Extraction of vanadium from chloride solution with high concentration of iron by solvent extraction using D2EHPA Guoping Hu a,b,c , Desheng Chen a,c , Lina Wang a,c,⇑ , JingChong Liu a,b,c , Hongxin Zhao a,c , Yahui Liu a,c , Tao Qi a,c,⇑ , Changqiao Zhang b , Ping Yu b a National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Beijing 100190, PR China b School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, PR China c Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China article info Article history: Received 4 December 2013 Received in revised form 20 January 2014 Accepted 22 January 2014 Available online 30 January 2014 Keywords: Reduced vanadium-bearing titanomagnetite concentrate Chloride solution Vanadium Solvent extraction Bis (2-ethylhexyl) phosphoric acid abstract Vanadium (IV) bearing chloride solution with the Fe (II)/V (IV) mass ratio of 60 was prepared to simulate the acidic liquor by hydrochloric acid leaching of reduced vanadium-bearing titanomagnetite. Extractant of bis (2-ethylhexyl) phosphoric acid (D2EHPA) was used to extract vanadium from the solution. Under the optimal extraction conditions of equilibrium H + concentration of 0.27–0.42 mol/L, D2EHPA concen- tration (v/v, diluted in n-heptane) of 10%, extraction temperature of 20–25 °C, equilibrium time of 60 min, phase ratio (O/A) of 1:1, more than 99% of vanadium can be extracted. Loaded organic phase were stripped by dilute H 2 SO 4 solution under the optimal stripping conditions of H 2 SO 4 concentration of 20 wt.%, phase ratio (O/A) of 10:1, stripping time of 120 min, and 98% of vanadium can be stripped. The concentrations of V and Fe in the stripping solution were 13.0 g/L and 3.9 g/L, respectively. V 2 O 5 products with purity of 99.2% were obtained after oxidation, precipitation and calcination. The overall separation coefficient of V and Fe was 200. Experimental results indicated that V (IV) can be also separated from other metal ions such as Mg (II), Ni (II), Zn (II), Ca (II), Al (III) and Cu (II) in the chloride solution. A flow sheet on the recovery of vanadium from vanadium-bearing chloride solution containing high concentration of iron was proposed. Ó 2014 Elsevier B.V. All rights reserved. 1. Introduction Vanadium is an important metal with many useful properties such as hardness, tensile strength, fatigue resistance, specific physiological functions, good corrosion resistance at low tempera- ture and high melting point, which determine that it is widely used in a lot of areas, such as steel and iron, aerospace, catalysts, power-generation, machine tools industry, automotive, agricul- tural, construction and nuclear reactor components [1–6]. Chemical extraction of vanadium was reported from black shale [7], titanomagnetite ores [8], stone coal [9,10], spent catalyst [11] and oil or orimulsion fly ashes [12,13], etc. Vanadium-bearing titanomagnetite is an important resource in China, and the blast furnace process is most widely employed in China. First, the blast furnace technology is used to produce vanadium-bearing molten iron and Ti-bearing blast furnace slag. Then, the molten iron is exposed to oxygen atmosphere to form pig iron and vanadium slag. At last, vanadium slag is roasted by sodium salts and leached by water or acid to recover vanadium. However, the utilization of Ti in the blast furnace slag is comparatively difficult [14–16]. As the new construction materials (plasticizers and synthetics, i.e. chlorinated hydrocarbons) developed, many new types of equipment were invented with high erosion resistance. The chloride metallurgical process also gets more and more attention because of its moderate extraction conditions, strong reactivity and high efficiency [17]. Research on the leaching of metals using HCl solution has been studied widely [18–20]. Recently, the HCl leaching process of reduced vanadium-bearing titanomagnetite concentrate was proposed in our group. The reduction of vanadium-bearing titanomagnetite concentrates before HCl leaching was used to improve the leaching rate of iron and vanadium, and the leached slag can be used to extract titanium. Thus, the leaching liquor containing Fe (II) of 70 g/L, V (IV) of 1.2 g/L, Ca (II) of 9.7 g/L, Mg (II) of 5.8 g/L, Fe (III) of 2.0 g/L was obtained. As the concentration of Fe was high, it was difficult to separate Fe and V by selective precipitation. Therefore, developing http://dx.doi.org/10.1016/j.seppur.2014.01.031 1383-5866/Ó 2014 Elsevier B.V. All rights reserved. ⇑ Corresponding authors at: Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China. Tel.: +86 10 82544848 (L. Wang). Tel.: +86 10 62631710 (T. Qi). E-mail addresses: linawang@home.ipe.ac.cn (L. Wang), tqgreen@home.ipe.ac.cn (T. Qi). Separation and Purification Technology 125 (2014) 59–65 Contents lists available at ScienceDirect Separation and Purification Technology journal homepage: www.elsevier.com/locate/seppur