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碱法钛白粉清洁生产中熔盐反应产物偏钛酸钠制备偏钛酸的研究
文献类型：学位论文
| 作者 | 杨轩 |
| 学位类别 | 硕士 |
| 答辩日期 | 2009-06-05 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 齐涛 |
| 关键词 | 制备工艺 酸解 水解 偏钛酸 |
| 其他题名 | The preparation of metatitanic acid from Na2TiO3 produced by molten salt reaction in TiO2 cleaner production process |
| 学位专业 | 环境工程 |
| 中文摘要 | 氢氧化钠低温熔盐分解高钛渣制备钛白粉是一种钛白粉生产新技术，由熔盐反应产物偏钛酸钠制备出合格的偏钛酸是新工艺中的关键步骤，偏钛酸的性质直接影响到钛白粉产品的质量。本论文以熔盐反应产物偏钛酸钠为前驱体，对偏钛酸的制备过程和不同因素对偏钛酸性能的影响规律开展研究，探索较优的偏钛酸制备工艺条件和偏钛酸质量的有效控制方法，主要研究成果如下： （1）通过水洗去除熔盐反应产物偏钛酸钠中的水溶性杂质，熔盐反应产物Na2TiO3在水洗过程中发生体内水解，晶形被破坏，晶格中部分钠离子被H3O+置换，水洗料接近无定型；（2）水洗料在盐酸体系中通过酸处理过程可一步制备偏钛酸。在盐酸溶液中随着温度升高，水洗料发生溶解-水解-脱水-晶化过程，50℃时水洗料的酸解率最高，温度超过60℃，发生酸溶-水解耦合反应，产物在较低温度下是无定型物质，80℃以上产物晶化形成偏钛酸晶体颗粒。最终水解产物的晶型取决于酸处理过程中的低温反应阶段，高温反应过程不影响水解产物的晶型，用不同的钛氧离子聚合体生长基元模型可以较好地解释实验中水解产物晶型随低温酸处理条件的变化规律； （3）研究了水洗料在盐酸介质中的溶解动力学，为开发在稀酸介质中制备偏钛酸新工艺提供参考依据。研究表明水洗料在稀盐酸介质中的溶解反应过程符合标准2级反应动力学模型，介质酸度对钛溶解速率有显著影响，温度影响不大； 建立了反应动力学方程式： ；（4）研究了以水洗料在硫酸体系中制备偏钛酸的过程。水洗料在不同浓度的硫酸溶液中，于50℃下溶解4h，反应基本达到平衡，利用MATLAB拟合酸溶实验数据，得到钛液浓度与水洗料用量和钛液浓度、F值与硫酸浓度的关系，确定了不同性质钛液的配制方法。确定了在硫酸体系中处理水洗料制备偏钛酸的工艺，偏钛酸的制备工艺条件如下：钛液浓度大于190g/L（以TiO2计），F值1.8~2.1，稳定性不低于500，微沸状态下水解4h以上。 |
| 英文摘要 | There is a new process to produce titanium dioxide, based on the decomposition of titanium slag by molten NaOH. The preparation of the qualified metatitanic acid from sodium metatitantate, the product of molten salt reaction, is the key step of the new technology because the quality of metatitanic acid directly affects the quality of titanium dioxide products. In this paper, the process to produce metatitanic acid from sodium metatitantate and the influence over the performance of metatitanic acid were investigated. The research also focused on the preparation conditions and the effective quality control methods of the metatitanic acid. The main points are as follows: (1) The water-soluble impurities in sodium titanium were removed by washing the molten salt reaction products. After the washing process, Na2TiO3 was hydrolyzed with destroyed crystal lattice, and the Na+ ions were replaced by H3O+. The washed material was nearly amorphous. (2) The washed material was treated in HCl solution to prepare the metatitanic acid. In hydrochloric acid solution, when the temperature increased, the following reactions occured for the washed material: dissolution, hydrolysis, dehydration and crystallization. In 50℃, the solubility of the washed material was the highest. When the temperature exceeded 60℃, the dissolution-hydrolysis coupling reaction was carried out, producing amorphous material in low temperature. While the metatitanic acid crystal particles were formed by crystallization process when the temperature exceeded 80 ℃. The final hydrolysis product depends on the process of acid treatment at low temperature, while the high temperature reaction has no effect on the crystal structure of the hydrolysis product. Different ion polymer model can explain the crystallization process. (3) The dissolution kinetics of the washed material in hydrochloric acid was studied. The results showed that the process for the washed material dissolved in hydrochloric acid matched the standard secondary dynamic model. The concentration of H+ had a significant effect on dissolution rate, but the temperature had less effect. The reaction kinetics equation was (4)In sulfuric acid solution, the preparation of metatitanic acid was studied. The dissolution equilibrium of the washed material was obtained in different concentrations of sulfuric acid solution at 50℃ for 4h. MATLAB program was adopted to fit the experimental data. The relationships between the concentration of sulphuric acid, the mass of the washed material, the concentration of titanium dioxide and F value were determined. The preparation conditions of the hydrolysis process were as follows: TiO2 concentration greater than 190g / L, F value 1.8 ~ 2.1, the stability greater than 500 and hydrolysis time at least 4h in boiling point. |
| 语种 | 中文 |
| 公开日期 | 2013-09-23 |
| 页码 | 87 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1646]  |
| 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 | 杨轩. 碱法钛白粉清洁生产中熔盐反应产物偏钛酸钠制备偏钛酸的研究[D]. 中国科学院研究生院. 2009. |
入库方式： OAI收割
来源：过程工程研究所
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