WorldWideScience

Sample records for brown coal seam

  1. The effect of CO{sub 2} on the geomechanical and permeability behaviour of brown coal: Implications for coal seam CO{sub 2} sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Viete, D.R.; Ranjith, P.G. [Department of Civil Engineering, Building 60, Monash University, Victoria 3800 (Australia)

    2006-03-03

    Theory from fracture mechanics and thermodynamics coupled with the results of experimental studies provides evidence to suggest that the adsorption of carbon dioxide on coal causes a decrease in the coal strength. Coal weakening by the introduction of CO{sub 2} to a coal seam may induce fracturing, causing a permeability increase under in situ conditions. Such effects present significant implications for proposals regarding the storage of CO{sub 2} in coal seams. A uniaxial and triaxial laboratory study was carried out to explore the effects of the adsorption of CO{sub 2} on the compressive strength and permeability of southeast Australian brown coal. Comparison of the stress-strain response of air-saturated and CO{sub 2}-saturated specimens revealed a compressive strength decrease in the order of 13% and an elastic modulus decrease of about 26% for the uniaxial testing, but no significant strength or elastic modulus decrease for the triaxial testing. The absence of an adsorptive effect on the mechanical behaviour of the triaxial specimens may have been due to an insufficient saturation period under simulated ground conditions, or due to mechanical variability in the brown coal test specimens, however, further testing is required to reveal the reason for the apparent negligible strength reduction with CO{sub 2} adsorption at the higher confinement. Carbon dioxide outflow measurements during the stress-strain process demonstrated an initial permeability decrease with pore closure, followed by a significant increase in specimen permeability with fracturing. Issues that require consideration in the application of these results to coal seam CO{sub 2} sequestration include: whether the expected regional and localised in situ stresses are sufficient to initiate fracturing with adsorptive weakening; how coal properties (e.g. rank, moisture content) are likely to affect the geomechanical influence of CO{sub 2} adsorption, and the expected magnitude of the proposed fracture

  2. Geomorphology of coal seam fires

    Science.gov (United States)

    Kuenzer, Claudia; Stracher, Glenn B.

    2012-02-01

    Coal fires occur in underground natural coal seams, in exposed surface seams, and in coal storage or waste piles. The fires ignite through spontaneous combustion or natural or anthropogenic causes. They are reported from China, India, USA, South Africa, Australia, and Russia, as well as many other countries. Coal fires lead to loss of a valuable resource (coal), the emission of greenhouse-relevant and toxic gases, and vegetation deterioration. A dangerous aspect of the fires is the threat to local mines, industries, and settlements through the volume loss underground. Surface collapse in coal fire areas is common. Thus, coal fires are significantly affecting the evolution of the landscape. Based on more than a decade of experience with in situ mapping of coal fire areas worldwide, a general classification system for coal fires is presented. Furthermore, coal seam fire geomorphology is explained in detail. The major landforms associated with, and induced by, these fires are presented. The landforms include manifestations resulting from bedrock surface fracturing, such as fissures, cracks, funnels, vents, and sponges. Further manifestations resulting from surface bedrock subsidence include sinkholes, trenches, depressions, partial surface subsidence, large surface subsidence, and slides. Additional geomorphologic coal fire manifestations include exposed ash layers, pyrometamorphic rocks, and fumarolic minerals. The origin, evolution, and possible future development of these features are explained, and examples from in situ surveys, as well as from high-resolution satellite data analyses, are presented. The geomorphology of coal fires has not been presented in a systematic manner. Knowledge of coal fire geomorphology enables the detection of underground coal fires based on distinct surface manifestations. Furthermore, it allows judgments about the safety of coal fire-affected terrain. Additionally, geomorphologic features are indicators of the burning stage of fires

  3. Is coal seam gas polluting groundwater?

    International Nuclear Information System (INIS)

    Landholders are adamant that coal seam gas is contaminating their groundwater, but natural geological processes make their accusations difficult to prove. Now science is starting to fill in the cracks.

  4. Controlling Effects of Surrounding Rock to Coal Seam Gas Occurrence

    OpenAIRE

    Laibin Wang; Shiwen Zhang; Jinshan Shen; Zhongwen Zhang; Xiaotong Yang

    2013-01-01

    Surrounding rock of coal seam was one of the important factors to gas occurrence. The coal seam gas occurrence was studied by the index of roof strata thickness or sand content rate; we found that there were certain shortcomings. In order to reasonably evaluate the influence of coal seam surrounding rock on gas occurrence in Panji mining area, we quantitatively evaluated the effect of coal seam surrounding rock on gas occurrence by influence coefficient of roof strata thickness, and built si...

  5. Coal seam gas and the atmosphere

    International Nuclear Information System (INIS)

    Specified world coal resources grow with progressing exploration. A present figure would exceed 12Tt. The gases generated by continuing metamorphism of coal continuously penetrate overlying strata to escape into the atmosphere. Mining intercepts some of these gases which mix with return ventilation air, or in part may be conducted or sucked to the surface. In Australia, seam gas drainage is new and less than 20% of underground mined coal has concurrent drainage. The fairly recent contact metamorphism of many Australian coal measures has caused displacement of some of the CH4 by C02, thus reducing the local applicability of seam gas drainage with utilisation based on purity of CH4 and flammability. Both the totals to date of CH4 (2.5Pm3) and CO2(3.3Pm3) produced from coal resources and their annual additions (40Mm3 and 24Mm3 respectively) appear to be quite insignificant in total atmospheric volumes. The gases released annually in return airs are estimated at 37Gm3 of CH4 and 5Gm3 of C02, with an esimtated 3Gm3 of CH4 drained. Seam gas drainage is encouraged, aiming to replace CH4 by CO2 whilst recovering significant energy; even combustion of CH4 in mine return airs is considered, with possible energy and environment benefit. 14 refs., 1 tab., 3 figs

  6. Influences Determining European Coal Seam Gas Deliverability

    Science.gov (United States)

    Clark, G.

    2009-04-01

    Technically the coal basins of Europe have generated significant Gas In Place figures that has historically generated investor's interest in the development of this potential coal seam gas (CSG) resource. In the early 1980's, a wave of international, principally American, companies arrived, established themselves, drilled and then left with a poor record of success and disappointed investors. Recently a second wave of investment started after 2002, with the smaller companies leading the charge but have the lesson been learned from the past failures? To select a CSG investment project the common European approach has been to: 1. Find an old mining region; 2. Look to see if it had a coal mine methane gas problem; 3. Look for the non-mined coal seams; and 4. Peg the land. This method is perhaps the reason why the history of CSG exploration in Europe is such a disappointment as generally the coal mining regions of Europe do not have commercial CSG reservoir attributes. As a result, investors and governments have lost confidence that CSG will be a commercial success in Europe. New European specific principles for the determination of commercial CSG prospects have had to be delineated that allow for the selection of coal basins that have a strong technical case for deliverability. This will result in the return of investor confidence.

  7. Early maturation processes in coal. Part 1: Pyrolysis mass balances and structural evolution of coalified wood from the Morwell Brown Coal seam

    CERN Document Server

    Salmon, Elodie; Lorant, François; Hatcher, Patrick G; Marquaire, Paul-Marie; 10.1016/j.orggeochem.2009.01.004

    2009-01-01

    In this work, we develop a theoretical approach to evaluate maturation process of kerogen-like material, involving molecular dynamic reactive modeling with a reactive force field to simulate the thermal stress. The Morwell coal has been selected to study the thermal evolution of terrestrial organic matter. To achieve this, a structural model is first constructed based on models from the literature and analytical characterization of our samples by modern 1-and 2-D NMR, FTIR, and elemental analysis. Then, artificial maturation of the Morwell coal is performed at low conversions in order to obtain, quantitative and qualitative, detailed evidences of structural evolution of the kerogen upon maturation. The observed chemical changes are a defunctionalization of the carboxyl, carbonyl and methoxy functional groups coupling with an increase of cross linking in the residual mature kerogen. Gaseous and liquids hydrocarbons, essentially CH4, C4H8 and C14+ liquid hydrocarbons, are generated in low amount, merely by clea...

  8. Numerical Simulation Study on the Coal Seam Pulse Water Infusion

    OpenAIRE

    Meng Junqing; Zhao Bi; Ma Yechao

    2014-01-01

    In the process of coal seam pulse water infusion, liquid-solid coupling effect exists in coal seam between the stress field and seepage field. Based on the basic principle of liquid-solid coupling, the dynamic liquid-solid coupling effect of stress and seepage field during coal seam pulse water infusion is simulated through secondary development of ABAQUS software, during this process the mathematical model of the strain accumulation model due to the periodic ...

  9. Coal Seams in the Horna Nitra Valley - the Cigel Mining Are

    International Nuclear Information System (INIS)

    According to the statistics data, coal will become with no doubt the most important energy source in the 21-st century. The Horna Nitra Valley represents one of the main fuels - energy centre of Slovakia. Deposits of caustobioliths - brown coal and lignite present significant raw material potential. The mining companies, along with run-in extraction methods of coal reserves, are giving their time to a research of untraditional coal processing technologies. An in-situ monitoring of coal seams geo-technological properties contributes in a significant way to obtain some complex knowledge on interactions of certain determining factors which influence the coal gases formation underground. (author)

  10. Draft Genome Sequence of Clostridium sp. Maddingley, Isolated from Coal-Seam Gas Formation Water

    OpenAIRE

    Rosewarne, Carly P.; Greenfield, Paul; Li, Dongmei; Tran-Dinh, Nai; Bradbury, Mark I.; Midgley, David J.; Hendry, Philip

    2013-01-01

    Clostridium sp. Maddingley was isolated as an axenic culture from a brown coal-seam formation water sample collected from Victoria, Australia. It lacks the solventogenesis genes found in closely related clostridial strains. Metabolic reconstructions suggest that volatile fatty acids are the main fermentation end products.

  11. Draft Genome Sequence of Clostridium sp. Maddingley, Isolated from Coal-Seam Gas Formation Water.

    Science.gov (United States)

    Rosewarne, Carly P; Greenfield, Paul; Li, Dongmei; Tran-Dinh, Nai; Bradbury, Mark I; Midgley, David J; Hendry, Philip

    2013-01-01

    Clostridium sp. Maddingley was isolated as an axenic culture from a brown coal-seam formation water sample collected from Victoria, Australia. It lacks the solventogenesis genes found in closely related clostridial strains. Metabolic reconstructions suggest that volatile fatty acids are the main fermentation end products. PMID:23405323

  12. On the quantitative determination of coal seam thickness by means of In-Seam Seismic Surveys

    Czech Academy of Sciences Publication Activity Database

    Schott, W.; Waclawik, Petr

    Vol. 5. Ostrava: Ústav geoniky AV ČR, 2014 - (Koníček, P.; Souček, K.; Heroldová, N.). s. 47-48 ISBN 978-80-86407-49-4. [5th International Colloquium on Geomechanics and Geophysics. 24.06.2014-27.06.2014, Ostravice, Karolínka] Institutional support: RVO:68145535 Keywords : In-Seam Seismic (ISS) * coal seam thickness * wave guide * dispersion Subject RIV: DH - Mining, incl. Coal Mining

  13. The geomechanics of gas recovery from coal seams

    Science.gov (United States)

    Klimov, D. M.; Karev, V. I.; Kovalenko, Yu. F.

    2015-05-01

    A new approach for the creation of scientific foundations for effective and environmentally safe recovery of methane from coal seams is proposed. A virgin coal seam possesses very low permeability. Free gas is contained in isolated microscopic pores and cracks of the coal seam under a pressure close to the rock pressure. An oriented system of cracks, which forms a coupled system of filtration channels, can be formed by means of directed unloading of the rock pressure from the seam due to expanding gas energy. The parameters of the manufacturing effect on the seam are determined based on physical modeling of actual mechanical and filtration processes using the experimental installation of truly three-axial loading and mathematical modeling.

