*通信作者, E-mail:luoyulin04@163.com(Y.L.), jiajieli@ustb.edu.cn (J.L.)

The integrated CO2 absorption and mineralization, which achieves low-temperature desorption of organic amine solutions through CO2 mineralization. However, the role of CO2-rich absorbents in CO2 mineralization needs further study. This paper investigates the influence of CO2-rich AMP solution on the carbonation of steel slag, through aqueous carbonation of steel slag at 40 °C and material characterization. The results show that the carbonation conversion of steel slag reaches the maximum (88.3%) after 30 min of reaction, slightly decreases at 60 min, and then rebounds at 90 min. The carbamate formed by the reaction of AMP and CO2 is easily hydrolyzed to release HCO3-/CO32-, which promotes the rapid carbonation of Ca2+ in steel slag to form aragonite-type CaCO3 and C-S-H gel in the early stage (30 min); enhances the dissolution of CaCO3 and C-S-H gel to form soluble calcium bicarbonate and SiO2 crystals in the middle stage (60 minutes); and leads the hydration-carbonation reaction of the exposed unreacted steel slag particles to form CaCO3 with poor thermal stability and C-S-H gel in the long term (90 min). The results from this paper provide theoretical foundation for AMP as an absorbent in the integrated CO2 absorption and mineralization process.