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Ferrosilicon

Ferrosilicon is a ferroalloy consisting of iron and silicon (10-90 % silicon). The common compositions in the market (based on the weight percentage of silicon) are 15%, 45%, 75%, and 90%. At the ferroall factory, 75% ferrosilicon is produced. Ferrosilicon melts between 1210-1315 ℃ and the density is 32.8 gr/cm3. Below chemical components can be seen in detail.

FeCaTiCrMnAlPSCSi
19-22 1 0.2 0.2 0.3 0.7-2 0.03 0.02 0.1 73-78



Ferrosilicon is produced 12000 tons per year, and the ISIC code is as below:

Product NameLatin NameCode ISICStandard
Ferrosilicon 75% Ferrosilicon 75% 2710512317 ASTM A 100-07

Uses
As an essential ferroalloy, ferrosilicon plays a prominent role in the production of steel and cast iron. As a De-oxygenator, ferrosilicon is a perfect alloy to create demanded properties like anti-corrosion, solidity, and heat resistance. Moreover, ferrosilicon is the basis in the production of pre-alloys like ferrosilicon magnesium. This substance is used to optimize the melted malleable cast iron. In brief, there are beneficial uses of ferrosilicon in the industry as bellow:
• As a de-oxygenator in steel production
• As an alloying element in steel and cast iron production
• Nucleation in grey cast irons’ production
• As a reviver in other ferroalloys’ production

Ferrosilicon’s consumption per ton of steel production is different at different factories. It fluctuates between 0.3-0.5 percentages. However, the consumption of stainless steel is 5 to 10 times more than that of carbon steel. Stainless steel production is growing very fast. That is why we are surrounded by ferrosilicon products.

Production method
Ferrosilicon is produced in an electronic arc furnace, and the production process is through reviving the rich silica minerals (quarts) and iron scraps with carbon materials (coal & coke).
In the following section, the production process of FeSi is briefly discussed:
The primary materials are quarts as the main source of silicon, coal and coke as the prime source of carbon, and iron scraps as the chief providers of iron. Through determined weight percentages, these materials are combined and the initial composition is charged into the furnace via transfer pipes. Three graffiti electrodes enter the furnace from above and move downwards. Next, via imposing a high voltage difference, there will be an electronic arc, and the melting process of the charged materials begins. The principal reaction here is reviving the silica with carbon and producing the melted silicon:

(Chemical equation)

Likewise, oxygen reacts with iron scraps resulting in melted iron:

(Chemical equation)

Melted iron and silicon are combined and cast. After cooling, the final product is ground, graded and packed (if required). The central part of the furnace is too hot for the CO2 to be created. The following reaction happens when CO goes up and is combined with air at the upper side of the furnace.