In order to curb the anthropogenic influence on climate change, systems for storing CO2 to prevent it from escaping into the atmosphere must be developed in the future, in addition to emission-free technologies. The sequestration of CO2 gas in industrial residues by mineral carbonation seems to be suitable for this purpose. In the course of the investigations, the planning and commissioning of an apparatus with which a suspension of waste material and water in a ratio of 1/20 can be gasified without overpressure is carried out. In addition to the contents of carbonate-forming alkaline earth metals, such as Ca and Mg in the samples, there is a clear influence of the particle size of the powder. Four synthetic manufactured slags between 70.32 wt % and 90.91 wt % lower storage yields are determined when the particle size class is increased from 0-250 µm to 250-500 µm. Raising the process temperature to 40 °C causes increased storage behaviour in two of the four slags and decreased storage behaviour in the other two, which appears to be associated with reduced solubility of the magnesium constituents. The experiments with real slags from the LD process and the Waelz process, respectively, illustrate the ability of these to absorb CO2, although in some cases significant differences in yield are evident. In part, samples with lower storage potentials bind more carbon dioxide than those with significantly higher ones. This suggests the presence of poorly soluble compounds, differences in comminution behaviour, increased formation of inert carbonate shells around individual particles or increased hydration. An evaluation of long-term stability emphasis the durability of the setting, as none of the samples lost more than 1 wt % in mass, with most even showing gravimetric increases due to changes in ambient moisture conditions. The effect of sequestration on the leaching behaviour for heavy metals from the residues cannot be clearly defined. While only one of the samples shows a decreased Cr concentration in the eluate after carbonation, the solubility for Mo increases in both after purging with CO2.