Stabilization of basic oxygen furnace sl

Treatment and disposal of Basic Oxygen Furnace (BOF) slag, a residue of the steel production process characterized by high basicity and propensity for heavy metal leaching, is a costly burden on metallurgical plants; a sustainable valorization route is desired. The stabilization of BOF slag through a novel hot-stage carbonation approach was investigated to reduce its environmental impact. The methodology involved analyzing the carbonation effect on the slag at varying temperatures and pressures, specifically focusing on CO2 uptake and its relation to particle size, surface area, and free lime content. Results indicated that the optimum carbonation rate occurred at temperatures between 830-850 °C under 1 atm CO2, with minimal effects observed from pressure variations between 0.2 to 20 bar and the presence of steam. This process significantly stabilized free lime present in the slag, leading to a marked reduction in basicity and leaching of hazardous heavy metals such as Ba, Co, and Ni. The findings underscore the potential for using hot-stage carbonation as an effective strategy for the sustainable management of BOF slag in metallurgical operations.