  14. Applied on bolting-cable anchor support of full-seam roadway in weaker thick coal seam

    Institute of Scientific and Technical Information of China (English)

    赵庆彪; 张生华; 郭励生

    2003-01-01

    The designing method and the supporting mechanism of both bolt and small cable anchor for full-seam roadway in the weaker thick coal seam are systematically analyzed, and the construction technology and the supporting results are briefly summarized.

  15. New research facility for the coal seam gas industry

    Energy Technology Data Exchange (ETDEWEB)

    Massarotto, P. [University of Queensland, Qld. (Australia). School of Engineering

    2009-10-01

    A new Geo-engineering Centre, for Gas Coal Dynamics, using earth sciences, mining and chemical engineering expertise in coal seam gas, coal bed methane extraction, and geosequestration of greenhouse gases, has been established at the University of QUeensland. The article outlines it mission, capabilities, areas of expertese and facilities and equipment. 3 photos.

  16. High resolution processing of 3D seismic data for thin coal seam in Guqiao coal mine

    Science.gov (United States)

    Li, Qiaoling; Peng, Suping; Zou, Guangui

    2015-04-01

    Accurate identification of small faults for coal seams is very important for coal-field exploration, which can greatly improve mining efficiency and safety. However, coal seams in China are mostly thin layers, ranging from 2-5 m. Moreover, the shallow coal seam with strong reflection forms a shield underneath thin coal seam which is only about 40 m deeper. This causes great difficulty in seismic processing and interpretation. The primary concern is to obtain high-resolution seismic image of underneath thin coal seam for mining safety. In this paper, field data is carefully analyzed and fit-for-purpose solutions are adopted in order to improve the quality of reprocessed data and resolution of target coal seam. Identification of small faults has been enhanced significantly.

  17. Polycyclic aromatic hydrocarbon formation under simulated coal seam pyrolysis conditions

    Institute of Scientific and Technical Information of China (English)

    Liu Shuqin; Wang Yuanyuan; Wang Caihong; Bao Pengcheng; Dang Jinli

    2011-01-01

    Coal seam pyrolysis occurs during coal seam fires and during underground coal gasification.This is an important source of polycyclic aromatic hydrocarbon (PAH) emission in China.Pyrolysis in a coal seam was simulated in a tubular furnace.The 16 US Environmental Protection Agency priority controlled PAHs were analyzed by HPLC.The effects of temperature,heating rate,pyrolysis atmosphere,and coal size were investigated.The results indicate that the 3-ring PAHs AcP and AcPy are the main species in the pyrolysis gas.The 2-ring NaP and the 4-ring Pyr are also of concern.Increasing temperature caused the total PAH yield to go through a minimum.The lowest value was obtained at the temperature of 600 ℃ Higher heating rates promote PAH formation,especially formation of the lower molecular weight PAHs.The typical heating rate in a coal seam,5 ℃/min,results in intermediate yields of PAHs.The total PAHs yield in an atmosphere of N2 is about 1.81 times that seen without added N2,which indicates that an air flow through the coal seam accelerates the formation of PAHs.An increase in coal particle size reduces the total PAHs emission but promotes the formation of 5- and 6-ring PAHs.

  18. On the quantitative determination of coal seam thickness by means of in-seam seismic surveys

    Czech Academy of Sciences Publication Activity Database

    Schott, W.; Waclawik, Petr

    2015-01-01

    Roč. 52, č. 10 (2015), s. 1496-1504. ISSN 0008-3674. [International Colloquium on Geomechanics and Geophysics /5./. Karolinka, 25.06.2014-27.06.2014] R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support: RVO:68145535 Keywords : in-seam seismic (ISS) * ISS wave * Love wave * coal seam thickness * dispersion Subject RIV: DH - Mining , incl. Coal Mining Impact factor: 1.332, year: 2014 http://www.nrcresearchpress.com/doi/full/10.1139/cgj-2014-0466#.VgqE1Zc70mt

  19. Morphogenetic classification of coal seam washouts in Donbass mines

    Energy Technology Data Exchange (ETDEWEB)

    Shul' ga, V.F.; Vashchenko, V.I.

    1982-09-01

    The paper evaluates washout types in coal seams in Donbass mines. Five washout types are characterized: trough-shaped, V-shaped or U-shaped, lentil-shaped, consisting of groups of small lentils and discontinuous washouts which consist of a number of coal and rock partings. Each of the 5 washout types is shown in a scheme. The following aspects of coal seam washouts are discussed: dimensions, shape, angle of inclination of trough walls, washout dimensions in relation to coal seam thickness, rock types filling washout zones. Effects of seam washouts on longwall mining are analyzed. Morphogenetic characteristics of 5 washout groups are given. Investigations show that trough-shaped, U or V-shaped washouts are of epigenetic origin and lentil-shaped, discontinuous washouts consisting of a number of rock and coal partings and washouts with groups of rock lentils are of syngenetic origin. Washout classification is shown in a table. Classification is aimed at optimizing the mining system in washout zones. It considers washout dimensions, washout dimensions in relation to coal seam thickness and rock type filling the washout (sandstone, agrillite or aleurite). System for coding information on washouts is described.

  20. Theory of gas extraction from coal seams and its use

    Institute of Scientific and Technical Information of China (English)

    FAN Xi-sheng

    2012-01-01

    Gas extraction is one of the main measures of control and use of gas of coal mines.At present,the design method is under the experimental period and do not satisfy the need of practice.In this paper,the theory of gas extraction of coal seams based upon Darcy law was studied.Mathematical model of gas extraction of coal seams was established and two kinds of solving approaches based on computer software and linear approximation were given.The rightness and the validities of the model were examined with a practical example.Results obtained can be used to determine and optimize the parameters related etc.

  1. Impacts of Coal Seam Gas (Coal Bed Methane) and Coal Mining on Water Resources in Australia

    Science.gov (United States)

    Post, D. A.

    2013-12-01

    Mining of coal bed methane deposits (termed ';coal seam gas' in Australia) is a rapidly growing source of natural gas in Australia. Indeed, expansion of the industry is occurring so quickly that in some cases, legislation is struggling to keep up with this expansion. Perhaps because of this, community concern about the impacts of coal seam gas development is very strong. Responding to these concerns, the Australian Government has recently established an Independent Expert Scientific Committee (IESC) to provide advice to the Commonwealth and state regulators on potential water-related impacts of coal seam gas and large coal mining developments. In order to provide the underlying science to the IESC, a program of ';bioregional assessments' has been implemented. One aim of these bioregional assessments is to improve our understanding of the connectivity between the impacts of coal seam gas extraction and groundwater aquifers, as well as their connection to surface water. A bioregional assessment can be defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion, with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are now being carried out across large portions of eastern Australia which are underlain by coal reserves. This presentation will provide an overview of the issues related to the impacts of coal seam gas and coal mining on water resources in Australia. The methodology of undertaking bioregional assessments will be described, and the application of this methodology to six priority bioregions in eastern Australia will be detailed. Preliminary results of the program of research to date will be assessed in light of the requirements of the IESC to provide independent advice to the Commonwealth and State governments. Finally, parallels between the expansion of the industry in Australia with that

  2. Distribution of Heavy Hydrocarbon in Coal Seams and Its Use in Predicting Outburst of Coal

    Institute of Scientific and Technical Information of China (English)

    蒋承林; 李增华; 韩颖

    2003-01-01

    In order to verify whether any special gas component exists in outburst samples or not, coal samples from both outburst coal seams and non-outburst coal seams were collected. Some gases were extracted from the samples and analyzed qualitatively and quantitatively on chromatogram-mass spectrograph. The qualitative analysis show that there is no special gases in coal seams. And the quantitative analysis indicates that the heavy hydrocarbon content in coal samples from outburst coal seams is apparently higher than that from non-outburst district ones, which reflects the damage of geological tectonic movement to coal body in history. Therefore, the heavy hydrocarbon content of coal sample can be used as an index to predict coal outburst.

  3. Coal seam methane distribution and its significance in Pingdingshan mining area

    Institute of Scientific and Technical Information of China (English)

    郭德勇; 周心权; 沈少川; 张晓萍

    2002-01-01

    A study aimed at the coal seam group E and F in Pingdingshan mining area has been completed. This study is on the relationship of the coal-seam methane reserve to coal thickness, coal rank, coal seam depth, surrounding rock and geological structure and other factors. The study indicates that different geological factor plays different role in controlling the law of coal-seam methane reserve. The coal-seam methane rich area, which was formed because of various factors and comprehensive effect, is the coal and methane outburst-prone area, and also the key area for coal-bed methane recovery. Among all factors, coal seam depth and geological structure is more important factor in affecting coal-seam methane content in Pingdingshan mining area.

  4. Brown coal and the climate

    International Nuclear Information System (INIS)

    The undisputed aims of a sensible energy policy are safety, reasonable prices, environmental compatibility and saving resources. Each energy source and every form of energy conversion and use has specific advantages and disadvantages which must be weighed up. It is in favour of brown coal that it can succeed in international competition and therefore offers security of supply, economy, productivity and employment. The mining and use of brown coal comply with the highest environmental standards, in international comparison. Against this, mining brown coal by strip mining inevitably involves intervention in the environment and the social structure of the coalfield. Burning brown coal to generate electricity in powerstations is specifically connected with high CO2 emission. (orig.)

  5. Coal seam methane as a natural gas supply

    International Nuclear Information System (INIS)

    An explosive hazard for coalminers, coalbed or coal seam methane will be extracted from large coal fields in Queensland and piped to major industries. Transfield and Tri-Star Petroleum consider the Bowen Basin coal/gas field to contain approximately 4PJ/km2 or up to 16,000PJ, which represent 20% of Australia's known natural gas reserves: enough to supply Queensland, at current consumption rates, for 400 years

  6. Gray Comprehensive Evaluation Method on Coal Seam Water Injection in Order of Difficulty

    OpenAIRE

    Liu Xiao Li; Zhang Zhi Ye; Li Meng Qian

    2016-01-01

    In order to evaluate the coal mine water injection accurately, the gray comprehensive evaluation is applied in this paper, the depth of coal seam, the development degree of coal seam crack, porosity, gas pressure in coal seam, wetting edge of coal, firmness coefficient of coal are chosen as the main index to evaluate the method of water injection into coal mine. The results show that the gray comprehensive evaluation model has a relatively high reliability and accuracy, which can be used to p...

  7. Research on drawing coal effects in the dipping and steep--dipping coal seams

    Institute of Scientific and Technical Information of China (English)

    胡伟; 王窈惠

    2002-01-01

    Controllable drawing roof coal mining method is applied either to rently inclined seam or to big dipping seam. This paper sums up four corresponding methods according to conditions of our country, and analyses the coal-recovering effects and proves applicated conditions and measures for improving by "drawing coal theory of the ellipsoid". Its conclusion basically consists with practice. This work is of guiding meaning for designing drawing coal technology.

  8. Palaeoenvironmental reconstruction of Hüsamlar coal seam, SW Turkey

    Indian Academy of Sciences (India)

    Zeynep Büçkün; HüLya İnaner; Riza Görkem Oskay; Kimon Christanis

    2015-06-01

    The Ören and Yatağan Basins in SW Turkey host several Miocene coal deposits currently under exploitation for power generation. The present study aims to provide insight into the palaeoenvironmental conditions, which controlled the formation of the Hüsamlar coal seam located in Ören Basin. The coal seam displays many sharp alternations of matrix lignite beds and inorganic, lacustrine sediment layers. The coal is a medium-to-high ash lignite (10.47–31.16 wt%, on dry basis) with high total sulphur content (up to 10 wt%, on dry, ash-free basis), which makes it prone to self-combustion. The maceral composition indicates that the peat-forming vegetation consisted of both arboreal and herbaceous plants, with the latter being predominant in the upper part of the seam. Mica and feldspars contribute to the low part of the seam; carbonates are dominant in the upper part, whereas quartz and pyrite are present along the entire coal profile. The sudden transitions of the telmatic to the lacustrine regime and reverse is attributed to tectonic movements that controlled water table levels in the palaeomire, which affected surface runoff and hence, clastic deposition.

