This project is conducting further investigation into the carbonation process of Fe-rich slags as a potential method for CO2 sequestration. Building upon the findings from another CR3 project titled “Structure-property relations of slags, application, and carbonation potential,” which demonstrated the ability of modified Fe(II)-slags to carbonate at relatively low temperature (65°C) and pressure (5 bar CO2), this study aims to explore fundamental aspects of carbonation under ambient temperature and pressure conditions (e.g., in a curing chamber). The storage of CO2 in these slags might open new ways of applications (by forming beneficial phases) or lead to a stabilization and safer disposal from a geotechnical perspective. Next to that, the ability to immobilize the metal contaminants is of paramount importance obviously and carbonation may assist in doing so. Given the abundance of Fe(III) in nature, there is significant potential in the formation and stabilization of Fe(II)-carbonates, such as ankerite (Cax,Fe1-x)CO3) and siderite (FeCO3), particularly at lower temperatures. This research holds promise for innovative approaches to carbon storage and utilization.