The processes of iron oxides’ reduction have a complex physicochemical mechanism, with the participation of solid, liquid, and gaseous substances. The article discusses the existing models for the reduction of iron oxides and provides data on the thermodynamic possibility of carrying out the reactions of their reduction through the solid and gas phases. Experimental data on the reduction of iron from industrial scale, obtained by the DSC (differential scanning calorimetry) method, show the kinetic dependence of the rate and completeness of recovery on external factors: pressing pressure during sample preparation and the reagents’ composition. The pressing pressure, under conditions of iron ions’ solid-phase diffusion, has the significant effect by increasing the reagents’ contact area. Under conditions of iron ions’ comprehensive diffusion, the pressing pressure does not affect the reduction processes rate. The introduction of 10 mass.% flux into the raw mixture composition leads to a partially liquid-phase diffusion of iron ions and weakens the effect of the pressing pressure in this process. An ion diffusion-catalytic mechanism is proposed to describe the observed effects during the reduction of iron oxide of technogenic origin.

The stabilization of refining slags in ladle treatment with alumina fluxes is studied. In refining, the slag is stabilized in the presence of alumina fluxes thanks to isomorphic replacement of a calcium ion by alkali-metal ions and to decrease in the dicalcium-silicate content in the melt as a result of its replacement by aluminum-bearing phases.

There are two main kinds of slag in modern steelmaking industry: the electric arc furnace slag (the EAF slag) which is produced in the manufacture of crude steel by the electric arc furnace process and the ladle furnace basic slag (the LF slag) which is produced at the final stages of steelmaking, when the steel is desulfurized in the transport ladle, during what is generally known as the secondary metallurgy process.