Ferro silicon nitride(Fe-Si) is a new kind of material. It is mainly used in the steel industry and refractory.
What is ferro silicon nitride?
Ferro silicon nitride is mainly composed of Si3N4, free iron, FeSi, and a small number of impurities. It uses Ferro Silicon (FeSi75) as raw material and uses nitrogen and a high-temperature synthesis process to prepare.
The ferro silicon nitride lump of grey white color is used for steelmaking. It is mainly used in the production of oriented silicon steel or HRB400 rebar.
The ferro silicon nitride powder of grey white and dark brown color is used for blast furnace and refractory material.
What are the uses of ferro silicon nitride?
Ferrosilicon nitride can be used as a steel alloy addition, as refractory production blast furnace mud, and other refractory materials.
Ferro silicon nitride used in steel industry
In the steel industry, ferrosilicon nitride is used in the production of oriented silicon steel or HRB400 rebar. It can steadily add a certain amount of nitrogen to molten steel. China consumes hundreds of tons of ferrosilicon nitride a year.
In recent years, due to the improvement of smelting technology, the production of high-strength microalloyed steel in China developing rapidly.
The strengthening microalloying elements of steel mainly include vanadium, niobium, titanium, etc. To produce a ton of HRB400 steel bars, using FeV50+FeSiN costs $7 less than using VN12 and $20 less than using FeV50 alone. The use of ferrosilicon nitride reduces the production cost of construction steel and improves the economic benefit of enterprises.
Ferro silicon nitride used in taphole clay of large blasting furnace
Nitriding ferro silicon contains Si3N4, which is widely used in taphole clay of large blasting furnaces. Compared with silicon nitride, ferrosilicon nitride has many advantages:
- FeSiN contains metal phase Fe which accelerate the sintering process.
- FeSiN is much cheaper than silicon nitride.
Ferrosilicon nitride is widely used in taphole of blast furnaces in developed countries, which treats the plugging of blast furnace mud, meets the needs of blast furnace iron tapping, and becomes an indispensable component of the modern large blast furnaces.
| Since the 1970s | Japan took the lead in using ferrosilicon nitride in taphole clay of blast furnace. | The excessive preparation cost has greatly restricted its further development. |
| In the 1990s | Baosteel added ferrosilicon nitride in the taphole clay of the blast furnace. | Improve the properties of taphole clay, meet the requirement of iron-making. |
| In the 2020s | Most large-scale steel enterprises in China used ferrosilicon nitride in the taphole clay of blast furnaces. | The price of ferro silicon nitride is only half that of silicon nitride. The number of blast furnace tapping times is generally reduced from 18 times to 12 times, and the lowest is reduced to 6 times. The consumption of taphole clay has been reduced from 1.2kg/ton to 0.5kg/ton of iron. |
Ferro silicon nitride used in refractory industry
Ferrosilicon nitride contains Si3N4 and Fe. It has a series of excellent properties such as good high-temperature performance, small thermal expansion coefficient, good thermal shock resistance, and resistance to slag penetration. Therefore, it is widely used in refractory materials.
- Al2O3-SiC-C series refractory material
Ferro silicon nitride is widely used in tap hole clay, iron ditch material, and refractory brick.
- Fe-Si3N4-SiC composite material
Fe-Si3N4-SiC with high-temperature property is widely used in blast furnace, aluminium cell,etc. It can improve the thermal shock resistance of the material and has a good application prospect in the high temperature field.
- Other refractory materials
University of Science and Technology Beijing used corundum and spinel as raw materials, adds fine powder of ferrosilicon nitride, and produces low cost corrosion-resistant, anti-oxidation, and chromium-free refractory materials. This material with excellent physical properties, it can replace magnesite-chrome brick used in RH refining furnace.
With the development of technology, people have a deep understanding of ferrosilicon nitride, and the use of ferrosilicon nitride will be broadened. We look forward to a better prospect for the application of ferrosilicon nitride.