Al^(3+)对偏钛酸煅烧过程的影响和作用机制研究  

Study on the effect and mechanism of Al^(3+)during the calcination of metatitanic acid

作　　者：路瑞芳[1,2] 杨芳 刘婵 郝琳 Lu Ruifang;Yang Fang;Liu Chan;Hao Lin(State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization,Pangang Group Research Institute Co.,Ltd.,Panzhihua 617000,Sichuan,China;School of Chemistry and Chemical Engineering,Chongqing University,Chongqing 400030,China;School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China)

机构地区：[1]钒钛资源综合利用国家重点实验室,攀钢集团研究院有限公司,四川攀枝花617000 [2]重庆大学化学化工学院,重庆400030 [3]天津大学化工学院,天津300072

出　　处：《钢铁钒钛》2023年第4期25-32,共8页Iron Steel Vanadium Titanium

基　　金：国家自然科学基金青年科学基金项目(编号:22108019)。

摘　　要：硫酸法钛白生产工艺中,偏钛酸经不同盐处理和高温煅烧后获得适宜粒径的金红石二氧化钛是制备颜料钛白的基础,铝系盐处理是目前普遍采用的盐处理体系之一,但目前铝盐在煅烧过程的作用机制尚不明确。以硫酸法钛白生产中间物料二洗偏钛酸为原料,仅以硫酸铝作为盐处理剂,在马弗炉里升温至800~950℃条件下煅烧。利用XRD、SEM、HRTEM等分析手段研究了Al^(3+)在煅烧过程中对TiO_(2)晶型转变和粒子生长的影响。结果表明,不同铝盐加量以及煅烧温度对TiO_(2)晶型转变、粒子生长以及Al^(3+)的存在状态具有显著影响。铝盐加量较低时,Al^(3+)以取代模式掺入TiO2晶格中,置换Ti^(4+),使晶胞体积变小,晶体内部键长变短,不利于原子重排和断键过程,导致晶型转变率降低。随着铝盐加量的增加,过量的Al^(3+)在TiO_(2)表面以Al_(2)O_(3)的形式存在,同时相同煅烧温度下得到的锐钛型或金红石型TiO_(2)粒子粒径减小。In the production of titanium dioxide by sulfate process,obtaining rutile titanium dioxide with suitable particle size through different salt treatments and high-temperature calcination of metatitanic acid is the basis for preparing titanium pigments.Aluminum salt treatment is currently one of the commonly used salt treatment systems,but the mechanism of aluminum salt in the calcination process is still unclear.In this study,the intermediate material in the production of titanium dioxide by sulfate process,metatitanic acid after second washing,was used as raw material,and only aluminum sulfate was used as salt treatment agent.The material was calcined in a muffle furnace at a temperature of 800-950℃.The effects of Al^(3+)on the crystal transformation and particle growth of TiO_(2)during the calcination process were studied using XRD,SEM,HRTEM,and other analytical methods.The results show that dif-ferent amounts of aluminum salts and calcination temperatures have significant effects on the crystal transformation,particle growth,and existence form of Al^(3+)in TiO_(2).When the amount of aluminum salt is low,Al^(3+)is doped into the TiO_(2)lattice in a substitution mode,displacing Ti^(4+),reducing the crystal cell volume and shortening the internal bond length of the crystal,which is not conducive to the atomic rearrangement and bond breaking processes,leading to a decrease in the crystalline transformation rate.And with the increase of the amount of aluminum salt added,excessive Al^(3+)exists as Al_(2)O_(3)on the TiO_(2)surface.At the same time,with the increase of the amount of aluminum salt added,the particle size of anatase or rutile TiO_(2)obtained at the same calcination temperature decreases.

关 键 词：钛白 偏钛酸 Al离子掺杂 晶型转变 

分 类 号：TF823[冶金工程—有色金属冶金] TB34[一般工业技术—材料科学与工程]