Dorda, Jerzy

Kozłowska, Beata

Walencik, Agata

Zipper, Wiktor

EPJ Web of Conferences

English

Repozytorium Uniwersytetu Śląskiego RE-BUŚ

             Title: Radioactivity of dumps in mining areas of the Upper Silesian Coal Basin  in Poland  Author: Beata Kozłowska, Agata Walencik, Jerzy Dorda, Wiktor Zipper  Citation style: Kozłowska Beata, Walencik Agata, Dorda Jerzy, Zipper Wiktor. (2012). Radioactivity of dumps in mining areas of the Upper Silesian Coal Basin  in Poland. “EPJ Web of Conferences” (vol. 24 (2012), art. no. 05006), doi 10.1051/20122405006        Radioactivity of dumps in mining areas ofthe Upper Silesian Coal Basin in PolandB. Kozlowska∗, A. Walencik, J. Dorda and W. ZipperUniversity of Silesia, Institute of Physics, Department of Nuclear Physicsand Its Applications - Uniwersytecka 4 St., 40-007 Katowice, PolandAbstractUnderground coal mining is associated with large quantities ofgangue. In the past, the majority of gangue was not utilized but wasplaced in the vicinity of the coalmines forming cone-shaped dumps.Some of them contained even millions of tons of rock. Nowadays, en-vironmental precautions extort larger utilization of any kind of wastematerials, for example in road construction, civil engineering or asstowing in underground abandoned workings. Examination of the com-position of waste dumps, including radioactivity, is thus an importantissue. The paper presents results of a radiological survey carried outin several dumps located in the Upper Silesian Coal Basin in the southof Poland. Measurements of samples were carried out with the useof a gamma-ray spectrometer. Activity concentration results for theuranium and thorium decay chains are discussed.1. IntroductionThe Upper Silesian Coal Basin (USCB) is located in Silesia in Poland andthe Czech Republic. Apart from coal it also contains a number of otherminable resources (methane, cadmium, lead, silver and zinc). Resources ofcoal go down to a depth to 1000 meters. This area is a home of altogether5 million people.∗E-mail: beata.kozlowska@us.edu.plEPJ Web of ConferencesDOI: 10.1051/C© Owned by the authors, published by EDP Sciences , 2012,epjconf 20122/24 05006 (2012)405006 - SIFThis is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Article available at http://www.epj-conferences.org or http://dx.doi.org/10.1051/epjconf/20122405006Underground coal mining is associated with the production of greatamounts of rock waste. It is estimated that for 1 t of output coal, there isabout 0.4 t of waste material [1]. In the past, the majority of wastes, mainlygangue, was not utilized but was transported and placed in the vicinity ofthe coalmines forming cone–shaped dumps. Some of them contained evenmillions of tons of rock. Therefore, in Poland, especially in Silesia there aremany coal waste dumps. Recently, there were counted 136 coal waste dumpswith 750 million tons of waste in the area on the Upper Silesia region. Theirtotal area is about 3 500 000m2 [2]. For example the waste dump in Laziskahas a height of 90m, a surface of 30 000m2 and weight of 17 million tons.Nowadays, environmental precautions ask for larger utilization of any kindof waste materials, for example in road construction, civil engineering or asstowing in underground abandoned workings.Prior to any use of waste materials studies are required in order to avoidany hazard, including radioactivity, for the environment and the humanbeings. Assessing the radioactivity of waste is quite important due to thefact that they might be used in the production of building materials forresidential constructions. Figure 1 presents the location of seven dumpsfrom where the samples were taken for these studies.The long lasting mining industry influenced the Silesian environmentand landscape. In the post–mining areas of proper management, dumps arethe subject of land reclamation, which in consequence leads to formationof walking and recreational forest areas (Figure 2). However, the scenariomight also be quite different. The waste stored in dumps includes in itscomposition a significant amount of material, mostly coal and pyrite, whichis reactive. The contact of those components with oxygen leads to naturaloxidation and heat production, which may cause spontaneous heating andburning of the waste. The external factors such as height and volume ofthe dump, the gradient of slopes and the meteorological conditions are veryimportant, too [1]. Burning dumps are dangerous for people and also arethe source of air pollution and dust in its neighborhood. When a dumpburns its temperature varies between 900 and 1200 ◦C.Summarizing, monitoring of the dump composition, and its radioactivity,is an extremely important issue.2. Measurements and methodsThe studied material comprises waste samples collected from outcrops in thedumps of USCB. The samples were collected from 9 places (see Figure 1). InEPJ Web of Conferences05006-p.2Figure 1: Location of dumps used as sampling points on the background of thegeological map (post–Quaternary) of the Upper Silesian Coal Basin, including tec-tonic elements: 1. dump of Murcki – Staszic coal mine, Katowice, 2. dump ofSaturn coal mine, Czeladz´, 3. dump of Mikulczyce coal mine, Zabrze – Mikulczyce,4. dump of S´la¸sk coal mine, Ruda S´la¸ska, 5. dump of Marcel coal mine, Radlin,6. dump “Skalny” of Boleslaw S´mialy coal mine, Laziska, 7. dump “Waleska” ofBoleslaw S´mialy coal mine, Laziska, 8. dump of Ziemowit coal mine, Le¸dziny, 9.dump of “Poko´j” and “Florian” steal mills, S´wie¸tochlowice.ER201005006-p.3Figure 2: The coal waste dump Marcel after land reclamation (photograph byB.K.).total, 43 samples representing different waste material were collected. Thematerial from the Murcki-Staszic, Marcel and Waleska coal mine dumps wasrepresented mostly by soil with slag. The Murcki-Staszic dump is nowadaysbeing reclaimed with grass and