颗粒态γ-C_(2)S、β-C_(2)S、C_(3)S矿物固碳速率的差异及微观机理  

Mechanism Investigation and Difference in Carbon Sequestration Rates of Granularγ-C_(2)S,β-C_(2)S and C_(3)S Minerals

作　　者：许扬帆 钱春香[1,2] 裴嘉炜 XU Yangfan;QIAN Chunxiang;PEI Jiawei(School of Materials Science and Engineering,Southeast University,Nanjing 211189,China;Research Center for Green Construction Materials&Carbon Utilization,Southeast University,Nanjing 211189,China)

机构地区：[1]东南大学材料科学与工程学院,南京211189 [2]东南大学绿色建材与固碳利用研究中心,南京211189

出　　处：《硅酸盐学报》2025年第2期325-338,共14页Journal of The Chinese Ceramic Society

基　　金：国家重点研发计划项目(2021YFB3802000,2021YFB3802004);国家自然科学基金项目(52172016,51738003)。

摘　　要：矿物固碳是当下极具环保价值和工业价值的研究之一。本工作深入研究了γ-C_(2)S、β-C_(2)S、C_(3)S 3种矿物固碳反应速率与反应接触面、微观演化之间的关联,揭示了固碳速率差异的微观机理。结果表明:γ-C_(2)S、β-C_(2)S固碳率发展规律相似,均符合Box Lucas1模型;2种C_(2)S颗粒表面的碳酸钙晶体以方解石为主,趋向(104)热力学稳定面优势生长。γ-C_(2)S颗粒表面的碳酸钙呈地幔生长到外延生长,前期的外延生长导致了更大的反应接触面,在反应后期仍具有反应活性,同时方解石晶粒尺寸较大;而β-C_(2)S呈外延生长到地幔生长,前期的地幔生长导致了较密集的成核,晶粒尺寸发展更稳定,后期反应能力较差。C_(3)S初期固碳反应最快,反应5 min后迅速停滞,符合缩核反应模型;反应初期,C_(3)S表面针状文石与立方状方解石错杂生长,其致密结构造成了固碳反应过早停滞,随着反应进行,文石向方解石转变。Introduction Mineral carbon sequestration is a crucial area of research in both environmental protection and industry.While much of the existing research has focused on the direct carbon sequestration of minerals to enhance cementation properties,there is a gap in understanding the interface micro-structure evolution of mineral powder particles during the carbonization process for the use of supplementary cementing materials.This study delves into the investigation of three calcium silicate minerals found in steel slag,examining the single-particle carbonization reaction rate and the micro-evolution process of the reaction interface at a micron scale.The goal is to uncover the differences and mechanisms behind the carbon fixation reaction rates of these three calcium silicate minerals.Methods Three types of calcium silicate minerals,namelyγ-C_(2)S,β-C_(2)S,and C_(3)S,were prepared using the sintering method.A time gradient experiment was conducted on these minerals,and the evolution of multi-scale products was observed and analyzed through various microscopic techniques.Quantitative analysis using XRD and TG-DTG was employed to compare the carbon sequestration rates of the three minerals,and reaction equations were constructed through fitting analysis.The morphology,crystal structure,and growth characteristics of calcium carbonate products during the carbon sequestration reactions of the three minerals were analyzed using SEM,TEM,and crystal size calculations.The correlation between the differences in carbon sequestration rates among the three minerals and the evolution of micro-structure was elucidated.Results and discussionγ-C_(2)S had the highest carbon sequestration rate,which was 47.40%after 2880 min of carbon sequestration,reaching 92.65%of the theoretical carbon sequestration,and still had an exposed reaction surface at the later stage of the reaction.During the carbon sequestration process ofβ-C_(2)S,the carbon sequestration rate increases and the particle size,grain size and structure distribution of

关 键 词：硅酸二钙 硅酸三钙 固碳反应 碳酸钙 晶体生长 

分 类 号：X701[环境科学与工程—环境工程] P579[天文地球—矿物学]