地质学报2024，Vol.98Issue(8)：2336-2350,15.DOI:10.19762/j.cnki.dizhixuebao.2024198
宁东煤田横城矿区太原组煤中关键金属的物质来源和富集机理
The origin of detrital material and enrichment mechanism of critical elements of Taiyuan Formation coals within Hengcheng mining area in Ningdong coalfield
摘要
Abstract
The mineralogy and geochemistry of No.9 coal seam within the Taiyuan Formation of the Hengcheng mining area,Ningdong coalfield,were studied to determine the distribution,occurrence,and enrichment characteristics of critical elements in coal and to evaluate its potential for comprehensive utilization. The results revealed that:① No.9 coal in the Hengcheng mining area is characterized by high vitrinite content,extremely low-low ash yield,and medium-high sulfur content. ② The dominant mineral in the coal is kaolinite,occurring as cell fillings,lenticular shapes,and thin layers. The coal seam floor mainly consists of quartz,kaolinite,and muscovite,which are mainly of clastic origin. ③ Major elements in the coal seam are mainly SiO2 and Al2O3. The coal exhibits slight enrichment in Li,Zr,Nb,Hf,Pb,and Th. Li,Pb,and Th are mainly hosted by kaolinite,Zr and Hf are found in zircon,and Nb is present in kaolinite and anatase. The No.9 coal seam in this mining area formed in a tidal flat-lagoon environment affected by seawater. The lower part of the coal seam developed in a low swamp environment characterized by limited iron source supply,while the upper part formed in a high swamp environment with a severe iron source deficiency. This resulted in a distinct sulfur distribution:pyrite sulfur dominates the lower coal seam,whereas organic sulfur is prevalent in the upper part. The detrital material in the coal mainly originates from two sources:the Yinshan ancient land,which contributed Proterozoic terrigenous detrital material,and the Alashan block,which supplied detrital material from the early Carboniferous. The enrichment of critical elements such as Li,Zr,and Nb in the coal is mainly controlled by the input of alkali-peralkaline materials. Water/rock interactions also contribute to the activation,migration,and redistribution of these critical elements. The Li2O content in coal ash exceeds the cut-off grade,and REO,Ga,and Zr are close to the corresponding cut-off grade. Therefore,comprehensive development and utilization of Li-Ga-Zr-REY resources from this coal seam is a promising prospect.关键词
关键金属/赋存状态/富集机理/宁东煤田/太原组Key words
critical element/mode of occurrence/enrichment mechanism/Ningdong coalfield/Taiyuan Formation引用本文复制引用
黄鹏程,马少东,郭雅杰,史禹韬,曹佳亮,李宝庆,田继军,姬晓燕,上官云飞,庄新国..宁东煤田横城矿区太原组煤中关键金属的物质来源和富集机理[J].地质学报,2024,98(8):2336-2350,15.基金项目
本文为国家重点研发计划项目(编号2021YFC2902005)、国家自然科学基金项目(编号42272207)和宁夏地质事业发展专项(编号640000233000000011005)联合资助的成果. （编号2021YFC2902005）
