Ferrosilicon is a commonly used additive in the steelmaking process. It has a good deoxidation effect in the steelmaking process. This is because ferrosilicon reacts with oxygen in molten steel to form silicon dioxide, which floats on the surface of molten steel to achieve a good deoxidation effect. The selection of ferrosilicon raw materials also has a great influence on the quality of ferrosilicon.
The main use of ferrosilicon is as a deoxidizer and alloy material for steelmaking. Phosphorus and sulfur are impurities that greatly affect the quality of steel. When ferrosilicon contains more phosphorus, ferrosilicon is easy to powder. Therefore, the phosphorus and sulfur contents are required to be very low. Phosphorus exists in silica in the form of phosphorus pentoxide, and most of phosphorus pentoxide is reduced to ferrosilicon by carbon during the smelting process. Therefore, it is required that the phosphorus pentoxide in the silica does not exceed 0.02%.
The sulfur content in silicon dioxide, because in the smelting process, silicon sulfide is formed from sulfur and silicon, such as SiS, SiS2 and other compounds, these compounds are volatile and run away at high temperature, so the sulfur content of silicon dioxide is not required.
The content of calcium oxide and magnesium oxide in silica is relatively high, which will increase the amount of slag during smelting and corrode the tap hole. For this reason, the total content of calcium oxide and magnesium oxide in the silica is required to be less than 1%.
The selection principle of ferrosilicon raw material is less impurities. If the impurity content is too high, it is easy to cause excessive infiltration of impurities into the molten steel in practical applications, thereby affecting the quality of the steel.