超细碳酸钇热分解行为及焙烧工艺的研究  

Thermal Decomposition Behavior and Roasting Process of Ultrafine Yttrium Carbonate

作　　者：饶明璐 高国华 陈金发 昝苗苗 肖燕飞[1] Rao Minglu;Gao Guohua;Chen Jinfa;Zan Miaomiao;Xiao Yanfei(Faculty of Materials Metallur-gy and Chemistry,Jiangxi University of Science and Technology,Ganzhou 341000,China)

机构地区：[1]江西理工大学材料冶金化学学部,江西赣州341000

出　　处：《中国稀土学报》2022年第2期276-285,共10页Journal of the Chinese Society of Rare Earths

基　　金：江西省青年科学基金项目(20202ACB214003);江西省“双千计划”科技创新高端人才(青年)项目(jxsq2019201116);江西省青年井冈学者奖励计划项目(QNJG2019056)资助。

摘　　要：超细Y_(2)O_(3)同时具有尺寸效应和稀土元素的双重特性,有着更加特殊的性质,在陶瓷、发光材料等方面多有应用。目前工业上主要通过液相沉淀法获得超细前驱体,进而焙烧获得超细Y_(2)O_(3);然而,在前驱体焙烧过程中,一般都需添加表面活性剂来避免团聚的发生,使焙烧前后产物的粒径和形貌具有良好的一致,最终获得粒度均匀的超细Y_(2)O_(3);但表面活性剂的使用造成了成本的增加。本文以前期碳酸钠沉淀获得的超细碳酸钇为对象,研究了其热分解行为和焙烧工艺,以期在不添加表面活性剂的条件下解决焙烧过程中团聚的问题。研究表明:超细碳酸钇(Y_(2)(CO_(3))_(3)·2H_(2)O)的热分解过程分为三个阶段,第一阶段焙烧温度低于360℃,为脱水过程;第二阶段焙烧温度在360~550℃,失去2个CO_(2),生成Y_(2)O_(2)CO_(3);第三阶段温度在550℃以上,继续失去CO_(2),生成Y_(2)O_(3)。Kissinger法求得三个阶段的表观活化能E分别为45.07,485.14,496.24 kJ·mol^(-1),指前因子A分别为3.68,5.51×10^(28),6.06×10^(27)s^(-1)。同时超细碳酸钇在50℃下干燥24 h后,在200℃保温3 h,350℃保温1 h,550℃保温2 h的三段式保温,升温速率9℃·min^(-1)的条件下,可以得到D_(50)=3.00μm,(D_(90)-D_(10))/2D_(50)=0.89的超细Y_(2)O_(3)粉体。Ultra-fine yttrium oxide has more special properties because of its dual characteristics of size effect and rare earth elements.It has many applications in ceramics,luminescent materials,etc.At present,the in⁃dustry mainly obtains ultrafine precursors by liquid precipitation method,and then being roasted to obtain ultra⁃fine yttrium oxide.However,in the precursor calcination process,it is generally necessary to add a surfactant to avoid agglomeration,so that the particle size and morphology of the products before and after calcination have a good agreement,and finally obtain ultra-fine uniform particle size yttrium oxide.But the use of surfactants cause an increase in costs.In this article,the ultrafine yttrium carbonate obtained by the precipitation of sodium car⁃bonate in the previous period was used as the research object,and its thermal decomposition behavior and roast⁃ing process were studied,in order to solve the problem of agglomeration during the roasting process without add⁃ing surfactants.The results indicated that thermal decomposition reaction is divided into three stages.The first stage roasting temperature is lower than 360℃,which is the dehydration process.The second stage roasting temperature is about 360~550℃,two CO_(2)are lost,Y_(2)O_(2)CO_(3)is generated.The third stage roasting temperature is above 550℃.CO_(2)was lost continuously and Y_(2)O_(3)was generated.The apparent activation energies of the three stages obtained by the Kissinger method are 45.07,485.14,and 496.24 kJ·mol^(-1),the exponential factors are 3.68,5.51×10^(28)and 6.06×10^(27)s^(-1),respectively.At the same time,the best roasting process was determined,the results showed that after drying at 50℃for 24 h,roasting with three-stage heat preservation at 200℃for 3 h-350℃for 1 h-550℃for 2 h,and heating rate at 9℃·min^(-1),the ultrafine yttrium oxide powder with D_(50)=3.00μm and(D_(90)-D_(10))/2D_(50)=0.89 can be obtained.

关 键 词：超细碳酸钇 热分解 动力学参数 焙烧条件 

分 类 号：O614.33[理学—无机化学] TF845.6[理学—化学]