  9. Palaeoenvironmental reconstruction of Hüsamlar coal seam, SW Turkey

    Science.gov (United States)

    Büçkün, Zeynep; İnaner, Hülya; Oskay, Riza Görkem; Christanis, Kimon

    2015-06-01

    The Ören and Yatağan Basins in SW Turkey host several Miocene coal deposits currently under exploitation for power generation. The present study aims to provide insight into the palaeoenvironmental conditions, which controlled the formation of the Hüsamlar coal seam located in Ören Basin. The coal seam displays many sharp alternations of matrix lignite beds and inorganic, lacustrine sediment layers. The coal is a medium-to-high ash lignite (10.47-31.16 wt%, on dry basis) with high total sulphur content (up to 10 wt%, on dry, ash-free basis), which makes it prone to self-combustion. The maceral composition indicates that the peat-forming vegetation consisted of both arboreal and herbaceous plants, with the latter being predominant in the upper part of the seam. Mica and feldspars contribute to the low part of the seam; carbonates are dominant in the upper part, whereas quartz and pyrite are present along the entire coal profile. The sudden transitions of the telmatic to the lacustrine regime and reverse is attributed to tectonic movements that controlled water table levels in the palaeomire, which affected surface runoff and hence, clastic deposition.

  10. 18 CFR 270.302 - Occluded natural gas produced from coal seams.

    Science.gov (United States)

    2010-04-01

    ... produced from coal seams. 270.302 Section 270.302 Conservation of Power and Water Resources FEDERAL ENERGY... produced from coal seams. A person seeking a determination that natural gas is occluded natural gas produced from coal seams must file an application with the jurisdictional agency which contains...

  11. Legal aspects connected with methane recovery from coal seams

    International Nuclear Information System (INIS)

    There are several companies in Germany vesting interest in the recovery of methane from coal seams, this process not to form part of the coal mining activities on site, thus not forming part of the mining operation plan. The provisions of the mining law are such that there is room for integrating technological progress not foreseeable at the time of legislation, so that the Mining Act offers framework conditions which are able to cover such activities as the independent methane recovery. Coal mining companies see the chance of starting a new type of business and combine it into an enlarged range of products covering methane, coal, and minerals. (orig./HSCH)

  12. Feasibility of an Integrated Thin Seam Coal Mining and Waste Disposal System

    OpenAIRE

    Basu, Kohinoor

    1997-01-01

    The depletion of more attractive thicker and easily accessible coal seams in the central Appalachia will direct attention towards the extraction of coal seams thinner than 28 in. This thesis investigates the feasibility of an integrated mining and backfilling system applicable to thin seams. Two conceptual mining systems, namely Auger mining and Self Advancing Miner, have been proposed for this purpose. Both these systems are designed to remotely mine coal from the seams. Several ...

  13. CO2 Sequestration in Unmineable Coal Seams: Potential Environmental Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Hedges, S.W.; Soong, Yee; McCarthy Jones, J.R.; Harrison, D.K.; Irdi, G.A.; Frommell, E.A.; Dilmore, R.M.; Pique, P.J.; Brown, T.D

    2005-09-01

    An initial investigation into the potential environmental impacts of CO2 sequestration in unmineable coal seams has been conducted, focusing on changes in the produced water during enhanced coalbed methane (ECBM) production using a CO2 injection process (CO2-ECBM). Two coals have been used in this study, the medium volatile bituminous Upper Freeport coal (APCS 1) of the Argonne Premium Coal Samples series, and an as-mined Pittsburgh #8 coal, which is a high volatile bituminous coal. Coal samples were reacted with either synthetic produced water or field collected produced water and gaseous carbon dioxide at 40 οC and 50 bar to evaluate the potential for mobilizing toxic metals during CO2-ECBM/sequestration. Microscopic and x-ray diffraction analysis of the post-reaction coal samples clearly show evidence of chemical reaction, and chemical analysis of the produced water shows substantial changes in composition. These results suggest that changes to the produced water chemistry and the potential for mobilizing toxic trace elements from coalbeds are important factors to be considered when evaluating deep, unmineable coal seams for CO2 sequestration.

  14. THE UTILIZATION TECHNOLOGIES OF METHANE PRODUCED FROM UNDERGRAUND COAL SEAMS

    OpenAIRE

    Gökhan AYDIN; Karakurt, İzzet

    2009-01-01

    A few coal mines use coalbed methane recovered from coal seams. As well as being unable to use gas means waste of an economically valuable source, it contributes to global warming. Gases recovered from coal mines can be used for various applications as an alternative source to natural gas or such as generation of power related to methane concentration. In cases the sale and/or use of gas would not be profitable, the best way for decreasing gas emissions is to destroy methane via flaring. In t...

  15. Deep coal seams as a greener energy source: a review

    International Nuclear Information System (INIS)

    Today, coal and oil are the main energy sources used in the world. However, these sources will last for only a few decades. Hence, the investigation of possible energy sources to meet this crisis has become a crucial task. Coal bed methane (CBM) is a potential energy source which can be used to fulfil the energy demand. Since the amount of carbon dioxide (CO2) emitted to the atmosphere from the use of CBM is comparatively very low compared to conventional energy sources, it is also a potential mitigation option for global warming. This paper reviews CBM recovery techniques with particular emphasis on CO2-enhanced coal bed methane (CO2-ECBM) recovery. The paper reviews (1) conventional CBM recovery techniques and problems associated with them, (2) CBM production-enhancement methods, including hydro-fracturing and enhanced CBM recovery techniques, such as N2-ECBM and CO2-ECBM, (3) the importance of the CO2-ECBM technique compared to other methods and problems with it, (4) the effect of CO2 injection during the CO2-ECBM process on coal seam permeability and strength and (5) current CO2-ECBM field projects and their progress. Although conventional CBM recovery methods are simple (basically related to the drawdown of the reservoir pressure to release methane from it), they are inefficient for the recovery of a commercially viable amount of methane from coal seams. Therefore, to enhance methane production, several methods are used, such as hydro-fracturing and ECBM (N2-ECBM and CO2-ECBM). The CO2-ECBM process has a number of advantages compared to other methane recovery techniques, as it contributes to the mitigation of the atmospheric CO2 level, is safer and more economical. However, as a result of CO2 injection into the coal seam during the CO2-ECBM process, coal mass permeability and strength may be crucially changed, due to the coal matrix swelling associated with CO2 adsorption into the coal matrix. Both injecting CO2 properties (gas type, CO2 phase and pressure

  16. Deep coal seams as a greener energy source: a review

    Science.gov (United States)

    Ranathunga, A. S.; Perera, M. S. A.; Ranjith, P. G.

    2014-12-01

    Today, coal and oil are the main energy sources used in the world. However, these sources will last for only a few decades. Hence, the investigation of possible energy sources to meet this crisis has become a crucial task. Coal bed methane (CBM) is a potential energy source which can be used to fulfil the energy demand. Since the amount of carbon dioxide (CO2) emitted to the atmosphere from the use of CBM is comparatively very low compared to conventional energy sources, it is also a potential mitigation option for global warming. This paper reviews CBM recovery techniques with particular emphasis on CO2-enhanced coal bed methane (CO2-ECBM) recovery. The paper reviews (1) conventional CBM recovery techniques and problems associated with them, (2) CBM production-enhancement methods, including hydro-fracturing and enhanced CBM recovery techniques, such as N2-ECBM and CO2-ECBM, (3) the importance of the CO2-ECBM technique compared to other methods and problems with it, (4) the effect of CO2 injection during the CO2-ECBM process on coal seam permeability and strength and (5) current CO2-ECBM field projects and their progress. Although conventional CBM recovery methods are simple (basically related to the drawdown of the reservoir pressure to release methane from it), they are inefficient for the recovery of a commercially viable amount of methane from coal seams. Therefore, to enhance methane production, several methods are used, such as hydro-fracturing and ECBM (N2-ECBM and CO2-ECBM). The CO2-ECBM process has a number of advantages compared to other methane recovery techniques, as it contributes to the mitigation of the atmospheric CO2 level, is safer and more economical. However, as a result of CO2 injection into the coal seam during the CO2-ECBM process, coal mass permeability and strength may be crucially changed, due to the coal matrix swelling associated with CO2 adsorption into the coal matrix. Both injecting CO2 properties (gas type, CO2 phase and pressure

  17. Stochastic reservoir simulation for the modeling of uncertainty in coal seam degasification

    Science.gov (United States)

    Karacan, C. Özgen; Olea, Ricardo A.

    2015-01-01

    Coal seam degasification improves coal mine safety by reducing the gas content of coal seams and also by generating added value as an energy source. Coal seam reservoir simulation is one of the most effective ways to help with these two main objectives. As in all modeling and simulation studies, how the reservoir is defined and whether observed productions can be predicted are important considerations.

  18. Geological processes that control lateral and vertical variability in coal seam moisture contents-Latrobe Valley (Gippsland Basin) Australia

    International Nuclear Information System (INIS)

    A study throughout the Latrobe Valley coal measures of coal moisture distribution using downhole bore data and 3D digital models of large bore data sets indicates lateral and vertical moisture variability is controlled by a number of factors. These include burial, type of overburden, age of the seam, marine influence, coal lithotype and lateral compression on folds and monoclines. The same rules appear to apply to the adjacent Alberton coal measures in the south Gippsland Basin, suggesting these factors may be widespread in other brown coal basins where moisture contents are still equilibrating through differential compaction. In Gippsland average moisture down seam decreases by 1-2% per seam and at a rate of approximately 1% every 20 m. Weight average moisture content for each seam decreases on average at a rate of 0.5% every 1 million years. A stepwise decrease in moisture content between the ∼100 m thick major seams of 1-7% reflects large intervals of time are represented by the relatively thinner (1-10 m thick) interseam sediments. Compression by monoclinal folding can decrease moisture contents up to 7%. For any given depth, moisture content appears higher on anticlines due to a lowered intensity of compression than in adjacent synclines. It is considered likely that coals folded over anticlines are more fractured, thereby containing greater amounts of free water. Use of the lower moisture coals and monoclinal coals may be preferable for future power station developments. Despite an increase in overburden/coal ratios, there would be significant savings in a lowered coal volume to calorific value, and a consequent reduction in greenhouse gas emission

  19. STUDY ON THE RELATIONSHIP BETWEEN THE DIVERSITY COAL MASS STRUCTURE AND LITHOTYPE OF COAL IN MULTI-COAL SEAM MINE

    Institute of Scientific and Technical Information of China (English)

    吴基文; 赵志根; 陈资平

    1999-01-01

    Through site observation and indoor measurements in XieJiaji No.2 Coal Mine in Huainen and Luling Coal Mine in Huaibei, it is discovered that the fragmentation degree are different in different coal seams in same mining district and even in sublevels of the same coal seam, the coal mass structures exist much difference. By analyzing the relationship between the constitution of coal matters and the epigenesis breakage of coal. This paper points out that the internal factor which causes the diversity of the coal mass structure comes from the diversity in the contents of telocollinite and desmocollinite in the vitrinite. The contenet of desmocollinite is higher than that of telocollinite in intact coal seam (sublevel) but the former is less than the later in breaking sublevel, the diversity of constituent content more affects the epigenetic fragmentation degree of coal seam. The content of desrnocollinite proves lower than that of telocollinite in the broken coal seam. The new understanding has directing, and reference for the study of coal petrology, coal mine gas geology and coal methane.

  20. Variation in gas drainage rate from a coal seam during mining

    Institute of Scientific and Technical Information of China (English)

    Li; Gang; Qi; Qingxin; Li; Hongyan; Fan; Xisheng

    2012-01-01

    Gas flow patterns during draining of gas from a coal seam during mining are discussed.The coal seam is treated as a dual medium with both pores and cracks.The seepage,diffusion,and desorption processes are treated using a gas flow equation that describes flow around drill holes.MATLAB is used to solve the differential equations.The permeability tracer test results from a mined coal seam are used to study the variation in gas drainage from a coal seam during mining.The results show that mining can increase the permeability of a coal seam,which then increases the gas drainage.There are inflection points in this variation over time.A close relationship between this variation and the rate of change in coal seam permeability is observed.

