Title: Iron Extraction from Industrial Wastes of Uzbekistan via Thermochemical Conversion
Authors: Mutalibkhonov S.S.
Volume: 10
Issue: 6
Pages: 86-91
Publication Date: 2026/06/28
Abstract:
Industrial waste streams, particularly red mud from alumina production and steel slag, contain substantial iron reserves that remain largely unutilized. This research synthesizes recent advances in iron extraction from high-iron bauxite residue (red mud) and steel industry byproducts through multiple processing pathways. Hydrochemical conversion at 120°C achieved 96.27% aluminum extraction and 69.55% iron enrichment using ferrous sulfate in alkaline media, while carbothermic smelting reduction at 1400-1500°C attained 98.36% iron recovery with metallurgical-grade pig iron. Thermodynamic analysis reveals that hematite (Fe?O?) reduction to magnetite (Fe?O?) is energetically favorable across 1300-1500°C (?G = -235.48 to -280.87 kJ/mol with carbon), with transition from interfacial reaction control (E? = 30.9 kJ/mol) at initial stages to diffusion control at later stages. Magnetization roasting using CO gas promotes selective Fe?O??Fe?O? transformation at 650°C with 91.25% recovery and apparent activation energy of 38.31 kJ/mol, demonstrating superiority over coal-based methods. X-ray diffraction and M?ssbauer spectroscopy confirm predominantly nonstoichiometric magnetite formation (Fe?.??O? to Fe?.??O?), while scanning electron microscopy reveals particle size reduction from 10 ?m to 1-5 ?m with enhanced magnetic properties. This comprehensive approach transforms economically and environmentally hazardous industrial waste into valuable secondary iron resources, reducing energy consumption by 50-60% compared to conventional pyrometallurgical processes and enabling circular economy pathways for ferrous metals.