高碱低模数体系中硅酸钙的结晶行为及杂质含量控制研究

For the purpose of solving the problem of the crystal transformation control and high impurity contents in the process of the utilization of desilication solution, which is generated in the recycle of the polymetallic waste residue, one-step preparation and modification of hydrophobic calcium silicate with low impurity and water contents has been proposed. Through a multidisciplinary research method, nucleation and growth behavior, and crystallization kinetics of calcium silicate in the complicated system will be deeply studied. Meenwhile, the function mechanism of impurities in the phase transformation process, the competitive mechanism of the combination on silicon oxygen tetrahedron chain between surface modifiers, impurities, and hydroxyls, the design and optimization of the surface modifiers, and structure-activity relationship control of calcium silicate will also be researched. The results will proved a key theoretical support to realize the one-step modification and preparation of hydrophobic calcium silicate with low impurity and water contents in the highly alkaline and low-modulus system.

围绕高硅多金属废渣资源化利用所产生的高碱低模数脱硅液，本项目针对其制备硅酸钙系列材料过程中，硅酸钙晶型转化控制困难及杂质含量高的问题，提出了一步改性制备低含水率、低杂质离子含量的疏水硅酸钙产品新方法，通过多学科方法综合交叉，深入开展复杂体系下硅酸钙成核、生长行为及动力学研究、杂质离子在硅酸钙晶型转化过程中的作用原理、表面改性剂与杂质及羟基基团在硅氧四面体链端结合的竞争机制、表面改性剂设计与优化、硅酸钙构效关系调控等方面的研究，从而为实现高碱低模数脱硅液一步改性制备低含水率、低杂质含量的疏水型硅酸钙产品提供关键理论支撑。

围绕高硅多金属废渣资源化利用问题，本项目以高碱低模数脱硅液和高硅水淬渣为原料，开展高硅固废制备多孔硅酸钙系列材料研究，重点针对硅酸钙的结晶控制和晶型转化问题，形成了高碱性低模数脱硅液制备硅酸钙系列材料及应用的新方法，建立高碱低模数体系下硅酸钙结晶动力学模型，明晰高氢氧根、低硅酸根浓度对于硅酸钙的成核、生长的影响规律；基本确定杂质对于硅酸钙晶型转化的影响机理和表面改性方法；形成多种含硅固废制备低杂质含量、低含水率硅酸钙的工艺路线；以固废基硅酸钙为填料制备纤维增强防火板，抗折强度大于8MPa，不燃性中超温时长在1500s左右，完全满足国标GB8624-2012的燃烧性能等级和分级的A1级技术指标要求，性能提升明显，相关研究成果发表学术论文4篇，申请国家发明专利1项，授权发明专利1项，国际会议邀请报告2次，培养硕士研究生2名。本项目研究为固废利用制备高性能材料过程提供扎实的基础理论支撑。