Carbonation of basic oxygen furnace slag with metalworking wastewater in a slurry reactor

► Carbonation of BOF slag with metalworking wastewater was successful in CO2 capture. ► The higher conversion (89.4%) with a capacity of 0.283 g CO2/g BOF slag was achieved. ► The optimum operating conditions were an L/S ratio of 20 and a flow rate of 1 L min−1. ► The product on BOF slag was identified as crystallized calcite based on SEM and XRD. ► The carbonation mechanism could be well expressed by a surface coverage model.