Slagging in Steel Making

The slagging process of molten steel is to control the type and quantity of slag material and add slagging agent, so that slag has oxidation or reduction properties to meet the needs of the steelmaking reaction in the furnace. Production practice shows that slag making is an important means to realize the steelmaking process, and making slag is a prerequisite for making steel. Because, slag will seriously affect the physical and chemical reactions in the furnace, not only is it difficult to remove sulfur, phosphorus and other impurity elements, but also reduce the furnace life, extend the steel-making time, increase raw material consumption and so on.



As far as the chemical properties of slag are concerned, there are mainly two types of steel slag: oxidation slag and reduction slag. In order to strengthen the dephosphorization and desulfurization process, both are alkaline slag; the difference is that they have different requirements for the content of FeO in slag. The sign of reducing slag is that the FeO content in Slag is very low, and the lower the FeO content, the stronger the deoxidation and desulfurization ability of slag. Usually the FeO content of the reducing slag is not more than 0.5%. The purpose of making reducing slag has two main purposes: one is to reduce the oxygen content of the molten steel, so as to reduce the burning loss of the alloying elements added when adjusting the composition of the molten steel. The second is to desulfurize more effectively. Although the oxidation slag can also remove part of the sulfur, the effect is far less than that of reduction refining.
The dephosphorization process in steelmaking is mainly carried out at the interface between steel and slag and two phases. Therefore, to make slag, we must try to make slag have physical and chemical properties suitable for dephosphorization reaction; at the same time, we must carefully control the slag making process, that is, adjust the composition of slag with the temperature change during the smelting process, so that the slag physical and chemical properties It can be well coordinated to fully remove the phosphorus in molten steel and reduce the erosion of the furnace lining by slag.