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1
Content available remote Innowacyjna metoda badania paliw stałych jako sposób na bezpieczne i zrównoważone wykorzystanie węgli koksowych
Dreger Marcin, Celary Piotr
Przemysł Chemiczny
|
2024
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T. 103, nr 2
307--310
PL
Opracowano nowy model obliczeniowy określający niebezpieczeństwa związane z procesem koksowania (koksowanie bezpieczne, koksowanie ryzykowane oraz koksowanie niebezpieczne), oparty na badaniach uwzględniających wilgotność, zawartość popiołu, siarki i części lotnych, rozszerzalność, dylatację, skurcz, objętość oraz wskaźniki wytrzymałości koksu po reakcji (CSR) i umiarkowany wskaźnik reaktywności koksu (CRI).
EN
A new computational model detg. the danger of the coking process (safe coking, risky coking, and dangerous coking) was developed considering humidity, ash and S contents, volatile matter content, dilatation, contraction, volume as well as indicators of coke strength after reaction and coke reactivity. The coking coal classifier was recommended for energy and coking plants sectors to improve the coal quality control, decrease wear of the coke plant chambers and protect the environment.
2
Content available Wpływ zawartości części lotnych na właściwości sorpcyjne węgli kamiennych w kontekście zagrożenia wyrzutami gazów i skał
Dreger Marcin
Przegląd Geologiczny
|
2024
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Vol. 72, nr 1
46--52
EN
The classification of gas and rock outburst hazard based on the volatile content of coalis assessed. The complexity of gas and geodynamic hazards, and of the geological and mining conditions of the Upper Silesian Coal Basin, make it difficult to effectively assess the gas androck outburst. Safe mining operations in coal seams prone to outbursts should be based on specified analyses of gas, geological and mining conditions, and consider the coal characteristics, including the volatile content and sorption properties. An original method for determining the adsorption isotherm is described: it allows for more precise determination of methane pressure, and of the possibility of gas accumulation at higher pressures. A coal classification is developed based on the volatile content(Vdaf) in relation to the possibility of a gas-geodynamic phenomenon.
3
Content available The outburst probability index (Ww) as a new tool in the coal seam outburst hazard forecasting
Dreger Marcin, Celary Piotr
Journal of Sustainable Mining
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2024
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Vol. 23, iss. 1
55--60
EN
Gas and rock outbursts are one of the most unpredictable natural hazards in Polish and worldwide underground mining. The complexity and unpredictability of this phenomenon make forecasting and underground prevention difficult to achieve. Gas-geodynamic phenomenon occurs in greater intensity in the southern part of the Upper Silesian Coal Basin (USCB) - close to the Bzie-Czechowice fault zone. The relatively low firmness of coal combined with high methane content and pressure may result in a coal seam outburst. To forecast the gas and rock outburst occurrence, the sorption capacity and gas diffusion parameters are used in Polish coal mining. To provide a new, more direct and helpful tool for outburst hazard occurrence interpretation - an outburst probability index (Ww) has been developed in the CLP-B Laboratory. The components of the simple formula are: methane content, firmness of coal, desorption intensity, effective diffusion coefficient and methane sorption capacity. The four numerical ranges are provided to define the probability of the coal seam outburst occurrence. The new method proposed by the CLP-B Laboratory simplifies the outburst hazard prediction and can be used successfully in the coal mines to foresee the forthcoming danger. The result of the outburst probability index reflects changes in each component, which makes it adequate in long-term outburst research in the new drifting roadways.
4
Content available Time variability of methane extraction from hard coal deposits in the Upper Silesian Coal Basin (Poland) in relation to geological and mining conditions
Kędzior Sławomir, Dreger Marcin
Journal of Sustainable Mining
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2023
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Vol. 22. iss. 2
89--99
EN
The extraction and economical use of methane from coal mines in the Upper Silesian Coal Basin, Poland (USCB) have shown a variable tendency in recent decades, with numerous fluctuations from year to year. In 2021, approximately 286 million m3 of methane was collected from coal mines, which accounted for approximately 40% of the total emissions of this gas to mine workings. Due to the fact that the economical use of coal mine methane brings environmental, economic and work safety benefits, increasing its extraction is an urgent need. Trends in changes in the amount of mined methane in the entire USCB and in the deposits where the most methane was extracted in the last 25 years were analysed. The most important potential factors influencing the variability of coal mine gas extraction were taken into account, i.e. elements of the geological structure, coal extraction, methane emissions, mining and technical conditions, etc. The directions for using the collected methane and the main consumers were discussed. The aim is to indicate the most important problems faced by coal mining in terms of the capture and management of methane over the last 25 years and to outline possible solutions.
