山西平朔矿区4#煤中镓的分布规律与富集机理

Distribution law and enrichment mechanism of Ga in 4# coal seam in Pingshuo mining area in Shanxi province

采用光学显微镜、X射线衍射和电感耦合等离子质谱等方法对采自平朔矿区4#煤中的样品进行分析,并对镓的分布、赋存和富集因素进行了讨论。结果表明4#煤中镓的平均含量达35.70mg/kg,推算出平朔矿区4#煤中的镓储量约为6.32万t。4#煤中整体镓含量较高,但分布不均匀,并呈现出顶底板及夹矸中含量较高的接触富集现象;在显微镜下发现煤中有很多粘土矿物与勃姆石,表明镓的富集主要与粘土矿物(如高岭石)和勃姆石有关;镓的富集受陆源区母岩性质、沉积环境和后生淋滤作用等地质因素的多方面影响,本研究区镓的富集则主要受控于陆源区母岩性质。

In this paper,the optical microscopy,X-ray diffraction,ICP-MS and other methods are used to analyze the sample taken from 4#coal seam in Pingshuo Mining area,and the distribution,occurrence and enrichment mechanism of Ga in it are also discussed.The results indicate that the average content of Ga in 4#seam reaches 35.70 mg/kg,from which it is deduced that the Ga reserves in 4#seam is approximately 63.2kt.But it distributes unevenly and shows a regular pattern that the Ga content is higher near the roof and floor and in the dirt band.Lots of clay minerals and boehmite are found in coal with the microscopy,which shows that the concentration of Ga is primarily related to clay minerals（such as kaolinite）and boehmite.The enrichment of the Ga is influenced by many geological factors,such as the properties of the terrigenous parent rock,depositional environment and epigenetic leaching effect,etc,and the enrichment of Ga in this study area is mainly controlled by the properties of terrigenous parent rock.