矿渣粉与超细铁尾矿粉在无熟料固结体中的协同水化机制  

Synergistic Hydration Mechanism of Slag Powder and Ultrafine Iron Tailings Powder in Non-clinker Consolidated Body

作　　者：安树好 刘娟红[1,2,3] 张月月 李康 AN Shuhao;LIU Juanhong;ZHANG Yueyue;LI Kang(College of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China;Beijing Key Laboratory of Urban Underground Space Engineering,University of Science and Technology Beijing,Beijing 100083,China;Research Institute of Urbanization and Urban Safety,University of Science and Technology Beijing,Beijing 100083,China;State Key Laboratory of High-speed Railway Track Technology,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;Railway Engineering Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China)

机构地区：[1]北京科技大学土木与资源工程学院,北京100083 [2]北京科技大学城市地下空间工程北京市重点实验室,北京100083 [3]北京科技大学城镇化与城市安全研究院,北京100083 [4]中国铁道科学研究院集团有限公司高速铁路轨道技术国家重点实验室,北京100081 [5]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081

出　　处：《材料导报》2023年第22期113-122,共10页Materials Reports

基　　金：国家自然科学基金(51834001)。

摘　　要：超细铁尾矿粉表面非晶态铝硅酸盐矿物成分具有水化活性,能够形成较高强度的无熟料固结体,但存在早期水化速率快、后期强度低的缺点。本工作考察了掺入矿渣粉对超细铁尾矿基无熟料固结体微观结构及强度的影响,分析了硬化浆体中水化产物的形貌、种类及含量的差异,并研究了二者在无熟料固结过程中的协同水化硬化机制。结果表明:磨细铁尾矿粉和矿渣粉质量比在1∶1时无熟料固结体28 d可以获得78 MPa以上的强度,XRD、TG-DSC分析结果及SEM微观形貌显示铁尾矿粉和矿渣粉的水化产物一致,均为铝掺杂水化硅酸钙(C-(A)-S-H)和钙矾石(AFt),固结体中AFt的生成量早期与矿渣粉的比例呈正相关关系,后期受体系中SO_(3)含量的控制,固结体的线性膨胀率与AFt含量呈正相关关系,矿渣粉和铁尾矿粉复配可以明显改善试样硬化体的孔结构,二者比例在1∶1时孔径分布最优。本研究证实了矿渣粉与超细铁尾矿粉在无熟料固结过程中有明显的水化协同效应,超细铁尾矿粉表面非晶态成分的早期水化产物对硬化浆体早期起到固结和填充效应,矿渣粉的持续水化补充了后期新的水化产物,二者在水化过程中的协同机制增加了体系中水化产物的生成量,改善了浆体的孔结构,提高了密实度,使固结体获得较高的力学性能和体积稳定性。The amorphous aluminosilicate mineral composition on the surface of ultrafine iron tailing powder has hydration activity and can form a high strength clinker free consolidated body.However,it has the disadvantages of fast hydration rate in the early stage and low strength in the later stage.In this work,the effect of slag powder on the microstructure and strength of ultra-fine iron tailings based non-clinker consolidated body was investigated,the difference of the morphology,type and content of hydration products in hardened paste was analyzed,and the synergistic hydration hardening mechanism of the two mixtures in the process of non-clinker consolidation was studied.The results showed that when the ratio of ground iron tailings powder to slag powder was 1∶1,the strength above 78 MPa could be obtained without clinker consolidation in 28 days;XRD,TG-DSC analysis results and SEM micro morphology showed that the hydration products of iron tailings powder and slag powder were the same,both of which were aluminum-substituted calcium silicate hydrate(C-(A)-S-H)and Ettringite(AFt);the amount of AFt in the consolidated body was positively related to the proportion of slag powder in the early stage and controlled by the content of SO_(3) in the system in the later stage;the linear expansion rate of consolidated body was positively correlated with AFt content;the pore structure of hardened samples could be improved obviously by adding slag powder and iron tailing powder,and the pore size distribution was optimal when the ratio of slag powder to iron tailing powder was 1∶1.This study confirms that slag powder and superfine iron tailing powder have obvious hydration synergistic effect in the process of non-clinker consolidation.The early hydration products of the amorphous components on the surface of superfine iron tailing powder play a consolidation and filling effect on the hardened slurry in the early stage.Their synergistic effect in the hydration process increases the amount of hydration products in the system,impr

关 键 词：超细铁尾矿粉 矿渣粉 无熟料固结体 非晶态成分 协同水化机制 

分 类 号：TB321[一般工业技术—材料科学与工程]