Extraction kinetics of silicon, aluminum, and calcium from dubersay basalt by electric smelting

Abstract

This article presents experimental results of extraction of silicon, aluminum into ferrous alloys and calcium into calcium carbide by electric smelting of basalt from Dubersay deposit. The studies were performed using thermodynamic simulation and electric smelting in arc furnace. The thermodynamic simulation was performed using HSC-5.1 software based on the principle of minimum Gibbs energy. The studied blend was smelted in one-electrode lined arc furnace. The experimental results of extraction of silicon, aluminum, and calcium from Dubersay basalt demonstrated that under equilibrium conditions, interaction of basalt with carbon and iron was accompanied by formation of CaSiO3, Al2SiO3, FeSi, SiO2, SiC, CaSi, Na2SiO3, SiO(g), Si(g), CaC2, CaO, Ca(g), Al2O3, Al, Al(g). During electric smelting of basalt it was detected that without lime silicon and aluminum were maximally extracted into alloy, and calcium into calcium carbide – in 30-45 min, herewith, the maximum extraction rate (76.5%) was observed for silicon extraction into alloy, and the minimum rate (65.3%) – for calcium extraction into carbide; when 25% of lime were added to basalt, the rate of calcium extraction into calcium carbide increased to 87.3% with simultaneous decrease in the rates of silicon and aluminum extraction into alloy to 71.4% and 60%; respectively; in order to achieve the rate of silicon and aluminum extraction into alloy of 76.1-76.8% and 70.0-72.4%, respectively, and of calcium into calcium carbide of 77-79.4% with production of calcium carbide of 235-239 dm3/kg, the electric smelting of basalt should be performed with 7.3-11.2% of lime from basalt weight in 36.2-33.9 min.