The Slag Regime of Equipment Used for the Secondary Treatment of Steel and the Durability of Its Refractories

The composition of the ladle slag in units designed for the secondary treatment of steel needs to be optimized in order to increase the service life of the units’ linings. On the one hand, the slag subjects the refractories to chemical wear. On the other hand, under certain conditions the slag is capable of forming a protective crust inside the units. The Nizhniy Tagil Metallurgical Combine has chosen certain refractories for the most heavily worn part of the lining of its vacuum chambers, since only the installation of a lining of a differentiated design that equalizes the rate of wear around the lining’s perimeter will allow the desired effect to be obtained from optimizing the composition of the slag. An efficient composition for the slag was also chosen, the slag having high contents of MgO and Al2O3. The use of such a slag helps form a protective slag crust of the composition MgO·Al2O3 on spinel refractories having the compositions MgO·Cr2O3 and MgO·Al2O3.