Thermodynamic model and electric smelting of a mixture of cake from leaching of vanadium-containing quartzites with coal beneficiation tailings

The article presents the results of studies of obtaining a ferroalloy from a mixture of coal beneficiation tailings and cake from leaching of vanadium-containing quartzites (black shales) of the Balasauskandyk deposit. The study was carried out using the HSC-6.0 software package, using the Equilibrium Compositions module and the second-order rotatable planning method (Box-Hunter plan), followed by geometric optimization of equilibrium process parameters. Based on the studies on the interaction of coal beneficiation tailings and cake from leaching of vanadium-containing quartzites in the presence of iron, it was found that under equilibrium conditions, an increase in the ratio of coal beneficiation tailings to leaching cake, which allows increasing the degree of silicon extraction in FeSi, Si, is accompanied by undesirable development of SiC formation and positive decrease in the degree of gaseous SiO formation. In the temperature range of 1500-2000 degrees C, an increase in the tailings to the cake ratio from 0 to 1.7 increases the degree of silicon extraction into the alloy to 67.8% at 1900 degrees C and aluminum to 33.94% at 2000 degrees C. Ferrosilicon of the FeSi45 grade, with 51.1-66% Si extraction into it, is formed in the temperature range of 1703-1900 degrees C from a mixture of tailings and cake with their ratio from 0.38 to 1. By electric smelting of a mixture of tailings (containing 30-47% C) with cakes with a ratio from 1.0 to 0.32 together with steel cuttings, a ferroalloy - ferrosilicon of the FeSi45 grade with a content of 37-42% Si was obtained.