WANG Yunlong1,2, ZHENG Liugen1,2, CHEN Yongchun3, CHEN Xing1,2, ZHANG Qian1,2, WU Zhiwei1,2, REN Zixin1

（1.School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China;
2.Engineering Laboratory for Mine Ecological Restoration in Anhui Province, Hefei 230601, China;
3.National Engineering Laboratory of Coal Mine Ecological Environment Protection, Anhui Huainan 232011, China）

Abstract: Coal samples were collected from the Shanxi Formation group 1 coal seam in the Zhangji and Xinjier coal mine of Huainan coalfield, and the total mercury content was measured to investigate the spatial distribution. The occurrence of mercury in coal was analyzed by the float-sink test, sequential extraction experiments and correlation analysis. The cause of mercury enrichment in coal of Shanxi Formation was discussed in combination with the depositional environment. The results showed that : (1) the mercury content in coal ranged from 0.03 to 0.93 μg·g-1, and the arithmetic mean value was 0.21 μg·g-1, which is higher than the background value of mercury in coal in China and the world. (2) There were obvious differences in coal mercury content of Shanxi Formation. The arithmetic mean value of mercury in Zhangji coal mine was 0.35 μg·g-1, and that in Xinjier coal mine was 0.12 μg·g-1. Due to the complex depositional environment and sedimentary facies, the distribution of mercury content in the same coal seam was quite different. (3) The results of correlation analysis, float-sink test and sequential extraction experiments showed that mercury in coal mainly exist in sulfide. The mineral analysis showed that pyrite is the main carrier of mercury in coal, with mercury mainly exist in the solid solution state as the primary pyrite in Zhangji coal mine, while mainly occurs in the metagenetic pyrite that filled with fractures in Shanxi Formation coal in Xinjier coal mine.

Key words: Shanxi Formation; coal; mercury content; occurrence

EARTH AND ENVIRONMENT Vol.49, No.2, Tot No.340, 2021, Page 180-188