山西平朔矿区4号煤地球化学特征及古环境意义
发布时间:2018-01-08 22:26
本文关键词:山西平朔矿区4号煤地球化学特征及古环境意义 出处:《中国地质大学(北京)》2017年硕士论文 论文类型:学位论文
【摘要】:平朔矿区坐落于山西朔州市,地处宁武煤田北部。区内含煤地层包括本溪组、太原组和山西组,太原组地层厚72.90~125.14m,平均107.65m,组内4、9、11号煤是主要可采煤层。太原组整体上表现为海退的趋势,从下而上,依次为潮坪、咸水泥炭沼泽、半咸水泥炭沼泽、泻湖、三角洲、泥炭沼泽等沉积环境。以太原组顶部的4号煤为研究对象,系统采集煤层及顶底板样品,采用ICP-MS、XRF、XRD等技术手段对样品中常量、微量元素以及矿物含量进行系统地测试分析,利用煤岩学、矿物学、地球化学等方法对4号煤层的煤岩煤质特性、矿物学及地球化学特征进行分析,取得了如下认识:(1)4号煤整体属于中低灰分、中高挥发分、低水分、特低硫分煤,且有机硫占绝大部分;Ro在0.70%左右,达到气煤阶段。(2)4号煤煤灰中矿物类型多样,含量最多的是高岭石,其次为勃姆石。此外,菱铁矿、金红石、锐钛矿、磷灰石、六水泻盐、磷铝钙石、磷铈铝石、毒砂、石英等矿物仅在几个分层样品中出现。(3)和中国煤均值相比,微量元素Cu、Ga、Se、Hg、Sr、Zr和Pb相对富集,Li、Co、Ni、Ge、As、Rb、Sb、Cs、Ba和Tl则相对亏损。(4)4号煤中稀土元素含量变化较大,轻稀土元素是稀土元素富集的主要贡献者。与轻稀土相比,重稀土更具有有机亲和性。(5)Li、Ni等元素主要以硅酸盐和黏土矿物为载体;Zn、W、Cu和Co具有强亲硫性,主要赋存在硫化物、硫酸盐等矿物中;Tl、Sb、Mo主要与硫化物相关;In与Ti、Fe、Ca、Mg金属元素有较好的相关关系,表明In可能伴生在含此类金属的矿物中。(6)4号煤形成于陆相、较潮湿、低氧-贫氧的环境。在煤层上部沉积环境逐渐转为干燥,导致煤中盐度增大,从而造成Ba、Ca、Sr、Th、Ga等具有气候意义元素的富集。
[Abstract]:Shanxi is located in Pingshuo mining area of Shuozhou City, located in the Northern District of Ningwu coalfield. Coal bearing strata including Benxi group, Taiyuan group and Shanxi group, Taiyuan group stratum thickness 72.90~125.14m, average 107.65m, group 4,9,11 coal is the main coal seam of Taiyuan group. The overall performance of the regression trend, from the bottom up in the tidal flat, salty water peat swamp, brackish water peat swamp, lagoon, Delta, peat swamp sedimentary environment in Taiyuan. The top 4 Coal Group as the research object, collecting system of roof and floor samples, using ICP-MS, XRF, XRD and other technical means of samples of constant, trace elements and the mineral content of systematic test and analysis, using coal petrography, mineralogy, geochemical characteristics of coal and other methods of No. 4 coal seam, the mineralogical and geochemical characteristics analysis, the following conclusions are achieved: (1) No. 4 coal overall belongs to low ash, high volatile 鍒,
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