A New Approach for the Comprehensive Utilization of Vanadium Slag

Although vanadium slag contains various valuable metals, including vanadium, titanium, chromium, iron, etc., it is only used to extract the vanadium due to technical limitations. In order to realize the comprehensive utilization of vanadium slag, a new approach was proposed in this work. First, the hydrogen reduction of vanadium slag was investigated. The phase and micromorphology evolution of the vanadium slag under different reduction conditions were discussed in detail. The results showed that the pyroxene and olivine surrounding the spinel in vanadium slag were reduced selectively into metallic iron and silica under appropriate reduction conditions, and the structures were destroyed. Then, the method of recovering metallic iron from the reduced vanadium slag with ferric chloride solution was investigated. The results showed that more than 98 pct of metallic iron in the reduced vanadium slag can be leached selectively by ferric chloride solution, and the vanadium, titanium, and chromium were left in the deironized intermediate. Finally, the extraction of vanadium, titanium, and chromium from the deironized intermediate by the oxalic acid hydrothermal leaching method was studied, and the leaching recoveries were 96.8, 94.7, and 95.4 pct, respectively. This approach provides insights into the comprehensive utilization of vanadium slag, which is especially favorable for low-grade vanadium slag.