Temperature effect on improving the carbon fixation properties of steel slag

Abstract

As an important way to reduce CO2 emissions, mineral carbon dioxide (CO2) sequestration had received widespread attention. Due to its low cost and secondary use, steel slag (SS) was regarded as a suitable material for carbon fixation. By keeping the pressure, time, and solid-liquid ratio accord, carbon sequestration properties of SS at different temperature were discussed. The composition of the Carbonized Steel Slag (CSS) was analyzed with the aid of XRD and FT-IR. SEM and EDS were utilized to examine the microstructure and elemental distribution of CSS. BET method was employed to analyze the pore characteristics of the CSS. Quantitative analysis of the production was performed in conjunction with TGA. The results revealed that the generated calcium carbonate (CaCO3) was mainly distributed in three places, which were the surface of SS, the external water environment, and the pores inside the slag. At 30 to 60℃, the carbon sequestration capacity was improved with temperature increasing. While the temperature exceeded 60℃, the effect of carbon sequestration was reduced. The results proved that the best effect of carbon sequestration in SS was at 60℃.