An improved internal gelation process without cooling the solution for preparing uranium dioxide ceramic microspheres. Issue 2 (1st February 2018) - Li, Sa
Abstract: An improved internal gelation process for the preparation of UO2 ceramic microspheres with diameter of 790±20 µm is described. The UO2 ceramic microspheres are prepared by optimizing feed solution compositions and heating up rate during sintering and calcination steps. The two feed solutions Hexamethylenetetramine (HMTA)-urea and UO2 2+ were mixed just before the drop formation driven by two liquid chromatographs at room temperature without Cooling the Solution. A urea/UO2 2+ mole ratio of 1.45 is applied to ensure the stability of the solution. After accurate washing steps to wipe out the impurities, good spherical and little cracked UO2 ceramic microspheres will be obtained at a heating-up rate of 5 K/min during sintering and calcination. Different from the traditional methods reported previously, solution which is not cooled is employed during the improved process in this paper.