Abstract: Steel slag carbonate reaction can effectively transform free calcium oxide in steel slag into the carbonates and achieve the purpose of volume stabilization. The carbonation process of steel slag and the kinetics were studied with unreacted core model in this paper. The variation of the particle pore mechanism during the reaction process was found outaccording to the literatures, the diffusion coefficient was corrected then the relationship between the diffusion coefficient and the conversion ratio was obtained. According to this model, the controlling process of the reaction of different particle size was judged. It was found that theparticle size of steel slagshould be controlled within 180 μm.

Key words: steel slag, f-CaO, carbonation, kinetics, diffusion coefficient