Estimations of Clarkes for Carbonaceous biolithes: World averages for trace element contents in black shales and coals

Кетрис, М. П.; Yudovich, Ya. E.

doi:10.1016/j.coal.2009.01.002

Cited by 1,203 publications

(814 citation statements)

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“…The average lead content in the tested raw coals is 22.9 mg/kg, which is close to the average value of the Pb content in coals from USCB and more than twice the value of the world average Pb content in hard coal, which is 9.0 ± 0.7 [6]. The clark value (global average value) of lead for sedimentary rock is 12 mg/kg; thus the enrichment factor EF [43] for the analyzed raw coals is 1.9.…”

Section: Lead Distribution In Products Of Coal Cleaning Processesmentioning

confidence: 52%

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Investigations of the effectiveness of lead disposal from hard coal through the cleaning process

et al. 2016

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Abstract. Lead, belonging to the category of toxic heavy metals, poses a major threat to the environment and the health and life of living organisms. Anthropogenic sources of lead emissions to the atmosphere include coal combustion, pyrolysis and gasification processes. This metal enters the atmosphere through the fly ashes and gases, causing chemical imbalance in the ecosystem. One way of reducing the emissions of heavy metals into the atmosphere due to the thermochemical processing of coal involves removing impurities from the fuel prior to its use, e.g. through the coal cleaning processes. The removal of heavy metals from coal through these processes is possible due to the fact that these elements are mostly related to the mineral matter, which is separated from the organic matter. This paper presents the results of investigations of the removal efficiency of lead from coals through the coal cleaning processes in industrial plants. Additionally, the distribution of lead among individual products of these processes was identified. Raw coals, coal concentrates, intermediate products and waste from five plants of mechanical processing of coking coal were analyzed. The determination of the lead content was performed with the use of Flame Atomic Absorption Spectrometry (FAAS). Moreover, for all the samples, a proximate analysis and ultimate analysis as well as the determination of the content of main elements of mineral matter were conducted. In order to confirm the mode of occurrence of lead in coal mineral matter, an elemental analysis was conducted with the use of an electron microprobe. The results of the investigations showed that with a significant reduction of mineral matter in the coal cleaning processes, the lead content is decreased, as a result of both, the application of the gravity and flotation methods. The analyzed metal accumulates primarily in the waste and/or intermediate products of coal cleaning. The lead content in the obtained coal concentrates does not exceed 25 mg/kg. The microprobe examinations confirmed the presence of lead in sulphides, mainly in the form of galena.

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Section: Lead Distribution In Products Of Coal Cleaning Processesmentioning

confidence: 52%

“…The large share of the combustion processes in lead emission can be attributed to the fact that coal is usually enriched with heavy metals, including lead [6]. A number of geochemical research works have shown that Polish coals, i.e.…”

Section: Introductionmentioning

confidence: 99%

Investigations of the effectiveness of lead disposal from hard coal through the cleaning process

et al. 2016

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“…However, Rb, Ba, Bi, Mo, and Sb, are depleted in the coal (CC < 0.5). The concentrations of the remaining elements (0.5 < CC < 2) are close to the corresponding averages for world hard coals [27].…”

Section: Trace Elementsmentioning

confidence: 62%

“…Compared to the averages for world hard coals [27], and based on the enrichment classification of trace elements in coal by Dai et al [28], a number of trace elements are enriched in Songshao coal. Lithium has a concentration coefficient (CC: ratio of element concentration in Songshao coals vs. world hard coals) >10.…”

Section: Trace Elementsmentioning

confidence: 99%

Geological Controls on Mineralogy and Geochemistry of an Early Permian Coal from the Songshao Mine, Yunnan Province, Southwestern China

