the quality of the steel, deoxidation must be carried out in the final stage of steelmaking. The chemical affinity between silicon and oxygen is large. Therefore, ferrosilicon is a strong deoxidizer for steel making. It is used for precipitation and diffusion deoxidation.
2. The role of ferrosilicon in cast iron.
Used as an inoculant and spheroidizing agent in the cast iron industry.
Cast iron is an important metal material in modern industry. It is cheaper than steel. And easy to melt and smelt.
Cast iron has excellent casting properties and much better seismic performance than steel. The addition of a certain amount of ferrosilicon to the cast iron prevents the formation of carbides in the iron and promotes the precipitation and spheroidization of the graphite.
3. The role of ferrosilicon in the production of ferroalloys.
Can be used as a reducing agent in the production of ferroalloys.
The chemical affinity between silicon and oxygen is very large. Moreover, the high silicon ferrosilicon has a very low carbon content. Therefore, high silicon ferrosilicon is a reducing agent commonly used in the production of low carbon iron alloys.
4. The use of ferrosilicon in other areas.
The finely or atomized treated ferrosilicon powder can be used as a suspension phase in the beneficiation industry. It can be used as a coating for welding rods in the electrode manufacturing industry. High silicon ferrosilicon can be used in the chemical industry to make products such as silicone.
Effect of carbon on ferrosilicon
Ferrosilicon contains a fixed amount of carbon. Too low carbon will affect the quality of steel during smelting.
One of the raw materials used to produce ferrosilicon is called coke. It serves as a reducing agent in the process of making ferrosilicon.
When the temperature reached 1187 ° C, the coke began to dissolve. The higher the silicon content in the ferrosilicon, the lower the carbon content.
When the silicon content in the ferrosilicon is more than about 30%, most of the carbon in the ferrosilicon exists in a silicon carbide (SiC) state. Silicon carbide is easily reduced by oxidation of silicon dioxide or silicon monoxide.
Silicon carbide has a low solubility in ferrosilicon. Especially when the temperature is low. The silicon carbide remaining in the ferrosilicon is very low. Therefore, ferrosilicon has a very low carbon content.