Method for extracting salts and temperature-regenerated extracting composition

A process for deionizing water by extraction in a liquid medium with thermal regeneration, applied to the extraction of at least one alkaline cationic species and of a complementary anionic species from a saline liquid aqueous solution, the saline liquid aqueous solution comprising:

• a salt of the at least one alkaline cationic species, and
• a salt of a cationic species of an alkaline earth metal, the process comprising the following steps:
• a) mixing in a first reactor, at a first temperature, a liquid hydrophobic organic phase and the saline liquid aqueous solution, in order to subsequently obtain a treated liquid aqueous solution and a liquid hydrophobic organic phase charged with the at least one alkaline cationic species and the complementary anionic species,
• the liquid hydrophobic organic phase comprising an extracting molecule of the at least one alkaline cationic species, a solvating molecule of the complementary anionic species;
• b) separating the treated liquid aqueous solution and the liquid hydrophobic organic phase charged with the at least one alkaline cationic species and the complementary anionic species;
• and
• c) mixing in a second reactor, the liquid hydrophobic organic phase, charged with the at least one alkaline cationic species and the complementary anionic species, with a regeneration liquid aqueous solution, in order to subsequently obtain a regenerated liquid hydrophobic organic phase and a regeneration liquid aqueous solution charged with the at least one alkaline cationic species and the complementary anionic species, the difference between the first and second temperatures varying from 30° C. to 150° C.;
• wherein the extracting molecule of the at least one alkaline cationic species is a macrocycle, the cycle of which is formed from 16 to 24 atoms and functionalized with ester or ketone groups.