5
Content available Methane emissions and hard coal production in the Upper Silesian Coal Basin in relation to the greenhouse effect increase in Poland in 1994-2018
Dreger Marcin
Mining Science
|
2021
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Vol. 28
59--77
EN
The Upper Silesian Coal Basin (USCB) is the largest coal basin in Poland and one of the largest in Europe. It is the most industrialised region in the country. The main natural source of energy is hard coal, which was produced by 65 mines in the early nineties. The USCB geology is very diverse and not homogeneous. Coal deposits situated in the central, southern, and western regions are mostly covered by impermeable Miocene deposits, which helped methane (CH4) to accumulate in the past. Methane is one of the most dangerous natural hazards in Polish underground mining because it is an explosive gas. CH4is also the second strongest greenhouse gas after carbon dioxide, but its radiative power is 20–25 times stronger than the radiative power of CO2. Polish coal mines release 470 thousand Mg (average) of CH4 yearly and it contributes to the greenhouse effect increase. Year after year, Upper Silesian coal mines are going to extract hard coal from deeper seams where the methane content in coal seams is much higher. To keep workers safe, CH4 needs to be captured and released to the open-air atmosphere or used in the power and heat production.
6
Content available remote Effect of applied stress increments of the secondary deformation modulus and the ratio between the secondary and primary moduli of sandy gravel and crushed aggregate in static plate load tests
Kraszewski Cezary, Rafalski Leszek, Ćwiąkała Michał, Dreger Marcin
Roads and Bridges - Drogi i Mosty
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2020
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Vol. 19, no. 4
283--296
EN
The static plate load test is widely used in transport engineering, primarily for determining the bearing capacity of the subgrade and the structural layers. It is also used for assessing the compaction of soil and aggregates on the basis of the ratio between the secondary and primary moduli. The results of the authors' own tests, presented in this article, are preceded by an analysis of the static plate load test methods used in different countries and interpretation of the results obtained from them. The data obtained in the static plate load tests of sandy gravel and crushed aggregate blanket layers were analysed in order to determine the effect of the applied stress increment of the secondary deformation modulus and the ratio of moduli. Strong linear relationships were established between the secondary moduli obtained for the stress increment ranges of 0.10 MPa and 0.15 MPa for both materials. It was established that application of different stress increment ranges in the static plate test of sandy gravel and crushed aggregate had no significant effect on the ratio between secondary and primary deformation moduli. Conversely, different stress increment values had a marked effect on the secondary modulus of deformation.
PL
Badanie VSS jest w inżynierii komunikacyjnej metodą stosowaną powszechnie, głównie do pomiaru nośności podłoża i warstw konstrukcyjnych. Badanie to wykorzystuje się również do oceny zagęszczenia gruntów i kruszyw na podstawie oceny stosunku wtórnego modułu odkształcenia do pierwotnego modułu odkształcenia, oznaczonego jako wskaźnik odkształcenia. Wyniki badań własnych przedstawione w niniejszym artykule poprzedzono analizą stosowanych metod badań podłoża płytą VSS w różnych krajach oraz interpretacją wyników tych badań. W celu ustalenia, jak zakres naprężeń wpływa na wartość wtórnego modułu odkształcenia oraz wskaźnika odkształcenia przeprowadzono analizę wyników badań płytą VSS nośności warstw ochronnych wykonanych z pospółki i kruszywa łamanego. Stwierdzono, że w przypadku obu materiałów istnieją silne zależności liniowe pomiędzy wtórnymi modułami odkształcenia zbadanymi przy zakresach przyrostu naprężenia 0,1 MPa oraz 0,15 MPa. Ustalono, że stosowany różny zakres przyrostu naprężeń w badaniu VSS nie ma istotnego wpływu na wskaźnik odkształcenia pospółki i kruszywa łamanego. Natomiast różny zakres tych naprężeń wpływa na wartość wtórnego modułu odkształcenia.
