V.A. Salina, V.I. Zhuchkov, A.V. Sychev.
ABSTRACT
The results of thermodynamic simulation of the carbothermal process of chromium reduction from the Cr2O3–FeO–CaO–SiO2–MgO–Al2O3 oxide system in the temperature range (Т) 1673-1973 К after 50 К at total system pressure of 0.1 MPa and the amount of 2.24 m3 N2 are given in this article. The compositions of chromium ore, wt. %: 38 Cr2O3; 11.1 FeO; 0.17 CaO; 15 SiO2; 29.7 MgO; 6 Al2O3 and slag of low carbon ferrochrome (LC FeCr), wt. %: 13 Cr2O3; 4 FeO; 41.6 CaO; 21.2 SiO2; 12.8 MgO; 7.4 Al2O3 added to the ore in an amount of 0; 5; 10; 20% was used as the oxide system. Carbon was used as a reducing agent, the amount of which was increased by 10% for the quantity stoichiometrically required for the reduction of Fe and Cr and by 8% by mass of the metal for the formation iron, chromium, and silicon carbides. Thermodynamic simulation was performed using the HSC Chemistry 6.12 software package developed from Outokumpu, Finland. Thermodynamic data of the CrO (II) compound were entered into the software package database. The thermodynamic characteristics of the CaCr2O4, SiC, Cr3C2, Cr7C3, Cr23C6, Fe3C, Al4C3 available in the database were specified. The results of thermodynamic simulation were showed that the increase in the process temperature from 1673 to 1973 К increase the degree of chromium reduction (ηCr) at different slag contents in the composition of the system. The increase in the slag content in the system from 0 to 20% decreases ηCr from 94.8 to 94% at the temperature 1973 К. The highest value the degree of chromium reduction was obtained for the composition of the system with 0% slag. The chemical composition of the metal at the temperature 1973 К and with out slag is, wt. %: 65.6 Cr; 22.7 Fe; 0.26 Si; 11.5 C. The thermodynamic simulation results can be used to development the technology for producing a chromium-containing alloy using slag of low carbon ferrochrome in the metallurgical conversion.
KEY WORDS:
oxide system, carbothermal process, thermodynamic simulation, temperature, degree of chromium reduction, chemical composition of the metal.
DOI: 10.31857/S0235010620060110