6107845x

In a process for the preparation of purified phosphoric acid from wet, raw phosphoric acid containing sulphate and fluoride components said sulphate component for sulphuric acid by contacting the raw phosphoric acid with a substantially water immiscible aliphatic C.sub.4 -C.sub.8 alcohol to form an aqueous phase and an organic liquid phase containing extracted phosphoric acid, some sulphate ions and fluorides, separating the organic liquid phase from the aqueous phase, contacting the separated organic phase with an aqueous solution containing calcium ion to precipitate out sulphate ion, as calcium sulphate, containing the remaining organic phase with an aqueous phase whereby phosphoric acid transfers from the organic phase to the aqueous phase with some of the fluoride in the form of HF or SiF.sub.4 thereby to provide an aqueous solution of phosphoric acid substantially free of cationic impurities and partially defluorinated, the improvement in which the aqueous solution is treated with water vapor or hot gas thereby to produce a defluorinated aqueous solution having a ponderal ratio of F/P.sub.2 O.sub.5 of less than 10 ppm.