The distribution and occurrence of mercury in Chinese coals

Abstract

Mercury is one of the most concerned hazardous elements in coals. 1018 coal samples of different coal-forming periods, coal-accumulating areas and coal ranks all over the country were collected to study the distributions of mercury in Chinese coals. The modes of occurrence of mercury were studied with float-sink experiments of 10 coals from different basins in China and correlation analyses were conducted between concentrations of mercury and maceral and sulfur contents, as well as the ash yield. The theoretic concentrations and affinities of mercury in vitrinite, inertinite, clay and pyrite were then calculated following the methods proposed by Solari. The weighted average concentration of mercury in Chinese coals is 0.154 lg/g, which is similar to that in the word coals in general. The mercury concentrations vary largely in the coals of different coal-forming period and coal-accumulating areas as geological settings play key roles in determining the geochemistry of mercury. The concentrations of mercury in coals from south and southwest China and those from North China of C 3 -P 1 are relatively higher while those from North China of J 1-2 and Northeast of J 3 -K 1 relatively lower. The general distribution trends of mercury are very similar to that of ash yield, sulfur contents in coals. Pyrite is the dominant carrier of mercury in most coals, especially in some high-sulfur coals with abundant epigenetic pyrite formed during diagenesis and metamorphism. Mercury has higher affinity to vitrinite than to inertinite in most coals, which accords with the geological origin of macerals and geochemistry of mercury.

A new ecological risk assessment index for metal elements in sediments based on receptor model, speciation, and toxicity coefficient by taking the Nansihu Lake as an example

“…The calculated release coefficients of the above metals are listed in Table 4 (Tech, 1986;Mou, 1999;Bai et al, 2004;Xu et al, 2008). The release coefficients of 10 metals in sediments calculated according to this method are listed in an increasing sequence: Cr < Tl < As < Sb < Zn < Be < Pb < Cu < Cd < Hg.…”

“…Different from Be, about half of the sites in the upper and lower sections of the lake had E r i values higher than 40 for Sb, reaching moderate ecological risk. Coal development and utilization was the primary source of Be and Sb pollution in environment (Bai et al, 2004;Hulo et al, 2016;He and Wan, 2004;Cai et al, 2016). Thus, the industries of metallurgy, mining, thermal power generation, etc., in Jining, Zhaozhuang, Xuzhou, etc., around the Nansihu Lake were the sources of Be and Sb in environment.…”

Clean coal geology in China: Research advance and its future

“…There are many researches on trace elements in domestic Chinese coals (Chen et al 1986;Sun and Jervis 1986;Wang and Ren 1994;Huang et al 1999Huang et al , 2001Liu et al 1999a;Ren et al 1999a, b;Bai et al 2004;Tang and Huang 2004;Dai et al 2006bDai et al , 2012aDai et al , b, 2014Dai et al , 2018Song et al 2010;Cheng et al 2013;Bai et al 2014Bai et al , 2017aXie et al 2014;Zhang et al 2016;Zhou et al 2017;Wang et al 2019b) and in coals from other nations (Gluskoter 1975;Bouška 1981;Swaine 1990Swaine , 2000Swaine and Goodarzi 1995;Finkelman 1993Finkelman , 1995Finkelman and Gross 1999;Ketris and Yudovich 2009; Say-Gee and Wan 2011; Nakajima and Taira 2014;Hot et al 2016;Arbuzov et al 2019). The authoritative background values of trace elements in Chinese coals were obtained by Dai et al (2012a, b) and an evaluation formula of enrichment coefficients of trace elements was established by Dai et al (2014).…”

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

“…Numerous investigations on the elemental geochemistry in coals from north China have been carried out [7][8][9][10][11][12][13][14][15][16][17][18][19] and have revealed that various valuable elements can be found in high concentrations which gives them considerable economic significance [9,15,17,[20][21][22][23]. Dai et al [24] suggested that rare metals, such as REY, Cr, Ti, Li, Be, Au, Ag, Pt, Pd, etc., have high potential for industrial utilization in some Chinese coals.…”