贵州凯里梁山组高硫煤中稀土元素的富集及其地质成因

Enrichment of Rare Earth Elements in High Sulfur Coal of Liangshan Formation from Kaili,Guizhou,China and Geological Origin

基于电感耦合等离子质谱、X射线衍射等测试结果,分析了贵州省东部凯里地区下二叠统梁山组高硫煤中稀土元素的分布特征,探讨了稀土元素在煤中赋存方式和地质成因。结果表明:凯里煤中稀土元素含量远高于中国煤、美国煤和世界煤中稀土元素含量的平均值,轻稀土元素相对富集,煤层中稀土元素的物质来源具有一致性。研究认为:煤中稀土元素的赋存与黄铁矿有关,也存在一部分稀土元素通过原生富集而赋存在惰质组和壳质组中的可能性;相对较弱的泥炭沼泽水动力条件以及偏碱性还原的环境更有利于稀土元素在煤中的富集,海水对泥炭沼泽的影响是造成煤中富硫以及利于稀土元素富集环境条件发育的一个重要原因。

Based on the experimental results by the inductively coupled plasma mass spectrometry （ICP-MS）, X- rays diffraction （XRD） and so on, the distribution, occurrence and geological controls of the rare earth elements （REEs） in the high-sulfur coal seam of the Lower Permian Liangshan Formation from Kaili, eastern Guizhou was investigated. The results showed that the REEs content in the Kaili coal seam is evidently higher than the average contents of REEs in Chinese, America as well as the world＇s coals, and the light REEs （LREEs） are comparatively rich, indicating that the source of those in the coal seam was consistent. It was suggested that some of REEs in the coal seam might occur in pyrite, and the other with primary enrichment might be hosted in inertinite and exinite. The peat bog with the weaker water dynamics, subalkaline and reduction was in much favor of the REEs enrichment in the coal seam. The effect of the sea water on the peat bog is one of the important causes in the occurrence of the sulfur- and REEs accumulated environment in the coal.