MgO-C refractories are widely used in steel industry especially in steel ladles, BOF and EAF. They are exposed to mechanical and thermal stresses as well as interaction with corrosive media. In contact with slag or metal most severe wear can be observed, that’s why high purity raw materials must be used to withstand those conditions. Usually, in order to strengthen the thermo-mechanical properties of MgO-C materials, they are achieved by introducing antioxidant additives, which at high temperatures create ceramic forms that strengthen their structure. However, other additions may be considered in this area. Aggregates containing CaO and MgO-bearing aluminates improve selected slag resistance but also are one of the most promising solutions for stabilization for steel ladle lining.
Application in the laboratory test different grain sizes of aluminate aggregate to MgO-C refractories improved the slag resistance by contact layer formation, but also allowed to control the secondary dimensions change after heating end thermal expansion. Research included tests of the possibility of using recycled raw materials in combination with aluminates. Obtained results enabled to design a complete ladle lining construction optimal for ladles with silicon-killed steel process and high thermomechanical stress in advanced secondary metallurgy. Laboratory samples and post mortem samples observation of microstructure by SEM/EDS method allow to explain influence aluminates on slag attack and thermal stress resistance especially by joints enforcement.