  1. Gray Comprehensive Evaluation Method on Coal Seam Water Injection in Order of Difficulty

    Directory of Open Access Journals (Sweden)

    Liu Xiao Li

    2016-01-01

    Full Text Available In order to evaluate the coal mine water injection accurately, the gray comprehensive evaluation is applied in this paper, the depth of coal seam, the development degree of coal seam crack, porosity, gas pressure in coal seam, wetting edge of coal, firmness coefficient of coal are chosen as the main index to evaluate the method of water injection into coal mine. The results show that the gray comprehensive evaluation model has a relatively high reliability and accuracy, which can be used to predict the difficulty degree of water injection.

  2. In-mine geoelectric investigations for detecting tectonic disturbances in coal seam structures

    Science.gov (United States)

    Gyulai, Ákos; Dobróka, Mihály; Ormos, Tamás; Turai, Endre; Sasvári, Tibor

    2013-10-01

    The methods of in-mine seam-sounding and transillumination (geoelectric tomography) for the detection of tectonic disturbances of coal seams were developed by the Department of Geophysics of the University of Miskolc in the 1970-80's with the effective support of the former "Borsod" Coal Mines Ltd. The paper gives an overview about the theory of seam-sounding and a special geoelectric tomographic inversion, and introduces the in-mine geoelectric seam-sounding and transillumination measurement systems using vertical electrode dipoles. In the second part the paper, the results of an in-mine geoelectric measurement are presented, which was carried out in order to detect tectonic disturbances of the Miocene aged coal seams situated in Slovakia. As results of the geophysical investigation, the authors forecasted the tectonic features in the coal seam. The company confirmed the results by independent information about seam disturbances and tectonic features arising from the excavation of the investigated area.

  3. Evaluation of coal bed methane potential of coal seams of Sawang Colliery, Jharkhand, India

    Indian Academy of Sciences (India)

    Anil M Pophare; Vinod A Mendhe; A Varade

    2008-04-01

    The coal seams of Sawang Colliery, East Bokaro Coalfields are bituminous to sub-bituminous in nature and categorized as high gaseous seams (degree II to degree III level). These seams have the potential for coal bed methane (CBM) and their maturity increases with increasing depth, as a result of enhanced pressure-temperature conditions in the underground. The vitrinite maceral group composition of the investigated coal seams ranges from 62.50-83.15%, whereas the inertinite content varies from 14.93-36.81%. The liptinite content varies from 0.66% to 3.09%. The maximum micro-pores are confined within the vitrinite group of macerals. The coal seams exhibit vitrinite reflectance values (Ro% calculated) from 0.94% (sample CG-97) to 1.21% (sample CG-119). Proximate analyses of the investigated coal samples reveal that the moisture content (M%) ranges from 1.28% to 2.98%, whereas, volatile matter (VM%) content is placed in the range of 27.01% to 33.86%. The ash content (A%) ranges from 10.92% to 30.01%. Fixed carbon (FC%) content varies from 41.53% to 55.93%. Fuel ratio variation shows a restricted range from 1.53 to 1.97. All the coal samples were found to be strongly caking and forming coke buttons. The present study is based on the adsorption isotherm experiments carried out under controlled P-T conditions for determination of actual gas adsorption capacity of the coal seams. This analysis shows that the maximum methane gas adsorbed in the coal sample CG-81 is 17m3/t (Std. daf), at maximum pressure of 5.92MPa and experimental temperature of 30°C. The calculated Langmuir regression parameters PL and VL range from 2.49 to 3.75MPa and 22.94 to 26.88m3/t (Std. daf), respectively.

  4. Nitrogen Injection To Flush Coal Seam Gas Out Of Coal: An Experimental Study

    Science.gov (United States)

    Zhang, Lei; Aziz, Naj; Ren, Ting; Nemcik, Jan; Tu, Shihao

    2015-12-01

    Several mines operating in the Bulli seam of the Sydney Basin in NSW, Australia are experiencing difficulties in reducing gas content within the available drainage lead time in various sections of the coal deposit. Increased density of drainage boreholes has proven to be ineffective, particularly in sections of the coal seam rich in CO2. Plus with the increasing worldwide concern on green house gas reduction and clean energy utilisation, significant attention is paid to develop a more practical and economical method of enhancing the gas recovery from coal seams. A technology based on N2 injection was proposed to flush the Coal Seam Gas (CSG) out of coal and enhance the gas drainage process. In this study, laboratory tests on CO2 and CH4 gas recovery from coal by N2 injection are described and results show that N2 flushing has a significant impact on the CO2 and CH4 desorption and removal from coal. During the flushing stage, it was found that N2 flushing plays a more effective role in reducing adsorbed CH4 than CO2. Comparatively, during the desorption stage, the study shows gas desorption after N2 flushing plays a more effective role in reducing adsorbed CO2 than CH4.

  5. Application of Seismic Anisotropy Caused by Fissures in Coal Seams to the Detection of Coal-bed Methane Reservoirs

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Coal-bed methane is accumulated in micro-fissures and cracks in coal seams. The coal seam is the source terrace and reservoir bed of the coal-bed methane (Qian et al., 1996). Anisotropy of coal seams is caused by the existence of fissures. Based on the theory of S wave splitting: an S wave will be divided into two S waves with nearly orthogonal polarization directions when passing through anisotropic media, i.e. the fast S wave with its direction of propagation parallel to that of the fissure and slow S wave with the direction of propagation perpendicular to that of the fissure.This paper gives the results of laboratory research and field test on the S wave splitting caused by coal-seam fissures. The results show that it is feasible to detect fissures in coal seams by applying the converted S wave and finally gives the development zone and development direction of these fissures.

  6. A penetrative addictive for water infusion in coal seams

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The manufacturing process, characteristics, and application results of a rod-like penetrative additive (the penetrative rod)were discussed. The components and functions of the penetrative rod were studied carefully. A large number of orthogonal combinedtests were carried out and over 100 sample molds were made. Ultimately the components were decided after careful selection amongthese molds, mainly including hygroscopic major components and auxiliary material. The results of on-site practical applicationshow that such an addictive can increase the water penetrative ability effectively and has a remarkable effect on preventing dust pro-duction during coal seam excavation. The penetrating radius, the infusing velocity and the dust-preventive effect were systematicallystudied.

  7. Influence of Mining Thickness on the Rationality of Upward Mining in Coal Seam Group

    Directory of Open Access Journals (Sweden)

    Y. Li

    2016-04-01

    Full Text Available This study aimed to determine the influence of mining thickness on the rationality of upward mining in coal seam group. Numerical simulation and theoretical analysis were performed to investigate the influence of the mining thicknesses of initial mining seam on the destruction and pressure relief effect of the upper coal seam in a high-gas coal seam group. The mechanical model of the roof failure based on the mining thickness was established by assuming that the gob formed after adjacent panels have fully been caved is the infinite plane. On the basis of this model, an equation was derived to calculate the roof failure height of the panel. Considering the geological conditions of No. 9 and No. 12 coal seams of Zhaogezhuang Coal Mine, economic effectiveness, and proposed techniques, we concluded that the top layer (4 m of the No. 12 coal seam should be mined first. The top layer of the No. 9 coal seam should be subsequently mined. The topcaving technique was applied to the exploitation of the lower layer of the No. 12 coal seam. Practically monitored data revealed that the deformation and failure of the No. 2699 panel roadway was small and controllable, the amount of gas emission was reduced significantly, and the effect of upward mining was active. The results of this study provide theory basics for mine designing, and it is the provision of a reference for safe and efficient coal exploitation under similar conditions.

  8. Pressure relief, gas drainage and deformation effects on an overlying coal seam induced by drilling an extra-thin protective coal seam

    Institute of Scientific and Technical Information of China (English)

    LIU Hai-bo; CHENG Yuan-ping; SONG Jian-cheng; SHANG Zheng-jie; WANG Liang

    2009-01-01

    Numerical simulations and field tests were used to investigate the changes in ground stress and deformation of, and gas flow from, a protected coal seam under which an extra-thin coal seam was drilled. The geological conditions were: 0.5 meter min-ing height, 18.5 meter coal seam spacing and a hard limestone/fine sandstone inter-stratum. For these conditions we conclude: 1) the overlying coal-rock mass bends and sinks without the appearance of a caving zone, and 2) the protected coal seam is in the bending zone and undergoes expansion deformation in the stress-relaxed area. The deformation was 12 mm and the relative defor-mation was 0.15%. As mining proceeds, deformation in the protected layer begins as compression, then becomes a rapid expansion and, finally, reaches a stable value. A large number of bed separation crannies are created in the stress-relaxed area and the perme-ability coefficient of the coal seam was increased 403 fold. Grid penetration boreholes were evenly drilled toward the protected coal seam to affect pressure relief and gas drainage. This made the gas pressure decrease from 0.75 to 0.15 Mpa, the gas content de-crease from 13 to 4.66 m3/t and the gas drainage reach 64%.

  9. Thermal effects of magmatic sills on coal seam metamorphism and gas occurrence

    Science.gov (United States)

    Wang, Liang; Cheng, Long-biao; Cheng, Yuan-ping; Yin, Guang-zhi; Cai, Chun-cheng; Xu, Chao; Jin, Kan

    2014-04-01

    Igneous intrusions in coal seams are found in 80 % of coal mines in the Huaibei coalfield, China, and coal and gas outburst accidents have occurred 11 times under a 120-m-thick sill in the Haizi mining field. The magma's heat had a significant controlling effect on coal seam gas occurrence. Based on theoretical analysis, experimental tests and site validation, we analyzed the temperature distribution following magma intrusion into coal measure strata and the variations in multiple physical parameters and adsorption/desorption characteristics between the underlying coal seams beneath the sill in the Haizi mining field and coal seams uninfluenced by magma intrusion in the adjacent Linhuan mining field. The research results show that the main factors controlling the temperature distribution of the magma and surrounding rocks in the cooling process include the cooling time and the thickness and initial temperature of the magmatic rock. As the distance from sill increases, the critical effective temperature and the duration of sustained high temperatures decrease. The sill in the Haizi mining field significantly promoted coal seam secondary hydrocarbon generation in the thermally affected area, which generated approximately 340 m3/t of hydrocarbon. In the magma-affected area, the metamorphic grade, micropore volume, amount of gas adsorption, initial speed of gas desorption, and amount of desorption all increase. Fluid entrapment by sills usually causes the gas pressure and gas content of the underlying coal seams to increase. As a result, the outburst risks from coal seams increases as well.

  10. Permeability Prediction in Deep Coal Seam: A Case Study on the No. 3 Coal Seam of the Southern Qinshui Basin in China

    OpenAIRE

    Pinkun Guo; Yuanping Cheng

    2013-01-01

    The coal permeability is an important parameter in mine methane control and coal bed methane (CBM) exploitation, which determines the practicability of methane extraction. Permeability prediction in deep coal seam plays a significant role in evaluating the practicability of CBM exploitation. The coal permeability depends on the coal fractures controlled by strata stress, gas pressure, and strata temperature which change with depth. The effect of the strata stress, gas pressure, and strata tem...

