Process for producing sintered mixed oxides which are soluble in nitric acid from solutions of nitrates
US4871479A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 1988 |
| Grant date | Oct 3, 1989 |
| Priority date | — |
| Expiry date | Jun 22, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E30/30
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process is disclosed for producing sintered mixed metal oxide nuclear f pellets containing UO.sub.2 and the oxide of at least one other fissionable or rare earth element M, the pellets being directly soluble in nitric acid without nitric acid additive or prior treatment of the pellets. The process comprises the steps of mixing together nitrate solutions of the elements, concentrating the mixture of solutions, thermally denitrating the concentrated nitrate mixture without additives, to obtain an intermediate mixed oxide powder, calcining the intermediate mixed oxide powder, reducing the calcined mixture, stabilizing the uranium oxide UO.sub.2 in the reduced oxide mixture, shaping and pressing the resulting stabilized, reduced oxide mixture to obtain pellets of green material, sintering the pellets of green material and grinding the sintered pellets. The intermediate steps of this process produce mixed oxide powders of high flowability and good sinterability without the necessity of crushing which tends to produce troublesome effluent or dangerous aerosols of solids.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.