Mineral Carbonation of Basic Oxygen Furn

Mineral carbonation is a method in carbon capture and utilization (CCU) in which carbon dioxide reacts with natural or synthetic mineral phases to form carbonates. In this study, BOF slag consisting of various mineral components was crushed into different particle size fractions and exposed to a CO2-rich hot off-gas over various durations. The total inorganic carbon (TIC) content, however, did not increase significantly throughout the experimental duration, indicating limited carbonation. Depth analysis using phenolphthalein did not show a homogeneous carbonation front, but rather an irregular carbonation pattern, supported by elemental mapping from microprobe analyses. The solubility of the slag exhibited an increase with carbonation, suggesting enhanced leachability of soluble elements, notably sulfate and calcium. The leaching concentrations of environmentally relevant elements were also analyzed, revealing variable behavior; for instance, molybdenum concentrations increased, while chromium remained stable, and vanadium levels decreased. The results suggest that while carbonation of BOF slag is limited, the process influences the leachability of various elements, which is crucial for evaluating the environmental impacts of using such materials in waste management applications.