7
Content available remote Bentonite-loess slurry for construction of diaphragm walls and bored piles
Dreger Marcin, Przygoda Mieczysław, Kraszewski Cezary, Mitrut Muchał, Rafalski Leszek, Wojdal Mariusz
Roads and Bridges - Drogi i Mosty
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2020
|
Vol. 19, no. 2
97--106
EN
Bentonite fluids are used in narrow excavations in technologies of slurry walls and bored piles. If bentonite is characterised by high liquid limit, production of support fluid with sufficiently high density and accompanying low viscosity is impossible. The aim of the presented research was to verify the usefulness of loess for modification of bentonite slurries. Various bentonite-loess mixtures and suspensions activated with sodium carbonate were tested. It was noted that an addition of loess results in a decrease in liquid limit of the bentonite-loess mixture. Testing of suspensions produced from different bentonite-loess mixtures enabled determination of the optimum sodium carbonate content as well as the minimum bentonite-loess mixture content in the suspension ensuring the required density. The influence of loess content on viscosity and water bleed was then investigated, which enabled determination of loess content range at which suspensions with the required density fulfil also the requirements regarding viscosity and bleed. It was ascertained that an addition of loess enables production of bentonite-loess slurries with adequate properties. Based on the presented results, a patent was obtained and production of bentonite-loess mixture for use in technology of slurry walls was initiated.
PL
Zawiesiny bentonitowe wykorzystuje się do wykonywania wykopów wąsko przestrzennych w technologii ścian szczelinowych, a także w technologii pali wierconych. Jeśli bentonit charakteryzuje się dużą granicą płynności, nie jest możliwe wytworzenie zawiesiny o wystarczająco dużej gęstości i małej lepkości. Celem badań było sprawdzenie przydatności lessu do modyfikowania właściwości zawiesin bentonitowych. Wykonano badania kompozycji bentonitowo-lessowych i zawiesin aktywowanych węglanem sodu. Stwierdzono, że dodatek lessu powoduje zmniejszenie granicy płynności kompozycji bentonitowo-lessowej. Badania zawiesin zawierających kompozycje bentonitowo-lessowe pozwoliły na określenie optymalnej zawartości węglanu sodu oraz niezbędnej ilości bentonitu i lessu w zawiesinie zapewniającej wymaganą gęstość. Następnie zbadano zależności pomiędzy zawartością lessu a lepkością umowną i odstojem zawiesin, co pozwoliło na określenie dodatku lessu, przy którym zawiesiny o wymaganej gęstości spełniają kryteria lepkości i odstoju. Stwierdzono, że dodatek lessu umożliwia uzyskiwanie zawiesin bentonitowo-lessowych o odpowiednich właściwościach. Na podstawie przedstawionych wyników badań uzyskano patent i uruchomiono produkcję kompozycji bentonitowo-lessowej do zawiesin przydatnych w technologii ścian szczelinowych.
8
Content available remote Stabilizacja gruntów wapnem palonym w inżynierii komunikacyjnej – teoria i praktyka
Kraszewski Cezary, Dreger Marcin, Mitrut Michał, Przygoda Mieczysław
Inżynieria Morska i Geotechnika
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2020
|
nr 2
82--86
PL
Technologia stabilizacji gruntów wapnem palonym w budownictwie komunikacyjnym z uwzględnieniem najnowszych wymagań normowych oraz katalogów projektowania nawierzchni jak również dotychczasowych doświadczeń. Wymagania, badania i technologia wykonywania robót drogowych z zastosowaniem wapna jako spoiwa.
EN
The technology of soil stabilization with quicklime in road construction taking into account the latest standard requirements and pavement design catalogs as well as previous experience. The requirements, tests and technology of road works using lime as a binder.
