潘集煤矿二叠纪主采煤层中微量元素亲和性研究

安徽淮南煤田位于华北地台南端 ,发育了华北地区二叠纪含煤岩系中层位最高的可采煤层。采用仪器中子活化分析法 (INAA)测试了淮南煤田潘集煤矿二叠纪主采煤层 13个样品的 36个微量元素的浓度分布 ,并对其共生组合特点、地球化学特征及稀土元素配比模式作了初步分析 ,结果表明 ,煤中不同微量元素显示出不同的亲和性质。元素Br,As ,Sb ,Ni和Co等趋于在煤中富集 ,其中Br的有机亲和性最大。元素Na ,K ,Rb ,Th ,Hf,Zr ,Ta和REE则在煤层与顶底板接触带的碳质泥岩中富集 ,表现出与细粒陆源碎屑物更强的亲和性。其它元素倾向性不甚明显 ,但Fe ,Ca ,Sr ,HREE等元素在海水影响强度增大的煤层中含量增加。元素As,Cs,Ni,Fe和Ca在煤层中含量变化较大 ,其变异系数大于 1,其它元素则相对稳定 ,表明同一矿区煤层中微量元素含量在不受其它地质作用明显叠加影响时具有一定的稳定性。本区煤层稀土元素配比模式与华北其它地区C—P纪煤基本类似 ,普遍存在Eu亏损现象。 ∑REE在煤中分布范围为30× 10 -6～ 95× 10 -6,在顶板泥岩中超过 2 0 0× 10 -6。煤层中部 ∑REE降低 ,HREE相对富集。聚类分析表明 ,元素As ,Se ,Ag和Fe关系密切 ,这与煤中黄铁矿等成岩矿物有直接关系 ,泥炭沼泽演化期间或之后海水的直接或间接影响会促使这

THE AFFINITY OF TRACE ELEMENTS OF PERMIAN COAL FROM PANJI MINE IN HUAINAN COAL FIELD

The Huainan coal field lies in southern part of North China Platform and there are most important coal beds in Upper Permian Formation in the field. The 36 trace elements in 13 coal samples from the Later Permian Period from Panji mine in Huainan coal field were determined using INAA technique. Furthermore, their geochemical features of trace elements and REE are discussed. The trace elements in coal beds show different affinities to organic matter or to minerals, e.g. the elements Br, As, Sb, Ni and Co tend to concentrate in coal. Meanwhile, the elements Na, K, Rb, Th, Hf, Zr, Ta and REE are richer in roof and floor rocks. In fact, the detritus finer than 2 μm plays a more important role than hosting these elements. The other elements demonstrate nuclear tendency in coal or in roof and in bedding rocks. The elements Fe, Ca, Sr and HREE correlate with seawater. The elements As, Cs and Ni, vary very much in content and their variant coefficients can exceed 1. Trace elements in coals of Panji mine are relative constant due to absence of effects of strong geological process on the coal beds. The ∑REE ranges from 30×10 -6 to 95×10 -6 in coals and are higher than 200×10 -6 in roof and floor rocks. Moreover their Normalized distribution patterns are very similar with those of Permian coals in other parts of North China. ∑REE decreases in the midst of coal bed but the HREE are relatively richer than of roof rocks.Cluster analysis of some hazardous elements, shows that the elements As, Se, Ag and Fe are in the same group,because they may occur in pyrite and their concentrations rise when swamps or coal beds were affected by seawater. The coals in this field have a relatively lower content and therefore have more security than the others.