寒武纪黑色页岩中钒赋存状态研究——以通山县钒矿为例

Study of Vanadium in Early Cambrian Black Shales——A Case Study of the Tongshan Mine,South China

早寒武世黑色页岩中含有大量的钒元素,含量>0.5 wt%,但钒的赋存形式尚未明确探知,限制了其工业开采价值。研究区位于湖北省通山县上陈村,含钒矿层主要赋存于王音铺组和观音堂组碳硅质页岩内。矿石主要由石英、(水)白云母、伊利石、锐钛矿和有机质组成。扫描电镜及电子探针分析结果显示,主要含钒矿物为锐钛矿及(水)白云母,其V_2O_3含量分别为1.31%~5.24%及2.61%~2.86%。全岩地球化学数据显示V主要与Al_2O_3/K_2O呈正相关关系,n(V)/n(V+Ni)为0.79~1.00,n(V)/n(Cr)为2.40~24.68,表明该区域岩石形成于被动大陆边缘还原环境;稀土总量较小,明显负Ce异常,且呈左倾模式,LREE/HREE为0.28~0.74,平均值为0.43,总体特征与海相热水沉积物相符。

Early Cambrian black shales show extremely enrichment of V（ 〉0. 5 wt%）,however,the occurrence form of V is still remain unclear,which limits the industrial value of V-hosting black shales. The study area is located in Shangchen village,Tongshan County,Hubei Province,and the vanadium ores are mainly preserved by carbonaceous siliceous shale of the Wangyinpu Formation and Guanyintang Formation. The ores are dominant by quartz,muscovite,illite,anatase and organic matter. According to the scanning electron microscopy and electron probe analyses,anatase and muscovite are main V-hosting minerals with V2 O3 contents of 1. 31% - 5. 24% and 2. 61% - 2. 86%,respectively. The positively correlated V and Al2O3/K2 O,and high V/V ＋ Ni（ 0. 79 - 1. 00） and V/Cr（ 2. 40 - 24. 68） ratios of the black shales of the Shangchen village indicate that this carbonaceous succession was deposited in a reducing environment of a passive continental margin. The rocks also have low REEs concentrations,obviously negative Ce anomaly,low LREE/ratios,which are consistent with a marine hot-water origin.