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 Mg 2 SiO 4 , octagonal columnar MgAl 2 O 4 , and MgO–Mg 2 SiO 4 –MgAl 2 O 4 –Mg 3 B 2 O 6 dense layers, thereby contribute to overall performance improvements.