关键词: 钢渣, 二氧化碳捕获与封存, 直接矿化, 间接矿化

Abstract: In recent ten years,the technology of CO2 capture and sequestration by mineralization of alkaline industrial solid wastes has been rapidly developed,and is considered as one of the effective technologies to utilize solid waste and mitigate global warming. Steel slag is a high-yield calcium-rich solid waste,which has excellent availability and economic value for CO2 capture and sequestration. This paper reviewed the methods of CO2 capture and sequestration ( CCS) with mineralization of steel slag,including direct mineralization and indirect mineralization methods. Firstly,the wet and dry methods of direct mineralization were analyzed,and it was found that the efficiency of wet mineralization was superior to that of dry mineralization. Factors such as reaction temperature,reaction time,steel slag particle size and liquid-solid ratio can all affect the diffusion of calcium and magnesium ions in steel slag and the reaction rate with CO2. The principle of improving the efficiency of wet mineralization at present can be basically attributed to promoting the mineralization reaction in the direction of positive reaction. Then, two important steps of the indirect mineralization method were analyzed,including ion leaching and carbon sequestration in leaching solution. It was believed that the carbon sequestration efficiency largely depends on the leaching rate of Ca2+ and Mg2+. The effects of strong acid and weak acid reaction conditions on ion leaching were summarized,as well as the process route and optimization methods of the CO2 capture and sequestration in leaching liquid. Finally,the future research directions in this field were prospected. For example,it is necessary to improve and perfect the thermodynamic and kinetic theoretical system of CO 2 capture and sequestration by steel slag. In order to realize the industrial development of this technology,it is necessary to carry out pilot research on large-scale industrialization and develop high-value application of carbonated steel slag.

Key words: steel slag,carbon dioxide capture and sequestration (CCS),direct mineralization,indirect mineralization