This paper reports experimental data about the extraction of phosphoric acid from concentrated aqueous feeds (3 to 14 M H₃PO₄) by the mixture of di-isopropyl ether (DiPE) and tri-n-butylphosphate (TBP) at 25 °C: distribution ratios of H₃PO₄ and water, and change of phase volume ratio during extraction. Then, a simple model based on the extraction isotherms of H₃PO₄ and water as well as on the mass balance of these two compounds is developed in the case of the mixture of 90% wt DIPE and 10% wt TBP that corresponds to the solvent used at the industrial scale for the production of purified phosphoric acid.