In this study, the mixed solvent of octanol (NOA) and methyl isobutyl ketone (MIBK) was used as extractant to purify wet process phosphoric acid from hydrochloric acid route. Densities and viscosities of leachate, extraction phase and raffinate phase were determined at 293-333 K, respectively. And the relation between density and temperature or phosphoric acid concentration can be expressed as a linear equation, with the maximum deviation of 0.0011 and 0.0027 g cm(3), respectively. Meanwhile, the viscosity of leachate, extraction phase and raffinate phase were measured since its importance on mass transfer occurred in the process of phosphoric acid extraction. And the relation between viscosity and temperature or phosphoric acid concentration can be summarized as a unitary quadratic equation, with the maximum deviation of 0.4489 and 0.1122 mPa.s, respectively. The results show that the densities and viscosities from experiment are generally in good agreement with calculated values from those equations obtained by regression analysis. The combined expanded uncertainty in the reported densities and viscosities are 0.3% and 5.5% of the measured values respectively, each with a coverage factor, k = 2. (C) 2018 Elsevier Ltd.