Title: Hydrogen-Based Recovery of Iron from Copper Smelter Slags: Thermodynamic Analysis, Kinetic Modeling of Fayalite and Magnetite Reduction
Authors: Mutalibkhonov S.S., Kholikulov D.B., Khojiev Sh.T., Shaymanov I.I.
Volume: 10
Issue: 5
Pages: 21-37
Publication Date: 2026/05/28
Abstract:
- In Almalyk (Uzbekistan), with an annual production of 150 thousand tons of copper, more than one million tons of slag waste is generated during the smelting and conversion into matte in Reverberatory, Flash-smelting, and Vanyukov furnaces. Almalyk MMC copper smelter slag and metallurgical byproducts represent significant sources of iron and valuable metals. This comprehensive research review synthesizes 25 peer-reviewed Scopus-indexed articles (2003-2025) examining hydrogen-based recovery of iron from slag minerals, particularly fayalite (Fe?SiO?) and magnetite (Fe?O?). The review employs the IMRaD framework and integrates thermodynamic calculations using Gibbs free energy minimization, Ellingham diagram analysis, kinetic modeling with Arrhenius formulation, and experimental characterization data. Key findings reveal that hydrogen reduction of magnetite proceeds via first-order kinetics with apparent activation energies of 99.3 kJ/mol for copper slag systems, while fayalite decomposition requires significantly higher energies (194.81-248.96 kJ/mol) and benefits from CaO promotion. Optimal industrial conditions operate at 900-1250°C with hydrogen partial pressures of 5-10% in multi-stage configurations. Liquid-phase mass transfer and product layer diffusion control rate-limiting steps. Integration of thermodynamic equilibrium modeling with kinetic framework enables process optimization for metallurgical waste valorization, resource recovery, and circular economy implementation.