Nano-laminated BN modified graphite reinforced unfired MgO-C refractories: Preparation, properties and strengthening mechanism

To solve the problem of deterioration of oxidation resistance and thermal shock resistance caused by low carbonization of MgO-C refractories, nano-laminated BN modified graphite was prepared by the molten salt method to reinforce unfired MgO-C refractories. The findings revealed that the introduction of nano-laminated BN modified graphite significantly improved the mechanical properties. Moreover, the oxidation index of MgO-C refractories with 4 wt% nano-laminated BN modified graphite was 34% lower than that of the unadded sample, and the residual strength after thermal shock was significantly increased by 224%. Furthermore, incorporating nano-laminated BN modified graphite facilitated the formation of columnar Mg2SiO4, octagonal columnar MgAl2O4, and MgO-Mg2SiO4-MgAl2O4-Mg3B2O6 dense layers, thereby contribute to overall performance improvements.