溶胶-凝胶法制备掺钛UO_2微球工艺和性能影响因素研究

Investigation of Factors Affecting Preparation and Performance of Titanium-Doped of UO_2 Microspheres by Sol-Gel Method

针对溶胶-凝胶法制备掺钛UO2微球中出现的掺钛凝胶微球粘连严重、烧结过度、微球抛光面腐蚀等现象,通过改进工艺条件和参数来解决工艺中出现的问题。结果表明:增加胶凝时间不仅能解决凝胶球的挤压变形问题,而且能大大改善凝胶球的粘连问题;降低烧结温度可以得到表面更加光滑的烧结体;选用浓硝酸(w=68%)和高纯H2O(二者体积比为2∶1)作为腐蚀微球抛光表面的侵蚀剂,在很短的时间内就可以显现出清晰的晶界轮廓。

The effect of various factors on obtained by the preparing experiment. The UO2 microspheres with titanium-doped can be addition of surfactant Span80 can contribute to lessen the adhesion between gel balls, though it can＇t be eliminated completely. When the added amount of Span80 is more than 0.15%, the roundness sphericity of gel balls is reduced evidently. Extending gelatinization time can not only resolve the problem of extrusion and distortion but also the adhesion between gel balls. The smoothness of UO2 microspheres with doped titanium is increasing with the decreasing of sintering temperatures. The doped titanium is helpful for the sintering of UO2 microspheres. With concentrated HNOa （w= 68G） and high-purity H20 （V（HNOa） ： V（H2O）=2 ： 1） as erodent, the grain boundary of the microsphere shows soon.