【摘要】 以混合碳酸稀土为原料 ,经煅烧、酸溶活化、再煅烧的两步煅烧法制备了CeO2 超细粉末。考察了第一步煅烧温度对煅烧中间产物酸溶性能和铈的氧化程度的影响 ,分析了煅烧和酸溶过程中的相关反应。结果表明 :第一步煅烧过程的温度控制不仅影响Ln2 O3·CeO2 的酸溶性能 ,而且还决定了最终产物CeO2 的物性。确定了制备超细CeO2 的合适条件是 :第一步煅烧温度为 80 0℃ ,用硫酸进行酸活化处理 ,控制pH值在 2左右 ,过滤洗涤后的活性中间产物CeO(OH) 2 再经第二次煅烧可以得到CeO2 含量在 90 %以上 ,粒度分布均匀且中位粒径D50 在 0 5～1.5 μm范围的超细CeO2 粉末。当第二步煅烧温度在 70 0～ 80 0℃之间 ,产物粒度小于 1μm ;当第二步煅烧温度为 80 0～ 10 0 0℃时 ,产物粒度在 1～ 1.5 μm之间。更多还原

【Abstract】 The ultrafine CeO 2 powder was prepared with mix rare earth carbonates as raw material by a process of annealing, acid active treating, and the second annealing. The influence of the first annealing temperature on the oxidation degree of cerium and the acid dissolution characteristic of intermediate were investigated. It was found that the temperature of the first annealing process influences not only on the acid dissolution property of Ln 2O 3·CeO 2, but also on the physical characteristics of final CeO 2 powders. The suitable preparation conditions for ultrafine ceria powder were suggested as follow: annealing mix rare earth carbonate at 800 ℃, treating with sulphate acid by controlling solution pH value around 2, filtrating and washing with water, and calcining the active intermediate CeO(OH) 2 at a temperature selected from 700 to 1000 ℃. The final product contains CeO 2 over 90% and the particle medium size D 50 range from 0.5 to 1.5 μm according to the final annealing temperature selected. When annealing between 700～800 ℃, the medium particle size of product is less than 1 μm, when annealing between 800～1000 ℃, the medium particle size of product is between 1～1.5 μm.更多还原