LAUSR

Abstract Leach solutions of vanadium (V) slag was generated from (NH4)2SO4 (AS) roasting and water leaching process. After separating titanium (Ti) from the solutions, the remaining liquor contains a large amount of V and iron (Fe). In this study, a system composed of trioctyl tertiary amine (N235) and sulfonated kerosene was used to separate V; moreover, the feasibility, mechanism, and energy evaluation of this system were also investigated. The results indicated that the single-stage V extraction rate was 86.35% using 40% N235 (v/v) and 60% sulfonated kerosene, an initial pH of 1.23, an organic/aqueous phase ratio (O/A) of 1.5:1, a temperature of 298.15 K, and an extraction time of 1 min. Based on McCabe-Thiele analysis, over 99% of the V was extracted by three-stage countercurrent extraction. Using the slope method and Fourier transform infrared (FT-IR) spectroscopy, the V extracted by N235 was proposed to exist as [(R3NH)4·H2V10O28]. Using 1.4 mol/L ammonia water, over 90% of the V could be stripped. The effects of the impurities Si, Ca, Al, Mg, and Mn on V recovery were negligible. A preliminary material and energy calculation (MEC) indicated that 113.64 kg V2O5 could be recovered from 1000 kg raw V slag using 5.57 × 106 kJ of heat and 974.45 kWh of electricity.