准东煤田的煤炭资源丰富且为我国重要的煤炭生产基地, 对其煤田煤层和上覆地层元素特征的研究有利于后期的勘探、开发与利用。为了探究表层盐碱土中的元素对准东煤田大井矿区西山窑组浅部煤层元素特征的影响, 借助X 射线荧光光谱仪、电感耦合等离子体质谱仪、X 射线衍射仪和扫描电子显微镜等仪器, 分析样品的元素含量特征和矿物学特征。试验结果显示: 大井矿区西山窑组浅层煤中的微量元素除Sr 元素外含量都很低, 可能与成煤环境中泥炭的快速沉积有关。样品的灰分分析数据和微量元素测试数据显示, 样品中的Sr 元素和Na 元素自上而下含量逐渐降低。X 射线衍射仪和扫描电子显微镜的分析结果表明, 盐碱土中的Sr 元素主要赋存在天青石中, 煤中的Sr 元素则以类质同象的方式存在于重晶石中; 盐碱土中的Na 以黏土矿物、钠长石、无水芒硝和NaCl 的形式存在, 而煤中则主要以NaCl 的形式存在。部分煤中的稀土元素呈重稀土配分模式, 可能是地表水淋滤表层盐碱土后入渗下伏煤层的结果。综合样品的元素学和矿物学的测试结果, 推测煤中的Sr 元素和Na 元素主要来源于地表盐碱土。结合样品中微量元素、稀土元素配分模式和矿物学的变化特征, 针对地表盐碱土对大井矿区浅部煤层元素特征的影响进行研究并合理推测煤层中Sr 元素和Na 元素的物质来源, 对大井矿区今后的煤田地质研究具有一定的借鉴意义, 建议下一步的工作重点应聚焦在利用同位素以确定物质来源的可靠性。

There are abundant coal resources in Zhundong coalfield, which is an important coal production base.The study on the characteristics of coal seam and overlying strata elements is conducive to the exploration, exploita⁃tion and utilization in later period. In order to explore the influence of elements in surface saline⁃alkali soil on the ele⁃ment characteristics of shallow coal seams in Xishanyao formation of Dajing Mining Area, X⁃ray fluorescence spec⁃trometer, inductively coupled plasma mass spectrometer, X⁃ray diffractometer and scanning electron microscope wereused to analyze the element content characteristics and mineralogical characteristics of the samples. The test resultsshow that the contents of trace elements in coal are very low except for Sr element, which may be related to the rapiddeposition of peat in the coal⁃forming environment. The ash analysis data and trace element test data of the samples show that the contents of Sr element and Na element in the samples decrease gradually from top to bottom. The analy⁃sis results of X⁃ray diffractometer and scanning electron microscope show that Sr element in saline⁃alkali soil is mainlystored in celestite, and Sr element in coal is stored in heavy minerals in the form of homologous analogy; Na in sa⁃line⁃alkali soil is stored in clay minerals, sodium feldspar, anhydrous mica and NaCl, while in coal, it is mainlystored in the form of NaCl. The rare earth elements in some coal show a heavy rare earth distribution pattern, whichmay be the result of infiltration of surface saline⁃alkali soil after leaching of surface water. Based on the test results ofelementology and mineralogy of the samples, it is speculated that the Sr element and Na element in coal mainly comefrom surface saline⁃alkali soil. Combined with the distribution patterns of trace elements and rare earth elements insamples and the variation characteristics of mineralogy, regarding to influence of surface saline alkali soil on the ele⁃mental characteristics of shallow coal seams in Dajing mining area, the material sources of Sr and Na elements in coalseams were inferred. It has certain reference significance for the future coal field geological research in Dajing miningarea. The next step should focus on the reliability of material source determination by isotope.