Thermodynamic Simulation of Reduction Processes at the Production of Ferrochrome

Abstract

The possibility of reduction process of chromium from the Cr2O3 – FeO – CaO – SiO2 – MgO – Al2O3 system by carbon using the method of thermodynamic simulation was showed in the article. The compositions of chromium ore of the deposit Rai-Iz and dust of cyclones of the low-carbon ferrochrome in an amount of 0; 5; 10; 20% were used as a components of the system. The carbon was used a reducing agent. The thermodynamic simulation was performed using the HSC Chemistry 6.12 software package developed from Outokumpu, Finland. The thermodynamic characteristics of CrO (II) compound were entered into the software package’s database. The thermochemical data of compounds CaCr2O4, Fe3C, Cr3C2, Cr7C3, Cr23C6, SiC were refined. The calculations were performed using the “Equilibrium Compositions” module in the temperature range 1500 – 1700°C at a temperature increment of 100°C, at a total pressure of 0.1 MPa in the system and 2.24 m3of N2. It was determined that the increase in the dust amount from 5 to 20% did not affect practically at the reduction degree of chromium which is equal 90.2; 93.4; 94.6% respectively at the temperatures of 1500, 1600 and 1700°C. The chemical composition of the metal is, %: 65.6 – 65.1 Cr; 22.7 – 23.2 Fe; 11.5 – 11.6 C; 0.2 – 0.26 Si at the temperature of 1700°C. The thermodynamic simulation results can be used to develop technology for producing ferrochrome using wastes of metallurgical production.