Influence of Fe2O3 on the Hydration Resistance of MgO-Al-C Bricks

In order to improve the hydration resistance of MgO-Al-C bricks, Fe2O3 was chosen as an additive according to thermodynamic calculations. MgO-Al-C refractories were prepared by using Si, Fe2O3 or both as additives. The effects of additives on the hydration resistance of specimens were investigated. XRD was conducted to determine the phase composition. The results showed that the hydration resistance of MgO-Al-C bricks would be slightly bettered with addition of only Si. However, it was helpful when Fe2O3 was added along with Si. The mechanism is that Fe2O3 could decompose to give off oxygen during heating, which could promote the oxidation of Al powder and inhibit the formation of Al4C3 and AlN.