Abstract: In order to reveal the influence of desulfurization gypsum on the properties of steel slag-based carbonized building materials， the effects of different curing time and desulfurization gypsum dosage on the compressive strength and carbon sequestration effect of the test pieces， and the effect of carbon sequestration on the compressive strength of the test pieces were studied. The results showed that: ① When the mass ratio of desulfurization gypsum to steel slag is 6.25%， the strength and curing efficiency of the steel slag-based test piece are significantly improved. When the water-binder ratio is 0.2 and the moulded strength is 9 MPa， the compressive strength of the test piece reaches 32 MPa with the one day curing. ② With the increasing of the amount of desulfurization gypsum， the carbon sequestration per unit mass of the test pieces decreases， while the carbon sequestration per unit mass of the steel slag increases. ③ The carbon sequestration of 1 d or 3 d is basically positive correlation with the compressive strength，because the hydration reaction of steel slag is slow and does not contribute much to the early strength. The carbonization reaction is critical for the enhancement of compressive strength of the test pieces， especially the early strength. ④ When the moulded strength is 27 MPa， the carbon sequestration of the specimens cured for 6 hours and 10 hours reaches 76.21% and 87.54% of the specimens carbon sequestration curing for 1 d， and the compressive strength of the specimens curing for 6 h was more than 25 MPa. Therefore， the test pieces become the carbonized products according with strength requirements after the carbonized curing for 6 h.

Key words: Steel slag, Carbonized building materials, Desulfurization gypsum, Carbon sequestration