摘要
本工作采用水热脱水法制备了超细氧化锆粉末,研究了不同工艺条件对粉末团聚状态和晶型的影响.实验结果表明,在190～250℃范围内水合氧化锆完全脱水时,脱水温度和时间可按下式表示:t=2.8148×10^(-5) exp(6278/T).粉末的晶型与沉淀时的 pH 值有关,而与脱水条件无关;本法制得的粉末具有较小的团聚参数,在沉淀初期引进具有静电效应或位阻效应的表面活性剂,能获得粒经(d_(50))为80nm 基本上无团聚的氧化锆粉末.
A hydrothermal method for producing ultrafine zirconia powder which could be used in fine ceramics is developed.Aqueous slurry of hydrous zirconia prepared by adding alkali to the solution of zircon salt is dehydrated at 190～250 ℃ to form ultrafine zirconia powder. The process may produce anhydrous powders directly and high temperature calcination is not required to convert hydroxide to oxide as in most of other methods.The powder obtained has an average diameter of 80nm with minimal agglomeration.The factors influencing the rate and degree of dehydration of hydrous zirconia,the particle size and the crystal structure are studied.The relation between temperature and duration of dehydration can be expressed as: t=2.8148×10-Sexp(6278/T) The crystal structure of ZrO_2 powder is dependent upon the pH value of the precipitation and independent of the hydrothermal conditions.The agglomeration state of ZrO_2 powder is influenced by the pH value of the precipitation,the concentration of zircon sulphate solution and the content of hydrous zirconia in the slurry,and can be improved efficiently by adding a small amount of surfactants and washing the products with alcohol during filtration.
出处
《化工冶金》
CSCD
北大核心
1993年第1期22-29,共8页
基金
国家自然科学基金
北京中关村地区联合分析测试中心的资助
关键词
氧化锆
水热法
超细粉末
Zirconia
Hydrothermal method
Ultrafine powder
