山西西铭煤矿煤中稀土元素地球化学特征及指示意义

采用电感耦合等离子体质谱(ICP-MS)及X射线荧光光谱(XRF)等方法,分析山西西铭煤矿2号、3号、8 号和9号煤中稀土元素的含量特征和赋存状态,并根据稀土元素Ce、Eu、Gd、Y和常量元素Al₂O₃/TiO₂的异常揭示其成煤环境及物质来源。研究结果显示:(1)西铭煤矿煤中稀土元素含量与世界煤值和美国煤值基本相等,但低于中国煤中稀土元素含量的平均值;稀土元素以中-重稀土富集型为主,其次是轻稀土富集型和轻-中稀土富集型。(2)西铭煤矿成煤环境总体上以弱还原性为主,且受酸性沼泽水环境影响。(3)煤中稀土元素的物质来源主要为陆源碎屑物质,判断其沉积源岩为酸性或中-酸性岩浆岩。

Geochemical Characteristics of Rare Earth Elements and the Indicative Significance in the Ximing Coal Mine,Shanxi Province

Concentration characteristics and state of occurrence of rare earth elements (REEs) in No.2,No.3, No.8 and No.9 coals of the Ximing Mine in Shanxi were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence spectrometry (XRF). According to the anomalies of Ce, Eu, Gd, La, Y and TiO₂/Al₂O₃, we revealed the formation environment of coal and the possible REE sources. The results show that: (1) The REE contents of the Ximing coal is very similar to the global average value and the value of the United States coal, but lower than the average value of the Chinese coal. The REEs are mainly MREE-HREE-enriched, followed by LREE and LREE-MREE-enriched. (2) The coal-forming environment is mainly weakly reducing and affected by acidic marsh water environment. (3) The REEs source may have been mainly terrigenous detrital materials, and the sedimentary source rocks are determined to be felsic or intermediate-felsic magmatic rocks.