THERMODYNAMIC MODELING OF THE PROCESS OF SMELTING A COMPLEX CHROMIUM-MANGANESE-SILICON-CONTAINING FERROALLOY

This article presents the results of thermodynamic modeling of the process of smelting chromium-manganese-silicon-containing ferroalloy from technogenic raw materials of Kazakhstan. Thermodynamic modeling of chromium-manganese-silicon-containing ferroalloy was carried out using the HSC Chemistry 6 software package (Outokumpu, Finland), based on the principles of minimizing the Gibbs energy and thermodynamic variational principles. Thermodynamic analysis for modeling the process of smelting a complex alloy was carried out in the temperature range from 500 to 2000 ℃ for four real charge compositions (with a 5% deficiency of solid carbon, with a normal course of the regime, and with an excess of solid carbon of 5% and 10% of the stoichiometry). The mechanism of combined carbothermic reduction of silicon, manganese, chromium and iron was studied using the Fe-Cr-Mn-Si-Al-Ca-Mg-C-O system. The calculations performed allowed us to fully study all the physicochemical processes occurring during smelting of chromium-manganese-silicon-containing ferroalloy using the carbothermic method. Based on the thermodynamic data, the optimum consumption of solid carbon per 100 kg of charge (chromium and manganese dust) was determined to be 10.75 kg. The chemical composition of the ferroalloy at 1800 °C is, %: Cr - 35.84; Mn - 24.47; Si - 16.25 and Fe - 22.63. Keywords: complex ferroalloy, carbothermic process, chromium-manganese-silicon-containing ferroalloy, thermodynamics, reduction.