Process and Mechanism of Leaching Vanadium from Vanadium-bearing Steel Slag with Sub-molten Salt
GAO Ming-lei CHEN Dong-hui LI Lan-jie SHI Li-xin ZHENG Shi-li
Vanadium and Titanium Engineering Technology Research Center, Chengde Iron and Steel Group Co.Ltd., HeBei Iron and Steel Group Co.Ltd. Vanadium and Titanium Engineering Technology Research Center, Chengde Iron and Steel Group Co.Ltd., HeBei Iron and Steel Group Co.Ltd. Research Center of Vanadium and Titanium Engineering Technology, Chengde Iron and Steel Group Co. LTD Vanadium and Titanium Engineering Technology Research Center, Chengde Iron and Steel Group Co.Ltd., HeBei Iron and Steel Group Co.Ltd. Institute of Process Engineering, Chinese Academy of Sciences
Abstract：The process and mechanism of vanadium dissolution from vanadium-bearing steel slag with sub-molten salt medium were studied. The results showed that the dissolution mechanism of vanadium from the slag with sub-molten salt was the decomposition of Ca2SiO4, Ca3SiO5, Ca2Fe2O5, etc., in solid solution phases with vanadium, and the vanadium was transformed to soluble vanadates. In addition, the problems of high calcium content and difficult leaching were resolved effectively using sub-molten salt system by adjustment of leaching conditions. In comparison with the traditional process operated at 850℃ and 4~6 h, the reaction temperature in the sub-molten salt was dropped to 220~240℃ and reaction time to 1~2 h, significantly decreasing the energy consumption and promoting efficiency. Chemical conversion rate of vanadium with the sub-molten salt could reach 85% (NaOH medium) and 97% (KOH medium), respectively. V and Cr could be co-leached in oxidizing atmosphere KOH medium. The application of sub-molten salt reaction medium could realize the high efficiency and clean extraction of vanadium from vanadium-bearing steel slag.
2013, Vol. 13 
