From Waste to Resource: A Comprehensive Review on the Multifaceted Utilization of Steel Slag

The steel industry generates a massive byproduct, steel slag (SS), amounting to ۱۵-۲۰% of global crude steel output, whose stockpiling poses significant environmental risks due to heavy metal leaching and resource waste. This review synthesizes current research on the sustainable utilization of steel slag, transforming this industrial residue into a valuable resource across multiple sectors. The physicochemical properties of SS, including high density, wear resistance, and a composition rich in CaO, SiO۲, and Fe۲O۳, underpin its diverse applications. In construction, SS serves as a high-performance aggregate in asphalt and concrete, enhancing mechanical properties, durability, and pavement performance while conserving natural resources. In agriculture, its nutrient content and liming capacity improve soil quality, crop yields, and act as a low-cost fertilizer. For environmental remediation, its alkaline and porous nature enables effective adsorption of heavy metals and nutrients from wastewater. Most notably, steel slag shows considerable promise for CO۲ sequestration through mineral carbonation, contributing to climate change mitigation and the production of low-carbon building materials. This review concludes that the large-scale, technically sound utilization of steel slag is not only an imperative waste management strategy but also a cornerstone for advancing the circular economy within the steel and construction industries.

Keywords:

Steel Slag , Waste recycling , Environmental friendly materials