固废基地聚合物硅铝相溶解重构及钙作用机制与纳米改性研究

Portland cement production has had a serious effect on energy conservation, emission reduction, and environmental protection. Geopolymer is a new low-carbon cementitious material which is made from sialic resource by mineral polycondensation. Single geopolymeric precursor is a restriction of co-disposing multiple solid wastes (SW). Traditional research methods used in cement are difficult to test geopolymeric mechanism and three dimensional texture. In this project, SW-based geopolymers are prepared from precursor of high calcium fly ash and flue gas desulfurization residues etc. Advanced and multi-disciplinary testing technologies and scientific theory such as Dynamic Light Scattering, Isotopic Tracer Method, High-Resolution Nanoprobe, and Wood's Metal Intrusion, etc. are used for real time and dynamic study. Mechanism of dissolution and reorganization of sialic phase, gelation process, mineral compositions, setting and hardening are researched. Mechanism of mineral change, bond junction, and distribution of calcic compositions in geopolymerization are also studied. Core coordination numbers of geopolymer, degree of polymerization, bond lengths and angles, functional group and molecular transformation etc. are further tested and analyzed. Geopolymeric information in a molecularly and atomic scale are obtained. Optimum activated nano-materials are used to modify geopolymer to be with compact structure and good performance. This work widens precursor resource and deepens research on geopolymeric forming mechanism and texture. Additionally, it will lay a theoretical and practical basis of using geopolymer to co-dispose multiple solid wastes.

硅酸盐水泥生产严重影响节能减排和环境保护。地聚合物是硅铝质原料经矿物聚缩而成的新型低碳胶凝材料。地聚合物先驱物单一制约其协同处置多种固废，且沿用传统水泥研究方法难以科学表征地聚合物的形成机制和三维织构。本课题利用高钙粉煤灰、脱硫灰等作先驱物研制固废基地聚合物。课题采用多学科的动态光散射、同位素示踪、高分辨纳米探针、伍德合金侵入法等先进测试技术和科学理论，实时、动态地研究先驱物中硅铝相溶解重构机制、凝胶化过程、物相组成、凝结和硬化机制；研究钙质组分对地聚合物反应的作用机制，钙物相转变、结合状态及分布情况等以及地聚合物的核配位数、聚合度、键长和键角、官能团和分子变换，获得其在分子、原子层次上的信息。并优选纳米活性材料对地聚合物优化改性，制备结构致密且性能优良的地聚合物，研究其纳米改性机制。本课题研究可大大拓宽地聚合物先驱物来源，深化其形成机制和织构研究，为其协同处置多种固废打下理论和实践基础。

地聚合物是硅铝质原材料经矿物聚缩而成的新型低碳胶凝材料。近年来，以偏高岭土和低钙粉煤灰为先驱物制备地聚合物很多，但以高钙粉煤灰、脱硫灰渣等含钙固废作为先驱物制备地聚合物的研究鲜有报道。本项目主要以高钙粉煤灰等固体废弃物为原材料制备地聚合物，研究体系中硅、铝、钙三相的作用机制及纳米改性研究。课题组采用X射线衍射分析、环境扫描电镜、1H低场核磁共振、电感耦合等离子体发射光谱仪等先进测试技术，重点研究了固废先驱物中硅、铝、钙三相溶解重构机制，以及钙质组分对地聚合物凝胶体系的影响和作用机制，并提出了梯度酸溶解法辨识地聚合物和水化产物的方法。优选天然纳米材料和化学合成纳米材料对固废基地聚合物进行改性研究，研制了结构致密且性能优良的含钙固废基地聚合物。本项目的研究成果拓宽了地聚合物先驱物的范围，深化了其织构形成机制研究，为地聚合物协同处置多种固废打下了理论和实践基础。通过本项目的研究，在SCI/EI收录期刊上发表SCI论文6篇，EI论文6篇；申请国家发明专利3项，已授权国家发明专利1项；参加国际会议1次。