  11. Impacts of Coal Seam Gas (Coal Bed Methane) Extraction on Water Resources in Australia

    Science.gov (United States)

    Post, David

    2016-04-01

    While extraction of methane from shale gas deposits has been the principal source of the recent expansion of the industry in the United States and Europe, in Australia extraction of methane from coal bed methane deposits (termed 'coal seam gas' in Australia) has been the focus to date. The two sources of methane share many of the same characteristics including the potential requirement for hydraulic fracturing. However, as coal seam gas deposits generally occur at shallower depths than shale gas, the potential impacts of extraction on surface and groundwater resources may be of even greater concern. In Australia, an Independent Expert Scientific Committee (IESC) has been established to provide scientific advice to federal and state government regulators on the impact that coal seam gas and large coal mining developments may have on water resources. This advice is provided to enable decisions to be informed by the best available science about the potential water-related impacts associated with these developments. To support this advice, the Australian Government Department of the Environment has implemented a programme of research termed 'bioregional assessments' to investigate these potential impacts. A bioregional assessment is defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are currently being carried out across large portions of eastern Australia underlain by coal reserves. Further details of the programme and results to date can be found at http://www.bioregionalassessments.gov.au. Surface water and groundwater modelling is now complete for two regions where coal seam gas development may proceed, namely the Clarence-Moreton and Gloucester regions in eastern New South Wales. This presentation will discuss how the results of these

  12. Impacts of Coal Seam Gas (Coal Bed Methane) Extraction on Water Resources in Australia

    Science.gov (United States)

    Post, David

    2015-04-01

    While extraction of methane from shale gas deposits has been the principal source of the recent expansion of the industry in the United States and Europe, in Australia extraction of methane from coal bed methane deposits (termed 'coal seam gas' in Australia) has been the focus to date. The two sources of methane share many of the same characteristics including the potential requirement for hydraulic fracturing. However as coal seam gas deposits generally occur at shallower depths than shale gas the potential impacts of extraction and hydraulic fracturing on surface and groundwater resources may be of even greater concern for coal seam gas than for shale gas. In Australia an Independent Expert Scientific Committee (IESC) has been established to provide scientific advice to federal and state government regulators on the impact that coal seam gas and large coal mining developments may have on water resources. This advice is provided to enable decisions to be informed by the best available science about the potential water-related impacts associated with these developments. To support this advice the Australian Government Department of the Environment has implemented a three-year programme of research termed 'bioregional assessments' to investigate these potential impacts. A bioregional assessment is defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are currently being carried out across large portions of eastern Australia underlain by coal reserves. Further details of the program and results to date can be found at http://www.bioregionalassessments.gov.au. In this presentation the methodology for undertaking bioregional assessments will be described and the application of this methodology to six priority bioregions in eastern Australia

  13. The division of coal species in seams by the digital logs in Juye coalfield

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Z. [Shandong Coal Geologic Engineering Surveying Institute, Jinan (China)

    1997-12-31

    The division of coal species is based generally on the sampling and analysis. For coal seams with complex texture and higher degree of metamorphism, the qualitative division of coal species is more complex. Using the geophysical characters of coal seams reflected by logging data, combined with the data obtained from the geological description of cores, coal-petrologic identification and coal quality analysis and so on, the better effects are obtained in the comprehensive qualitative classification of coal species. 2 refs., 5 figs., 2 tabs.

  14. Mathematical modeling for coupled solid elastic-deformation and gas leak flow in multi-coal-seams

    Institute of Scientific and Technical Information of China (English)

    孙培德

    2002-01-01

    Based on the new viewpoint of solid and gas interaction mechanics, gas leakage in a double deformable coal seam can be understood. That is, under the action of geophysical fields, the methane flow in a double deformable coal seam can be essentially considered to be compressible with time-dependent and mixed permeation and diffusion through a pore-cleat deformable heterogeneous and anisotropy medium. Based on this new viewpoint, a coupled mathematical model for coal seam deformation and gas leakage in a double coal seam was formulated and numerical simulations for gas emission from the coal seam are presented. It is found that coupled models might be closer to reality.

  15. Study on dragline-bulldozer operation with variations in coal seam thickness

    Energy Technology Data Exchange (ETDEWEB)

    Wei Zhou; Qing-xiang Cai; Shu-zhao Chen [China University of Mining & Technology, Xuzhou (China). School of Mining and Safety Engineering

    2007-09-15

    The dragline is one of the most promising surface mining machines in China. This paper studies the interaction between the working bench advancing speed and the stripping volume with variation in coal seam thickness. Adjusting the bulldozing volume (depth) and/or changing the dragline bench height are proposed as means to ensure a smooth and economical mining operation. When the coal seam is getting thicker it is recommended to reduce the bulldozing volume (depth) for a higher dragline efficiency. When the coal seam is getting thinner it is recommended to increase the bulldozing volume (depth) to ensure the dragline can work at the proper bench height. 7 refs., 1 tab.

  16. Combined ANN prediction model for failure depth of coal seam floors

    Institute of Scientific and Technical Information of China (English)

    WANG Lian-guo; ZHANG Zhi-kang; LU Yin-long; YANG Hong-bo; YANG Sheng-qiang; SUN Jian; ZHANG Jin-yao

    2009-01-01

    Failure depth of coal seam floors is one of the important considerations that must be kept in mind when mining is carried out above a confined aquifer. In order to study the factors that affect the failure depth of coal seam floors such as mining depth, coal seam pitch, mining thickness, workface length and faults, we propose a combined artificial neural networks (ANN) prediction model for failure depth of coal seam floors on the basis of existing engineering data by using genetic algorithms to train the ANN. A practical engineering application at the Taoyuan Coal Mine indicates that this method can effectively determine the network struc-ture and training parameters, with the predicted results agreeing with practical measurements. Therefore, this method can be applied to relevant engineering projects with satisfactory results.

  17. Behaviors of overlying strata in extra-thick coal seams using top-coal caving method

    Directory of Open Access Journals (Sweden)

    Bin Yu

    2016-04-01

    Full Text Available Accidents such as support failure and excessive deformation of roadways due to drastic changes in strata behaviors are frequently reported when mining the extra-thick coal seams Nos. 3–5 in Datong coal mine with top-coal caving method, which significantly hampers the mine's normal production. To understand the mechanism of strata failure, this paper presented a structure evolution model with respect to strata behaviors. Then the behaviors of strata overlying the extra-thick coal seams were studied with the combined method of theoretical analysis, physical simulation, and field measurement. The results show that the key strata, which are usually thick-hard strata, play an important role in overlying movement and may influence the mining-induced strata behaviors in the working face using top-coal caving method. The structural model of far-field key strata presents a “masonry beam” type structure when “horizontal O-X” breakage type happens. The rotational motion of the block imposed radial compressive stress on the surrounding rock mass of the roadway. This can induce excessive deformation of roadway near the goaf. Besides, this paper proposed a pre-control technology for the hard roof based on fracture holes and underground roof pre-splitting. It could effectively reduce stress concentration and release the accumulated energy of the strata, when mining underground coal resources with top-coal caving method.

  18. Assessment of the Influence of Fractures on the Dynamics of Coal Seam Fires by Numerical Experiments

    Science.gov (United States)

    Wuttke, Manfred W.; Zeng, Qiang

    2016-04-01

    Uncontrolled burning coal seam fires still constitute major problems for the coal industry by destroying the resource, a serious hazard for the local people by severe environmental pollution, and a tremendous threat to the global environment by the emission of greenhouse gases and aerosols. In particular when the seams are lying shallow the alteration of the immediate surrounding of the coal seam fire feeds back on the dynamics of the fire. Thermal stress induced fracturing produces direct connections of the fire zone with the atmosphere. This influences the supply with oxygen, the venting of the exhaust gases, and the dissipation of heat. The first two processes are expected to enhance the fire propagation whereas the latter effect should slow it down. With our dedicated coal seam fire code ACME ("Amendable Coal-fire Modeling Exercise") we study these coupled effects of fractures in simulations of typical coal seam fire scenarios based on data from Xinjiang, China. Fractures are predefined as 1D/2D objects in a 2D/3D model geometry and are opened depending on the passage of the heat wave produced by the coal seam fire.

  19. Maceral and geochemical characteristics of coal seam 1 and oil shale 1 in fault-controlled Huangxian Basin, China

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Y.Z.; Wang, B.S.; Lin, M.Y. [University of Petroleum, Beijing (China)

    1998-12-31

    Seven samples of coal seam 1 and oil shale 1 from the fault-controlled Hangxiang Basin were analysed by coal petrographic and geochemical methods. High huminite ratios and high contents of sesquiterpenoids and diterpenoids indicate that coal seam 1 and oil shale 1 are predominantly composed of terrestrial higher plant material. Two ternary diagrams of `facies diagnostic` macerals and biomarkers were used to interpret the depositional environments of organic matter in coal seam 1 and oil shale 1.

  20. Schemes for development and mining of level coal seams without leaving support coal pillars

    Energy Technology Data Exchange (ETDEWEB)

    Bakhtin, A.F.; Batmanov, Yu.K.; Taratuta, N.K.

    1982-07-01

    Methods are illustrated for longwall mining without leaving support pillars for strata control. Comparative evaluations in Soviet coal mines show that with increasing mining depth coal losses associated with support pillars increase. Use of support pillars also increases rock burst hazard and increases cost of support repairs in mine roadways. Proportion of coal from longwall mining without leaving coal support pillars increased from 36 % in 1976 to 52% in 1980. Two variants of longwall mining without support pillars are analyzed: with repeated use of longwall gate roads and without their repeated use. Comparative investigations show that longwall mining with the repeated use of the gates (one of the gate roads) is used in coal seams with the most convenient mining and geological conditions, whereas the second system is used under more difficult conditions. Schemes with repeated use are designed for thin coal seams, at a depth not exceeding 600 m, under conditions of stable roof and floor (when the floor consists of less stable rocks absence of water influx is the condition). Repeated use of gate roads is economical when, in spite of repeated gate road use, cost of support repair and maintenance is low. Fifteen schemes for longwall mining with and without repeated use of gateroads are compared. The results of evaluations are shown in a table. Recommendations on the most economical mining schemes are made.

  1. Ground Penetrating Radar Signal Processing Algorithm in Advance Detection of Coal Seam

    OpenAIRE

    Wang Shuqi; Wang Zhen

    2013-01-01

    According to the electromagnetic propagation characteristics of Ground Penetrating Radar (GPR) in the medium, how to identify the target in coal seam using the relative permittivity of the dielectric object is studied, the identification algorithm of dielectric object based on electromagnetic echo field intensity with propagation loss and reflection loss are analyzed. The simulation results show that coal seam attenuation coefficient has extremely weak infl...

  2. Numerical investigation of coal seam gas detection using airborne electromagnetics

    Science.gov (United States)

    Abdulla, Mohamed

    The use of airborne electromagnetic (AEM) techniques has been mostly utilized in the mining industry. The various AEM systems enable fast data acquisition to detect zones of interest in exploration and in some cases are used to delineate targets on a production scale. For coal seam gas (CSG) reservoirs, reservoir thickness and the resistivity contrast present a new challenge to the present AEM systems in terms of detectability. Our research question began with the idea of using AEM methods in the detection of thin reservoirs. CSG reservoirs resemble thin reservoirs that have been and are currently being produced. In this thesis we present the results of a feasibility analysis of AEM study on coal seam reservoirs using synthetic models. The aim of the study is to contribute and bridge the gap of the scientific literature on AEM systems in settings such as CSG exploration. In the models we have chosen to simulate both in 1-D and 3-D, the CSG target resistivity was varied from a resistive to a conductive target (4 ohm.m, 150 ohm.m, and 667 ohm.m) to compare the different responses while the target thickness was fixed to resemble a stack of coal seams at that interval. Due to the differences in 1-D and 3-D modelling, we also examine the differences resulting from each modelling set up. The results of the 1-D forward modeling served as a first order understanding of the detection depths by AEM for CSG reservoirs. Three CSG reservoir horizontally layered earth model scenarios were examined, half-space, conductive/resistive and resistive/conductive. The response behavior for each of the three scenarios differs with the differing target resistivities. The 1-D modeling in both the halfspace and conductive/resistive models shows detection at depths beyond 300 m for three cases of target resistivity outlined above. After the 300-m depth, the response falls below the assumed noise floor level of 5% response difference. However, when a resistive layer overlies a conductive host

  3. Annual Change Detection by ASTER TIR Data and an Estimation of the Annual Coal Loss and CO2 Emission from Coal Seams Spontaneous Combustion

    OpenAIRE

    Xiaomin Du; Suping Peng; Haiyan Wang; Sergio Bernardes; Guang Yang; Zhipeng Li

    2014-01-01

    Coal fires, including both underground and coal waste pile fires, result in large losses of coal resources and emit considerable amounts of greenhouse gases. To estimate the annual intensity of greenhouse gas emissions and the loss of coal resources, estimating the annual loss from fire-influenced coal seams is a feasible approach. This study assumes that the primary cause of coal volume loss is subsurface coal seam fires. The main calculation process is divided into three modules: (1) Coal f...

