Method of recovering phosphoric acid

Purpose: To increase the working life of phosphoric acid thereby reduce the phosphoric acid loss and decrease the generation of secondary wastes in a case of decontaminating radioactive metal wastes by electrolytic polishing using phosphoric acid as the electrolyte. Method: Degraded phosphoric acid containing dissolved metals such as Fe, Ni and Cr in an electrolyte tank for electrolytic-polishing decontamination for radioactive metal wastes is extracted by a pump, and then sent through a filter to an anionic exchange resin tower, where the phosphoric acid can be selectively absorbed onto the resins in a non-dessociation state. Then, the effluents containing metal ions are stored in a liquid waste tank. And then, by delivering water to the resin tower, the phosphoric acid can be desorbed and then returned to the electrolyte tank. (Kawakami, Y.)