Trace element geochemistry of self-burning and weathering of a mineralized coal waste dump: The Novátor mine, Czech Republic

Křı́bek, Bohdan; Sýkorová, Ivana; Veselovský, František; Laufek, František; Malec, Jan; Knésl, Ilja; Majer, Vladimı́r

doi:10.1016/j.coal.2017.03.002

Cited by 24 publications

(10 citation statements)

References 45 publications

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“…Most of the previous work reported the structural changes C-C and C-H bond, changes in caking properties, petrographic compositions, coke properties (Banerjee et al 2000;Xia and Yang 2014;Cimadevilla et al 2005;Smędowski and Piechaczek 2016;Tamamura et al 2015;Kříbek et al 2017) etc. in weathered coal.…”

Section: Introductionmentioning

confidence: 99%

Effect of weathering on physico-chemical properties and combustion behavior of an Indian thermal coal

Aich

Nandi

Bhattacharya

2018

Int J Coal Sci Technol

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An open air stockpile of conical shape was formed with 3.5 m base diameter and 5 m height using 500 tons of-200 mm size ROM thermal coal on a concrete floor. Coal sample from the stockpile were collected at 30 days interval for analysis of various chemical properties like; proximate analysis, ultimate analysis, gross calorific value (GCV) and various combustion related properties such as ignition temperature, peak temperature, burnout temperature, maximum combustion rate, ignition index, burnout index, combustion performance index and combustion rate intensity index. Experimental results show that, due to weathering of coal fixed carbon decreased from 35.6% to 19.9%, elemental carbon (C) decreased from 46.6% to 28.6%, hydrogen (H) decreased from 3.3% to 2.9% and GCV decreased by up to 55% of original value during 330 days of storage of coal in an open atmosphere. Ash content of coal increased form 29.2% to 46.6% due to loss of combustibles. Sulfur (S) of coal was found to get increased from 0.33% to 1.08% during storage. The activation energy of coal combustion increased from 22 kJ/mol to 54 kJ/mol. Variation in combustion parameters signifies that weathering has significant negative impact on coal combustion properties as coal become difficult to ignite.

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Section: Introductionmentioning

confidence: 99%

Effect of weathering on physico-chemical properties and combustion behavior of an Indian thermal coal

Aich

Nandi

Bhattacharya

2018

Int J Coal Sci Technol

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“…Mn, Ag, Sn, and Co, with their affinity to Fe, reflect the presence of Fe oxides, and vanadium and thallium the presence of clay minerals. There is no correlation of Rb with the presence of K-feldspar in the dump although some affinity to illite is noted, as in the Starzykowiec coal-waste dump (Ward, 2002(Ward, , 2016Ribeiro et al, 2010;Ciesielczuk et al, 2014a;Křibek et al, 2017). Invariable amounts of other elements reveal nothing of the thermal activity.…”

Section: Chemical Compositionmentioning

confidence: 99%

“…The mode of occurrence of the element dictates its behaviour and its environmental impact (Finkelman, 1993). Active fires in the coal-bearing waste can mobilize elements through direct condensation from escaping gas, interaction with coal waste, and evaporation of acidic solutions possibly enriched in metals (Křibek et al, 2017). Increasing heat first causes changes in organic matter, and then in mineral matter (Ciesielczuk et al, 2014a(Ciesielczuk et al, , 2014b and references herein).…”

Section: Chemical Compositionmentioning

confidence: 99%

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Structure and thermal history of the Wełnowiec dump, Poland: A municipal dump rehabilitated with coal waste

