LAUSR

Abstract A novel leaching method for selectively separating vanadium from calcification roasted vanadium‑chromium slag (V Cr slag) was proposed, using sodium bicarbonate (NaHCO3) as the leaching medium. Vanadium disulfide (VS2), which can be used as an energy storage material, was prepared in-situ by a hydrothermal reaction from the vanadium-containing leaching solution, without purification. VS2 was characterized by XRD, SEM, XPS, and BET. Results show that the leaching extent of vanadium was 92.98% when the calcification roasted materials were treated with 80 g/L NaHCO3 solution and leached at 100 °C for 120 min. Additionally, only 1.84% silicon, 0.05% chromium, 0.06% iron, and 0.05% manganese were co-leached along vanadium, meaning that an effective selective vanadium extraction was achieved. The leaching solution was treated with thioacetamide (TAA) in a hydrothermal reaction at 140 °C for 16 h, which resulted in a vanadium recovery of 96.00%. The reaction generated flower-like VS2, with vanadium and sulfur in the form of V4+ and S2−. The BET specific surface area of the flower-like VS2 was 21.63 m2/g. As an anode material for Li-ion batteries, the initial discharge capacity of the flower-like VS2 reached 1119.83 mAh/g at current density of 100 mA/g, which was favorable for ion storage. This process not only achieved the selective extraction of vanadium, but also provided a new mechanism to shorten the preparation process of VS2 while generating a product with added value.