湖北崇阳石煤中钒的价态分配

On the Oxidation States of Vanadium in Chong Yang Stone Coal

  • 摘要: 含钒石煤是我国一种新型钒矿资源,从石煤中提取精钒(V2O5>98%)的生产关键是钠盐氧化焙烧,本文着重于石煤中钒的价态研究,探讨钒的氧化和转化规律。崇阳石煤中钒分配率:V(Ⅲ)占98.77%V(Ⅳ)占1.23%。阐述了焙烧过程中钒的氧化状态,经历了还原区、氧化还原区,氧化区和平衡区等不同分布状况。在提钒过程中氯化钠起加速钒的氧化和生成可溶钒的双重作用。在此基础上结合矿物晶体结构的分析,确定了钠化焙烧的转化条件:775℃,焙烧15min,矿:盐=100:10;η焙达81.2%。

     

    Abstract: V-bearing stone coal is a new kind of vanadium resource.The oxids tion states of vanadium in the Chong Yang stone coal were analyzed by means of electroanalysis and mineral separation, the result shows that it contains 98.77% of V (Ⅲ) and 1.23% of V (Ⅳ).neither V (Ⅱ) nor V (Ⅴ).The distribution of oxidation states of V shows that both organic matter and pyrite could prevent V (Ⅲ) from oxidizing to V (Ⅳ),below 400℃,the oxidation states of V are mainly dependent upon reducing minerals, but over 400℃, the temperature is the most important factor. At about 520℃, V (Ⅲ) is completely oxidized into V(Ⅳ):at 700-1000℃ 82% of V in the stone coal are oxidized into V(Ⅴ), over the range of high temperature no more V is oxidized into V(Ⅴ), an equilibrium, between V (Ⅳ) and V (Ⅴ) is established.Salt roasting may play very important role in extracting V from the stone coal,from the results of our experiment it is considered that NaC1 can not only promote the oxidation of V, but also react with V to form soluble vanadate.The best conditions for roasting are temperature 775℃ for 15 minutes and mineral:salt=100:10 by weight, η reaches 81%.

     

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