Abstract: Unburnt magnesia-calcium refractories were prepared by using synthetic magnesia-calcium sand and fused magnesia sand as main raw materials, anhydrous phenolic resin as binder and ferrocene as catalyst.The effect of ferrocene on the properties of unburnt magnesia\|calcium refractories in reducing atmosphere was investigated,and the microstructure of the samples were observed and analyzed by SEM and XRD.The results show that: (1) The addition of ferrocene improves the cold crushing strength,hydration resistance and high temperature performance of the unburnt magnesia-calcium refractories,and their hydration resistance and slag resistance are significantly improved.The increase of refractoriness under load and the improvement of compressive creep performance enhance the practical application ability; (2) Observing the microstructure of the unburnt magnesia-calcium refractories with 1% ferrocene content,it is found that the anhydrous phenolic resin is catalyzed to form an in-situ synthetic grid structure,and iron and carbon elements are mainly distributed in the organic grid structure,performances can be improved; (3) After heat treatment at 1 200 ℃ in a reducing atmosphere,the introduction of ferrocene will still improve the bulk density,apparent porosity and cold crushing strength of the sample.The in-situ synthesis of the organic grid structure and the particle distribution of iron and carbon are still retained even at high temperatures,and are not completely destroyed.

Key words: Reducing atmosphere, Unburnt magnesia-calcium refractories, Ferrocene