Thermodynamic and experimental substantiation for obtaining ferrosilicon from tripoli

Abstract

The article examines the results of studying the possibility of obtaining ferrosilicon from tripoli. The studies included the thermodynamic modeling using the HSC-6.0 software package, based on the minimum Gibbs energy principle, and electric melting of tripoli in an arc single-phase electric furnace. The effect of temperature and the amount of carbon on the extraction degree of silicon into alloys and the silicon concentration in these alloys were determined. It was found that the interaction products of tripoli with carbon and iron under equilibrium conditions are mainly FeSi2, Fe3Si, FeSi, Fe5Si3, SiC, SiO(g), CaSiO2, MgSiO3, Al, Si, CO; the silicon extraction degree of 70–77% and its concentration in the alloy of 44.9–47.7% were achieved in the temperature range of 1830–2000 °C in the presence of 34–38% of carbon and 29% of iron; in the temperature range of 1700–1900 °C, the extraction degree of silicon into the alloy was 50–77.1%, and the concentration of silicon in the alloy at 1900 °C was 45–45.85%. During the electric melting of tripoli together with coke and steel shavings, depending on the composition of the charge, FS25 and FS65 ferrosilicon was formed.