In situ graphitization role on oxidation resistance and physicomechanical properties of resin-bonded Al₂O₃-MgO castables

The properties of carbon-containing refractories (CCRs) depend on the presence of carbon with features close to graphite. However, the thermosetting resins that are used to bind such refractories together during the initial preparation stage usually produce non-graphitic carbon when sintered, which can impair their overall performance. Based on this, ferrocene was used to induce graphitic carbon generation from a resole-type phenolic resin during a sequential carbonization operation. The resin formulation containing the graphitizing agent was then used to prepare resin-bonded Al₂O₃-MgO castables. The role of in situ graphitization of the modified binder on the properties such as cold crushing strength, apparent porosity, and oxidation resistance was examined. The results show that crystallization of the binder carbon can improve the castable oxidation resistance. At ambient temperature, no significant difference was observed in the samples' physicomechanical properties. Nevertheless, holding time during the initial curing stage at 50°C played a significant role on those properties.