Process and Kinetic Study on Preparation of Nanometer Y2O3 by Roasting of Basic Yttrium Carbonate
In addressing the issue of easy-agglomeration during the roasting process to prepare nanometer Y2O3 powder by liquid precipitation method,the influence of roasting conditions on the morphology and particle size of Y2O3 and kinetic behavior of nanometer basic yttrium carbonate,obtained with the mixed precipitation agents of sodium carbonate and sodium bicarbonate,were systematically studied.The results show that under the conditions of a roasting temperature of 860 ℃,a heating rate of 5.375 ℃/min,and a roasting time of 1 h,nanometer Y2O3 with good dispersion of D50=0.050 μm and(D90—D10)/(2D50)=0.98 is obtained,and its morphology is similar to that of precursor basic yttrium carbonate.The thermal decomposition of roasting basic yttrium carbonate precursor(Y(OH)CO3·H2O)to prepare nanometer Y2O3 powder includes two stages.In the first stage,Y(OH)CO3·H2 O decomposes to generate Y(OH)CO3,with an apparent activation energy E of 90.23 kJ/mol,a pre-exponential factor A of 7.46 X 105,and a reaction order n of 0.75.In the second stage,Y(OH)CO3 decomposes to generate Y2O3,with an apparent activation energy E of 236.55 kJ/mol,a pre-exponential factor A of 1.31 × 1011,and a reaction order n of 0.82.
万方数据