Pierwoła

Ciesielczuk

Misz‐Kennan

et al. 2018

International Journal of Coal Geology

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The Wełnowiec municipal dump, Katowice, Poland, rehabilitated with coal waste, is self-heating and igniting. This paper presents a novel application of the use of electrical-and resistivity geophysical methods in the investigation of burning coal waste to help explain why the heating occurred. Geoelectrical methods allowed the internal structure of the dump to be revealed, and the municipal wastes and their rehabilitation cover containing coal waste to be differentiated. Instead of a planned 2.2-m-thick multi-barrier system, the cover consists of irregularly distributed material of varying thickness (< 1 to 8 m) and organic carbon content (> 5%). This caused the fire to arise 3-4 years after the coal waste deposition. In areas where the rehabilitation layer is < 3 m thick, a landslide enabled oxygen access, initiating self-heating. Changes in conductivity clearly identify sites of active burning where measured conductivity values are more than twice those for parts of the dump with no thermal activity. Field observations in particular, complemented to a degree by petrographic, mineralogical and geochemical data, enabled four types of heating zones to be distinguished, namely, (1) initial zones of fire overtaking new volumes of coal waste, (2) active zones with temperatures < 400-500°C in exhalation vents, (3) overburned zones characterized by long-lasting high temperatures (800-900°C) and (4) short-lived zones, ephemeral (< 1-2 months) with temperatures between 70 and 100°C. The geophysical methods applied could not distinguish between these zones. The combined results strongly suggest that the use of coal waste as a remediation layer covering waste dumps should be prohibited. Coal waste which, by its nature, is too prone to unpredictable self-heating and self-ignition with the potential environmental consequences that follow. water (rain); these are pyrolytic or/and hydropyrolytic processes (Fabiańska et al., 2013; Misz-Kennan and Fabiańska, 2011). Factors that influence the self-heating process can be classified as internal and external. Internal factors relate to coal-waste composition and condition, e.g., of mineral matter (contents of quartz, feldspars, clay minerals, carbonates, and sulphides) and coal-bearing rocks (maceral composition, especially of oxidation-prone vitrinite), coal rank, moisture content, granulation, and degree of weathering. External factors include dump shape and height, convection related to atmospheric conditions, i.e., wind and rain, insolation and grain segregation (Krishnaswamy et al., 1996a, 1996b; Kaymakçi and Didari, 2002). Self-heating and self-ignition of coal waste can be triggered spontaneously within a dump. If preventative measures are not taken, or the

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“…During the fieldwork, the coalified trunks have been wasted and covered by a thin layer of sandstone in unexploited areas (Figure 4), and the coalified trunks once covered the mined coal have been wasted in a gangue dump near the open-pit mine. Previous studies have shown that both weathered coal gangue and burnt or unburnt waste dump from coal mine have potential impacts on the local environment [72,73] and human health [74]. However, the potential environmental impacts of coalified trunks in the Wulantuga Ge-coal deposit have never attracted attention.…”

Section: Environmental Impacts Of Coalified Trunkmentioning

confidence: 99%

New Data and Evidence on the Mineralogy and Geochemistry of Wulantuga High-Ge Coal Deposit of Shengli Coalfield, Inner Mongolia, China

et al. 2019

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The mode of occurrence and origin of highly-enriched trace elements, especially Ge, in Wulantuga high-Ge coal deposit have been widely reported. In this study, coal samples and several coalified trunks embedded within the roof strata are collected, which provides a good opportunity to further confirm if Ge is mainly associated with organic matter. Minerals in coal samples are mainly quartz, kaolinite, montmorillonite, pyrite, and gypsum, along with trace albite, barite, chlorite, and Fe-oxide, while those in coalified trunk samples include melanterite, pyrite, and gypsum, with traces of chlorite and magnesiocopiapite. Germanium, As, W, Sb, Hg, Be, and Cs are enriched in coal samples, and these elements are also enriched in the coalified trunks and roof glutenite. The elevated contents of Ge, As, W, Sb, and Hg were almost exclusively derived from the influx of hydrothermal fluids as evidenced by the presence of pyrite veins and chamosite as well as enhanced elemental associations of Ge-W and As-Sb-Hg in the studied lignite samples. The coalified trunks in the study area should be taken into consideration due to the high contents of hazardous elements that cause potential environmental impacts during mining waste disposal and land reclamation.

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Trace element geochemistry of self-burning and weathering of a mineralized coal waste dump: The Novátor mine, Czech Republic

Cited by 24 publications

References 45 publications

Effect of weathering on physico-chemical properties and combustion behavior of an Indian thermal coal

Effect of weathering on physico-chemical properties and combustion behavior of an Indian thermal coal

Structure and thermal history of the Wełnowiec dump, Poland: A municipal dump rehabilitated with coal waste

New Data and Evidence on the Mineralogy and Geochemistry of Wulantuga High-Ge Coal Deposit of Shengli Coalfield, Inner Mongolia, China

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