摘要
针对TiCl_4气相水解制备TiO_2粉体存在Cl含量高的问题,开展了流化床TiCl_4气相水解制备高纯TiO_2。系统地研究了反应条件、煅烧后处理对TiO_2粉体的纯度、形貌、晶型、比表面积的影响。结果表明,TiO_2内部结构和晶型的转变有利于Cl的脱除;提高煅烧温度使TiO_2的内部结构由多孔疏松向致密结构转变,晶型结构由锐钛矿相向金红石相转变,从而有利于提高Cl的脱除率;与空气煅烧比较,水蒸气气氛下的脱氯效率明显提高,归因于水蒸气与TiO_2颗粒内残余的多羟基氯化物进一步反应;氢气气氛下可进一步提高Cl的脱除率,800℃煅烧2 h后Cl的脱除率达到95%,主要归因于氢气还原TiO_2使其晶型结构发生转变。
Synthesis of high purity TiO2 powder by fluidized gas hydrolysis method is investigated. To tackle the problem of high C1 content remained in the TiO2 powder, the hydrolysis reaction conditions and subsequently calcination at air, steam and H2 are mainly investigated for dechlorination. The results show that the structure and phase transition of TiO2 are two key factors that affect the efficiency of dechlorination. With the increase of the calcination temperature, the internal structure of TiO2 is changed from porous to dense structure, and the crystalline structure is transformed from anatase to futile. The structure and phase transition of TiO2 are beneficial to increasing the removal rate of Cl. Compared with the air calcination, the dechlorination efficiency in water vapor atmosphere is obviously improved, which is attributed to the further reaction of water vapor and the multi hydroxyl chloride in the TiO2 particles. Compared with air and steam calcination, the removal rate of C1 can be further improved up to 95% under the atmosphere of hydrogen at 800℃ for 2h, which is mainly attributed to the reduction of TiO2 structure by hydrogen reduction.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2017年第10期3978-3984,共7页
CIESC Journal
基金
国家自然科学基金项目(21325628
U1462128)
国家重点基础研究发展计划项目(2015CB251402)
国家重大科学仪器设备开发专项项目(2011YQ12003908)~~
关键词
流化床
水解
二氧化钛
超细粉体
团聚
fluidized-bed
hydrolysis
TiO2
ultrafine powders
agglomeration
