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AssigneeComurhex
InventorsRoland Bachelard, Pierre Lakodey
Estimating the term…
A process for the production of uranium trioxide having a large specific surface by the thermal denitration of hydrated uranyl nitrate corresponding to the formula UO.sub.2 (NO.sub.3).sub.2 .multidot.xH.sub.2 O, in which 2.ltoreq.x.ltoreq.6, characterized in that, in a first stage, the said nitrate is treated in the form of a liquid at room temperature in the range from 160.degree. C. to 260.degree. C. until a solid phase containing at least 55% by weight of uranium is obtained and, in a second stage, the said solid phase is progressively heated to a temperature of at most 600.degree. C. at a heating rate of at most 1000.degree. C. per hour, and is kept at this temperature of at most 600.degree. C. until a second solid phase of UO.sub.3 having a large specific surface is obtained. The UO.sub.3 product produced has a specific surface of at least 10 m..sup.2 g.sup.-1.
A process for the production of uranium trioxide having a large specific surface by the thermal denitration of uranyl nitrate hexahydrate corresponding to the formula UO.sub.2 (NO.sub.3).-xH.sub.2 O, in which 2.ltoreq.x.ltoreq.6, the improvement comprising carrying out the denitration process in two stages, said first stage comprising heating liquid uranyl nitrate hexahydrate to a temperature in the range of from 160.degree. C. to 260.degree. C. to obtain a solid phase containing at least 55% by weight of uranium, and said second stage comprising progressively heating said solid phase at a heating rate of not more than 1000.degree. C. per hour to a temperature of not more than 600.degree. C. and holding said solid phase at the said temperature for a period of at most six hours to obtain a second solid phase of UO.sub.3 having a specific surface larger than 10 m.sup.2 /g.
Dependencies are inferred from the claim text.