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为了制备高温气冷反应堆用燃料芯核,致密UO_2微球,研究了一种新的溶胶-凝胶工艺.该流程具有经典的溶胶-凝胶工艺的优点,但克服了它们的缺点.已经知道,合理的配方设计和良好的干燥条件是克服破裂困难的关键因素.影响胶滴尺寸及其分布的控制因素是:极限流量、几何因子、物理因子和振动因子.微球干燥和焙烧参数的优化是依据热分析曲线来确定的.用SEM方法观察了热处理过程中的微观结构的变化.观察了真空烧结的重结晶现象.观察了UO_2·nH_2O的化学气相沉积.结果表明:晶粒大小随烧结温度增加而增加.本工艺适合于制备500μm直径的微球.其产率为90%.球度优于1.08.球径范围为470-530μm.1400-1450℃真空条件下的烧结密度范围为10.71-10.76 g/cm~3.
In order to prepare fuel core and dense UO 2 microspheres for high temperature gas-cooled reactor, a new sol-gel process has been studied, which has the advantages of classical sol-gel process but overcomes their disadvantages. , Reasonable formula design and good drying conditions are the key factors to overcome the rupture.The control factors that affect the size and distribution of the droplet are the limit flow rate, geometry factor, physical factor and vibration factor.The optimization of microsphere drying and calcination parameters Is determined by the thermal analysis curve.The microstructure changes during the heat treatment were observed by SEM.The recrystallization of the vacuum sintering was observed.The chemical vapor deposition of UO_2 · nH_2O was observed.The results show that the grain size with the sintering The temperature is increased and increased.This process is suitable for the preparation of 500μm diameter microspheres with a yield of 90% Sphericity better than 1.08 Spherical diameter range 470-530μm.1400-1450 ℃ under vacuum sintering density range of 10.71 -10.76 g / cm ~ 3.