熔盐法钛白清洁生产技术中锆钛分离方法研究
文献类型：学位论文
| 作者 | 马学琴 |
| 学位类别 | 硕士 |
| 答辩日期 | 2012-05-22 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 齐涛 ; 初景龙 |
| 关键词 | 锆 氟化钠 二氧化钛 氢氧化钠 |
| 其他题名 | Separation of Zirconium and Titanium in the Cleaner Production of Titanium Dioxide by Molten Salt Method |
| 学位专业 | 化学工艺 |
| 中文摘要 | 碱熔盐法钛白清洁生产新工艺是一种不同于传统硫酸法、氯化法制备钛白的新工艺，但其钛白产品中杂质锆含量明显高于其它工艺。本文系统研究锆在碱熔盐法钛白工艺各工序中的存在形态与走向，通过理论与实验分析详细研究钛锆分离工艺并优化了工艺条件，成功地分离杂质元素锆，完善了碱熔盐法钛白工艺流程，降低了产品中杂质锆含量，为制备高纯二氧化钛奠定了基础。主要研究内容和成果如下：（1）熔盐反应阶段锆与氢氧化钠发生反应，生成的反应料经水洗、酸洗及酸溶，此时钛与锆经历相同的反应过程；制备出的硫酸氧钛溶液在水解过程中，约12%锆发生水解，吸附在偏钛酸上，经洗涤后进入到产物TiO2中。当产品中ZrO2含量超过0.05wt%时，将抑制TiO2的晶型转化及颗粒生长，提高晶型转化温度。（2）发明了含氟离子溶液洗涤偏钛酸脱锆新方法，考察了氟盐用量、洗液酸度、反应温度、反应时间及液固比对锆去除率的影响。结果表明，在优化的洗涤脱锆工艺条件下，产物TiO2中ZrO2含量降至0.05 wt%以下，一次去除率高达87.1%。脱锆后偏钛酸的晶型、颗粒大小及形貌无明显改变。推测反应机理为在反应过程中HF与锆络离子团在偏钛酸表面发生竞争吸附，并分别计算了晶面吸附能。（3）研究了苦杏仁酸及其衍生物选择性沉淀硫酸氧钛溶液中的锆的新方法，结果表明锆沉淀率高于85%，并可以最大程度减少钛的损失。在硫酸氧钛溶液中添加氟化钠，可以有效地抑制水解过程中锆的水解，经此法水解后产品中ZrO2含量可降低至0.075 wt%。 |
| 英文摘要 | The preparation of titanium dioxide by alkaline molten method is a novel cleaner process which differs from the traditional sulfate process and chloride process. A higher content of zirconium (Zr) as a new kind of impurity in the product of TiO2 preparaed by this novel process than the other processes was detected. This paper system systematically studied the form and distribution of zirconium in the alkaline molten method. By analyzing the theoretical and experimental mechanism, a novel method of zirconium removal was studied in detail and the technical conditions were optimized. The impurity of zirconium was successfully removed by the new process, resulting in an increase of the purity of product, which would lay the foundations for the preparation of high-purity TiO2. The following achievements and innovative progresses were exhibited. (1) The study shows that the same reaction processes had occurred between zirconium and titanium in alkaline molten salt method. After the caustic fusion of zircon and NaOH, the molten reaction product was washed and dissolved, which resulted in the dissolution of zirconium in the titanyl sulfate (TiOSO4) solution. About 12% of zirconium were hydrolyzed and adsorbed on hydrous titanium dioxide (HTD), remaining in TiO2 powder. When the content of ZrO2 exceeded 0.05wt% in the product, the existence restrained the crystal transformation and grain growth, and improved the crystal transformation temperature. (2) A new method of removing Zr from HTD by NaF solution was proposed in this paper. The effect of the main parameters of pH, NaF dosage, temperature, and retention time on the removal of Zr was studied. The results showed that the ZrO2 content in the TiO2 product dropped to 0.05 wt% on the optimum conditions, which represented the highest Zr removal of 87.1%. The crystal form, particle size and morphology had no significant change after Zr removal. The possible mechanism of the removal process was also discussed. It revealed that there was competitive adsorption between HF and complex ions of zirconium on HTD surface. The adsorption energy was determined by theoretical calculation respectively. (3) A selective precipitation method of zirconium from TiOSO4 solution with mandelic acid and its derivatives was proposed. The results show that the precipitation rate of zirconium was more than 85%, and the co-precipitation rate of titanium was minimized. The hydrolysis of Zr was effectively inhibited by adding sodium fluoride into TiOSO4 solution, and the content of ZrO2 in TiO2 powder was reduced to 0.075 wt% by this method. |
| 语种 | 中文 |
| 公开日期 | 2013-09-25 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1845]  |
| 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 | 马学琴. 熔盐法钛白清洁生产技术中锆钛分离方法研究[D]. 中国科学院研究生院. 2012. |
入库方式： OAI收割
来源：过程工程研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。