Effects of resin and graphite content on density and oxidation behavior of MgO-C refractory bricks

The effects of resin type and content as well as graphite content on physical and mechanical properties of MgO-C refractories, such as density, porosity and strength were studied. The samples were formulated with various amounts of graphite and resin, and their oxidation behavior was isothermally investigated using a thermo gravimeter (TG), in air and at a temperature ranges from 900 to 1300 °C. The results indicated that, low-viscosity resins improved compressibility, but it degraded the strength. Higher resin content also improved the compressibility, but it caused higher porosity after preheating at 600 °C. The results also showed that the porosity and density of tempered samples were decreased when graphite content were increased. During oxidation process, the rate of weight loss was high at the beginning, but it was gradually decreased when the thickness of decarbonized layer increased. Higher graphite content increased the weight loss, but it would reduce the thickness of oxidized layer.