1. Optimize the refining system and improve the smelting conditions.
In the refining process, light burnt dolomite is often added to increase the concentration of magnesium oxide in the slag, so as to increase the alkalinity and viscosity of the slag, and reduce the FeO content in the slag. After experiments by multiple manufacturers, the FeO content in the slag is controlled within When the content of MgO is about 0.5% and the content of MgO is controlled at about 12%, adjusting the viscosity of the slag can effectively reduce the erosion of magnesia carbon bricks by the slag.
2.Use better refractory materials.
Because the corrosion resistance and thermal shock resistance of magnesia carbon bricks are mainly affected by the raw materials of refractory bricks , such as the quality of magnesia, the distribution of particles and the selection of additives. The higher the purity of the magnesia used in magnesia-carbon bricks, the less B2O3 in impurities and the higher the carbon-sulfur ratio. At this time, the lining bricks have better corrosion resistance. The magnesia-carbon brick slag line with fused magnesia as raw material whose carbon content is controlled at about 14% has better corrosion resistance.
3.Change the masonry technology and optimize the brick design.
Regardless of whether it is a newly built ladle or a minor repaired ladle, we must pay attention to the structural problems of the refractory lining. Such as the difference between flat and vertical masonry, the dislocation of the new slag line and the joint during minor repairs, and the working layer and permanent layer during masonry,the treatment of cement and so on.
4. Control the argon blowing and power-on system.
LF furnaces generally have three-phase electrodes. If the position of the electrode is shifted, the heat of the steel slag near the electrode and the temperature of the slag will be too high, which will cause destructive erosion of the slag line magnesia carbon brick.
5.Add anti-oxidation coating to the inner lining of the ladle furnace.
In some units, when the ladle is built and baked, the carbon-containing working layer is not treated with anti-oxidation during the baking process. As a result, the magnesia carbon brick layer has an oxidized decarburization layer of tens of mm after the baking is completed. Therefore, the service life of the magnesia carbon brick at the slag line can be increased by adding an anti-oxidation coating.