  4. Mining a coal seam below a heating goaf with a force auxiliary ventilation system at Longhua underground coal mine, China

    Institute of Scientific and Technical Information of China (English)

    Wang Gang; Xie Jun; Xue Sheng; Wang Haiyang

    2015-01-01

    Extraction of a coal seam which lies not far below a heating goaf can be a major safety challenge. A force auxiliary ventilation system was adopted as a control method in successful extraction and recovery of the panel 30110 of the #3?1 coal seam, which is about 30–40 m below the heating goaf of the #2?2 seam at Longhua underground coal mine, Shanxi Province, China. Booster fans and ventilation control devices such as doors and regulators were used in the system. The results show that, provided that a force auxiliary ventilation system is properly designed to achieve a pressure balance between a panel and its overlying goaf, the system can be used to extract a coal seam overlain by a heating goaf. This paper describes the design, installation and performance of the ventilation system during the extraction and recovery phases of the panel 30110.

  5. Reduction of emissions by storing CO2 in coal seams - The EU's RECOPOL project

    International Nuclear Information System (INIS)

    This article describes and discusses the first European field-tests on the long-term storage of carbon dioxide (CO2) in unminable coal seams. The project, which is being realised in the Upper Silesian coal-mining area near the city of Katowice in Poland, is described. The RECOPOL (Reduction of CO2 emissions by storing CO2 in coal seams in the Silesian Coal Basin in Poland) project is being funded by the European Union and is to investigate the technical and economical feasibility of this form of carbon sequestration under the geological and infrastructural conditions to be found in Central Europe

  6. Permeability variation characteristics of coal after injecting carbon dioxide into a coal seam

    Institute of Scientific and Technical Information of China (English)

    Ni Xiaoming; Li Quanzhong; Wang Yanbin; Gao Shasha

    2015-01-01

    A theoretical basis for the optimization of carbon dioxide injection parameters and the development of the drainage system can be provided by identifying the permeability change characteristic of coal and rock after injection of carbon dioxide into the coal seam. Sihe, Yuwu, and Changcun mines were used as research sites. Scanning electron microscopy and permeability instruments were used to measure coal properties such as permeability and surface structure of the coal samples at different pH values of carbon dioxide solution and over different timescales. The results show that the reaction between minerals in coal and carbonate solution exhibit positive and negative aspects of permeability-the dissolution reaction between carbonate minerals in coal and acid solution improves the conductivity of coal whilst, on the other hand, the clay minerals in the coal (mainly including montmorillonite, illite and kaolinite) exhibit expansion as a result of ion exchange with the H+in acid solution, which has a negative effect on the per-meability of the coal. The permeability of coal samples increased at first and then decreased with immer-sion time, and when the soaking time is 2–3 months the permeability of the coal reached a maximum. In general, for coals with permeabilities less than 0.2 mD or greater than 2 mD, the effect on the permeabil-ity is low;when the permeability of the coal is in the range 0.2–2 mD, the effect on the permeability is highest. Research into permeability change characteristics can provide a theoretical basis for carbon diox-ide injection under different reservoir permeability conditions and subsequent drainage.

  7. Experimental Study on the Feasibility of Methane Drainage in Coal Seams with Compound Technique of Perforating and Fracturing

    Institute of Scientific and Technical Information of China (English)

    Luo Yong; Shen Zhaowu

    2007-01-01

    Compound technique of perforating and fracturing can effectively control the perforating direction and the fracturing expansion. The feasibility of this technique used in fracturing coal seams is analyzed. In this paper, the experiments of perforating and fracturing are carried out on samples of coal and the experimental effects are satisfactory. Compound technique of perforating and fracturing is promising in coal seams.

  8. Mechanism of Rock Burst Occurrence in Specially Thick Coal Seam with Rock Parting

    Science.gov (United States)

    Wang, Jian-chao; Jiang, Fu-xing; Meng, Xiang-jun; Wang, Xu-you; Zhu, Si-tao; Feng, Yu

    2016-05-01

    Specially thick coal seam with complex construction, such as rock parting and alternative soft and hard coal, is called specially thick coal seam with rock parting (STCSRP), which easily leads to rock burst during mining. Based on the stress distribution of rock parting zone, this study investigated the mechanism, engineering discriminant conditions, prevention methods, and risk evaluation method of rock burst occurrence in STCSRP through setting up a mechanical model. The main conclusions of this study are as follows. (1) When the mining face moves closer to the rock parting zone, the original non-uniform stress of the rock parting zone and the advancing stress of the mining face are combined to intensify gradually the shearing action of coal near the mining face. When the shearing action reaches a certain degree, rock burst easily occurs near the mining face. (2) Rock burst occurrence in STCSRP is positively associated with mining depth, advancing stress concentration factor of the mining face, thickness of rock parting, bursting liability of coal, thickness ratio of rock parting to coal seam, and difference of elastic modulus between rock parting and coal, whereas negatively associated with shear strength. (3) Technologies of large-diameter drilling, coal seam water injection, and deep hole blasting can reduce advancing stress concentration factor, thickness of rock parting, and difference of elastic modulus between rock parting and coal to lower the risk of rock burst in STCSRP. (4) The research result was applied to evaluate and control the risk of rock burst occurrence in STCSRP.

  9. Permeability prediction in deep coal seam: a case study on the No. 3 coal seam of the Southern Qinshui Basin in China.

    Science.gov (United States)

    Guo, Pinkun; Cheng, Yuanping

    2013-01-01

    The coal permeability is an important parameter in mine methane control and coal bed methane (CBM) exploitation, which determines the practicability of methane extraction. Permeability prediction in deep coal seam plays a significant role in evaluating the practicability of CBM exploitation. The coal permeability depends on the coal fractures controlled by strata stress, gas pressure, and strata temperature which change with depth. The effect of the strata stress, gas pressure, and strata temperature on the coal (the coal matrix and fracture) under triaxial stress and strain conditions was studied. Then we got the change of coal porosity with strata stress, gas pressure, and strata temperature and established a coal permeability model under tri-axial stress and strain conditions. The permeability of the No. 3 coal seam of the Southern Qinshui Basin in China was predicted, which is consistent with that tested in the field. The effect of the sorption swelling on porosity (permeability) firstly increases rapidly and then slowly with the increase of depth. However, the effect of thermal expansion and effective stress compression on porosity (permeability) increases linearly with the increase of depth. The most effective way to improve the permeability in exploiting CBM or extracting methane is to reduce the effective stress. PMID:24396293

  10. Hydraulic support stability control of fully mechanized top coal caving face with steep coal seams based on instable critical angle

    Institute of Scientific and Technical Information of China (English)

    TO Shi-hao; YUAN Yong; LI Nai-liang; DOU Feng-jin; WANG Fang-tian

    2008-01-01

    Analyzed the support instable mode of sliding, tripping, and so on, and believedthe key point of the support stability control of fully mechanized coal caving face with steepcoal seams was to maintain that the seam true angle was less than the hydraulic supportinstability critical angle. Through the layout of oblique face, the improvement of supportsetting load, the control of mining height and nonskid platform, the group support systemof end face, the advance optimization of conveyor and support, and the other control tech-nical measures, the true angle of the seam is reduced and the instable critical angle of thesupport is increased, the hydraulic support stability of fully mechanized coal caving facewith steep coal seams is effectively controlled.

  11. A method of determining the permeability coefficient of coal seam based on the permeability of loaded coal

    Institute of Scientific and Technical Information of China (English)

    Li Bo; Wei Jianping; Wang Kai; Li Peng; Wang Ke

    2014-01-01

    This study developed the equipment for thermo-fluid-solid coupling of methane-containing coal, and investigated the seepage character of loaded coal under different working conditions. Regarding the effective pressure as a variable, the variation characteristics of the gas permeability of loaded meth-ane-containing coal has been studied under the conditions of different confining pressures and pore pres-sures. The qualitative and quantitative relationship between effective stress and permeability of loaded methane-containing coal has been established, considering the adsorption of deformation, amount of pore gas compression and temperature variation. The results show that the permeability of coal samples decreases along with the increasing effective stress. Based on the Darcy law, the correlation equation between the effective stress and permeability coefficient of coal seam has been established by combining the permeability coefficient of loaded coal and effective stress. On the basis of experimental data, this equation is used for calculation, and the results are in accordance with the measured gas permeability coefficient of coal seam. In conclusion, this method can be accurate and convenient to determine the gas permeability coefficient of coal seam, and provide evidence for forecasting that of the deep coal seam.

  12. Numerical simulation and damage analysis of fissure field evolution law in a single coal seam mining

    Institute of Scientific and Technical Information of China (English)

    Feng Gao; Xingguang Liu; Chaofeng Ge; Hongmei Cheng

    2012-01-01

    Based on the different deformation and failure laws of coal and rock materials under tensile or compressive loads,the damage variable was defined to divide three phases from the damage and rupture point of view in order to reveal the fissured field evolution characteristics and spatial distribution of coal and rock in the single coal seam mining with low permeability and rich methane.According to the corresponding damage constitutive equations,the secondary development of the finite element program was completed.The fissures field evolution law of a coal mine with single coal seam mining was calculated and analyzed by this new program and the distribution areas and failure degree of the surrounding coal and rock structures with damage,fissure or rupture are given on the condition of mining.This paper provides a scientific basis for quantitative research and evaluation of the safe simultaneous production of coal and gas.

  13. Test studies of gas flow in rock and coal surrounding a mined coal seam

    Institute of Scientific and Technical Information of China (English)

    Lv Youchang

    2012-01-01

    An analysis of the variation rule of abutment pressure at the mining working face in a single coal seam and the mechanical behavior of surrounding rock during stoping is presented.Consideration of the elastic and plastic deformation zones that develop during the mining process allowed the determination of a relationship between horizontal stress and vertical stress.Based on this,a confined pressure unloading test was conducted by the use of the "gas-containing coal thermo-fluid-solid coupling 3-axis servo seepage" experimental apparatus.Thus,gas flow patterns in the elastic and plastic zones were derived from an experimental point of view.Darcy's law and the Klinkenberg effect were used to derive a gas flow equation for the elastic and plastic stress fields.The study of gas flow phenomena at the working face during coal mining is of great importance for the study of gas migration and enrichment oatterns.

  14. Decrease of desorption intensity of methane due to hydraulic fracturing of coal seam

    Czech Academy of Sciences Publication Activity Database

    Weishauptová, Zuzana; Medek, Jiří; Němec, Jaroslav

    Brisbane : Australian Journal of Mining, 1998 - (Golding, S.). s. 39 [International Conference on Coal Seam Gas and Oil. 23.03.1998-25.03.1998, Brisbane] R&D Projects: GA ČR GA105/94/1371 Subject RIV: DH - Mining, incl. Coal Mining

  15. The role of spatial variability in coal seam parameters on gas outburst behaviour during coal mining

    Energy Technology Data Exchange (ETDEWEB)

    Wold, M.B.; Connell, L.D.; Choi, S.K. (CSIRO Petroleum, Ian Wark Laboratory, Bayview Avenue, Clayton, Victoria, 3168 Australia)

    2008-06-13

    Gas outburst is recognized as a potentially fatal hazard to be managed during the mining of gassy coal seams. Gas outbursts in Australian coal mines have been associated with the presence of geological structures in the coal and surrounding rocks, having a range of spatial scales from millimetres to metres. The contributing mechanisms are influenced by coal gas reservoir variables including gas composition, fluid pressure, desorption pressure and rate, porosity, intrinsic permeability and relative permeability. They are also influenced by geomechanical variables such as strength, in situ stress and mining-induced stress. The work described here concerns the influence of variability of permeability and strength on outburst behaviour. Key coal properties are characterised for a field site in an operational underground coal mine and then used in a series of hypothetical simulations of outburst initiation. At the field site an array of horizontal holes was cored in-seam. Well tests for permeability and stress were performed in the holes and recovered core was tested in the laboratory for permeability, strength and sorption properties. For permeability and strength sufficient numbers of measurements were obtained to describe these properties statistically assuming that the measurements are uncorrelated spatially. Analysis of the cumulative probability distributions of the field and laboratory permeability data shows a strong size effect that cannot be linearly up-scaled. Using Monte Carlo techniques, these statistical descriptions are used to generate realisations of property values across the model grid used in the simulation analyses. The stochastic model approach demonstrates that the variability of the permeability and strength fields can lead to both outburst and non-outburst outcomes from the same measured input data, depending on the corresponding spatial distribution of permeability and strength at the face. These results suggest the potential application of

  16. Fuzzy Evaluation of Coal Seam Geological Condition of Fully-Mechanized Face in Ten-Million-Ton Mine

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Based on coal seam geological condition and mining technological characteristic in Jisan Mine, coal seam geological condition is quantitative evaluated by using fuzzy evaluation with the view of coal mining and coalface production. The structure and index system of evaluation factor, the membership functions and weights of evaluation factor, evaluation model and reliability in the coal seam geological conditions are expounded in detail. Eighty-two coalfaces which will be exploited is classified. All of these have provided a theoretical foundation for the selection of coal mining technology and for sustainable development of the coal mine.

