Classification and application of ferro silicon

Ferro silicon is divided into four categories according to the smelting method: high silicon ferrosilicon (GG), ordinary ferrosilicon (PG), low aluminum ferrosilicon (DL) and high purity ferrosilicon (GC). High purity ferro silicon refers to the ferro silicon with low content of impurity elements produced by outside furnace refining.

High silicon iron silicon can be used to prepare semiconductor pure silicon in the electrical industry, and can be used to manufacture silicone in the chemical industry.

The production of low aluminum ferro silicon is made by using natural silica as raw material, metallurgical coke as reducing agent and adding a certain amount of iron-bearing material in ore-heat electric furnace

High purity ferro silicon can be used as deoxidizer and alloy additive, mainly used in the production of steel cord, clean steel, non-oriented silicon steel, oriented silicon steel, high density plate, alloy steel and other high-end steel. Its deep processing materials are widely used in many fields such as electrical engineering and automobile manufacturing.

Use of ferro silicon

Used as deoxidizer and alloying agent in steelmaking industry. In order to obtain the chemical composition of qualified steel and ensure the quality of steel, in the final stage of steelmaking must be deoxidized, the chemical affinity between silicon and oxygen is very large, so ferro silicon is a strong deoxidizer for precipitation and diffusion in steelmaking.

Adding a certain amount of silicon to steel can significantly improve the strength, hardness and elasticity of steel, so when smelting structural steel (containing silicon 0.40-1.75%), tool steel (including SiO.30-1.8%), spring steel (including SiO.40-2.8%) and transformer silicon steel (containing silicon 2.81-4.8%), 

Ferro silicon 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 steel quality, reduce cost and save iron. It is especially suitable for continuous casting steel deoxidation requirements. Practice has proved that ferro silicon not only meets the deoxidation requirements of steelmaking, but also has desulfurization performance and has the advantages of heavy ratio and strong penetration

The production method of high quality ferro silicon products:

(1) Screening raw materials silica, reducing agent, steel or/silicon steel chips, silica for quartz stone or white silica, black silica, reducing agent for metallurgical coke and gas coke, or charcoal and gas coke, charcoal and petroleum coke and wood blocks, according to the exact composition content of various raw materials and the variety to be produced for all elements of the requirements, According to the known technology, the amount of each raw material is calculated, mixed and filled into the ore furnace according to the usual smelting conditions and operations of ferro silicon alloy smelting.

(2) Before oxygen blowing at the bottom of the furnace for refining and ferro silicon ore drawing, add the calculated amount of pre-fused slag or/and silica fume, quartz powder, CaF2 or CaO to the refined hot metal ladle to adjust the composition of the slag to the weight content of SiO2 > 60%, CaO < 30%, and other < 10%. After baking the pre-fused slag of the hot metal ladle to > 200℃, The hot metal is loaded into the ore furnace, and oxygen or air is blown into the bottom of the bag, oxygen and helium, air and helium, air and oxygen are refined outside the furnace. The gas pressure is > 0.5MPa, the gas flow rate is > 6Nm3/h, and the refining time is 30-40 minutes.

(3) The ferro silicon containing C < 0.03% is required to remove the silicon carbide (SiC) precipitated on the surface and the slag adhering to the surface of the ingot after cooling, so as to obtain high-quality ferro silicon products.