Mineralogy and geochemistry of Bobov Dol coals, Bulgaria

Vassilev, Stanislav V.; Yossifova, Mariana G.; Vassileva, Christina G.

doi:10.1016/0166-5162(94)90010-8

Cited by 64 publications

(38 citation statements)

References 6 publications

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“…Studies by Ward [14,15] revealed that minor boehmite may occur in some coals, but high concentration of boehmite in coal is unusual. Goodarzi et al [16] , Harvey et al [17] , Palmer et al [18] , Patterson et al [19] , Hower et al [20] and Vassilev et al [21] did not find boehmite in the coals from Canada, Australia, America, and Bulgaria. Tatsuo et al [22,23] found minor boehmite in the low-temperature ashes of the Eogene coals from the Ishikari Coalfield, Ashibetsu district, Japan.…”

Section: Boehmite: the Main Carrier Of Ga In Coalmentioning

confidence: 95%

Discovery of the superlarge gallium ore deposit in Jungar, Inner Mongolia, North China

Dai

Ren

2006

CHINESE SCI BULL

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Mineralogy and geochemistry of No.6 Coal from the Heidaigou Mine of the Jungar Coalfield of North China were studied using instrumental neutron activation analysis, inductively coupled-plasma mass spectroscopy, X-ray fluorescence spectrometry, and scanning electron microscope equipped with an energy-dispersive X-ray spectrometer. The results show that gallium concentration is as high as 44.8 μg·g −1 in the whole coal-channel sample, and varies from 30.1 μg·g −1 to 76.0 μg·g −1 (mean 51.9 μg·g −1 ) in the main minable benches of No.6 Coal. Such high concentration of Ga in the coal is far higher than the industrial grade (30 μg·g −1 ). The thickness of the main minable benches accounts for 81.9% of the whole coal bed. The laboratory high-temperature ashes (550℃) of the main minable coal benches also contain a high concentration of Ga, varying from 62.2 μg·g −1 to 178 μg·g −1 , with an average of 89.2 μg·g −1 .The boehmite significantly enriched in No.6 Coal is the main carrier of the high Ga in the coal. Average concentration of Ga in boehmite is 0.09%. The average content of boehmite is 6.1% in the whole coal and 7.5% in the main minable benches. Boehmite is derived from the bauxite in the weathered crust of the underlying Benxi Formation in the north of the basin during the peat accumulation. The colloidal idrargillite had been shortly transported from the weathered crust to the peat mire, and owing to the compaction of the overlying strata during the peat accumulation and early diagenesis, the idrargillite colloid had begun to be dehydrated, leading to boehmite formation. A preliminary estimation showed that the ensured and prospected reserves of Ga in No.6 Coal are up to 6.3 ×10 4 t and 8.57×10 5 t, indicating a superlarge gallium ore deposit. The particular paleogeography of the Jungar Coalfield and the peculiar carrier of Ga in coal suggest that this Ga ore deposit is unique in the world. Rare earth elements are also enriched in coal and laboratory ashes. The weighted average concentration of the total rare earth elements is 255 μg·g −1 and 830.36 μg·g −1 in the main minable benches and their laboratory ashes, respectively. Because Al is the main composition of boehmite, aluminum and rare earth elements in No.6 Coal are also the available and valuable resources.

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Section: Boehmite: the Main Carrier Of Ga In Coalmentioning

confidence: 95%

Discovery of the superlarge gallium ore deposit in Jungar, Inner Mongolia, North China

Dai

Ren

2006

CHINESE SCI BULL

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“…The formation of kaolinite is favored in acid environments and commonly occurs as a result of weathering of other aluminosilicates, such as alkali feldspars (Mason and Moore, 1982;Berry and Mason, 1983). Interaction of the precipitated alumina with any silica in solution results in the formation of authigenic kaolinite (Vassilev et al, 1994;Vassilev and Vassileva, 1996;Ward 2002). Chlorite was not identified in the samples.…”

Section: Geochemistrymentioning

confidence: 65%

Lignites from the Plains region of Alberta, Canada—Part 2: Elemental geochemistry

