氯化制备TiCl4及其精制的应用研究
文献类型：学位论文
| 作者 | 熊绍锋 |
| 学位类别 | 博士 |
| 答辩日期 | 2010-01-17 |
| 授予单位 | 中国科学院过程工程研究所 |
| 授予地点 | 过程工程研究所 |
| 导师 | 袁章福 |
| 关键词 | TiCl4 碳热氯化 复合流化床 精制 混合物除钒 |
| 其他题名 | Applied Study on Production of TiCl4 by Chlorination and Its Purification |
| 学位专业 | 无机化学 |
| 中文摘要 | 四氯化钛（TiCl4）在钛工业中占据了核心地位，它既是制备钛白和海绵钛的中间产物，又在军事、化工等行业具有广泛的用途。由于TiCl4的生产及其精制是两个重要工艺环节，因此，对其进行研究具有重要的意义。 国内较为成熟的TiCl4生产工艺是沸腾氯化工艺，该工艺相比其他工艺，具有产能大、排渣量小和环境友好等优点。但是它无法解决高镁钙原料氯化时伴随的粘结问题，而世界上可直接用于沸腾炉氯化的高品位钛资源仅占总量的7.0 wt%。一种新型复合流化床工艺在抗高镁钙原料粘结方面具有潜在的应用价值，它利用沸腾流化床内快速气流产生强烈的剪切力，起到抗粘结的作用。前期工作主要集中在复合流化床工艺的流态化模拟和冷、热态小型实验。本文进一步计算复合流化床氯化尾气的热力学平衡成分，并在前期工作的基础上进行工业化中试和对试验结果进行分析总结，最后对后续粗TiCl4的精制工艺也进行了研究。主要研究内容及结论如下： (1) 利用HSC软件计算碳热氯化反应尾气的平衡组成，与实验值的对比结果表明：尾气中CO/CO2的平衡摩尔比值rEq分别随碳矿比、氯气量的增加和温度的升高而增大。实验值rEx（0.2~0.3）与文献参考值rRe（约0.5）接近，而与平衡计算值rEq（≥4.3）存在差别。SEM-EDS等分析结果表明存在差异的主要原因是物料在复合流化床中的停留时间过短致使TiO2碳热氯化过程尚未达到平衡，以及钛渣中CaO、MgO和SiO2等氧化物杂质参与碳热氯化反应。 (2) 在前期确定的工艺条件下，进行了复合流化床生产TiCl4的工业中试。结果表明该工艺具有一定的抗粘结能力。在收尘渣中有相当数量的CaCl2、MgCl2等氯化物存在，说明反应过程中生成的氯化物部分被带出复合流化床反应器。 (3) 首次提出了针对高钒含量粗TiCl4的以铝粉和白油混合物为除钒试剂的精制工艺。通过单因素精制实验和正交实验对影响精TiCl4中钒含量的各重要因素进行了研究，得出最优工艺参数。四个影响因素包括：铝粉与粗TiCl4中初始钒含量的质量比（rAl/VOCl3）、白油与粗TiCl4中初始钒含量的质量比（rWMO/VOCl3）、反应时间和温度。为了使精TiCl4中钒含量最低，确定最优工艺条件为：每吨粗TiCl4（钒含量为0.2860 wt%）加入1.144 kg Al粉和4.29 kg白油，反应时间为40 min，反应温度为411 K。 (4) 热力学计算和除钒残渣XPS表征的结果表明混合物法的除钒机理包括：一是在白油热裂解生成的活性碳作用下VOCl3分别被还原为不溶于TiCl4的VOCl2和VCl4沉淀以及其他低价态、低沸点的钒氯化物而除去；二是在铝粉与TiCl4反应生成的TiCl3作用下VOCl3被还原为VOCl2沉淀而除去。 |
| 英文摘要 | Titanium tetrachloride (TiCl4) plays a key role in titanium metallurgy. It has found wide application in the production of titania and sponge titanium as intermediate, military affairs and chemical industry, etc. The research on preparation and purification of TiCl4 was meaningful due to its importance in the titanium metallurgical process. The mature fluidizing chlorination in China possessed the advantages of high production capacities, low slag quantity and environmentally benign characters. However, it is hard to resolve the agglomeration problem caused by titanium minerals with high content of MgO and CaO. The titanium-rich material with low content of MgO and CaO all over the world has accounted for 7 wt%, which can be suitable to fluidizing chlorination. A novel combined fluidized bed with potentially valuable application has been proposed to promote anti-agglomeration of material powder by strong shear force generated from interior turbulence. Previous work mainly focused on fluidization simulation of combined fluidized bed and cold and hot test on a small scale. In this work, equilibrium components of off-gas were further calculated and the results of pilot plant carried out on the basis of the prior research were analyzed and summarized. In addition, the subsequent purification of crude TiCl4 was also investigated. All the research contents and results are as following: (1) The equilibrium components of off-gas released from carbothermal reactions in the presence of chloride were calculated by using HSC software and their equilibrium values were further compared with the corresponding experimental values. The results indicated that equilibrium molar ratio of CO to CO2 increased with increasing carbon/slag ratio and reaction temperature but decreased with increasing chlorine amount. At the same time, the carbochlorination experiment for titanium slag was carried out using novel combined fluidized bed as chlorinator and experimental molar ratios of CO to CO2 of off-gas were obtained. The comparison of experimental, equilibrium and referenced molar ratios showed that REx (0.2~0.3) was nearly equal to RRe (0.5~1.2) but less than REq (≥4.3). Based on the analysis of appearances and components of furnace slag, the difference between REx and REq was mainly due to short retention time of starting materials in combined fluidized bed and carbochlorination of oxide impurities in the titanium slag. (2) The pilot plant for production of TiCl4 with combined fluidized bed has been carried out under the technological conditions identified by previous work. The results show that the combined fluidized bed is capble of anti-agglomeration to some extent. The existence of CaCl2 and MgCl2 in dust slag indicates that chlorides in appreciable quantity which lead to agglomeration discharged from the combined fluidized bed. (3) A novel purification process of crude TiCl4 containing high content of vanadium impurities (mainly existing as VOCl3) by adding the mixture of Al powder and white mineral oil (WMO) was first proposed. All the important factors affecting the removal of vanadium impurities were studied by single factor and orthogonal experiments with the aim to obtain optimum processing conditions. Four control factors include the wt ratio of Al powder to VOCl3 (A), the mass ratio of WMO to VOCl3 (W), reaction time (t) and temperature (T). The optimum purification conditions corresponding to minimum vanadium content are that the purified agent should be added in the ratio of 1.144 kg Al powder and 4.29 kg WMO per ton of crude TiCl4 besides that t is 40 min and T is 411 K based on crude TiCl4 with the vanadium content of 0.286 wt%. (4) Vanadium-removing mechanism was discussed based on the results of thermodynamic calculation and characterization of purification residues. It emphasizes that VOCl3 has been converted to insoluble VOCl2, VCl4 and other vanadium chlorides with lower valancy by active carbon, which results from pyrolytic cracking of WMO, and simultaneously reduced to VOCl2 by TiCl3 which was produced by the reaction of Al powder with TiCl4. Key words：TiCl4, Carbothermal chlorination, Combined fluidized bed, Purification, Removing vanadium with a mixture |
| 语种 | 中文 |
| 公开日期 | 2013-09-13 |
| 页码 | 142 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1266]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 熊绍锋. 氯化制备TiCl4及其精制的应用研究[D]. 过程工程研究所. 中国科学院过程工程研究所. 2010. |
入库方式： OAI收割
来源：过程工程研究所
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