Cause analysis of damaged electric arc furnace lining

During the smelting process, the furnace body of the electric arc furnace is in a high temperature state, and the electric arc furnace lining is continuously subjected to chemical erosion and mechanical erosion at high temperature. After each furnace of steel is smelted, the EAF refractories lining is damaged to varying degrees. Therefore, after each furnace is tapped, the furnace must be repaired in time, which is an important measure to ensure the normal smelting and prolong the furnace life.

Furnace lining includes furnace wall, furnace bottom and furnace roof. Among them, the furnace wall has the lowest service life, and its working conditions are the worst. Not only is it close to the arc, the temperature is high, and it is also susceptible to serious erosion by slag.

Furnace lining is generally composed of alkaline materials. Basic oxides (such as CaO, MgO, MnO) in slag have little corrosion effect on furnace lining, while acidic oxides (such as SiO2, TiO2, ZrO2, P2O5, etc.) in slag are corrosive to furnace lining. Great effect. Furnace age is mainly directly related to w(SiO2) in the slag. The basicity of basic electric arc furnace slag is generally between 24, which makes the slag have less erosion ability and higher impurity removal ability.

The furnace lining is seriously damaged or the magnesia used for repairing the furnace is not completely sintered and enters the slag, resulting in a large increase of MgO particles in the slag.

The poor fluidity of the slag directly affects the chemical reaction between the slag and the steel, which increases the inclusions in the steel and seriously reduces the quality of the steel.