Gentzis

Oikonomopoulos

Chagué‐Goff

2016

Energy Sources, Part A: Recovery, Utilization, and Environmenta

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Mineralogy and elemental concentration of two coal seams in Alberta, Canada, were determined using X-ray diffractometry and X-ray fluorescence (XRF). Minerals consist mainly of quartz and calcium minerals, the latter as calcite and vaterite, and oxalate (whewellite). Clay minerals are present as kaolinite, reflecting peat deposition in an acidic environment. Most elements in the coal show depletion compared to Clarke values. Some elements are associated with mineral matter (e.g., Ti, Ba, Si, Al, K, Mg, and Y) and increase with ash. Na, Mn, Sr, and Cu are associated with macerals. High phosphorous and strontium in one interval may be related to the high concentration of whewellite.

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“…Οι Κ-άστριοι πα ρουσιάζουν συχνότερα κλαστική προέλευση. Η συνύπαρξη όλων αυτών των ορυκτών υποδεικνύει κλαστικό μηχανισμό γένεσης (Vassilev et al 1994, Vassilev & Vassileva 1996. Ο ανυδρίτης μπορεί να προήλθε από αφυδάτωση της γύψου ή από αλληλεπίδραση οξειδίων ασβεστίου και οξειδίων θείου, που απελευθερώνονται κατά την οξείδωση οργανικού υλικού (Mitchell & Gluskoter 1976, Nankervis & Furlong 1980, Vassilev & Vassileva 1996, Ward et al 2001.…”

Section: αποτελέσματα ορυκτολογικής ανάλυσηςunclassified

Environmental Geochemical and Mineralogical Study of the Pellana Lignite (Prefecture of Lakonia)

et al. 2004

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The aim of this study is to estimate the environmental impacts in case of exploitation the Pellanalignites for power generation. The object of the study is to predict the element mobility during lignite combustion using mineralogical and geochemical data from bulk-lignite samples and their ashes of two cores from this area. The mineralogical determinations on the ashes revealed that quartz, K-feldspars and illitemicas are the major mineral phases contained in the lignite. The identification of anhydrite in ashes implies the presence of gypsum, althought neoformation of anhydrite from organic associated with Ca+2 and SO42 can not be excluded. These minerals correspond to primary phases. Oxides and hydroxides occur subordinately and probably represent minerals that do not correspond to primary phases. The results of the elemental analysis show that the major elements (>1000 ppm) are AI, Fe, Ca, Mg and Κ in the bulk samples of both cores. Minor elements (100-1000 ppm) are Na, Mn and Ba, while the concentrations of Be, Bi, Cd, Ce, Co, Cs, Cu, Eu, Ga, Hf, La, Li, Lu, Mo, Nb, Nd, Pb, Rb, Sb, Se, Sm, Sn, Sr, Tb, Te, Th, TI, U, Y, Yb and Zr do not exceed 100 ppm. The concentrations of many elements like As, Ba, Cr, Ni, V and Zn have a wide range among the bulk samples. In order to assess the geochemical affiliation of the studied elements, R-type factor analysis was applied on the element contents of bulk lignite and ash. The elements Ca, S, V, As, Μη, Mo, Na, Sb, Hf, Zr and U provide both organic and inorganic affiliations, while Se and Nb provide organic affiliations. To approach the mobility of each trace element, the relative enrichment factor (RE) was calculated. The most depleted trace elements according to RE mean (<0.5) are Hf and Sb, while the elements Se and Ba are moderately depleted (0.7>RE mean>0.5).

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Mineralogy and geochemistry of Bobov Dol coals, Bulgaria

Cited by 64 publications

References 6 publications

Discovery of the superlarge gallium ore deposit in Jungar, Inner Mongolia, North China

Discovery of the superlarge gallium ore deposit in Jungar, Inner Mongolia, North China

Lignites from the Plains region of Alberta, Canada—Part 2: Elemental geochemistry

Environmental Geochemical and Mineralogical Study of the Pellana Lignite (Prefecture of Lakonia)

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