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题名	碱熔盐法制取钛白新工艺掺杂及煅烧对产品质量影响的基础研究
作者	王勇
学位类别	博士
答辩日期	2011-05-25
授予单位	中国科学院研究生院
导师	齐涛
关键词	掺杂 煅烧 钛白粉 碱熔盐法 颜料性能
其他题名	Fundamental Research on Effect of Doping and Calcination on the Properities of Titanium Doxide White Pigment Prepared by Alkaline Molten Method
学位专业	化学工艺
中文摘要	碱熔盐法制备颜料级二氧化钛（钛白）工艺是一种不同于传统硫酸法、氯化法制备钛白的清洁生产新工艺，该新工艺具有高反应活性、介质可循环、产品可调控等优点。为了实现碱法钛白新工艺制备得到高品质的颜料级二氧化钛产品，并完善和优化碱法钛白清洁生产的工艺过程，本文重点研究了氢氧化钠熔盐法分解高钛渣制备颜料级二氧化钛新工艺中偏钛酸的离子掺杂和煅烧过程，系统分析了离子掺杂、煅烧过程中各种因素对于制备二氧化钛产品性能的影响，并对其相关的工艺过程及机理进行了系统的实验研究和理论分析。本论文主要在以下几个方面取得了创新成果：（1）从主要杂质种类及含量、微观结构、晶体晶型等方面，系统分析了碱（NaOH）熔盐法和传统硫酸法制备得到的偏钛酸存在的差异。发现碱法钛白未经过除杂工艺得到的偏钛酸中含有较高含量的Na2O、SiO2、ZrO2，该偏钛酸的微结构受到水解的影响很大。研究了碱熔盐法制备得到的偏钛酸在煅烧过程中的物理、化学变化，其中TiO2的晶型转化主要在850-980℃之间；晶粒、颗粒的生长主要受到煅烧温度的影响，在850-950℃之间生长迅速。（2）对碱熔盐法TiO2晶型转化动力学的研究结果表明，TiO2的晶型转化分为新相成核和相生长两个阶段。转化温度较低时，晶型转化机制为“表面成核”；转化温度较高时，则为“在已成核表面上的稳定长大过程”。（3）系统研究了K2O、P2O5、Al2O3和金红石型TiO2晶种的掺杂对于TiO2煅烧过程中的晶型转化、颗粒生长的影响。研究结果表明，K2O、P2O5、Al2O3的掺杂抑制晶型的转化，而金红石型TiO2晶种的掺杂则促进晶型的转化；K2O、P2O5、Al2O3的掺杂还分别起到抑制颗粒高温烧结、抑制颗粒的生长、抑制颗粒在高温煅烧下过度生长的作用。（4）通过控制离子掺杂和煅烧过程，完善了碱熔盐法制备颜料级二氧化钛新工艺。在优化的工艺条件下，制备得到了符合市场标准的金红石型和锐钛矿型的钛白粉产品。碱熔盐法制备得到颜料级TiO2产品在色度、金红石含量、杂质含量、消色力、纯度等方面的指标，都已经达到或超过硫酸法钛白产品。（5）系统研究了熔盐法生产过程中的三种主要杂质(Na2O、SiO2和ZrO2)对于最终TiO2产品颜料性能的影响。研究结果表明，Na2O、SiO2和ZrO2的存在都会抑制晶型的转化；Na2O与偏钛酸中残留的SO42-作用会使TiO2产生液相烧结，SiO2、ZrO2的存在会抑制颗粒的生长。进一步研究了钛白粉中残余其它杂质（Fe2O3、Nb2O5、PbO、MnO2、Cr2O3、CoO、CuO等）于TiO2产品质量的影响，并对其相关的影响机理进行了分析。（6）进一步分析了碱熔盐反应温度对于酸溶、水解过程的影响。研究了碱熔盐法TiO2产品中主要杂质Na2O、SiO2、ZrO2的形成过程，并提出了“水洗”脱Na2O，“碱洗+絮凝”除SiO2、ZrO2的除杂工艺。还分析了Na2O、K2O、Al2O3、P2O5的加入对于煅烧过程中SO42-脱除的影响。
英文摘要	Preparation of titanium dioxide white pigment by alkaline molten method is a novel cleaner process which differs from the traditional sulfate process and chloride process. The new process can realize the higher titanium extraction, the recycling of reaction medium and the controlling of TiO2 products. In order to prepare high quality titanium dioxide white pigment and to improve the alkaline molten method, the metatitanic acid obtained by NaOH molten method was controlled for doping and calcination. The effects of doping and calcination processes on the pigmentary properties of TiO2 products were studied systematically. In addition, the process of NaOH molten method and mechanism concerned were also investigated. The following achievements and innovative progresses were exhibited. (1) The differences of metatitanic acid prepared via sulfate method and NaOH molten salt method, such as main impurities, microstructure, and crystal phase composition were investigated. The unpurified metatitanic acid has higher contents of Na2O, SiO2 and ZrO2 due to the high reactivity of NaOH molten salt. Physical and chemical changes of metatitanic acid in calcination process were also studied. The results show that anatase-rutile phase transformation mainly occurs between 850-980oC and the TiO2 crystal growth quickly between 850-950oC. (2) Based on the kinetics research of phase transformation, TiO2 phase transformation process includes two stages: phase nucleation and phase growth. Phase transformation mechanism is “surface nucleation” at lower calcination temperature and is “stable growth on the nucleation surface” at higher calcination temperature, respectively. (3) The doping effects of K2O、P2O5、Al2O3 and rutile TiO2 nuclei on the phase transformation and crystal growth of TiO2 prepared by NaOH molten salt method were investigated. The results show that the anatase-rutile phase transformation was inhibited by adding K2O、P2O5、Al2O3, and was enhanced by adding the rutile TiO2 nuclei. At the same time, the K2O、P2O5、Al2O3 are also introduced during TiO2 calcination with the view to resist the sintering, to limit the growth of grains and to inhibit the excessive growth of TiO2 at higher temperature, respectively. (4) Anatase and rutile TiO2 white pigments were prepared by doping and calcination of metatitanic acid obtained by NaOH molten salt method, which approached the commercial pigments standards on color performance, rutile content, chemical purity and main impurities content, tint strength etc. (5) The influence of Na2O, SiO2 and ZrO2 which are the three main impurities in TiO2 prepared by NaOH molten salt method on the properties of TiO2 product were studied. The results show that TiO2 phase transformation and crystal growth was inhibited by the presence of Na2O, SiO2 and ZrO2, and TiO2 liquid phase sintering was occurred in the presence of Na2O and residual SO42-. Furthermore, the influence of other impurities, such as Fe2O3、Nb2O5、PbO、MnO2、Cr2O3、CoO and CuO on the properties of TiO2 products were investigated and the mechanisms concerned were also discussed. (6) Several key processes in NaOH molten salt method on the qualities of TiO2 products were further studied. The excessive molten salt reaction temperature could result in the difficulty of acid dissolution and the unexpectly early hydrolysis. The generation process of the three main impurities Na2O, SiO2 and ZrO2 was investigated and the appropriate removal method of these impurities was proposed. Meanwhile, the influence of adding Na2O、K2O、Al2O3、P2O5 on the removal of SO42- in the calcination process were also analyzed.
语种	中文
公开日期	2013-09-24
页码	145
内容类型	学位论文
源URL	[http://ir.ipe.ac.cn/handle/122111/1715]
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	王勇. 碱熔盐法制取钛白新工艺掺杂及煅烧对产品质量影响的基础研究[D]. 中国科学院研究生院. 2011.

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