淮北煤田二叠纪煤中稀土元素地球化学研究

从淮北煤田二叠系10，7，5，4和3煤层中采集34个样品，采用等离子体质谱（ICP-MS）、中子活化（INNA）、等离子体发射光谱（ICP-AES）等方法对样品中主量元素和稀土元素进行了测试，利用X射线衍射等方法对煤中矿物质及其煤质参数进行了测定。在各种测试的基础上，全面分析了稀土元素含量特征、空间分布规律、地球化学参数和分布模式，探讨了淮北煤田二叠纪煤中稀土元素的主要来源及其在煤中的主要赋存方式。研究表明：与华北和国内外其他地区相比，本区煤层中稀土元素相对富集；产于石盒子组煤中的稀土元素含量高于山两组的，在同一煤层中自下而下稀土元素含量有增高趋势，在顶底板中可能出现富集。Ce呈正异常，Eu明显负异常，不同煤层稀土元素的分布模式相似，稀土元素和灰分具有较好的正相关，∑REE与灰分、灰分中的主要元素以及典型陆源灰分中的微量元素正相关，与反映海相的低灰组分相关性较差。结合煤中矿物质的X射线衍射结果，分析获知，淮北煤田二叠纪成煤环境基本不受海水影响，稀土元素主要由陆源供给，而且主要赋存在以高岭石、伊利石为主的粘土矿物中。

Study on Geochemistry of Rare Earth Elements (REEs) in Permian Coal from Huaibei Coalfield

34 samples were collected from coal seams 1 0，7，5，4 and 3 of Permian coals in Huaibei coalfield． The abundances of the rare earth elements(REEs)and other elements in the samples were determined by inductively couple-plasma mass spectrometry(ICP-MS)，instrumental neutron activation analysis(INNA)and inductive1y couple-plasma atom emission spectrometry (ICP-AES)．The characterizations of the concentration．spacial distribution，geochemical parameters and distribution patterns of REEs are studied.Furthermore．the origin and occurrence of REEs in the samples are discussed．Compared with Chinese coals，world coals and American coals．the REEs are obviously enriched in Huaibei coalfield．The contents of REEs in the coal seams of the Lower and Upper Shihezi Formations are higher than those in the Shanxi Formation． They rise from the bottom to top in thesame coal seam because of the influence of sedimentary environment． According to the values of δCe positive and δEu negative anomalies，and the relationship between the REEs contents with ash yield is the sediments,it can be concluded that the sedimentary environment of the Permian coal in Huaibei coalfield was not influenced by seawater，and the source of REEs is terrigenous matters，and the REEs in coals are mainly concentrated in c1ay minerals such as kaolinite and illite．