Carbon dioxide capture, utilization and storage (CCUS) technology has been paid more and more attention as an important technical means to deal with the global climate and environmental crisis. Using the mineralization reaction of cement-based materials to absorb carbon dioxide can not only achieve the permanent storage of CO2 and improve the mechanical properties of the products, but also reduce the amount of cement in concrete, thus reducing a large amount of carbon dioxide emissions. In this paper, using OPC paste asraw material, the effects of different factors (temperature, CO2 content and CaCO3 doping amount) on the carbon sequestration and mechanical properties of cement were systematically studied, and the composition, micro-morphology and micro-pore structure of mineralization products were tested and analyzed. The interaction mechanism of temperature, CO2 and CaCO3 on the mineralization process of OPCpaste was summarized, and the micro reaction model of carbon dioxide mineralization OPC paste with calcium carbonate was summarized.The results show that it possesses 77.99% carbon sequestration at 70 ℃ and 6.7% strength gain at 28 days, and the optimal addition ofCO2 is 0.5%, and the addition of CaCO3 is able to increase the carbon sequestration and strength of OPC slurry, and the CO2 doping canbe increased to 3% while maintaining the strength gain when the CaCO3 addition is 10%.

马超(1998—),男,浙江宁波人,硕士研究生。E-mail:mc0311@zju.edu.cn

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MA Chao,WANG Tao,WU Bing,et al.Properties and mechanism of carbon dioxide mineralization portland cement paste[J].Clean Coal Technology,2024,30(4):130-136.