Process for immobilizing metallic sodium in glass form

A process for immobilizing metallic sodium in glass form, comprising the steps of:

• (A) introducing the following constituents, (i), (ii) and (iii) into a reactor:
• (i) a vitrified matrix precursor,
• (ii) sodium in the metallic state, and
• (iii) iron oxide Fe2O3, in an amount sufficient to ensure oxidation of the metallic sodium (ii) introduced,
• said constituents (i), (ii) and (iii) being introduced into the reactor in a dispersed form;
• (B) producing, by bringing constituents (i), (ii) and (iii) in dispersed form into contact with each other within the reactor, a homogeneous mixture of these constituents;
• (C) heating the mixture obtained to a temperature of between 1000 and 1600° C., whereby a homogeneous mixture in the molten state is formed, in which the sodium initially introduced is in the sodium oxide state;
• and
• (D) recovering the molten mixture thus obtained and cooling it, whereby a vitrified matrix of homogeneous composition is obtained that incorporates the initially introduced sodium as constituent oxide of the said vitrified matrix.