Enrichment and Occurrence of Mn in 5-2 Coal from Qinglongsi Coal Mine, Northern Ordos Basin, China

Junwei Qiao; Fangpeng Du; Shuangmei Wang; Furong Tan; Yonggang Zhang

doi:10.1021/acsomega.0c01863

Enrichment and Occurrence of Mn in 5^-2 Coal from Qinglongsi Coal Mine, Northern Ordos Basin, China

ACS Omega. 2020 Aug 6;5(32):20202-20214. doi: 10.1021/acsomega.0c01863. eCollection 2020 Aug 18.

Authors

Junwei Qiao^{1

2}, Fangpeng Du^{1

2}, Shuangmei Wang³, Furong Tan⁴, Yonggang Zhang⁵

Affiliations

¹ College of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China.
² Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, Xi'an 710054, China.
³ Jiangsu Geological and Mineral Resources Design and Research Institute, Xuzhou 221006, China.
⁴ Aerial Photogrammetry and Remote Sensing Bureau, China National Administration of Coal Geology, Xi'an 710199, China.
⁵ Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China.

Abstract

High concentrations of Mn were observed in 5^-2 coal (Jurassic age) from Qinglongsi coal mine in the Northern Ordos Basin. To study the occurrence characteristics and sedimentary environment of the 5^-2 coal (3.9 m), 22 samples were collected from a mining face. The test result indicates that the 5^-2 coal is in low-ash, high-volatile, very low-sulfur, and bituminous rank, with high inertinite content. The minerals in Jurassic 5^-2 coal are composed primarily of kaolinite, siderite, calcite, quartz, pyrite, K-feldspar, and fluorapatite. The Mn element is enriched in the upper part of the 5^-2 coal seam with an average of 1243.01 μg/g, which is about 17.5 times higher than the average of world hard coal. The concentration level of Mn has a positive correlation with that of Fe₂O₃ and carbonate minerals. A weak reduction environment of the coal-accumulating swamp may induce the enrichment of Mn, which is mainly carried by siderite in the 5^-2 coal.