Mineral matter in the Pennsylvanian coal from the Yangquan Mining District, northeastern Qinshui Basin, China: Enrichment of critical elements and a Se-Mo-Pb-Hg assemblage
Mineral matter in the Pennsylvanian coal from the Yangquan Mining District, northeastern Qinshui Basin, China: Enrichment of critical elements and a Se-Mo-Pb-Hg assemblage
复制标题
DOI：
10.1016/j.coal.2022.104178
复制
发表时间：
2022-12
影响因子：
5.6
通讯作者：
Yongjie Hou;S. Dai;V. Nechaev;R. Finkelman;Hongdong Wang;Shaowei Zhang;Shao-Jie Di
中科院分区：
文献类型：
--
作者：
Yongjie Hou;S. Dai;V. Nechaev;R. Finkelman;Hongdong Wang;Shaowei Zhang;Shao-Jie Di
沁水盆地作为中国最大的商业煤层气储层，备受关注，多项研究集中在该盆地煤炭的矿物学和元素地球化学方面。然而，矿物和元素的来源，特别是东北盆地的高灰分煤的来源尚未查明。本研究调查了中国山西省沁水盆地东北部新井煤矿宾夕法尼亚 8 号煤（包括顶板岩层和煤粉）的矿物学和地球化学特征。新疆煤是一种低灰、中硫的半无烟煤。研究煤中的矿物主要有高岭石、伊利石、方解石、铁白云石、菱铁矿、白云石、黄铁矿等。新疆煤的特点是富集Li、Zr、Hg，微富集F、Ga、Ge、Se、Sr、Mo、Hf、Pb。 Al2O3-TiO2、Zr/TiO2-Nb/Y图以及REY（稀土元素和Y）分布模式表明，研究矿床的沉积物源区以沁水盆地北部阴山高地的古老花岗岩、沉积岩和铝土矿为代表。本研究确定了3个地质因素（沉积物源区、热液注入和海水）为主导。对地球化学和矿物成分的影响。 Li和Ga等关键元素浓度升高主要来自沉积物源区。自生矿物包括硫化物、石英、碳酸盐、磷酸盐和幽辉石，以及煤层中 Se-Mo-Pb-Hg 组合的显着变化，表明新疆煤可能经历了多阶段的热液活动。相对较高的总硫含量（平均2.3%）、草莓状黄铁矿、Sr/Ba（3.3）和Th/U值（2.2）表明海水是影响新疆煤的另一个重要地质因素。
The Qinshui Basin, the largest reservoir of commercial coalbed methane in China, has attracted much attention and several studies have focused on the mineralogy and element geochemistry of coals in this basin. However, the sources of minerals and elements, particularly those of high-ash coals in the northeastern basin were yet unidentified. This study investigated mineralogy and geochemistry of the Pennsylvanian No. 8 Coal (including the roof strata and partings) from the Xinjing mine, northeastern Qinshui Basin, Shanxi Province, China. The Xinjing Coal is a low-ash, medium‑sulfur semi-anthracite. The minerals in the studied coals are mainly represented by kaolinite, illite, calcite, ankerite, siderite, dolomite, and pyrite. The Xinjing Coal is characterized by enriched Li, Zr, and Hg, and slightly enriched F, Ga, Ge, Se, Sr, Mo, Hf, and Pb. The diagrams of Al2O3-TiO2, Zr/TiO2-Nb/Y, as well as the REY (rare earth elements and Y) distribution patterns show that the sediment source region of the studied deposit is represented by the old granitoides, sedimentary rocks and bauxites of the Yinshan Upland located to the north of Qinshui Basin.In this study, three geological factors (sediment source regions, injections of hydrothermal fluids, and seawater) are identified as the dominant influences on geochemical and mineralogical compositions. Elevated concentrations of critical elements such as Li and Ga are dominantly derived from the sediment source region. Authigenic minerals including sulfides, quartz, carbonates, phosphates, and clausthalite, as well as the significant variations of Se-Mo-Pb-Hg assemblage across the coal seam, indicate that the Xinjing coal probably has been subjected to a multi-stage hydrothermal activities. Relatively high total sulfur contents (2.3% on average), framboidal pyrite, Sr/Ba (3.3) and Th/U values (2.2) suggest that seawater is another important geological factor affecting the Xinjing coal.