Patent ID: 7195745

Claim:
Process for the preparation of a product comprising a phosphate of at least one element M(IV) chosen from thorium(IV) and actinide(IV)s, wherein it comprises the following stages: a) mixing a solution comprising thorium(IV) and/or at least one actinide(IV) with a phosphoric acid solution in amounts such that the molar ratio PO 4 M ⁢ ⁢ ( IV ) where M(IV) represents the total concentration of thorium(IV) and/or actinide(IV)s, is from 1.4 to 2, b) heating the mixture of the solutions in a closed container at a temperature of 50 to 250° C. to precipitate a product comprising a phosphate of at least one element M chosen from thorium(IV) and actinide(IV)s having a P/M molar ratio of 1.5, and c) separating the precipitated product from the solution.