Erosion mechanism of magnesia carbon bricks for EAF linings
Generally, magnesia carbon bricks
are made of high-quality magnesia, high-purity graphite, silicon, silicon carbide and other additives, and are pressed with phenolic resin as a binder. The basic requirements of electric furnace for magnesia carbon bricks are:
(1) Low thermal conductivity to ensure less heat loss and improve the thermal efficiency of the electric furnace;
(2) The coefficient of resistance to thermal chemical and thermal physical corrosion is high, that is, it is required to have good volume stability;
(3) Anti-slag, anti-peeling, anti-oxidation and high compressive strength, so as to obtain low consumption and long life.
When baking a new lining, the following main reactions occur when the lining temperature reaches 750°C:
Reaction formula 1 is mainly that the generated magnesium gas and carbon monoxide gas migrate to the high temperature area along the pores, and reaction formula 2 is that the magnesium gas on the surface of the furnace wall is oxidized to magnesium oxide again by oxides, and it has a high composition with other trace compounds in the magnesia carbon brick. The melting point of petrographic compounds. Therefore, the key to maintaining the volume stability of EAF magnesia carbon bricks
is to control the temperature system of the oven and prevent the occurrence of a large number of reaction formula 1, which is very important in both converters and electric furnaces.