Enhanced Steelmaking Slag Mineral Carbonation in Dilute Alkali Solution

Abstract

Steelmaking slag mineral carbonation is a possible technology for the reduction of carbon dioxide (CO2) emissions to the atmosphere, which has been studied both in aqueous and dilute alkali medium. A set of variables, the stirring speed, reaction time, alkali to slag ratio and reaction temperature, were systematically investigated. The results indicated that reaction time, alkali to slag ratio and reaction temperature were the major factors for CO2mineral sequestration. Under the optimal conditions with the alkali to slag ratio of 4 % at 80 °C, 16.64 g CO2can be sequestrated in per 100g steel slag and both calcite and aragonite were generated. This work would be of significance to understand the reaction mechanism deeply and provide valuable information for further study in this field.

Evaluation of Potential Factors Affecting Steel Slag Carbonation

“…The carbonation of steel-making slag is influenced by the reaction time, an important element and economic indication. As a result of the formation of calcium carbonate, the CO 2 sequestration capability of steel-making slag increases as the reaction time increases [79]. Carbonation is rapid initially but decreases as the reaction time increases, eventually reaching equilibrium [29].…”

“…Figure 4 shows that the slag's ability to sequester CO 2 increased when the reaction time grew. This was due primarily to the formation of CaCO 3 [79].…”

“…[86] Carbonation time Increase The CO 2 sequestration capability of steelmaking slag increases as the reaction time increases. [79] Particle size -…”

“…The CO 2 sequestration capability of steelmaking slag increases [79] Decrease Carbonation occurs rapidly at first but slows as reaction time increases, eventually reaching equilibrium. [93] Particle size Increase Carbonation reaction slowed down with increasing grain size in stainless EAF of four grain sizes.…”