• Iron (Fe) is the most harmful impurity in recycled aluminum, forming detrimental Fe-rich phases (FRPs) that degrade alloy properties.
• The presence of Fe restricts recycled aluminum to lower-grade applications, limiting its substitution for primary aluminum.
• The review systematically summarizes existing Fe removal and deterioration mitigation methods, evaluating their industrial feasibility.
• Provides comprehensive theoretical guidance for future FRP control and supports grade preservation of industrial recycled aluminum.