Modes of Occurrence and Enrichment of Trace Elements in Coal from the Anjialing Mine, Pingshuo Mining District, Ningwu Coalfield, Shanxi Province, China

Abstract

In this paper, the mineralogical composition, concentrations, distribution, and modes of occurrence of the trace elements in coal from the Anjialing coal seam 9 in the Pingshuo mining district, Ningwu coalfield, were studied using optical microscopy, X-ray powder diffraction (XRD), inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), and sequential chemical extraction procedures (SCEPs). The identified minerals included mainly kaolinite, boehmite, pyrite, calcite, quartz, and muscovite. Compared to other hard coal from around the world, the coal from seam 9 was enriched with lithium (Li); slightly enriched with gallium (Ga), hafnium (Hf), zirconium (Zr), and mercury (Hg); typically enriched with lead (Pb), and depleted in arsenic (As). The results of the SCEPs analysis showed that Li, Ga, Zr, and Hf were mainly associated with clay minerals. Arsenic mainly occurred in its silicate and sulfide forms in pyrite and Pb was mainly associated with aluminosilicate, sulfide, and carbonate minerals.

Geochemical Characteristics of Critical Metal Elements in the No. 9 Coal Seam from the Xinyuan Mine, Northern Qinshui Coalfield, Shanxi Province, China

“…Coal-hosted critical metal elements are an important direction in the study of coal geology and mineral deposits. In recent years, researchers from the United States [7,8], Europe [9][10][11], Russia [12,13], South Africa [14] and China [15][16][17][18] have all conducted research in this field and achieved a set of high-level research results. The Qinshui coalfield is an important lean coal and anthracite base in Shanxi Province, and it is also one of the most important areas for coalbed methane exploration and exploitation.…”