31 research outputs found
PETROGRAPHY OF THE HELVETIAN LIGNITE … 50 years University of Mining and Geology
ABSTRACT The complicated coal seam (complex) in the south part of the Chukurovo basin was sampled and 25 samples were taken. Polished block samples were prepared and the petrographic composition of the coal was established. There were found macerals from the three maceral groups. Macerals from the Huminite group were textinite, texto-ulminite, eu-ulminite, attrinite, densinite, phlobaphinite, and psudo-phlobaphinite. The following liptinite macerals were observed: cutinite, sporinite, resinite, suberinite, alginite, liptodetrinite, and chlorophillinite (?). Fusinite, sclerotinite, and inertodetrinite presented the inertinite macerals. Their amount was very vow. Minerals found with reflected light were clay minerals, pyrite (euhedral, framboidal and massive) and epigenetic calcite. The peat bog was determined as wet forest bog according the maceral composition. According to the calculated indices of the coal facies (Groundwater Influence Index and Vegetation Index), the type of the peat bog was determined as "limnitic ombrotrophic bog forest". The Tissue Preservation Index (TPI) and Gelification Index (GI) was determined peat bog as "forested peatland", where the water level was increasing continuously or in a forested, continuously wet raised bog. On the basis of the huminite reflectance, the coal was determinate as "Lignite"
Mineralogy, geochemistry and pyrite content of Bulgarian subbituminous coals, Pernik Basin
Sulphides in Hard Coal Seams from the Orzesze Beds s.s. of Mudstone Series (Westphalian B) in the Eastern Part of the Upper Silesian Coal Basin
Z uwagi na dynamiczne zmiany klimatyczne, które częściowo spowodowane są użytkowaniem węgla, ważne jest badanie zawartości substancji szkodliwych. Niebezpieczne zanieczyszczenia powietrza, powstające podczas spalania węgla (np, As, Se, Hg, Pb, Sb), są często związane z minerałami siarczkowymi w węglu. Przedmiotem badań były siarczki, które występują w polskim węglu kamiennym. Siarczki są jedną z form występowania siarki w węglu. Przeprowadzona praca skupiła się głównie na charakterystyce form występowania siarczków w skali makroskopowej i mikroskopowej, a także analizie chemicznej w mikroobszarze. Badania były prowadzone dla pokładów 301–308 ze wschodniej części Górnośląskiego Zagłębia Węglowego, stratygraficznie zaliczanych do najwyższej części warstw orzeskich s.s. (westfal B). Zostały opróbowane pokłady węgla w wyrobiskach podziemnych kopalń Jan Kanty, Sobieski Jaworzno III , Wesoła i Ziemowit. [...]Due to dynamic climatic changes resulting, among others, from the use of coal, the content of harmful substances in coal is of particular importance. Dangerous air pollution resulting from the burning of coal (e.g. As, Se, Hg, Pb, Sb) is often associated with sulfide minerals in coal. The study focused on the sulphides occurring in Polish hard coal deposits. Sulfides are one of the forms of occurrence of sulfur in coal. In this paper, an emphasis has been placed on the characteristics of forms of occurrence of sulphides on both macroscopic and microscopic scale and on the chemical analysis in the micro area. The study has been conducted for the No. 301–308 seams from the eastern part of the Upper Silesian Coal Basin, stratigraphically belonging to the highest part of the Orzesze Beds s.s. (Westphalian B). The coal samples have been collected from the coal seams in the underground excavations of the following coal mines: Jan Kanty, Sobieski Jaworzno III , Wesoła and Ziemowit hard coal mine. [...
Chemistry, mineralogy and distribution of selected trace-elements in the Parvadeh coals, Tabas, Iran
Modes of Occurrence and Cleaning Potential of Trace Elements in Coals from the Northern Ordos Basin and Shanxi Province, China
Interdisciplinary studies on the technical and economic feasibility of deep underground coal gasification with CO<sub>2 </sub>storage in bulgaria
U and Th in some brown coals of Serbia and Montenegro and their environmental impact
Goal, Scope and Background. The objective of this paper is to determine and compare the concentrations of U and Th in soft to hard brown (lignite to sub-bituminous) coals of Serbia and Montenegro. It also presents comparison of the obtained data on U and Th concentrations with the published data on coals located in some other countries of the world. Almost the whole coal production of Serbia and Montenegro is used as feed coals for combustion in thermal power plants. Methods. Channel samples from open pit and underground mines and core samples were collected for hard and soft brown coals. For the analysis the samples were decomposed using microwave technique. Obtained solutions containing U and Th were analyzed by inductively coupled plasma mass spectroscopy (ICP-MS) using NIST standards. Results. Concentration of U from the investigated basins and the corresponding mine fields ranges within 0.60-70.10 mg/kg, 0.65-3.20 mg/kg, 0.95-6.59 rng/kg, 1.20-6.05 mg/kg, 0.80-6.66 mg/kg, 0.18-89.90 mg/kg, 0.19-4.14 mg/kg, and 0.28-3.52 mg/kg for the Kostolac, Kolubara, Krepoljin, Sjenica, Soko Banja, Bogovina East field, Senje-Resavica and Pljevlja basins, respectively. Concentration of Th ranges within 0.20-2.60 mg/kg, 0.846.57 mg/kg, 1.48-6.48 mg/kg, 0.12-2.71 mg/kg, 0.13-4.95 mg/kg, 0.14-3.48 mg/kg, 0.29-3.56 mg/kg, and 0.17-1.89 mg/kg for the Kostolac, Kolubara, Krepoljin, Sjenica, Soko Banja, Bogovina East field, Senje-Resavica and Pljevlja basins, respectively. Discussion. Brown coal from Senje-Resavica, Kolubara, Kostolac and Pljevlja ischaracterized by low U concentration. Coals form the Krepoljin, Soko Banja and Sjenica basins have slightly higher U concentrations than the mentioned group. The highest concentration of U is characteristic for the coal from the Bogovina East field. Concentration of Th in coals from Serbia and Montenegro has proved to be low. Out of all investigated coal basins, only the coal from the Krepoljin and Kolubara basins has high concentration of Th. The hydrothermally altered rocks of the Timok dacite-andesite complex, representing the basement of the Bogovina basin, could be a potential source of U, especially at the bottom part of the Lower seam of the Bogovina East field. Conclusions. This study shows that brown coals in Serbia and Montenegro (soft to hard brown coals or lignite to sub-bituminous) contain low levels of U (5.30 mg/kg, average value and 2.10 mg/kg geometric mean value) and Th (1.80 mg/kg, average value and 1.12 mg/kg geometric mean value). There are some obvious differences in concentration of U and Th in coals from different basins in Serbia and Montenegro. The approximate value for U and Th release mainly from power plants was 644.33 t and 983.46 t, respectively within the period 1965-2000 for the studied mines in Serbia, and 23.76 t and 15.05 t for the Potrlica mine (Montenegro) within the period 1965-1997. Recommendations. The coals in Serbia and Montenegro show no identifiable unfavourable impact on the surrounding environment, due to low natural radioactive concentration of U and Th, but further investigations concerning human health should be performed. Perspectives. Preliminary research revealed that in some Serbian coals (and, particularly, parts of the coal seam) U and Th content are rather high. Such coals should be carefully studied, as well as U and Th concentrations in ash, fly ash, waste disposals, nearby soil and ground water. Further studies should include determination of the radioactivity of all these products, and estimation of possible health impact.Free full text: [http://dx.doi.org/10.1065/espr2006.08.332