Abstract：In the context of carbon neutrality, carbon capture and storage using steel slag can achieve both carbon emission reduction and “using waste to treat waste”. Since steel slag contains more free calcium oxide, untreated steel slag has poor stability and is difficult to be used in other fields. After carbonation of steel slag, the free calcium oxide content of steel slag is greatly reduced, which can be used in building materials. It is the most promising method for steel slag treatment. Therefore, it is of direct guiding significance to investigate the carbonation reaction conditions of pure calcium oxide for improving the stability of carbon fixation by steel slag. The thermodynamic calculation of CaO and Ca(OH)2 carbonation was carried out by FactSage. The results showed that both CaO and Ca(OH)2 could spontaneously carbonate at 0-900 ℃. The influence of calcination temperature, CaO mass, liquid-solid ratio and CO2 flow rate on CaO carbonation rate was investigated. The results show that when the calcination temperature is 700 ℃, the mass of CaO is 3 g, the liquid-solid ratio is 1.67, and the CO2 flow rate is 35 mL/min, the carbonation rate is the highest, which is 60.9%. The results of this study can be a reference for improving the resource utilization of steel slag.
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2023, Vol. 42 