  17. Study on improving the permeability of soft coal seam with high pressure pulsed water jet

    Energy Technology Data Exchange (ETDEWEB)

    Xiao-Hong Li; Yi-Yu Lu; Yu Zhao; Yong Kang; Dong-Ping Zhou [Chongqing University (China)

    2008-12-15

    A new idea of improving the permeability of soft coal seams and increasing the rate of gas release by drilling and splitting the coal seam is presented. Based on the rock dynamic damage model, the dynamic damage properties and the fracture field's dynamic evolution mechanism were studied by theoretical analyses and numerical simulation of the condition of instantaneous dynamic load and flexible impact of a high pressure pulsed water jet. The results show that the effect of the impact, denudation and vibration caused coal to crack and improved permeability. A pulsed water jet gas drainage system has been developed and applied successfully in a typical mine rich in gas and of low permeability in Chongqing. The application demonstrates the high pressure pulsed water jet has effectively improved seam permeability with the drainage flux amounting to 7.8 times per 100 m of drainage hole. 8 refs., 6 figs.

  18. Geomechanics of subsidence above single and multi-seam coal mining

    Directory of Open Access Journals (Sweden)

    A.M. Suchowerska Iwanec

    2016-06-01

    Full Text Available Accurate prediction of surface subsidence due to the extraction of underground coal seams is a significant challenge in geotechnical engineering. This task is further compounded by the growing trend for coal to be extracted from seams either above or below previously extracted coal seams, a practice known as multi-seam mining. In order to accurately predict the subsidence above single and multi-seam longwall panels using numerical methods, constitutive laws need to appropriately represent the mechanical behaviour of coal measure strata. The choice of the most appropriate model is not always straightforward. This paper compares predictions of surface subsidence obtained using the finite element method, considering a range of well-known constitutive models. The results show that more sophisticated and numerically taxing constitutive laws do not necessarily lead to more accurate predictions of subsidence when compared to field measurements. The advantages and limitations of using each particular constitutive law are discussed. A comparison of the numerical predictions and field measurements of surface subsidence is also provided.

  19. Adult Education and Radical Habitus in an Environmental Campaign: Learning in the Coal Seam Gas Protests in Australia

    Science.gov (United States)

    Ollis, Tracey; Hamel-Green, Michael

    2015-01-01

    This paper examines the adult learning dimensions of protestors as they participate in a campaign to stop coal seam gas exploration in Gippsland in Central Victoria, Australia. On a global level, the imposition of coal seam gas exploration by governments and mining companies has been the trigger for movements of resistance from environmental…

  20. IMPROVING METHODS OF MODELING CANAL WAVES PROPAGATION PROCESS IN COAL SEAMS

    Directory of Open Access Journals (Sweden)

    SMIRNOV YU.M.

    2012-01-01

    Full Text Available There has been analyzed the principal methods of modeling the process of canal waves propagation in coal seams when carrying out mining geophysical studies. There has been established that the wave guide moving into the surface of the elastic half-space doesn’t practically change the main properties of the interferential waves propagating in them. There has been recommended to use Fourier integral describing the single pulse spectrum for studying the registered seismograms. There have been formulated the main problems of improving physical processes modeling in coal seams when carrying out their geological studying

  1. Technical and economic aspects of brown coal gasification and liquefaction

    International Nuclear Information System (INIS)

    A number of gasification and liquefaction processes for Rhenish brown coal are investigated along with the technical and economic aspects of coal beneficiation. The status of coal beneficiation and the major R + D activities are reviewed. (orig.)

  2. Dynamic effects of high-pressure pulsed water jet in low-permeability coal seams

    Energy Technology Data Exchange (ETDEWEB)

    Li, X.; Zhou, D.; Lu, Y.; Kang, Y.; Zhao, Y.; Wang, X. [Chongqing University, Chongqing (China)

    2009-09-15

    Mine gas extraction in China is difficult due to the as micro-porosity, low-permeability and high adsorption of coal seams. The pulsed mechanism of a high-pressure pulsed water jet was studied through theoretical analysis, experiment and field measurement. The results show that high-pressure pulsed water jet has three dynamic properties. The three dynamic effects can be found in low-permeability coal seams. A new pulsed water jet with 200-1000 Hz oscillation frequency and peak pressure 2.5 times than average pressure was introduced. During bubble collapsing, sound vibration and instantaneous high pressures over 100 MPa enhanced the cutting ability of the high-pressure jet. Through high-pressure pulsed water jet drilling and slotting, the exposure area of coal bodies was greatly enlarged and pressure of the coal seams rapidly decreased. Therefore, the permeability of coal seams was improved and gas absorption rate also decreased. Application results show that gas adsorption rate decreased by 30-40% and the penetrability coefficient increased 100 times. This proves that high-pressure pulsed water is more efficient than other conventional methods. 11 refs., 5 figs., 2 tabs.

  3. Forward Modeling of Azimuthal Anisotropy to the Reflected P Wave of Coal Seam

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun-gong; DONG Shou-hua; YUE Jian-hua

    2006-01-01

    Under the condition of weak anisotropy, the relation of P-wave anisotropy in direction to fractures of coal seams was researched in order to forecast the density and the direction of the fractures. Although the approximate solution by Rüger is suitable for thick reservoirs, it has some limitations for the composite reflected wave from both roofs and floors of coal seams, as well as multiple reflections. So first, the phase velocity and group velocity as well as their travel time were calculated about the reflected P-wave of the coal seam. Then, the anisotropic coefficients of both roofs and floors were calculated by Rüger formulae and last, the section versus azimuth in fixed offset can be gotten by convolution. In addition, the relation of amplitude of the composite reflected wave to azimuth angle was discussed. The forward modelling results of the coal azimuth anisotropy show these: 1) the coal seam is the strong reflecting layer, but the change of the reflectivity caused by the azimuth anisotropy is smaller; 2) if the azimuth angle is parallel to the crack strike, the reflectivity reaches up to the maximum absolute value, however, if the azimuth angle is perpendicular to the crack strike, the absolute value of the reflection coefficient is minimum; and 3)the reflection coefficient is the cosine function of the azimuth angle and the period is π.

  4. Dynamic effects of high-pressure pulsed water jet in low-permeability coal seams

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-hong; ZHOU Dong-ping; LU Yi-yu; KANG Yong; ZHAO Yu; WANG Xiao-chuan

    2009-01-01

    Mine gas extraction in China is difficult due to the characteristics such as mi-cro-porosity, low-permeability and high adsorption of coal seams. The pulsed mechanism of a high-pressure pulsed water jet was studied through theoretical analysis, experiment and field measurement. The results show that high-pressure pulsed water jet has three dynamic properties. What's more, the three dynamic effects can be found in low-perme-ability coal seams. A new pulsed water jet with 200-1 000 Hz oscillation frequency and peak pressure 2.5 times than average pressure was introduced. During bubble collapsing, sound vibration and instantaneous high pressures over 100 MPa enhanced the cutting ability of the high-pressure jet. Through high-pressure pulsed water jet drilling and slotting, the exposure area of coal bodies was greatly enlarged and pressure of the coal seams rapidly decreased. Therefore, the permeability of coal seams was improved and gas ab-sorption rate also decreased. Application results show that gas adsorption rate decreased by 30%-40% and the penetrability coefficient increased 100 times. This proves that high-pressure pulsed water is more efficient than other conventional methods.

  5. Brown coal derived products ameliorating soil acidity

    Energy Technology Data Exchange (ETDEWEB)

    Issa, J.; Patti, A.F.; Jackson, W.R. [Monash University, Clayton, Vic. (Australia). Centre for Green Chemistry

    2000-07-01

    Humic acid derived from brown coal, with added calcium, when applied to the soil surface, can increase pH deeper into the soil profile. The humates can move down with water percolating the soil. As they move down the added calcium bound to the humate's cation exchange sites (the acidic oxygen functional groups) can exchange with toxic aluminium ions and ions on exchange sites in the soil. Thus the soil pH is buffered, nutrient transport to plants assisted, and phytotoxic aluminium bound and rendered harmless to plants. K Humate is a commercially available source of humate (ex HRL Agriculture Pty Ltd Australia) derived from brown coal. It can be obtained by the treatment of brown coal with potassium hydroxide. Calsulmag is a commercial treated coal fly ash (also ex HRL Agriculture Pty Ltd) which can be used instead of lime due to its high inorganic calcium and magnesium content. When K humate and Calsulmag are combined in an aqueous mixture, and applied to the surface of an acidic soil, pH is increased (from 3.8 to 4.5) as is exchangeable calcium (30-50%), while exchangeable aluminium is decreased (30-50%), down to a 5 cm depth.

  6. In situ determination of sulphur in coal seams and overburden rock by PGNAA

    Science.gov (United States)

    Borsaru, M.; Berry, M.; Biggs, M.; Rojc, A.

    2004-01-01

    The prompt gamma neutron activation analysis technique was tested successfully for the determination of sulphur in coal seams and overburden rock. The logging tool employs a 3 μg 252Cf neutron source and a 50 mm dia × 100 mm BGO detector.

  7. In situ determination of sulphur in coal seams and overburden rock by PGNAA

    Energy Technology Data Exchange (ETDEWEB)

    Borsaru, M. E-mail: mihai.borsaru@csiro.au; Berry, M.; Biggs, M.; Rojc, A

    2004-01-01

    The prompt gamma neutron activation analysis technique was tested successfully for the determination of sulphur in coal seams and overburden rock. The logging tool employs a 3 {mu}g {sup 252}Cf neutron source and a 50 mm dia x 100 mm BGO detector.