trees slowly overgrowing its area. The mate-rial of four samples from the Skalny dump was soil, gravel, coal and gangue,whereas five samples were soil, clay and gravel. This dump is one of thebiggest in the Upper Silesia and even in Europe. It was used for the last220 years, so one can find many kinds of different materials there. Anotherdump with a variety of material was Saturn which was working for the last150 years. Since 2004 the coal mine is closed and the biological recultivationinto forests or meadows has been conducted in its dump. In some dumpswas also stored the precipitate from ponds.The studies of waste samples were carried out from 2005 to 2010. Allmeasurements were performed in the Department of Nuclear Physics andIts Applications of the Institute of Physics at the University of Silesia, Ka-towice, Poland. Each sample was transferred to the laboratory, where itEPJ Web of Conferences05006-p.4was analyzed, dried, crushed and ground to a fraction smaller than 0.2mmfor homogenization. The measurements were carried out in Marinelli ge-ometry, in 0.6 dm3 containers. The natural radioactivity of 226Ra, 232Th(228Ac) and 40K was determined using the a semi-conductor Ge(Li) gamma-ray spectrometer. The spectra were analyzed with the use of the TUKANsoftware, version 1.4, and the GANNAS spectrum analysis program [3]. Theenergy calibration and the detector efficiency curves were obtained on thebasis of standards prepared from certified materials from the InternationalAtomic Energy Agency and from the Central Laboratory for RadiologicalProtection from Warsaw, Poland.The activity of 226Ra was calculated as the weighted mean of the valuesobtained directly from the 186.2 keV line and the activities of 214Pb (241.9,295.2, 351.9 keV) and 214Bi (609.3, 1120.3 keV). The determination of thepresence of 232Th and calculation of its activity was based on the followinggamma-ray transitions: 228Ac (338.3, 911.1, 968.9 keV) and 212Pb (238.6,300.1 keV). 40K was calculated from the 1460 keV line. The detection limitfor the measurements calculated according to Curie method [4] was about1Bq kg−1 for each investigated isotope.3. Results and discussionThe content of the 226Ra, 232Th and 40K activity concentration in the 43samples of the Silesian coal waste dumps is graphically presented in theFigures 3A and 3B. Some basic statistical values are presented in Table I.For comparison, mean concentrations of these radionuclides in the soils ofthe Silesian Voivodship are also listed.As can be seen in Figures 3A and 3B the measured activity concentra-tion associated with 226Ra, 232Th and 40K is higher for the majority of thesamples than the average activity concentration of these radioisotopes in thesoil in the Upper Silesia region. It must be emphasized that the sampling atparticular dumps was performed randomly. The lowest levels of measuredradioactivity were measured in samples collected from dumps belonging tothe steel mill in S´wie¸tochlowice. For one sample, the obtained results weredistinctly higher than the average values. The obtained results suggest thatthis high content of 226Ra, 232Th and also 40K is connected with the spe-cific collection place, where probably also the precipitate from ponds wasdeposited. The high activity value of this particular sample suggests thatprior to any use a specific examination of the material must be done.ER201005006-p.5Figure 3: Comparison of A) 226Ra, 232Th and B) 40K activity concentration in themeasured samples with the average activity concentration of these radionuclidesreported for average soil (solid lines) in Upper Silesia.EPJ Web of Conferences05006-p.6Table I: Selected statistical parameters concerning 226Ra, 232Th and 40K content[Bq/kg] in the material from different coal waste dumps of USCB.Parameter 226Ra 232Th 40KNumber of samples 43 43 43Minimum 8 8 110Maximum 632 850 1250Arithmetic mean 62 67 496Standard deviation 91 124 242Median 51 51 507Geometric mean 46 45 433Mean for the Silesian Voivodship 31 28 3964. Summary and conclusionsThe mean 226Ra, 232Th and 40K contents in the dump samples of USCBwere 62, 67 and 496Bq kg−1, respectively. These values are very close totheir respective median values, which confirms their normal distribution.The obtained results concern TENORM values. The mean values are higherthan average data for the soils in the Silesian Voivodship, which are around30Bq kg−1 for 226Ra and 232Th and about 400Bq kg−1 for 40K.The results of gamma–ray measurements presented here give a piece ofcurrent information about the natural radioactivity content in samples incoal mine waste dumps in the USCB region. The majority of the collectedsamples present slightly elevated levels of natural radioactivity, however onecan find material of distinctly higher values. Since coal mine wastes areoften used in different applications, studies assessing their level of hazardfor the environment and human beings are necessary.References[1] SULKOWSKI J., DRENDA J., RO´Z˙AN´SKI Z., WRONA P., NaturalResources Management No. 24 (3) (2008). In Polish.[2] SIKORSKA-MAYAKOWSKA M., BARSZCZ A., GRABOWSKI D.,LEWANDOWSKI P., STRZELECKI R., Natural environment and theidentification of its hazards in the Silesian Voivodship (Pan´stwowy In-stytut Geologiczny, Warszawa) 2001. In Polish.ER201005006-p.7[3] GANAAS, Nuclear Analysis Software. Part 2: Gamma Spectrum Anal-ysis Activity Calculation and Neutron Activation Analysis, ComputerManual Series No. 3 (International Atomic Energy Agency, Vienna)1991.[4] CURIE L. A., Analytical Chemistry 40(3) (1968) 586-593.EPJ Web of Conferences05006-p.8

Radioactivity of dumps in mining areas of the Upper Silesian Coal Basin in Poland

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Radioactivity of dumps in mining areas of the Upper Silesian Coal Basin in Poland

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