Investigation of the selective oxidation roasting of vanadium‑iron spinel

Recently, a novel method of selective oxidation roasting to extract low valence vanadium (LVV) from vanadium slag was proposed to avoid the toxic V(V)-bearing waste and massive energy consumption in traditional process. In order to investigate the oxidation behavior of LVV in the selective oxidation roasting process, vanadium iron spinel Fe2VO4, the main phase containing vanadium in vanadium slag, was synthesized and its evolution of phase, morphology and bonding structure in the selective oxidation process were investigated systematically in this study. The results showed that the oxidation of Fe(II) prior to V(III) during selective roasting. It was feasible to destroy the structure of spinel by oxidizing Fe(II) selectively, while vanadium still existed in low valence and could be recovered easily, and the maximum recovery of LVV was 97.75%. This study could provide theoretical and technical guidance for extraction of LVV directly from vanadium raw material.