Stability Of Ferrosilicon Nitride

Ferrosilicon nitride is a mixture with Si3N4 as the main component, usually accompanied by free iron, non-ferrosilicon nitride, and a small amount of other components. It is widely used in steelmaking and refractory material production, especially blast furnace slurry. It can greatly improve the plugging properties of drilling fluid and meet the needs of blast furnace. The stability of ferrosilicon nitride shows well at high temperatures, especially in a nitrogen atmosphere, where it can maintain high stability.



A study of the high-temperature stability of ferrosilicon nitride in a nitrogen atmosphere showed that the phase composition changes with an increase in calcination temperature. For example, at a temperature of 1500 °C, phases such as β-Si3N4, α-Si3N4, Si2N2O, SiC and Fe3Si are present in the sample; at 1600°C, the β-Si3N4 content increases, and three ferrosilicon alloys - Fe3Si, Fe5Si3 and FeSi - coexist. At the same time, α-Si3N4 and Si2N2O disappear; when the temperature rises to 1700°C, the β-Si3N4 content decreases significantly, the α-Si3N4, Fe5Si3 and FeSi phases coexist, and the Fe3Si phase disappears.



The stability of ferrosilicon nitride is also related to its particle size. The larger particle size of ferrosilicon powder favors the nitride reaction because the larger ferrosilicon powder will not cause too fast a nitride reaction in the early stage of the reaction, thus avoiding overbaking. In addition, ferrosilicon nitride has a number of advantages, such as high fire resistance, good corrosion resistance, high mechanical strength, good thermal shock resistance, low thermal expansion rate, and high oxidation resistance.