| 摘要 |
The invention relates to sols in which the particles, which are preferably 10 to 120 millimicrons in diameter, consist of an intimate mixture of hafnia or zirconia, and an oxide of a quadrivalent actinide metal, e.g. urania. The hafnia or zirconia and the actinide metal oxide may be in solid solution, and the particles may contain less than 40 mol. per cent hafnia or zirconia. The sols are prepared by autoclaving at a temperature of at least 100 DEG C., e.g. 100 DEG to 200 DEG C., preferably 150 DEG C., and under a nonoxidizing atmosphere, e.g. nitrogen, (1) a freshly-prepared sol of hafnia or zirconia or a solution of a salt of zirconium or hafnium with a non-oxidizing acid, with (2) a freshly prepared sol of the actinide metal oxide or a solution of a salt of the actinide metal with a non-oxidizing acid, for a time sufficient to give the required sol, e.g. 2 to 40 hours, preferably about 20 hours. The solutions of both components may be the chloride or oxychloride. The autoclaved sol may be deionised by passing it over an ion exchange resin, and the particles in the autoclaved sol may be separated and redispersed in deionised water. Example 1 refers to the dilution of a mixed solution of uranous oxychloride and zirconyl chloride with deionised water. This solution was sealed into a glass pressure vessel under nitrogen and autoclaved for 20 hours at 150 DEG C. without agitation. The thus obtained sol was deionised and then concentrated and redispersed in a minimum amount of deionised water. |
