ferrosilicon smelting and application

Silicon and iron can form silicides such as Fe2Si, Fe5Si3, FeSi, FeSi2, etc. These are the main components of ferrosilicon. The silicon in ferrosilicon mainly exists in the form of FeSi and FeSi2, especially FeSi is relatively stable.

The main raw materials for smelting ferrosilicon are silica, coke and iron filings:

(1)Silica generally uses quartz and quartzite with a high content of SiO2. The content of SiO2 is required to be greater than 97%. Silica is a fairly stable oxide,it requires a relatively high temperature during reduction,if there is a high content For other compounds, much higher reaction temperatures will be required.

(2)The carbonaceous reducing agents used in production mainly include metallurgical coke, petroleum coke, pitch coke, bituminous coal and charcoal. Taking the silicon thermal method to produce ferrosilicon as an example, when choosing a carbonaceous reducing agent, the main indicators that should be considered are fixed carbon, ash, volatile and moisture. Generally speaking, charcoal is an ideal carbonaceous reducing agent, but charcoal is expensive; high-quality low-ash bituminous coal, gas coal coke, semi-coke and other carbonaceous reducing agents have excellent physical and chemical properties but poor mechanical strength; Relatively speaking, metallurgical coke has sufficient sources, low price, high fixed carbon, and high mechanical strength, so it is currently the most widely used as carbonaceous reducing agents.

(3)When ferrosilicon is produced, the iron-containing material is the regulator of the ferrosilicon composition.When smelting ferrosilicon in an electric furnace, steel scraps are generally used as iron-containing materials, which can promote the reduction of silicon dioxide during the reduction of silicon dioxide.In order to promote the melting of iron filings as soon as possible, the length of iron filings generally used does not exceed 100mm. In order to ensure the chemical composition and internal quality of ferrosilicon, alloy steel filings, non-ferrous metal filings and pig iron filings are not allowed, but only carbon steel scraps,and the iron content of steel scraps should be greater than 95%.

Ferrosilicon is widely used in industrial sectors such as steelmaking industry, foundry industry and ferroalloy industry.

(1)In the steelmaking industry, it is used as a deoxidizer and alloying agent. In addition, it uses the characteristics of high-temperature combustion of ferrosilicon powder to release a large amount of heat,so often used as a steel ingot cap heating agent to improve the quality and recovery rate of steel ingots.

(2)It is used as an inoculant and spheroidizing agent in the foundry industry. Adding a certain amount of ferrosilicon to cast iron can prevent the formation of carbides in the iron and promote the precipitation and spheroidization of graphite,therefore, in the production of nodular cast iron, ferrosilicon is a kind of important inoculant and spheroidizing agent.

(3)Used as a reducing agent in the ferroalloy industry, silicon has a great chemical affinity with oxygen,especially for high-silicon ferrosilicon, the carbon content is very low,so often used as a reducing agent for the production of low-carbon ferroalloys in the ferroalloy industry.

Among the various grades of ferrosilicon, the most widely used are 75% and 72% ferrosilicon. In the steelmaking industry, about 3-5kg of ferrosilicon is consumed per ton of steel produced. There are also other materials related to ferro silicon, such as ferro calcium silicon, ferro barium silicon, ferro barium calcium silicon etc, Anyang Huatuo Metallurgy Co.,Ltd in such materials for more than 10 years, if any interests welcome for consult.