Process for removing sulfate ions from extracted phosphoric acid with a barium compound

A process for removing sulfate ions from extracted phosphoric acid which is substantially free of metallic ion impurities and which has been prepared by extracting wet process phosphoric acid with an organic solvent which comprises:

• a. adjusting the extracted phosphoric acid concentration to a concentration greater than 70%;
• b. continuously adding said extracted phosphoric acid and a barium compound to be extracted phosphoric acid having a dissolved sulfate ion concentration of from 50 to 300 ppm, wherein the amount of barium compound added is sufficient to reduce the sulfate ion concentration in the added, extracted phosphoric acid to from 50 to 300 ppm wherey barium sulfate crystals are formed;
• c. continuously discharging the resulting slurry;
• d. subsequently adding to said resulting slurry an amount of a barium compound which is less than the stoichiometric equivalent amount of barium relative to the amount of dissolved sulfate ion which remains to form additional barium sulfate crystals, wherein the amount of barium compound added is such that the treated extracted phosphoric acid contains at least 5 ppm of sulfate ions;
• and
• e. separating said barium sulfate crystals from the resulting slurry at a temperature less than 80.degree. C and recovering purified extracted phosphoric acid.