A Review of Steel Slag Carbonation: Mechanisms, Applications, and Sustainability Assessment

Steel slag (SS), as a major solid waste of the steel industry, has CO₂ sequestration potential due to its rich calcium and magnesium alkaline components. SS carbonation is a promising strategy gaining industrial traction to simultaneously treat industrial solid waste and greenhouse gases. This article firstly describes the properties of SS and summarizes the research progress of SS carbonation. The classification of mineral carbonation technology is introduced, and the advantages and disadvantages are analyzed. The key factors affecting the SS carbonation are discussed. Then, the current industrial application status and life cycle assessment results are summarized. Finally, the conclusions are summarized, and the future research direction is proposed. Carbonation of SS can effectively fix CO₂ and produce high-value-added products, realizing a win-win situation of environmental and economic benefits, which is of great significance to the green transformation of the steel industry and the realization of the "double carbon" goal.