A sustainable method for high-efficient exploitation of low-grade vanadium-bearing shale ore by oxidation roasting pretreatment

Abstract

Vanadium (V), as a strategic metal, plays an important role in national security, economy, and infrastructure construction. The V-bearing shale ore should be vigorously developed in China because its’ vanadium reserves of 87% of the total. To solve the problem of environmental issues and high production cost problems in the traditional V extraction method for shale ore, oxidation roasting pretreatment with efficient and clean properties was proposed in this work. A V2O5 leaching efficiency of 94.33% was obtained under the pretreatment conditions of a roasting temperature of 700 °C, roasting time of 2 h, and particle size with −74 μm fraction of 80 wt%. The muscovite crystal was destroyed and the V was released from Al-O octahedral in the oxidation roasting process. Additionally, cracks and holes appeared on the surface of ore particles, which are conducive to the following acid leaching. The leaching residue was suitable for making silica fumes as a building material. Based on this study, a sustainable and high-efficient exploitation method was provided for the comprehensive utilization of V-bearing shale ore resources.