The Relationship between Trace Element Concentrations and Coal-Forming Environments in the No. 6 Coal Seam, Haerwusu Mine, China

Abstract

In order to study the relationship between trace element concentrations and coalforming environment in the No. 6 Coal, Haerwusu Mine, Inner Mongolia, China, 39 bench samples were taken from the opencast mine, following Chinese Standard Method GB/T 482-2008. The samples were analyzed by an optical microscope, a scanning electron microscope in conjunction with an energy-dispersive X-ray spectrometer (SEM-EDX) analysis, inductively coupled plasma mass spectrometric (ICP-MS). The results indicate that the average contents of vitrinite, inertinite, liptinite are 54.59%, 34.84% and 5.8%, respectively. The concentrations of Li and Ga in the No. 6 coal are higher than those of in world coals, and most of trace elements in the No. 6 coal are correlated with minerals, which are mainly clay minerals, carbonate minerals and sulfide minerals. Two samples were identified as dry forest swamp facies (FtM I), 19 samples as shallow water forest swamp facies (FtM II), and 13 samples as reed swamp facies (RM). Compared with the average contents of world coals, trace elements in No. 6 coal of Haerwusu mine are rich in Li and V, while contents of the other elements are close or lower than the average contents of world coals. However, the variations of CC (Concentration Coefficients) among each swamp type are small and irregular, which may indicate that the concentration of the selected trace elements in the coal is mainly dominated by regional coal-forming environment, not coal-forming microenvironment.

Binding characteristics of Cd2+, Zn2+, Cu2+, and Li+ with humic substances: Implication to trace element enrichment in low-rank coals

“…Most of these studies focused on the anomalous concentration of trace elements in coals and the affinity of these elements to the organic matters or the inorganic parts can be discerned on the level of mineral (Chu et al, 2015;Kang et al, 2014). However, the studies on the enrichment mechanisms and the origin of these elements in coals are scared (Qin et al, 2015b) and badly needed.…”

“…Recently, a variety of trace elements including Li, Ge, U, Hg is reported to be enriched in coal seams worldwide (Dai et al., 2014; Qin et al., 2015a, 2015b; Seredin et al., 2013; Sun, 2015; Sun et al., 2012, 2013a, 2013b, 2016). Most of these studies focused on the anomalous concentration of trace elements in coals and the affinity of these elements to the organic matters or the inorganic parts can be discerned on the level of mineral (Chu et al., 2015; Kang et al., 2014). However, the studies on the enrichment mechanisms and the origin of these elements in coals are scared (Qin et al., 2015b) and badly needed.…”

Geochemistry of Carboniferous–Permian Coal from the Wujiawan Mine, Datong Coalfield, Northern China: Modes of Occurrence, Origin of Valuable Trace Elements, and Potential Industrial Utilization

“…Datong coalfield is one of the most important coal-producing areas in China, and studies have been carried out on the mineralogy and geochemistry from the Carboniferous and Permian coals in, and adjacent to, the Datong coalfield [7,9,10,[16][17][18]20,[26][27][28]. Findings from these studies have shown that the sediment source is dominated by both Cambrian-Ordovician strata as well as Archean metamorphic rocks [9,10,[16][17][18]20,[26][27][28][29]. Additionally, the low temperature hydrothermal solution activities in this area have significantly influenced the abundance and modes of occurrence of trace elements present in the coal.…”

Geochemical Characteristics of Trace Elements in the No. 6 Coal Seam from the Chuancaogedan Mine, Jungar Coalfield, Inner Mongolia, China

“…The valuable trace elements associated with Jungar coal have been reported by many authors [1,[6][7][8][9][10][11][12], and the toxic trace elements have been investigated by several researchers [13][14][15][16]. However, these previous studies were essentially focused on the northern and central parts of the Jungar Coalfield, such as the Heidaigou Opencut Mine, the Haerwusu Opencut Mine, and the Guanbanwusu Mine (Figure 1) [4,5,7,17,18].…”