草酸盐沉淀法制备超细氧化铈的研究

Synthesis of Cerium Oxide Ultrafine Powers by Oxalate Precipitation

研究了草酸盐沉淀法制备超细氧化铈粉体的工艺。通过正交实验,研究了沉淀方式、沉淀剂的浓度、硝酸铈的浓度、反应温度、滴加速度等沉淀条件对氧化铈颗粒粒径的影响,找出了制备纳米氧化铈的最佳沉淀工艺条件。利用DTA/TG对氧化铈样品前驱体的热分解行为进行了分析,研究了焙烧和干燥条件对氧化铈粒径和比表面积的影响,由此确立了制备氧化铈合适的焙烧和干燥条件。结果表明采用草酸盐反向沉淀法可以得到超细氧化铈粉体,其体积中心粒径D50为1.011μm、比表面积为42.69 m2.g-1,晶体结构为立方晶系,CaF2萤石型结构,形状呈薄片状,分散性较好。

The synthesis process of cerium oxide ultrafine powers prepared by precipitation with oxalate was studied. The effects of precipitation mode, precipitator concentration, Ce（NO3）3 concentration, reaction temperature and feeding speed on particle size of CeO2 powders was investigated and the optimum preparation condition was gained by orthogonal experiment. The evolution behavior of the CeO2 powders precursor in the heating process was characterized by DTA/TG. The effects of calcination and drying conditions on par-ticle size and specific surface area of CeO2 powders was studied. So the suitable calcination and drying conditions of CeO2 powder preparation was determined. The result showed that the cerium oxide ultrafine powers could be obtained with oxalic acid as precipitate agent by reversed precipitation method. The volume median particle size, the specific surface area the prepared cerium dioxide was 1. 011 μm, 42.69 m^2·g^-1 respectively, and its crystal structure was cubic fluorite, and the shape was dispersed flake.