Thermodynamic Simulation of the Manufacture of Fe–Si–Ni–Cr Alloys

Resumo

The reduction of the elements of the system containing (wt %): 40 Cr₂O₃, 21 FeO, 15 Al₂O₃, 6 SiO₂, 16 MgO, 2 CaO, 0.006 P₂O₅ is subjected to thermodynamic simulation when the CaO content increases to a basicity of 3.15. Ferrosilicone (28% Fe, 65% Si; 7% Ni) is used as a reducer. For the simulation, the HSC Chemistry 6.12 software package developed by Outokumpu Research Oy (Finland) is used, and new thermodynamic constants for CrO and corrected constants for CaCr₂O₄ were introduced into its database. An increase in the reduction of chromium by 32.7% (from 64 to 95.1%) is found to occur when the slag basicity increases from 0.07 to 1.86. The rational slag basicity is 1.86–1.9. An increase in the reducer consumption from 0.5 to 1.05m_red leads to an increase in the reduction of chromium by 52.4 to 95.1%. The chemical composition of the synthesized metal is (wt %) 50.4 Cr, 1.97 Si, 3.3 Ni, 0.21 Al, 0.0050 P, and Fe for balance. The simulation results can be used to calculate the reduction of the chromium ore elements using ferrosiliconickel.