Wang

2016

Minerals

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This paper discusses the content, distribution, modes of occurrence, and enrichment mechanism of mineral matter and trace elements of an Early Permian coal from Songshao (Yunnan Province, China) by means of coal-petrological, mineralogical, and geochemical techniques. The results show that the Songshao coal is characterized by high total and organic sulfur contents (3.61% and 3.87%, respectively). Lithium (170.39 µg/g) and Zr (184.55 µg/g) are significantly enriched in the Songshao coal, and, to a lesser extent, elements such as Hg, La, Ce, Nd, Th, Sr, Nb, Sn, Hf, V, and Cr are also enriched. In addition to Hg and Se that are enriched in the roof and floor strata of the coal seam, Li, La, Ce, Pr, Nd, Sm, Gd, Y, Cd, and Sb are slightly enriched in these host rocks. Compared to the upper continental crust, rare earth elements and yttrium in the host rocks and coal samples are characterized by a light-REE enrichment type and have negative Eu, positive Ce and Gd anomalies. Major minerals in the samples of coal, roof, and floor are boehmite, clay minerals (kaolinite, illite, and mixed layer illite-smectite), pyrite, and anatase. Geochemical and mineralogical anomalies of the Songshao coal are attributed to hydrothermal fluids, seawater, and sediment-source rocks.

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“…The concentration of arsenic (As) is associated with pyrite in coal; high As values in coals from the Can formation (maximum 6413 ppm) were previously reported by Baba et al (2009). The average concentration of trace elements, including As, boron (B), cadmium (Cd), cobalt (Co), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn), were higher than the world coal average value reported by Swaine (1990) and Ketris and Yudovich (2009) and creates an ecological risk for the environment (Sanliyuksel Yucel 2013).…”

Section: Geochemistry Of Rock and Mine Waste Samplesmentioning

confidence: 87%

Generation of Acid Mine Lakes Associated with Abandoned Coal Mines in Northwest Turkey

Yücel

Balcı

Baba

2016

Arch Environ Contam Toxicol

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A total of five acid mine lakes (AMLs) located in northwest Turkey were investigated using combined isotope, molecular, and geochemical techniques to identify geochemical processes controlling and promoting acid formation. All of the investigated lakes showed typical characteristics of an AML with low pH (2.59-3.79) and high electrical conductivity values (1040-6430 lS/cm), in addition to high sulfate (594-5370 mg/l) and metal (aluminum [Al], iron [Fe], manganese [Mn], nickel [Ni], and zinc [Zn]) concentrations. Geochemical and isotope results showed that the acid-generation mechanism and source of sulfate in the lakes can change and depends on the age of the lakes. In the relatively older lakes (AMLs 1 through 3), biogeochemical Fe cycles seem to be the dominant process controlling metal concentration and pH of the water unlike in the younger lakes (AMLs 4 and 5). Bacterial species determined in an older lake (AML 2) indicate that biological oxidation and reduction of Fe and S are the dominant processes in the lakes. Furthermore, O and S isotopes of sulfate indicate that sulfate in the older mine lakes may be a product of much more complex oxidation/dissolution reactions. However, the major source of sulfate in the younger mine lakes is in situ pyrite oxidation catalyzed by Fe(III) produced by way of oxidation of Fe(II). Consistent with this, insignificant fractionation between d 34 S SO 4 and d 34 S FeS 2 values indicated that the oxidation of pyrite, along with dissolution and precipitation reactions of Fe(III) minerals, is the main reason for acid formation in the region. Overall, the results showed that acid generation during early stage formation of an AML associated with pyrite-rich mine waste is primarily controlled by the oxidation of pyrite with Fe cycles becoming the dominant processes regulating pH and metal cycles in the later stages of mine lake development.Acidic and highly metal-loaded effluents (acid mine drainage [AMD]) resulting from the exposure of pyrite and other metal sulfide minerals to weathering conditions are the principal environmental problems faced by the mining industry today (Dold and Spangerberg 2005).The formation mechanisms of AMD (e.g., oxidation of pyrite and other sulfide minerals) has been extensively studied

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Estimations of Clarkes for Carbonaceous biolithes: World averages for trace element contents in black shales and coals

Cited by 1,203 publications

References 21 publications

Investigations of the effectiveness of lead disposal from hard coal through the cleaning process

Investigations of the effectiveness of lead disposal from hard coal through the cleaning process

Geological Controls on Mineralogy and Geochemistry of an Early Permian Coal from the Songshao Mine, Yunnan Province, Southwestern China

Generation of Acid Mine Lakes Associated with Abandoned Coal Mines in Northwest Turkey

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