摘要
根据贵州毕节地区13个井田和勘探区各主采煤层煤样的工业分析、硫分及灰成分分析数据,评价了该地区晚二叠世煤的总体煤质特征,在此基础上重点探讨了煤中硫分和灰分与成煤环境的联系。研究表明,毕节地区煤炭资源具有特低全水分、中高硫分、中灰分、特低挥发分等特征,总体属无烟煤(WY3)。根据煤中硫分分布、硫分组成、灰分分布与灰分组成及其变化规律可以推测成煤环境。毕节晚二叠世各主采煤层硫分纵向变化规律可清晰"反演"研究区成煤期古海平面的两次大的海进与海退事件;硫分在研究区平面的分布具有"东南高、西北低"的特点,正是受到当时海水自南东向北西推进的影响;形态硫数据分析显示,煤中有机硫占全硫比重一般较小,明显不同于陆相煤层和浅水台地相煤层(后者以极高有机硫为特点)特征。此外,煤中灰分产率、煤灰成分指数以及灰成分三端元分析均揭示聚煤环境的还原性自西北向东南逐渐增强,与硫分分析的结论相一致。综合分析表明,毕节地区晚二叠世成煤环境以三角洲分流河道/间湾、潮控下三角洲平原、以及潮坪/泻湖等环境为主,海水影响作用较大的泻湖/潮坪环境下煤层中硫分较高,海水影响较弱的三角洲成煤环境下煤中硫分相对较低,并给出了三种沉积环境下一些煤质特质的变化范围。该研究结果与前人基于岩相古地理和元素地球化学方法所得出的结论相吻合。
According to test data of proximate analysis,sulfur content and ash composition of a large number of Late Permian coals that were sampled from 13 coal mines from Bijie city of Guizhou province,this paper provides an overall coal quality characteristic for Late Permian coal of Bijie city.On this basis,the correlation between sulfur and ash composition and coal formation environment was discussed in detail.The results show that Late Permian coal in the Bijie region is characterized by extra-low total moisture,medium-high sulfur,medium ash yield （air dried basis） and extra-low volatile （air dried ash free basis）,etc.,as a whole belongs to anthracite coal.Coal formation environment could be explained by detailed study of sulfur distribution,different sulfur forms,ash yield distribution and its composition in coal.Vertical variety of sulfur content in main mineable coal seams from Bijie could clearly inverse twice main marine transgression and regression within the study region during late Permian,meanwhile horizontal distribution of sulfur content in coal is mainly characterized by ＂southeast high but northwest low＂,which can be attributed to the progression of sea water from southeast to northwest.Analysis of sulfur forms indicates that organic sulfur in coal tends to account for only a small proportion,distinctly different from coal seams that formed in continental environment or shallow platform.In addition,analysis of ash yield,ash composition indicator and a Three Unit Method illustrates that during late Permian reducibility of coal formation environment in Bijie increased gradually from northwest to southeast,which is similar to the conclusion of sulfur mentioned above.Comprehensive analysis indicates that the types of coal formation environment in study area during late Permian were mainly delta distributary channels/bays,tide influenced lower delta plain,tidal flat and shallow lagoon,etc..Sulfur content is high in coal seams formed in tidal flat or shallow lagoon that influenced strongly by sea water,but is relative low when coal seam was formed in delta environment,where sea water influence was weak.The main conclusions in this paper are similar to those based on lithofacies paleogeography and element geochemistry proposed by other scholars.
出处
《地质学报》
EI
CAS
CSCD
北大核心
2013年第11期1763-1777,共15页
Acta Geologica Sinica
基金
教育部211重点学科建设基金(编号2009003)
贵州大学博士点建设基金资助的成果
关键词
毕节地区
晚二叠世
煤质特征
成煤环境
Bijie
late Permian
coal quality characteristic
coal formation environment
作者简介
程伟,男,1983年生.博士研究生,研究方向：煤地球化学.Email：wcheng1983@126.com.｜｜杨瑞东,男,教授,博士生导师,沉积矿床和地球化学研究方向.通讯地址：550025,贵州省贵阳市贵州大学研究生院.
通信作者：杨瑞东,男,教授,博士生导师,沉积矿床和地球化学研究方向.通讯地址：550025,贵州省贵阳市贵州大学研究生院.
