Abstract: The stone coal acidic leaching solution after hydrochloric acid leaching process usuallyhas high acidity and pH is relatively low.For investigating the best extraction parameters of vanadium(V) from the high concentration of hydrochloric acid/vanadium system with tertiary amine N235 as extractant without adjusting the acidic leaching solution pH，three-phase extraction process was studied，the effects of the extractant composition，HCl concentration in feed，extraction phase O/A ratio and extraction time on vanadium extraction efficiency were studied，and the structure of extracted complex in the process of recovering vanadium with N235 in different hydrochloric acid concentrations was analyzed with FT-IR.The results showed that V extraction efficiency after one-stage extraction was 83.93% under the optimum condition of HCl concentration in feed of 2 mol/L，feed simulation solution containing 1.82 g/L vanadium(V)organic phase N235 concentration in volume is 20%，extraction temperature is 25 ℃，O/A phase ratio of 0.5，and extraction duration of 2 min，extraction efficiency for three-stage counter-current extraction was 98.37%.Meanwhile，when tertiary amine N235 was used to recover vanadium from hydrochloric acid medium，the three-phase was always formed.When hydrochloric acid concentration in feed was more than 3.1 mol/L，structure of extracted complex was (R₃NH)₄·(H₂O)_n·H₂V₁₀O₂₈·(HCl)_x，otherwise，the structure of extracted complex was (R₃NH)₄·(H₂O)_n·H₂V₁₀O₂₈.

Key words: Vanadium, Hydrochloric acid system, N235, Third-phase, Solvent extraction, Separation