分散剂-硅微粉体系对提钛尾渣水化机理和显微结构的影响

Aluminate cement is widely used as refractory castable binder. The development of low cement and ultra low cement castable is promoted with the introduction of dispersing agent and super fine powder. Titanium tailings of blast furnace slag is peculiar in our country, which are the residues of extract Ti-Si-Fe alloy, with characteristics of rapid hardening, early strength, high strength and excellent performance, that are similar chemical composition, mineral composition to aluminate cement. To mention the problems whether titanium tailings can replace part of high price aluminate cement on some application. This project is researched on hydration mechanism and microstructure of titanium tailings with dispersant - silicon powder system, based on the particle dispersion and water and fine aggregate with dispersant, and filling effect and activity with micro silicon powder. The dynamics of hydration and hydration mechanism, the influence of mineral composition and microstructure of the system under different temperature is researched. The regulation and correlation between mechanical properties and product composition or microstructure is discussed, thus providing theoretical guidance and reference significance on titanium tailings for comprehensive utilization of and high added value.

铝酸盐水泥广泛用作耐火浇注料结合剂，引入分散剂和超细微粉促进了低水泥和超低水泥浇注料的发展。提钛尾渣是我国特有的高钛型高炉渣中提取Ti-Si-Fe合金后剩余的残渣，与具有快硬、早强、高强等优良性能的铝酸盐水泥化学成分、矿物组成相近。针对提钛尾渣是否能够替代部分售价较高的铝酸盐水泥进行一些应用的问题，本项目基于分散剂对颗粒的分散和用水量的调控及硅微粉的细集料填充和火山灰活性，在提钛尾渣引入分散剂-硅微粉体系。本项目系统研究分散剂-硅微粉体系对提钛尾渣的水化动力学及水化机理影响；探索分散剂-硅微粉体系对提钛尾渣的水化产物矿物组成和显微结构的影响；研究不同温度下分散剂-硅微粉体系对产物组成和显微结构调控与力学性能之间相关性，为提钛尾渣综合利用和高附加值提供理论指导和借鉴意义。

本项目围绕分散剂-硅微粉体系对提钛尾渣水化过程中的分散机制、水化机理、水化产物等关键科学问题，采用宏观性能研究与显微结构表征相结合，在前期研究基础上，对提钛尾渣的基本水化性能和显微结构进行了系统研究。首先，对比研究提钛尾渣的水化性能与铝酸钙水泥的水化性能；其次，分析不同种类和掺量的分散剂、不同掺量的SiO2微粉和分散剂-SiO2微粉对提钛尾渣浆体的流变性能、凝结时间、水化过程等的影响；最后，研究分析分散剂、SiO2微粉和分散剂-SiO2微粉对提钛尾渣水化产物物相组成和显微结构、力学性能等的影响。提钛尾渣浆体的zeta电位呈正值。当分散剂T掺量超过0.3%时，吸附和解吸已经基本达到平衡，pH值和流变性能变化不明显。分散剂T和SiO2微粉协同作用，提钛尾渣在水化过程主要受扩散控制，累积放热量增加，SiO2微粉促进水化产物水石榴石的生成，并可以改善提钛尾渣的水化产物显微结构，分散剂T和SiO2微粉协同作用下，不同龄期的提钛尾渣的硬化体力学性能提高。.项目完成原计划研究内容。本项目的意义在于资源化利用固体废弃物，为扩展提钛尾渣高附加值应用领域与范围提供了理论依据。本项目阐明分散剂和SiO2微粉对提钛尾渣水化机理和水化性能，对实现提钛尾渣深度开发、无污染的规模化消纳具有启示意义，为后续进一步扩宽提钛尾渣的高附加值综合应用提供理论基础。