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This article obtained using liquid phase precipitation method to prepare nano yttrium oxide powder preparation conditions, precursor thermal decomposition process and yttrium oxide grain growth kinetics behavior and get the following key findings: coarse yttria dissolved in concentrated nitric acid yttrium nitrate as raw materials, ammonia, potassium oxalate, ammonium oxalate, as a precipitating agent, the cationic surfactants as additives in the aqueous solution preparation of the yttrium oxide precursor, calcined in air to obtain a nano-yttria powders. The results showed that the use of ammonium oxalate precipitation agent precursor was prepared, the the yttria powder obtained after calcination loose delicate, agglomeration of small, high purity. Feeding methods, the raw reaction temperature, precursor washing drying process, calcination temperature and time of the precursor of the yttria particle size and dispersion. The results show that using flow prepared precursor and calcined yttria a grain diameter of less than 20 nm, smaller powder particle size distribution range, low reunion; small molecule alcohol (ethanol, n-butanol ) processing precursor can reduce particle agglomeration behavior; nonlinear temperature-programmed precursor drying at room temperature to a range of 110 ° C, which can effectively reduce hard agglomeration. XRD showed that the precursor calcined by the air of 600 ° C for 1h may initially formed yttria cubic phase, grain size with the calcination temperature and calcination time increased gradually increasing; However, when the calcination temperature exceeds 7h grain size with the extension of the roasting time is decreased. TG and DTA curves indicate that oxalic acid yttrium thermal decomposition process of the formation of yttria divided into five stages; DTA curve, four stages of activation energy calculated by Kissinger method. Found: the first stage is the precursor removal of adsorbed water and water of crystallization, the apparent activation energy E 1 = 42.13KJ/mol; second stage of oxalic acid yttrium decomposition, the apparent activation energy E 2 = 111.47KJ/mol; third stage for the thermal decomposition products of the oxidation process, the apparent activation energy E 3 = 94.28KJ/mol; fourth stage yttrium carbonate thermal decomposition process endothermic peak is not obvious, inconvenience calculated activation energy; the fifth stage amorphous yttrium oxide into the the cubic phase yttria process, the apparent activation energy E 5 = 195.38KJ/mol. XRD yttria grain growth kinetics study, the results showed that: in the range of 600 ~ 900 ℃, yttrium oxide grain growth exponent n lt; 0.2, the grain growth rate constant with increasing temperature increased significantly, roasting the higher the temperature, the faster the growth of the grain size of yttria; different activation energy of grain growth at low temperature and high temperature zone, below 690 ℃ 76.33 KJ / mol, higher than 690 ℃ for 527.11KJ/mol.
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