Abstract: The objective of the present innovation is a new process for the preparation of calcium phosphate granules of the hydroxyapatite type. The preparation process of a business for the said granules based on the invention is a hydrolysis process of a brushite dicalcium phosphate, in a basic milieu which is characterised by the fact that an aqueous suspension of brushite dicalcium phosphate is treated with lime, in the presence of an effective quantity of a carboxylic acid.

Abstract: The invention concerns a method for preparing a controlled mesoporous or mesostructured material, heat stable and at least partly crystallised, said method comprising steps which consist in: (A) forming an initial dispersion comprising: (1) at least partly crystalline colloidal particles of nanometric dimensions, whereof at least 50% of the population has a mean diameter ranging between 1 and 40 nm, and (2) a texturizer; (B) concentrating the resulting dispersion so as to obtain a solid by texturization and gradual aggregation of the colloidal particles; and (C) eliminating the texturizer in the resulting solid. The invention also concerns the partly crystalline and heat stable mesostructured products obtained by said method. The invention further concerns mesostructured materials, at least partly crystalline and heat stable, consisting essentially of a cerium, zirconium and/or titanium oxide. Said materials can be used in particular in catalysis.