Preparation of ThO{sub 2} microspheres

A method is proposed for preparing granulated ThO{sub 2} from its salt solutions by using cryogenics and solid-state conversion. It includes the following operations: dispersion of the starting solution in liquid N{sub 2}, preparation of cryogranules of the required size by imposing a certain vibrational frequency on the filler and charging the resulting drops in a DC field, solid-state conversion of the Th salts into the hydroxide by treating the cryogranules with cold NH{sub 3} solution and drying and calcining the hydroxide granules to prepare the granulated ThO{sub 2}. An experimental apparatus was used to determine the conditions and develop the optimal procedures for preparing the granulated ThO{sub 2}. The mechanisms of conversion of the Th(OH){sub 4} cryogranules into ThO{sub 2} was investigated by using thermal analysis.