Terminology High for silica fume

March 26, 2024

High-silica ore-use

(1) Used as a deoxidizer and alloying agent in the steelmaking industry. In order to obtain qualified steel with chemical composition and guarantee the quality of steel, deoxidation must be carried out in the final stage of steelmaking. The chemical affinity between silicon and oxygen is very high, so ferrosilicon is a strong deoxidizer for steelmaking for precipitation and diffusion. deoxidation. The addition of a certain amount of silicon to the steel can significantly increase the strength, hardness and elasticity of the steel, resulting in the smelting of structural steel (silicon containing 0.40-1.75%), tool steel (containing SiO. 30-1.8%), spring steel ( In the case of SiO. 40-2.8%) and silicon steel for transformers (2.81-4.8% silicon), ferrosilicon is also used as an alloying agent.

In addition, in the steel-making industry, the use of ferro-silicon powder at high temperatures can produce a large amount of heat, which is often used as a steel ingot cap heat-generating agent to improve the quality and recovery of steel ingots.

(2) Used as inoculant and nodulizer 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 performance and much better seismic resistance than steel. Especially ductile iron, its mechanical properties are at or near the mechanical properties of steel. The addition of a certain amount of ferrosilicon in cast iron can prevent the formation of carbides in the iron and promote the precipitation and spheroidization of the graphite. Therefore, in the production of spheroidal graphite cast iron, ferrosilicon is an important inoculant (helping to precipitate out graphite) and spheroidizing agent. .

(3) Used as a reducing agent in the production of ferroalloys. Not only is the chemical affinity between silicon and oxygen very high, but also the carbon content of high silicon ferrosilicon is very low. Therefore, high-silicon ferrosilicon (or silicon alloy) is a reducing agent commonly used in the production of low-carbon ferroalloys in the ferroalloy industry.

(4) Use in other areas. Ground or atomized ferro-silica powder can be used as a suspending phase in the beneficiation industry. It can be used as a coating for welding rods in electrode manufacturing. High silicon ferrosilicon can be used in the chemical industry for the manufacture of silicones and other products.

Among these uses, steelmaking, foundry and ferroalloy industries are the largest users of ferrosilicon. Together they consume about 90% more ferrosilicon. Among the various grades of ferrosilicon, the most widely used at present is 75% ferrosilicon. In the steel-making industry, about 3-5 kg of 75% ferrosilicon are consumed per 1 t of steel produced. Ferrosilicon grade and chemical composition

Grade Chemical Composition

Si Al Ca Mn Cr PSC

The range is not greater than

FeSi75AI1.0-b 72.0-80.0 1 1 0.5 0.5 0.04 0.02 0.2

FeSi75AI1.5-b 72.0-80.0 1.5 1 0.5 0.5 0.04 0.02 0.2

High Silicon Mine - Application

Ferrosilicon is an indispensable deoxidizer in the steelmaking industry. In the torch steel, ferrosilicon is used for precipitation deoxidation and diffusion deoxidation. Brick iron is also used as an alloying agent in steelmaking. Adding a certain amount of silicon to the steel can significantly increase the strength, hardness and elasticity of the steel, increase the magnetic permeability of the steel, and reduce the hysteresis loss of the transformer steel. General steel contains 0.15%-0.35% of silicon, 0.4%-1.75% of silicon in structural steel, 0.30%-1.80% of silicon in tool steel, 0.40%-2.80% of silicon in spring steel, and stainless steel in acid-resistant steel. Silicon is from 3.40% to 4.00%, heat-resistant steel is from 1.00% to 3.00%, and silicon steel is from 2% to 3% or more.

High-silicon ferrosilicon or silico-alloys are used in the ferroalloy industry as reducing agents for the production of low-carbon iron alloys. Ferrosilicon added to cast iron can be used as inoculant for nodular cast iron, and can prevent the formation of carbides, promote the precipitation and spheroidization of graphite, and improve the performance of cast iron.

In addition, ferrosilicon powder can be used as a suspension phase in the beneficiation industry, and as a coating for electrode in the electrode manufacturing industry; high-silicon-ferrosilicon can be used to prepare semiconductor pure silicon in the electrical industry, and can be used to manufacture silicone in the chemical industry.

In the steel-making industry, approximately 3 to 5 kg of 75% ferrosilicon are consumed for each ton of steel produced.