Wet versus slurry carbonation of EAF steel slag

The CO 2 uptake and Ca‐to‐carbonate conversion yield attained by wet and slurry‐phase carbonation of stainless steel slag are reported. A maximum CO 2 uptake of 180 g CO 2 /kg slag was achieved under wet conditions (50 °C, 3 bar CO 2 , 0.4 l/kg), corresponding to a Ca‐to‐carbonate conversion yield of 50%. The slurry‐phase process, even when adopting more energy‐intensive operating conditions, did not improve the CO 2 uptake kinetics and conversion yield in comparison to the wet treatment. The mineralogy of the carbonated slag exhibited a decreased content of silicate phases (Ca 2 SiO 4 in particular), a marked reduction of Ca and Mg oxides, and a noteworthy increase of calcite.