Co-recovery of iron, chromium, and vanadium from vanadium tailings by semi-molten reduction–magnetic separation process

Abstract

ABSTRACTA co-recovery process used to extract iron, chromium, and vanadium in the form of chromium–vanadium-bearing metallic iron from vanadium tailings via a semi-molten reduction-magnetic separation method was investigated. The effects of the reductant (carbon) dosage, temperature, and time on the recovery rates of iron, chromium, and vanadium were studied. The phase compositions, microstructures, and micro-constitutions of the reduced samples, products, and byproducts were analysed using X-ray powder diffraction, SEM and EDS. As the reduction temperature increased, the recovery of iron, chromium, and vanadium improved. When the carbon dosage was increased from 8 to 11%, the recovery enhanced; however, the recovery deteriorated with carbon dosage of over 11%. Under optimum conditions, two products were obtained, namely a primary product consisting of chromium–vanadium-bearing metallic iron, where the recovery rates of iron, chromium, and vanadium were over 98, 82, and 65%, respectively, and a byproduct consisting of titanium-bearing slag, where the titanium yield was approximately 68%. The co-recovery process exerts a significant influence on the recovery of valuable metals and the minimisation of hazardous materials for clean utilisation of vanadium tailings.