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.

Key words: vanadium-bearing steel slag, sub-molten salt, leaching, vanadium, chromium

摘要： 实验研究了采用钾系与钠系亚熔盐反应介质提取含钒钢渣中钒的工艺与机理. 结果表明，亚熔盐体系对含钒钢渣的提钒机理是通过分解硅酸二钙、硅酸三钙、铁酸钙等钒的固溶相，使钒以可溶性钒酸盐形式溶出，钢渣中高CaO对钒溶出的负面影响可通过调整浸出液中氢氧化钠(钾)浓度避免. 与传统工艺相比，亚熔盐体系反应温度由850℃降至220~240℃，反应时间由4~6 h降至1~2 h，在显著降低能耗、提高效率的同时，钒的一次转化率钠系可达85%，钾系可达97%；且在钾系亚熔盐氧化性气氛中实现钒、铬共提，基本实现了含钒钢渣中钒的高效清洁提取.

关键词: 含钒钢渣, 亚熔盐, 浸出, 钒, 铬