含钛泥浆再利用过程中二氯甲烷-四氯化钛二元系气液相平衡研究

Titanium-containing slurry is the major waste in the process of titanium metallurgy. Because of high titanium tetrachloride content and difficulty in recycling, the slurry has led to horrible waste of value resource. Moreover, the titanium-containing slurry is extremely easy to hydrolyze and release hydrogen chloride, which can not only wreak havoc on operator’s health but also cause destruction of the eco-environment. Therefore, harmless treatment and utilization of the titanium-containing slurry has become an urgent issue to tackle in our titanium industry. Previous research from our team showed that over 98% of titanium tetrachloride in the slurry could be selectively extracted by dichloromethane. This indicates that it has a good potential for industrial application. While, perfect basic data and further study on the elementary theory of distillation separation of dichloromethane and titanium tetrachloride in extracting solution are critical for the industrial application of this technology. Hence, this application will be carried out to solve this problem. Firstly, the concentration analytical method of dichloromethane and titanium tetrachloride in extracting solution will be established by infrared spectroscopy. Then, combining computer simulation with experiment, the vapor-liquid equilibrium data of dichloromethane-titanium tetrachloride system will be measured, the activity and activity coefficient of dichloromethane and titanium tetrachloride will be calculated and the vapor-liquid phase equilibrium of this system will be studied. Finally, the vapor-liquid equilibrium phase diagram of dichloromethane-titanium tetrachloride system will be structured and the law of vapor-liquid phase equilibrium of this system will be revealed, which would lay the foundation for the distillation separation of dichloromethane and titanium tetrachloride in extracting solution, which would also apply guidance for the resource utilization of titanium-containing slurry.

含钛泥浆是钛冶炼的主要废物，其四氯化钛含量高且难以回收，造成了有价资源的极大浪费；并且含钛泥浆极易水解释放氯化氢，不仅损害操作人员的身体健康，还造成生态和环境的破坏。因此，含钛泥浆资源的无害化利用，已成为我国钛工业亟待解决的问题。项目组前期研究表明，二氯甲烷可选择性萃取含钛泥浆中的四氯化钛，回收率在98%以上，表现出较大的工业应用潜力。而深入研究萃取液中二氯甲烷和四氯化钛精馏分离的基础理论，完善基础数据，是该方法能否工业应用的关键。本项目拟先采用红外光谱法建立溶液中二氯甲烷和四氯化钛的浓度分析方法；再通过实验和模拟相结合的手段，测定二氯甲烷-四氯化钛二元系的气液相平衡数据，计算二氯甲烷和四氯化钛的活度及活度系数，研究该二元系的气液相平衡关系；最终构建二氯甲烷-四氯化钛二元系的气液平衡相图，揭示其气液相平衡规律，奠定萃取液中二氯甲烷和四氯化钛的精馏分离基础，为含钛泥浆的资源化再利用提供指导。

针对含钛泥浆难处理的现状，提出了二氯甲烷选择性萃取四氯化钛处理含钛泥浆的新工艺。通过精馏实现萃取液中二氯甲烷和四氯化钛的深度分离，是该新工艺实现工业化应用的关键。而萃取液中二氯甲烷和四氯化钛组成了全新的二元系，精馏分离的相关基础数据缺乏。本项目以萃取液中二氯甲烷和四氯化钛为研究对象，研究新二元系的气液平衡规律涉及的：溶液中四氯化钛和二氯甲烷的分析方法、新二元系的气液平衡数据、气液平衡相图和气液平衡规律以及二氯甲烷和四氯化钛的精馏分离等基础问题，为含钛泥浆的资源化利用提供技术支撑和理论指导。.研究取得如下成果：1）采用红外吸收光谱和拉曼散射光谱，建立了溶液中CH2Cl2和TiCl4浓度分析方法。验证试验表明，采用红外吸收光谱和拉曼散射光谱均可对溶液中CH2Cl2和TiCl4进行定量分析。采用红外光谱分析溶液中CH2Cl2和TiCl4，误差分别为5.3%和6.6%；采用内标法利用拉曼光谱分析溶液中CH2Cl2和TiCl4，误差分别为2.56%和4.25%。2）采用RTF-R双循环ROSE气液平衡釜测定了CH2Cl2-TiCl4二元系的气液平衡数据，计算了CH2Cl2-TiCl4二元系的活度系数。利用Aspen Plus软件，采用Wilson和NRTL模型对测定的CH2Cl2-TiCl4二元系气液平衡数据进行了模拟和关联，得到了CH2Cl2-TiCl4二元系的Wilson和NRTL模型参数。模拟结果表明，Wilson和NRTL模型可以很好地描述CH2Cl2-TiCl4二元系的气液平衡规律，CH2Cl2-TiCl4二元系不存在共沸物，可以采用普通精馏的方法深度分离。3）采用Aspen Plus软件的DSTWU（精馏塔简捷设计模块），对CH2Cl2-TiCl4二元系的精馏分离进行了初步探讨：当塔板数为6，塔顶流出率为0.4，回流比为0.5，塔顶馏出液中TiCl4含量为16.72%时，塔底馏出液中TiCl4含量可达到99.96%，为合格的精TiCl4。4）依托项目申请国家发明专利2项，已授权1项；发表论文4篇，其中SCI 检索3篇，EI 检索1篇。此外，还有2篇论文已完成撰写和投稿，正在审稿和修改中。