OXIDATION-KINETICS OF GRAPHITE PHASE IN MAGNESIA-CARBON REFRACTORIES

Decarbonization of resin-bonded magnesia-graphite refractories, as one of the most important parameters for brick lining performance in service, has been studied kinetically in the temperature range from 1000 degrees to 1400 degrees C in air, where carbon burnout by oxygen is the dominant decarbonizing mechanism. The rate of carbon burnout was followed by gas analysis, measuring the amount of CO converted into CO2 as a function of reaction time. The experimental results have been rationalized using a mathematical model proposed for the oxidation kinetics, wherein the rate of inward diffusion of oxygen from the exterior atmosphere is predominant.