Vanadium Extraction from the Flotation Concentrate of Vanadium-Bearing Shale by Process of Non-Roasting Enhanced Acid Leaching and Thermodynamics

The purpose of this work is to significantly improve the vanadium grade of vanadium-bearing shale after flotation preconcentration, which is conducive to reducing the acid consumption and industrial costs in the subsequently enhanced acid leaching of vanadium. Vanadium concentrate from vanadium-bearing shale enriched by flotation is used for acid-leaching feed. The leaching effects of two kinds of acid-leaching systems were compared, and the mechanism of acid leaching on the mineral structure was also described. The difficulty of spontaneous reactions of vanadium-bearing minerals such as garnet in an acid-leaching system was studied through thermodynamics. Additionally, several characterization methods were used to evaluate the improvement of leaching performance. The addition of oxidants and fluorinating aids strengthens the acid-leaching process, which greatly destroys the structure of a garnet, which is conducive to the extraction of vanadium in a flotation concentrate. The leaching efficiency can reach 94.86%, and the acid consumption is also reduced. Through the mechanism study of the leaching system, it is expected that when the enhanced acid-leaching process is put into industrial production, the effective leaching of vanadium can be accurately controlled, and the difficulty of subsequent vanadium enrichment and purification can be reduced.