The Preparation And Characterization Of Spherical Yttrium Oxide

In this paper,the spherical yttrium oxide powder was prepared by the precipitation with ammonium bicarbonate.Yttrium chloride was raw materials that were prepared differently,one was the feed liquid precipitation that was a certain concentration,another one was the feed liquid precipitation that was added NH4Cl into it,then they were heated respectively to a certain temperature,when ammonium hydrogen carbonate solution was added into them with producing precipitation immediately,after aging, filtration, washing and drying the yttrium carbonate precipitation,finally yttrium oxide powders were obtained by calcination at the different temperature(from900℃to1400℃).The powder was characterized by the analysis method of the laser particle size analyzer, SEM,XRD,BET and Powder performance tester. The influence of the morphology, the particle size and the specific surface area of yttrium oxide was studied by the reaction temperature, the concentration of feed liquid, the aging time,the calcination temperature and the added mass fraction of NH4Cl.The study showed that different reaction temperature and concentration of feed liquid had a great influence on morphology, particle size and specific surface area of yttrium oxide.Particle size changed obviously with the increase of reaction temperature,the higher the concentration of concentration of feed liquid,the smaller the particle size,the morphology more different,not only the temperature and feed liquid but also the NH4Cl had a big influence on morphology and particle size of yttrium oxide,the particle size was bigger and the distribution more uniform with adding more NH4Cl into the feed liquid, the morphology of yttrium oxide had changed into needle-shaped particle from random particles between18and24hours,when the precipitation of yttrium carbonate was aging,the yttrium oxide was spherical that consist of acicular crystal for aging28hours,the calcination temperature was higher,the particle size was bigger,the specific surface area was smaller,the morphology was better,finally,the optimum process conditions were that the reaction temperature of the precipitation was93℃,the concentration of feed liquid was40 g/L, the aging time was28h, the calcination temperature was1400℃The precursor was analyzed by XRD,we knew that the structure of the precursors were Y2(CO3)3.2H2O and belong to the series of orthogonal crystal.according to analyze The decomposition of The precursor by TG-DSC,we calculate the number of the crystal water,then we find it was same as the result of XRD.We could produce different particle sizes of yttrium oxide that from30to60μm,the different properties demand,the different methods we took, the large, spherical,acicular particles of yttrium oxide were prepared directly by93℃ammonium bicarbonate solution precipitation,the good liquidity and high density of yttrium oxide were prepared by adding a mass fraction of NH4Cl to60℃liquid.