The separation of vanadium (IV) from iron (II) in hydrochloric acid leaching solution, which contained low concentration of vanadium (IV), high concentration of iron (II), and many kinds of impurities was investigated by solvent extraction with 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (P507). Under the optimal extraction conditions, i.e., initial pH of leaching solution of 0-0.6, extraction temperature of 30°C, extraction time of 15 min, P507 concentration(v/v) of 20%, and phase ratio (O/A) of 1:1, the extraction of vanadium (IV) and iron (II) was 70% and 5% in a single step. The sulfuric acid solution was used as the stripping agent. Under the optimal stripping conditions, i.e., stripping time of 12 min, stripping temperature of 30°C, phase ratio (O/A) of 4:1, and H2SO4 concentration of 368 g/L, nearly 100% of vanadium (IV) and 3% of iron (II) was stripped in a single step. Through one step extraction and stripping, a loaded stripping solution containing vanadium (IV) of 18.62 g/L and iron (II) of 0.37 g/L was obtained, showing a good separation of vanadium (IV) from iron (II). The results showed that vanadium (IV) could be also separated from other impurities such as aluminum, calcium, magnesium, and manganese.
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