Process for the purification and recovery of orthophosphoric acid by liquid-liquid extraction.

摘要

This purification process consists in bringing the aqueous solution (8) to be treated in contact, in an extraction column (2), with an organic solvent (10) for the extraction of orthophosphoric acid containing a trialkyl phosphate and a liquid saturated hydrocarbon; in washing the solvent (16) laden with acid with an aqueous washing solution (18); in reinjecting (22) the washing solution (20) leaving the washing column into the extraction column (2) at the point (22) where the concentrations of orthophosphoric acid in the washing solution (20) and the solution to be treated (8) respectively are identical, and in putting the laden and washed solvent (26) in contact with an aqueous solution (28) for reextraction capable of extracting (24) the orthophosphoric acid thus purified. <IMAGE>