煤中微量元素赋存异常的形成机理与地球化学研究

Coal is one of the most important energy resources in China. However, many trace elements occurred in coals, and under special geological conditions, they could be enriched to high concentration levels which were of environmental, technical, and economic significance. Based on our previous works, some abnormally enriched trace elements in the Guizhou, Huaibei, and Huainan coals will be chosen as our investigated subjects in this project. The contents of trace elements in these coals will be determined find out which elements were abnormally enriched. Furthermore, the distribution and modes of occurrence of these elements will be detailedly investigated to inquire their relationship with the geologic structures, evolution of depositional environment and tectonics with coal petrological, sedimentological, mineralogical, geological, and geochemical methods. The characteristics of abnorally enriched trace elements in different geologic backgrounds, and their associations with macerals, carbon and sulfur isotopes were used to infer the origins and genetic mechanism of these elements, to build a general geologic origin model, and to provide bases for recycling or environmental protection.

煤是中国最重要的能源之一，然而煤中赋存多种微量元素，且在特殊的地质条件下可能异常富集，形成共伴生矿床或产生环境危害。前期成果表明贵州部分煤田煤中多种有害微量元素异常富集，甚至导致地方性疾病的发生。本课题拟以贵州省部分煤田和安徽两淮煤田为例，选取不同沉积环境及地质构造背景下的煤为研究对象，综合煤岩学、沉积学、矿物学和元素地球化学理论，测试煤中微量元素含量，与煤中相应元素的背景值比较，确定异常富集的元素；根据对典型样品的分析，揭示岩浆侵入、区域地质构造（断层、背向斜和褶皱）与元素异常富集的关系，并结合显微煤岩组成、碳、硫和汞同位素数据，反演煤的沉积环境，进而归纳出煤中微量元素异常富集机理和地球化学成因模式，为煤中潜在的共伴生矿产资源利用和环境保护提供理论依据。

本课题以中国西南和安徽两淮煤田为例，以不同沉积环境和不同构造背景下的煤为研究对象，将煤岩学、沉积学、矿物学、地质学和元素地球化学理论相结合，利用高精密仪器和化学分析，测试煤中微量元素含量，确定异常富集元素种类；研究异常富集元素在受岩浆侵入和构造活动等影响的煤层中的分布特征及其精细化学结构，揭示不同特殊地质条件与煤中微量元素异常富集的关系，并结合显微煤岩组分及部分元素的同位素测试分析，反演成煤地质环境，进而归纳出煤中微量元素异常富集机理和地球化学成因模式，为煤中潜在的共伴生矿产资源利用和环境保护提供理论依据。