Abstract: In order to optimize the performance of MgO-C refractories, the fused magnesia, flake graphite and silicon powder-loaded ferric nitrate were used as the raw materials, and the thermosetting phenolic resin was used as the binder to prepare MgO-C refractories by high temperature nitriding. The effects of the addition of catalysts and different nitriding temperatures on the structure and properties of MgO-C refractories were investigated. The results show that when the nitriding temperature was 1 200 ℃, the addition of catalyst could promote the generation of α-Si3N4, SiC and Mg2SiO4, and significantly improved the mechanical strength of the material compared with the sample without catalyst. The α-Si3N4 formed in the sample with 1% catalyst showed granular and whisker-like morphologies, which were interwoven. Mg2SiO4 existed in a blocky morphology. As the nitriding temperature increased to 1 300 ℃, a small amount of acicular Mg2SiO4 was formed, and the blocky Mg2SiO4 grains grew. At this time, the material exhibited good mechanical strength, and the cold modulus of rupture and cold crushing strength were 10.82 MPa and 55.17 MPa, respectively.
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