Introduction
Ferrosilicon is an iron alloy made of iron and silicon. Ferrosilicon is an iron silicon alloy made of coke, steel chip, quartz (or silica) as raw materials by electric furnace smelting. Because silicon and oxygen are easy to combine into silicon dioxide, so ferrosilicon is often used in steelmaking as a deoxidizer, and because of the generation of SiO2 release a lot of heat, in the deoxygenation at the same time, to improve the temperature of molten steel is also beneficial. At the same time, ferrosilicon can also be used as an alloying element additive, widely used in low alloy structural steel, spring steel, bearing steel, heat-resistant steel and electrical silicon steel, ferrosilicon is commonly used as a reducing agent in ferroalloy production and chemical industry.
Purpose
(1) ferrosilicon is used as a deoxidizer and alloying agent in the steelmaking industry. In order to obtain chemically qualified steel and ensure the quality of steel, deoxygenation must be carried out in the final stage of steelmaking. The chemical affinity between silicon and oxygen is very large, so ferrosilicon is a strong deoxidizer for precipitation and diffusion deoxygenation in steelmaking. Adding a certain amount of ferrosilicon to the steel can significantly improve the strength, hardness and elasticity of the steel. Therefore, when smelting structural steel (containing 0.40-1.75% silicon), tool steel (containing SiO.30-1.8%), spring steel (containing SiO.40-2.8%) and silicon steel for transformers (containing silicon 2.81-4.8%), Ferrosilicon is also used as an alloying agent. 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 the quality of steel, reduce the cost and save iron. Ferrosilicon is especially suitable for continuous casting of molten steel deoxidation requirements, practice has proved that ferrosilicon not only meet the requirements of steelmaking deoxidation, ferrosilicon also has desulfurization performance and ferrosilicon has a large ratio, strong penetration and other advantages. In addition, in steelmaking industry, ferrosilicon powder is often used as ingot cap heating agent to improve the quality and recovery rate of steel ingot because it can release a lot of heat at high temperature.
(2) ferrosilicon is used as inoculating agent 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, and has excellent casting performance and much better earthquake resistance than steel. Especially ductile iron, its mechanical properties reach or close to the mechanical properties of steel. Adding a certain amount of ferrosilicon in cast iron can prevent the formation of carbide in iron and promote the precipitation and spheroidization of graphite. Therefore, ferrosilicon is an important inoculant (to help precipitate graphite) and spheroidizing agent in the production of ductile iron.
(3) ferrosilicon is used as a reducing agent in ferroalloy production. Not only the chemical affinity between silicon and oxygen is very large, but also the carbon content of high silicon ferrosilicon is very low. Therefore, high silicon ferrosilicon (or silicon alloy) is a kind of reducing agent commonly used in the production of low carbon ferroalloys in the ferroalloy industry.
(4)75# ferrosilicon is often used in the high temperature smelting process of magnesium metal in the PI Jiang method, and the magnesium in CaO.MgO is replaced. Every ton of metal magnesium is consumed about 1.2 tons of ferrosilicon, and ferrosilicon plays a great role in the production of magnesium metal.
(5) The use of ferrosilicon in other aspects. The fine or atomized ferrosilicon powder can be used as suspension phase in the mineral processing industry. It can be used as coating of electrode in welding rod manufacturing. High silicon ferrosilicon is used in the chemical industry to make products such as silicone.
Among these uses, the steelmaking industry, the casting industry, and the ferroalloy industry are the largest users of ferrosilicon. Together, they consume about 90% or more of the ferrosilicon. In a variety of different grades of ferrosilicon, the most widely used is 75% ferrosilicon. In the steelmaking industry, about 3-5kg75% ferrosilicon is consumed per 1t of steel produced.
