Research and prospect on extraction of vanadium from vanadium slag by liquid oxidation technologies
(1. National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology,
Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
2. School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China;
3. School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing),
Beijing 100083, China)
Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
2. School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China;
3. School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing),
Beijing 100083, China)
Abstract: A series of innovative green metallurgical processes using novel reaction media including the NaOH/KOH sub-molten salt media and the NaOH-NaNO3 binary molten salt medium, for the extraction of vanadium and chromium from the vanadium slag have been developed. In comparison with the traditional sodium salt roasting technology, which operates at 850 °C, the operation temperatures of these new processes drop to 200-400 °C. Further, the extraction rates of vanadium and chromium utilizing the new approaches could reach 95% and 90%, respectively, significantly higher than those in the traditional roasting process, which are 75% and approximate zero, respectively. Besides, no hazardous gases and toxic tailings are discharged during the extraction process. Compared with the conventional roasting method, these new technologies show obvious advantages in terms of energy, environments, and the mineral resource utilization efficiency, providing an attractive alternative for the green technology upgrade of the vanadium production industries.
Key words: vanadium slag; liquid oxidation; sub-molten salt; molten salt; vanadium; chromium; extraction