Analysis of Mechanical Performance and Microstructure of Steel Slag Processed with Accelerated Carbonation

The accelerated carbonation with different pressure steaming conditions was used to process the steel slag, so the slag could turn into a primary cementitious product with carbonation activity. XRD, FTIR, TG, N2 absorption BET surface area analyzer and SEM were used to characterize the mineral and chemical compositions and microstructure of each sample before and after the carbonation. The results show that: the carbonation products with different morphologies are formed under different temperature conditions. The optimum temperature for the accelerated carbonation for processing the steel slag is selected to be 90 °C, which results in the compressive strength of 32.8 MPa. The BET specific surface area of the steel slag reduces after carbonation, the sample density increased after carbonation.