CORROSION-RESISTANCE OF CARBON-CONTAINING MAGNESIA REFRACTORIES IN MELTS

The dissolution behavior of carbon-containing magnesia compared to the corresponding unfilled porous magnesia and to single crystal was studied in melts under forced convection, simulating the conditions in oxygen steelmaking. The technique used was capable of following both the rate of oxidation of carbon in carbon-containing magnesia in contact with simple melts and also the accompanying corrosion of magnesia. The study revealed that the carbon reduced the rate of corrosion of magnesia in borate and in silicate melts. The opposite occurred in vanadate melt. The dependence of corrosion rate of magnesia on the oxidation rate of carbon suggested that the role of carbon was to resist slag penetration by blocking the pores in viscous melts at the temperature range investigated.