含钛硅酸盐体系中有价组分的组合析出及其材料化研究

Due to the complexity of components and presence of acidic、basic and amphoteric elements in Ti-bearing blast furnace slag(Ti-slag)it is hard to precipitate the mutil target components and leads to low added uses of Ti-slag. Therefore we must resolve the key scientific problems of control of precipitation of combination for the target components and the growth mechanism of particles in the titanium contained silicate in the basic coprecipitation process. Using the titanium contained silicate of Fe3+ and Mg2+ contained Si、Al、Ti sol system (FMSAT) as the research object, tools of ICP、XRF and XPS are used to determine activities of correlative ions and the degree of super saturation of TiO(OH)2 and Al(OH)3 are deduced. And the macroscopic kinetics model of the target components is established.Systemic studies are performed to obtain the effects of reaction conditions on the structure and shapes of particles via FTIR and TEM. Thus the control mechanism of precipitation of combination for the target components (Ti-Al) can be clarified. Furthermore, the aluminum titanate is fabricated by the coprecipitates and the effects of the structure and composition on the thermal stability of aluminum titanate are also examined via EPMA and TG-DSC. Therefore we can not only provide the theory evidence of precipitation of combination for the target components in FMSAT but also give some basic research and good prospect for the high added uses of the Ti-slag.

含钛高炉渣成分杂且含有酸性、碱性和两性组分，在对其进行湿法处理中，难以对多目标组分进行有效分离，因而只能对其进行粗放式利用。为此，我们务必解决："含钛硅酸盐体系在共沉淀过程中，目标组分的组合析出及粒子生长控制机制"这一关键科学问题。本项目以含Fe3+和Mg2+的Si、Al、Ti溶胶的含钛硅酸盐体系(FMSAT)为研究对象，采用ICP、XRF和XPS等手段，建立通过测定相关离子活度，推导TiO(OH)2和Al(OH)3粒子过饱和度的方法，构建目标组分胶体粒子的宏观生长动力学模型；通过FTIR和TEM系统研究不同反应条件对粒子结构和形貌的影响，阐明FMSAT中目标组分的析出控制机制；并以目标组分制备钛酸铝，由EPMA和TG-DSC等分析其结构和组成与热稳定性的关系。本项目的顺利实施，不仅为FMSAT中目标组分的组合析出提供理论指导，而且为含钛高炉渣的高附加值利用提供了研究基础和很好的应用前景。

传统的含钛高炉渣利用方式中，往往只关注某一特定有价组分的提取，然而含钛高炉渣成分杂且含有酸性、碱性和两性组分，在对其进行湿法处理中，难以对多目标组分进行有效分离，因而只能对其进行粗放式利用。本项目提出对含钛高炉渣硫酸酸解液中的多元有价组分进行合理设计，探明有价组元Ti及Al在硅酸盐溶液中的碱性水解析出规律；Ti-Al-Si三元体系中，Si组元在pH约为1.9时开始析出；Ti与Al组元在分别pH约为3.5与5.0时开始析出；Ti、Al、Si的析出率随着pH值及反应温度的升高而升高，与Al/Ti的物质的量之比无关；探索了通过测定溶液体系pH值以及电导率变化来判断沉淀反应进程的方法。系统考察了滴定终点pH值，反应温度以及体系初始铝钛比对共沉淀物组成，结构以及性质的影响；查明产物胶体粒子在不同条件下的生成粒径、微观结构及组成变化规律；同时着重研究这一过程中各有价组分的迁移规律，实现多元有价组分的组合析出；并探明以水解产物作为前驱体，制备钛酸铝复合材料的可行性。并在探索获得的模拟体系中各组元析出规律指导下，以硫酸酸解实际含钛高炉渣浸出液为对象，制备出高热稳定性的钛酸铝复合材料。本项目的顺利实施，不仅为含钛硅酸盐中目标组分的组合析出提供理论指导，而且为含钛高炉渣的高附加值利用提供了研究基础和很好的应用前景。