High temperature mechanical properties of novel MgO–Al3BC3 refractories for electric arc furnace lining

In this study, novel MgO–Al3BC3 refractories were developed by gradually replacing flake graphite with Al3BC3 in unfired low–carbon MgO–C refractories. The high temperature mechanical properties of these novel refractories were investigated for the first time. The results demonstrated significant enhancements in cold crushing strength, thermal shock resistance, and hot modulus of rupture when compared with low–carbon MgO–C refractories. These enhancements can be attributed to the formation of an appropriate amount of boron–containing liquid phases within the novel MgO–Al3BC3 refractories at elevated temperatures. These liquid phases serve multiple functions, including acting as a mineralizer for MgAl2O4, facilitating self–healing by filling cracks and pores, and strengthening the bonding between the aggregate and matrix interface. Furthermore, the thermal stability of Al3BC3 enables it to maintain its functionality consistently, even at high temperatures. •The high temperature mechanical properties of novel MgO–Al3BC3 refractories were investigated for the first time.•The unique self–healing behavior of novel refractories reduces the occurrence of cracks between the aggregate and matrix.•The high thermal stability of Al3BC3 in refractories ensures its continuous functionality at high temperatures.•The optimized novel refractories exhibited exceptional HMOR value, as well as excellent thermal shock resistance.