Evolution of iron-based raw materials and their effect on the properties of MgO-Al-C slide plate materials

MgO-Al-C slide plate refractories were prepared using magnesia, aluminum powder, and carbon black as raw materials and phenolic resin as a binder. The evolution of three iron-based raw materials and their effects on the properties of MgO-Al-C slide plate materials were investigated. The obtained results showed that (1) the oxidation of iron and generation of a (Mg,Fe)O solid solution and composite spinel were accompanied by a volume expansion, which promoted bonding. When the addition of metallic iron was 2 wt.%, the strength and thermal shock resistance of the material improved. The residual strength ratio was 12.1% higher than that of the F0. (2) The added iron oxide transformed into magnesioferrite flakes and a magnesium-iron-aluminum composite spinel, which promoted the generation of tadpole-shaped magnesium aluminate whiskers and the densification of the material. When the content of iron (III) oxide was 2 wt.%, the strength and oxidation resistance of the material improved. The oxide layer area was decreased by 33% when compared with that of the F0. (3) Owing to the low thermal expansion coefficient of hercynite, microcracks were produced around it. When the loaded amount of hercynite was 6 wt.%, the thermal shock resistance of the material improved. The residual strength ratio was 12.5% higher than that of the F0. Graphical abstract