| 摘要 |
<PICT:0950510/C1/1> Granular uranium oxide product (UO2 with or without UO3 and/or U3O8) is prepared by forming a layer of an aqueous paste of uranium oxide or ammonium uranate, breaking the layer into lumps, heating the lumps sufficiently to dry their outer surfaces and thereafter heating the lumps more strongly to obtain completely dry discrete granules of the uranium oxide product. As shown in Fig. 1 a layer of ammonium uranate paste 12, formed on rotary filter drum 4 by the movement of the drum through bath 11 of a fluid paste of ammonium uranate, is removed from the drum and broken into a multiplicity of lumps 30 by scraper 13. The lumps fall through channel 14 on to endless conveyer 1 and are heated to a temperature ranging from 150 DEG to 250 DEG C., to form on their surface a dry outer layer, by coil 5 which is supplied by with combustion gas from heating apparatus 7 via conduit 6. The lumps are passed from conveyer 1 to conveyer 15 which is perforated to permit the passage therethrough of hot air. The air circulates in a generally counter-current fashion with respect to the movement of the lumps 30 on conveyer 15, and heats the lumps to a temperature ranging from 350 DEG to 400 DEG C. There is obtained at the delivery end of the conveyer 15, at 19, a porous granular uranium oxide product having a good mechanical resistance. Specifications 800,692 and 885,217 are referred to. |
