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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 AlO. The use of such a slag helps form a protective slag crust of the composition MgO·AlO on spinel refractories having the compositions MgO·CrO and MgO·AlO. [ABSTRACT FROM AUTHOR]

The formation of dense layers of slag crust in a rotary furnace when normal electrocorundum sludge is used in the charge to make mullite-corundum fireclay depends on the chemical-mineral composition of the charge and the components of the crust, wetting processes, and the effect of lower compounds of titanium on the physico-chemical processes which take place. [ABSTRACT FROM AUTHOR]

Results are presented from studies of the reasons for the formation and growth of slag crusts in the crucibles of induction furnaces during the smelting of cast iron. It is established that crust formation and adhesion of slag to the furnace lining are caused by interaction of the lining material with reactants in the melt. The degree of slag incrustation and adhesion depends on the technology used to smelt the cast iron. The formation of slag in the furnace is affected by the existence of large temperature gradients, motion of the melt due to its electromagnetic mixing, the scheduled and unscheduled introduction of additions into the furnace, the entry of harmful components into the furnace together with the charge materials, interactions between the melt, the slag, the furnace atmosphere, and the lining of the crucible, the temperature in the furnace, and the area and rate of reaction of the reactants. [ABSTRACT FROM AUTHOR]