添加剂在四氯化钛气相氧化过程中的作用机制  

Mechanism of Additives in Vapor Phase Oxidation Process of Titanium Tetrachloride

作　　者：吕滨 于学成 吴琼 姜志刚 臧颖波 王凯 

机构地区：[1]锦州钛业有限公司,辽宁锦州121005

出　　处：《稀有金属》2012年第5期780-784,共5页Chinese Journal of Rare Metals

基　　金：国家自然科学基金资助项目(50672014)

摘　　要：以气态四氯化钛为前躯体,水蒸气、三氯化铝和氯化钾为添加剂,采用高温气相氧化法制备出金红石型二氧化钛超细粉。通过热力学计算、X射线衍射(XRD)、粒度分析、扫描电镜联用X射线光电子能谱(SEM-EDX)等方法研究了水蒸气、三氯化铝和氯化钾在气相反应过程中的作用机制及二氧化钛粒子的形成过程。结果表明,水蒸气起到了成核剂的作用,它与四氯化钛及三氯化铝反应生成的相应氧化物提供了气相反应所需的晶核;三氯化铝作为晶型转化剂的同时,在改善二氧化钛表面状态等方面起到了重要作用;氯化钾是一种离子剂,它的加入提高了二氧化钛粉体的分散性,获得了均匀的粒度分布,细化了晶粒,改变了粉体的消色力。随着氯化钾加入量的逐渐提高,二氧化钛的消色力随之增加,当氯化钾的加入量在(100～120)×10-6时,消色力达到125%。研究同时表明,气相反应中二氧化钛微粒的形成过程可以分为:非均相成核—表面作用与晶型转化—颗粒长大与静电作用等基元步骤。Ultrafine rutile titanium dioxide powders were synthesized by a vapor oxidation process using titanium tetrachloride as a precursor and water vapor,aluminum trichloride,potassium chloride as additives.The mechanism of water,aluminum trichloride and potassium chloride in vapor phase oxidation process,and the formation course of titanium dioxide were analyzed by thermodynamic calculation,X-ray powder diffraction（XRD）,particle size measurement and scanning electron microscopy with X-ray photoelectron spectroscopy（SEM-EDX）.Water vapor could be called a nucleant agent here.It provided the crystal nucleus via reaction with titanium tetrachloride and aluminum trichloride.Aluminum trichloride also played an important role in phase transformation and surface shape of titanium dioxide.The adding potassium chloride adjusted the tinting strength of titanium dioxide for improving its dispersed property and particle size distribution size as an ionizing agent.The tinting strength of titanium dioxide increased with adding amount of potassium chloride.When the amount of potassium chloride was（100～120）×10-6 based on titanium dioxide,the tinting strength of titanium dioxide reached 125%.The formation course of titanium dioxide in vapor oxidation process included heterogeneous nucleation,surface action,phase transformation,grain growth,electrostatic interaction,etc.

关 键 词：气相氧化法 二氧化钛 金红石型 氯化法 消色力 

分 类 号：TQ134.11[化学工程—无机化工]