Abstract: A process for the embedding or containment of waste materials, especially of radioactive waste materials, by embedding in a ceramic matrix through the intermediary of the chemical precipitation of a hydrosol of the matrix, which is formed through the reaction of a nitrate with ammonia or ammonium hydroxide. In this process, the hydrosol is trickled in a pouring column into a precipitation bath, subsequent to the introduction of the material which is to be embedded, in which the hydrosol particles which are formed during the trickling gelatinize into gel particles. The gel particles are removed from the precipitation bath, washed, dried and finally sintered.