Exothermic Effects and Viscosity of Oxide Melts Formed During High-Temperature Reduction of Cr–Mn Ore Systems

This study investigates the exothermic effects and viscosity properties of multicomponent oxide melts during the high-temperature reduction of low-grade Cr–Mn ores. Unlike previous thermodynamic-focused research, this work provides experimental evidence of transient exothermic responses and correlates them with melt properties. High-temperature experiments identified pronounced exothermic effects in the 800–1600 °C range. Phase analysis (XRD, SEM–EDS) confirmed effective Cr and Mn reduction into Fe–Cr–Mn–Si alloys with minimal residual oxides in the slag. Effective viscosity, measured via the electrovibrational method at 1400–1650 °C, decreased monotonically with temperature. Arrhenius analysis was applied to determine activation energies and crystallization onset temperatures (Tcr). The results indicate low viscosity and high thermal stability of the slags, ensuring efficient metal–slag separation. These findings confirm the technological feasibility of using low-grade ores for Fe–Cr–Mn alloy production and provide a basis for optimizing industrial smelting.