磷渣掺杂硅铝基胶凝材料中硅对磷的四配位同构效应

Phosphorous slag is a by-product of yellow phosphorus production via electric furnace method, and using phosphorous slag to produce construction materials is an effective way to largely consume this solid waste. However, the high content of P2O5 (1-5%) in phosphorous slag leads to a serious retarding phenomenon in Portland cement, which limits the adding amount of phosphorous slag in the traditional cement and concrete. Controlling phosphorus effectively is a key point to improve the dosage of phosphorous slag in cementitious materials. In this project, with the guiding idea of isostructural effect of Si to P in silica-alumina based system, phosphorous slag doped silica-alumina based cementitious materials (abbreviated as PSA) are developed according to different [Si(Al)O4] polymerization degree of raw materials. Magic-angle spinning (MAS) nuclear magnetic resonance (NMR) and isothermal calorimeter technique combining with the coordination chemistry theory are adopted to investigate the coordination structure of Si, Al and P, and hydration kinetics of PSA. This research aims to reveal the isostructural effect of Si to P in the hydration process of PSA, establish a spatial structure model of Al-Si-P based hydration product, and also obtain the phosphorus doping behavior in PSA and the hydration mechanism of PSA. This research provides an effective way to solve the retarding problem of phosphorous slag in cementitious materials, and provides a new theory and technical support for full utilization of phosphorous slag and other phosphorous solid wastes.

磷渣是电炉法制备黄磷过程中排出的副产物，将磷渣应用于建材行业是实现其大宗利用的有效途径。然而，磷渣中较高的P2O5含量（1-5%）导致硅酸盐水泥缓凝现象严重，限制了其在传统胶凝材料中的掺配量。因此，如何在掺杂磷渣的胶凝材料中对磷元素进行有效控制是提高磷渣掺加量的一个关键问题。本项目以硅铝体系对磷的同构效应为指导思想，根据不同[Si(Al)O4]聚合度物料的复合协同效应，匹配设计并优化磷渣掺杂硅铝基胶凝材料。主要采用高分辨固体核磁共振、等温微量热测试技术及配位化学理论相结合的方法，从Si、Al、P等元素的配位结构及水化动力学层面研究并揭示磷渣掺杂硅铝基胶凝材料水化过程中硅对磷的四配位同构效应，建立Al-Si-P基水化产物空间结构模型，阐明磷渣掺杂硅铝基胶凝材料的水化反应机理及磷掺杂行为影响规律。从而克服磷元素对胶凝材料产生的危害，为磷渣及其他含磷固废的资源化高效利用奠定理论和技术基础。

针对磷渣中的磷组分对传统高钙基水泥和混凝土所引发的缓凝问题，该项目以硅铝体系对磷的同构效应为指导思想，根据不同[Si(Al)O4]聚合度物料的复合协同效应优化制备了磷渣硅铝基胶凝材料，有效解决了其中磷元素对胶凝材料的缓凝问题。通过对磷渣的结构特征及胶凝活性、磷渣掺杂硅铝基胶凝材料的水化产物结构、磷掺杂行为影响、磷渣掺杂硅铝基胶凝材料的水化动力学及反应机理进行深入研究，揭示了磷掺杂硅铝基胶凝体系中硅对磷的四配位同构效应，建立了Al-Si-P基水化产物（C-A-S-P-H凝胶）结构模型，获得了硅铝基胶凝体系中磷掺杂行为影响规律，并阐明了磷渣掺杂硅铝基胶凝材料的水化反应机理。项目研究成果为磷渣及其他含磷固废的资源化高效利用提供了理论和技术支持。项目执行期内，申请国家发明专利1项，发表SCI收录文章9篇，协助培养硕士毕业研究生4名。项目负责人参加相关国内学术会议交流并做口头报告4次；参加国外学术会议交流3次，其中口头报告2次，墙报展示1次。圆满完成了项目研究任务。