9
Content available Changes in the methane emissions and hard coal output in the Brzeszcze mine (the Upper Silesian Coal Basin, Poland)
Dreger Marcin
Geology, Geophysics and Environment
|
2020
|
Vol. 46, no. 2
159--174
EN
The paper presents the variability of methane emissions in mining excavations in the Brzeszcze mine (Poland) against the background of hard coal output, geological and mining factors. The geological structure of the Upper Silesian Coal Basin (USCB) is very diverse. The Brzeszcze coal deposit is located close to the large and permeable Jawiszowice fault which increases the methane hazard during mining activities performed close to this fault. The overall decrease in hard coal output (1988–2018) has coincided with a rapid increase in methane emissions (1997–2018). Throughout the study period, hard coal output decreased threefold from 3.9 to 1.2 million Mg annually. Coal extraction in high methane content beds (e.g. 510, 405/1, 364, 352) increases the total methane (CH4) emission into mining excavations, aggravating the methane hazard due to the high explosiveness of the gas. To protect miners, coal workings need to be continuously ventilated, taking the harmful gas out of the mine (ventilation air methane emission) or methane needs to be captured by underground methane systems (degassing). Every year, over 34 million m3 of CH4 is captured by the drainage systems and over 70 million m3 CH4 (average) is discharged through ventilation shafts into the atmosphere. The presence of the large, permeable regional dislocation, the Jawiszowice fault zone, shaped the methane concentration in the fault vicinity, when the highest methane emissions during coal mining was studied.
10
Content available remote Ocena nośności podłoża i podtorza kolejowego sondą dynamiczną
Kraszewski Cezary, Dreger Marcin, Szpikowski Mirosław, Mitrut Michał, Sobkowicz Piotr
Inżynieria Morska i Geotechnika
|
2019
|
nr 4
182--187
PL
Trudność oceny nośności podłoża i podtorza kolejowego eksploatowanych linii kolejowych z wykorzystaniem tradycyjnej metody obciążeń statycznych VSS, z powodu konieczności zamknięcia toru, rozebrania części podtorza do poziomu podłoża. Klasyczne metody określania nośności podłoża nawierzchni komunikacyjnych oraz nowatorska metodę badania sondą dynamiczną bez konieczności rozbiórki torowiska i przeprowadzane przez podsypkę tłuczniową. Wykorzystanie wyników z sondowań dynamicznych do obliczeń mechanistycznych opartych na modułach sprężystości E lub klasycznych opartych na modułach odkształcenia E2 .
EN
Difficulty in the assessment of the load bearing capacity of the railway subgrade of the railway lines under traffic with the use of the traditional method of static load VSS due to the need to close the traffic, dismantle the part of the track bed to the ground level. An overview of classic methods for determining the load bearing capacity of communication pavements and the innovative dynamic probe test method without dismantling of the track and carried out by crushed stone ballast. The use of the results from dynamic soundings for mechanistic calculations based on elastic moduli E or classic calculations based on static moduli E2 .
11
Content available Methane emissions in selected hard-coal mines of the Upper Silesian Coal Basin in 1997–2016
Dreger Marcin
Geology, Geophysics and Environment
|
2019
|
Vol. 45, no. 2
121--132
EN
Hard coal is extracted in the Upper Silesian Coal Basin (USCB) from deeper and deeper coal seams every year. In 2000, the average depth of coal extraction was 600 m, in 2010 – 700 m, but in the last two years (2016–2017) this has been extended to a depth of 770 m. The USCB is not homogeneous in layout in terms of methane hazard, but rather very diverse. Therefore, the USCB has been divided into seven gassy regions to show differences in methane danger distribution. Northern and central USCB regions (I, II and III) are the mostly naturally degassed, so the most dangerous gassy conditions are in the IV and V regions, where methane content in coal seams varies from 6 m3/Mg coaldafto above 18 m3/Mg coaldaf. The two westernmost USCB gassy regions (VI and VII) are poorer in methane than the IV and V areas. Six representative coal mines were chosen: Mysłowice-Wesoła, Budryk, Brzeszcze, Pniówek, Marcel and Rydułtowy-Anna based on their high hard coal production and total methane emissions. The reason for the highest methane emission in those regions might be fault tectonics facilitating methane migration and also the thick and continuous Miocene cover constituting a hermetic screen for gases in the southern part of the USCB.
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