Iron and steel slag properties and mechanisms for carbon dioxide fixation in a low-carbon society

This report presents carbon dioxide (CO₂) fixation properties of an iron and steel slag containing calcium, in order to contribute to a geotechnical application for the formation of a sound material-cycle society and a low-carbon society. To investigate the properties of CO₂ fixation, CO₂ fixation tests with constant flow were conducted. Results show that when the CO₂ concentration 4500 ?L- CO₂/L was flowed in a specimen by 0.05 L/min, for a non-aged steelmaking slag, the amount of CO₂ fixed was the maximum: 0.04 g- CO₂/g-slag. The amount of CO₂ fixed in the steelmaking slag resulted from about 20% of soluble calcium in the chemical reaction. Therefore, it is possible that the quantity of CO₂ fixation can be evaluated from the viewpoint of the mechanism of CO₂ fixation using the quantity of water-soluble calcium.