Abstract: The large-scale resource utilization of solid waste iron tailings (IOT) in the iron and steel industry is crucial
for the sustainable development of the concrete industry. This paper provides a systematic review of the comprehensive application
potential,performance modification mechanisms,and environmental benefits of using IOT as a raw material (fine aggregate
and cementitious material) in concrete. Analysis shows that the physical properties of IOT comply with standards for construction
sand,and its irregular particle morphology enhances mechanical interlocking at the interface. Chemically,IOT is primarily
composed of SiO2 (27. 65%~76. 83%) and Fe2O3 (2. 89%~46. 11%). Ternary diagram analysis of Si-Ca-(Al+Fe) indicates
that most samples possess the potential to replace cement. As a fine aggregate,IOT at replacement rates of 20% to 40% can optimize
the performance of various concrete systems,such as ultra-high performance concrete (UHPC) and sprayed concrete. As
a cementitious material,mechanical or chemical coupling activation is required to enhance its pozzolanic activity. After activation,
its strength activity index can exceed 72. 7%,meeting the requirements for supplementary cementitious materials. Life cycle
assessment confirms that the application of IOT can reduce the carbon footprint of concrete by 15% to 40% and resource
consumption by 29%. Furthermore,the leaching concentrations of heavy metals from IOT within the dense cementitious matrix
are significantly below the limits set by national standards,indicating controllable environmental risk. This review provides a systematic theoretical and technical basis for the large-scale application of IOT in low-carbon concrete.

Key words: iron ore tailings (IOT),concrete,aggregate,cementitious material,activation,environmental impact