Oxidation behaviour of magnesia-carbon materials prepared with petroleum pitch as binder

This paper deals with the effect of using petroleum pitch as binder on the oxidation behaviour of magnesia-carbon materials at temperatures below 1000 °C. The materials were prepared at lab scale and included magnesia, graphite, carbon black, sulphur and an external binder (i.e., coal-tar pitch and petroleum pitch). The carbon sources employed in the study exhibited different oxidation behaviours, graphite being the least reactive to air and carbon black the most reactive. For comparative purposes, the most significant differences are observed at the initial stages of oxidation. Thus, degradation of the magnesia-carbon material was found to start to be significant above 600 °C. However, at this temperature oxidation started to have an effect, allowing materials prepared with coal-tar pitch to be discriminated from those prepared with petroleum pitches. The latter materials exhibited a slightly higher resistance to oxidation.