The production process of ferroalloy mainly includes the following methods:
Blast furnace method: The smelting of ferroalloy in blast furnace is similar to the smelting of pig iron in blast furnace. The high temperature and reducing atmosphere of blast furnace are used to reduce alloy ore to make ferroalloy. The blast furnace method is mainly used to produce high carbon ferromanganese, low silicon ferrosilicon and specular iron. This method has high labor productivity and low cost, but the existence of oxidation zone in blast furnace limits the reduction of some high melting point or difficult to reduce oxides.
Electrothermal method: In the reduction furnace, electric energy is used as heat source and carbon is used as reducing agent to reduce ore to produce ferroalloy. The electrothermal method is suitable for the production of difficult to reduce oxides such as CaO, Al2O3, etc., but the disadvantage is that the product has a high carbon content. In order to obtain low carbon alloy, siliceous reducing agent is usually used instead of carbon.
Electric silicon thermal method: Silicon (such as ferrosilicon or silicomanganese alloy) is used to reduce ore, oxide or slag in an electric furnace, and lime is used as flux to produce ferroalloy. This method is suitable for producing micro-carbon ferrochrome, medium- and low-carbon ferrochrome, and ferromanganese, etc. The carbon content of the product depends on the carbon content of the raw materials.
Metallothermic method: also known as the off-furnace method, using aluminum, ferrosilicon and other reducing agents for reduction reaction, suitable for producing ferroalloys or pure metals with extremely low carbon content, such as ferrotitanium, ferromolybdenum, ferroboron, etc.
Converter method: Add liquid high-carbon alloy into the converter, blow oxygen to decarbonize and obtain medium- and low-carbon alloy. This method is mainly used to adjust the carbon content of the alloy.
