Title: Fayalite Destruction Of Copper Smelter Slags For Direct Reduced Iron Production: Kinetic Analysis And Thermodynamic Assessment
Authors: Mutalibkhonov S.S.
Kholikulov D.B.
Khojiev Sh.T.
Shaymanov I.I.
Volume: 10
Issue: 5
Pages: 28-36
Publication Date: 2026/05/28
Abstract:
Slag through fayalite (Fe?SiO?) destruction is crucial for sustainable resource utilization and circular economy implementation. This study synthesizes recent literature from Scopus-indexed journals to analyze the mechanisms, kinetics, and thermodynamic feasibility of coal-based reduction and alternative methods for fayalite decomposition. Isothermal coal-based reduction kinetics reveals a biphasic process with apparent activation energies of 175-202 kJ/mol (Stage 1) and 194-249 kJ/mol (Stage 2), controlled by phase boundary chemical reactions and diffusion mechanisms respectively. Thermodynamic calculations confirm reduction feasibility above 900°C with ?G° = -45.3 kJ/mol?¹ at 1200°C. Optimal process conditions achieve iron recovery of 85-98% at 1300°C with 15-25 wt% NaO + CaO addition and 30-35 wt% coal dosage. Alternative methods including alkali disaggregation, sodium sulfate disruption, and hydrogen reduction are evaluated. The resulting direct reduced iron (DRI) exhibits metallization degrees of 90-96% and can serve as high-quality burden material for electric arc furnace steelmaking, facilitating carbon reduction and tramp element dilution. This comprehensive analysis provides industrial guidance for optimized fayalite destruction processes and DRI production from secondary iron sources.