  8. Desorption isotherm as an criterion for methane content in coal seam

    Czech Academy of Sciences Publication Activity Database

    Medek, Jiří; Weishauptová, Zuzana

    Brisbane : Australian Journal of Mining, 1998 - (Golding, S.). s. 38 [International Conference on Coal Seam Gas and Oil. 23.03.1998-25.03.1998, Brisbane] R&D Projects: GA ČR GA105/94/1371 Subject RIV: DM - Solid Waste and Recycling

  9. Geological storage of carbon dioxide in the coal seams: from material to the reservoir

    International Nuclear Information System (INIS)

    CO2 emissions into the atmosphere are recognized to have a significant effect on global warming. Geological storage of CO2 is widely regarded as an essential approach to reduce the impact of such emissions on the environment. Moreover, injecting carbon dioxide in coal bed methane reservoirs facilitates the recovery of the methane naturally present, a process known as enhanced coal bed methane recovery (ECBM). But the swelling of the coal matrix induced by the preferential adsorption by coal of carbon dioxide over the methane in place leads to a closure of the cleat system (a set of small natural fractures) of the reservoir and therefore to a loss of injectivity. This PhD thesis is dedicated to a study of how this injectivity evolves in presence of fluids. We derive two poro-mechanical dual-porosity models for a coal bed reservoir saturated by a pure fluid. The resulting constitutive equations enable to better understand and model the link between the injectivity of a coal seam and the adsorption-induced swelling of coal. For both models, the pore space of the reservoir is considered to be divided into the macroporous cleats and the pores of the coal matrix. The two models differ by how adsorption of fluid is taken into account: the first model is restricted to surface adsorption, while the second model can be applied for adsorption in a medium with a generic pore size distribution and thus in a microporous medium such as coal, in which adsorption mostly occurs by micropore filling. The latter model is calibrated on two coals with different sorption and swelling properties. We then perform simulations at various scales (Representative Elementary Volume, coal sample, coal seam). In particular, we validate our model on experimental data of adsorption-induced variations of permeability of coal. We also perform simulations of seams from which methane would be produced (CBM) or of methane-free seams into which CO2 would be injected. We study the effect of various

  10. Stress Measurement in Coal Seam Ahead of Longwall Face - Case Study

    Czech Academy of Sciences Publication Activity Database

    Kukutsch, Radovan; Koníček, Petr; Waclawik, Petr; Ptáček, Jiří; Staš, Lubomír; Vavro, Martin; Hastíková, Alice

    Wollongong: The University of Wollongong, 2015 - (Aziz, N.; Kininmonth, B.), s. 54-61 ISBN 978-1-925100-23-5. [Coal Operators´ Conference. Wollongong (AU), 11.02.2015-13.02.2015] R&D Projects: GA MŠk(CZ) LO1406; GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : coal seam * stress measurement * destress blasting Subject RIV: DH - Mining , incl. Coal Mining http://ro.uow.edu.au/cgi/viewcontent.cgi?article=2205&context=coal

  11. Impact of longwall mining on groundwater above the longwall panel in shallow coal seams

    OpenAIRE

    Yang Li; Syd S. Peng; Jinwang Zhang

    2015-01-01

    Since longwall mining causes subsidence through the overlying strata to the ground surface, the surface water and groundwater above the longwall panels may be affected and drained into the lower levels. Therefore, loss or interruption of streams and overburden aquifers is a common concern in coal industry. This paper analyzed the potential effects of longwall mining on subsurface water system in shallow coal seam. In order to monitor different water level fluctuations throughout the mining pe...

  12. Coal seams, climate and intranamurian stratigraphical gap in the Upper Silesian Basin

    Czech Academy of Sciences Publication Activity Database

    Martinec, Petr; Kožušníková, Alena

    Izmir : Dokuz Eylül University, 1999 - (Nakoman, E.), s. 371-382 ISBN 975-441-152-2. [European Coal Conference/3./. Izmir (TR), 05.05.1997-10.05.1997] R&D Projects: GA AV ČR IAA3086504; GA ČR GA205/97/0307 Keywords : coal seams * stratigraphy * Upper Silesian Basin Subject RIV: DB - Geology ; Mineralogy

  13. Coupled flow and geomechanical processes during gas production from coal seams

    Energy Technology Data Exchange (ETDEWEB)

    Connell, L.D. [CSIRO Petroleum, Ian Wark Laboratory, Clayton, Victoria (Australia)

    2009-07-01

    Permeability in coal seams is sensitive to stress and pore pressure changes. An additional influence on this behaviour is the nature of the coal matrix to shrink with gas desorption and swell with adsorption. Concise relationships for permeability have been developed which incorporate these mechanisms, some of which are derived from a geomechanical basis such as the Shi-Durucan model and the Palmer-Mansoori model. While these expressions are attractive approaches for defining coal permeability during gas migration, the geomechanical behaviour has been simplified by assuming uni-axial strain and constant vertical stress. In this paper a coupled numerical model is developed and used to investigate the applicability of these geomechanical assumptions for gas drainage from coal seams. The modelling approach involved coupling the existing coal seam gas reservoir simulator, SIMED II, with the geomechanical simulator, FLAC3D. While SIMED II was used to simulate gas migration in a hypothetical coal seam and a series of production scenarios, FLAC3D simulated the geomechanical response of the coal and the adjacent non-coal geological formations to fluid pressure and gas content changes imported from SIMED II. The simulations, which considered a range of property values relevant to the San Juan basin, found that while the assumption of uni-axial strain introduced negligible discrepancy, the assumption of constant vertical stress leads to significant differences between the Shi-Durucan permeability estimate and that calculated from the SIMED-FLAC3D simulation, especially at early times during production. These differences were a result of the pressure and sorption strain changes induced by production leading to arching of stresses in the vicinity of the production well. The mechanism was shown to produce significant differences in the calculated gas rate particularly at early times during production. (author)

  14. The influence of hydrogeological disturbance and mining on coal seam microbial communities.

    Science.gov (United States)

    Raudsepp, M J; Gagen, E J; Evans, P; Tyson, G W; Golding, S D; Southam, G

    2016-03-01

    The microbial communities present in two underground coal mines in the Bowen Basin, Queensland, Australia, were investigated to deduce the effect of pumping and mining on subsurface methanogens and methanotrophs. The micro-organisms in pumped water from the actively mined areas, as well as, pre- and post-mining formation waters were analyzed using 16S rRNA gene amplicon sequencing. The methane stable isotope composition of Bowen Basin coal seam indicates that methanogenesis has occurred in the geological past. More recently at the mine site, changing groundwater flow dynamics and the introduction of oxygen in the subsurface has increased microbial biomass and diversity. Consistent with microbial communities found in other coal seam environments, pumped coal mine waters from the subsurface were dominated by bacteria belonging to the genera Pseudomonas and the family Rhodocyclaceae. These environments and bacterial communities supported a methanogen population, including Methanobacteriaceae, Methanococcaceae and Methanosaeta. However, one of the most ubiquitous micro-organisms in anoxic coal mine waters belonged to the family 'Candidatus Methanoperedenaceae'. As the Archaeal family 'Candidatus Methanoperedenaceae' has not been extensively defined, the one studied species in the family is capable of anaerobic methane oxidation coupled to nitrate reduction. This introduces the possibility that a methane cycle between archaeal methanogenesis and methanotrophy may exist in the anoxic waters of the coal seam after hydrogeological disturbance. PMID:26541089

  15. Determination of Fracture Initiation Locations during Cross-Measure Drilling for Hydraulic Fracturing of Coal Seams

    Directory of Open Access Journals (Sweden)

    Yiyu Lu

    2016-05-01

    Full Text Available When drilling coal-bearing sequences to enhance coal seam permeability by hydraulic fracturing (HF, the location where fractures are initiated is important. To date, most research on fracture initiation has studied the problem in two dimensions. In this study, a three-dimensional model to assess initiation location is developed. The model analyzes the stress state of both the borehole wall and the coal-rock interface and the model shows that the fracture initiation location is affected by in situ stress, the dip of the coal seam, and the angle between the borehole and the coal seam. How the initiation location changes near different types of geological faults is calculated by assuming typical in situ stresses for the faults. Following these calculations, physical experiments were carried out to emulate cross-measure hydraulic fracturing under stress conditions equivalent to those in the Chongqing Tonghua coal mine, China. Fracture initiation during the experiments was monitored by an acoustic emission system. The experimental results were consistent with the theoretical calculations. This implies that the three-dimensional model for assessing the locations of fracture initiation can be applied to forecast the initiation location of fractures generated by cross-measure drilling. The assessment model provides reference values for this type of drilling in underground mines.

  16. Numerical investigations on mapping permeability heterogeneity in coal seam gas reservoirs using seismo-electric methods

    Science.gov (United States)

    Gross, L.; Shaw, S.

    2016-04-01

    Mapping the horizontal distribution of permeability is a key problem for the coal seam gas industry. Poststack seismic data with anisotropy attributes provide estimates for fracture density and orientation which are then interpreted in terms of permeability. This approach delivers an indirect measure of permeability and can fail if other sources of anisotropy (for instance stress) come into play. Seismo-electric methods, based on recording the electric signal from pore fluid movements stimulated through a seismic wave, measure permeability directly. In this paper we use numerical simulations to demonstrate that the seismo-electric method is potentially suitable to map the horizontal distribution of permeability changes across coal seams. We propose the use of an amplitude to offset (AVO) analysis of the electrical signal in combination with poststack seismic data collected during the exploration phase. Recording of electrical signals from a simple seismic source can be closer to production planning and operations. The numerical model is based on a sonic wave propagation model under the low frequency, saturated media assumption and uses a coupled high order spectral element and low order finite element solver. We investigate the impact of seam thickness, coal seam layering, layering in the overburden and horizontal heterogeneity of permeability.

  17. Origin of banded structure and coal lithotype cycles in Kargali coal seam of East Bokaro sub-basin, Jharkhand, India: Environmental implications

    Indian Academy of Sciences (India)

    Ram Chandra Tewari; Zahid A Khan

    2015-04-01

    The Kargali seam of Early Permian Barakar cyclothems of East Bokaro sub-basin of Jharkhand, India is 12–30 m thick, splits into two parts, and extends throughout the length of the basin. It is made up of interbedded sequences and variable proportions of Vitrain, Clarain, Durain and Fusain. Application of embedded Markov chain model rejects the phenomenon of randomness in the repetition of coal lithotypes. The preferential upward transition path for coal lithotypes that can be derived for the Kargali top coal seam is: Vitrain → Clarain → Durain ↔ Fusain → Vitrain, and for the Kargali bottom coal seam is: Clarain ↔ Vitrain → Fusain → Durain → Clarain. By and large, the cyclic repetition of coal lithotypes is similar in the Kargali bottom and top seams. Among the noteworthy features are two-way transitions between Durain and Fusian in Kargali top and between Clarain and Vitrain in the case of Kargali bottom coal seam. Entropy analysis corroborates Markov chain and indicates the presence of type A-4 asymmetrical cycles of coal lithotypes. It is suggested that the banded structure of a coal seam is not a random feature and follows a definite cyclic pattern in the occurrence of coal lithotypes in vertical order and is similar to that described in Australian and European coal seams. Asymmetrical cyclic sequences are a normal, rather than an unusual condition, within coal seams. It is visualized that a gradual decline of toxic environment and ground water level resulted in the coal lithotype cycles in the Kargali seam of East Bokaro sub-basin. The close interbedding of Vitrain and Clarain is suggestive of seasonal fluctuation in anaerobic and aerobic conditions during peat formation.

  18. Impact of longwall mining on groundwater above the longwall panel in shallow coal seams

    Directory of Open Access Journals (Sweden)

    Yang Li

    2015-06-01

    Full Text Available Since longwall mining causes subsidence through the overlying strata to the ground surface, the surface water and groundwater above the longwall panels may be affected and drained into the lower levels. Therefore, loss or interruption of streams and overburden aquifers is a common concern in coal industry. This paper analyzed the potential effects of longwall mining on subsurface water system in shallow coal seam. In order to monitor different water level fluctuations throughout the mining period, three water wells were drilled down to the proposed deformation zone above the longwall panel. A GGU-SS-FLOW3D model was used to predict water table contours for the periods of pre- and post-mining conditions. The field data from the three water wells were utilized to calibrate the model. The field test and numerical model can help to better understand the dewatering of shallow aquifers and surface waters related to ground subsidence from longwall mining in shallow coal seam.

  19. Guiding-controlling technology of coal seam hydraulic fracturing fractures extension

    Institute of Scientific and Technical Information of China (English)

    Zhai Cheng; Li Min; Sun Chen; Zhang Jianguo; Yang Wei; Li Quangui

    2012-01-01

    Aiming at the uncontrollable problem of extension direction of coal seam hydraulic fracturing,this study analyzed the course of fractures variation around the boreholes in process of hydraulic fracturing,and carried out the numerical simulations to investigate the effect of artificial predetermined fractures on stress distribution around fractured holes.The simulation results show that partial coal mass occurs relatively strong shear failure and forms weak surfaces,and then fractures extended along the desired direction while predetermined fractures changed stress distribution.Directional fracturing makes the fractures link up and the pressure on coal mass is relieved within fractured regions.Combining deep hole controlling blasting with hydraulic fracturing was proposed to realize the extension guiding-controlling technology of coal seam fractures.Industrial experiments prove that this technology can avoid local stress concentration and dramatically widen the pressure relief scope of deep hole controlling blasting.The permeability of fractured coal seam increased significantly,and gas extraction was greatly improved.Besides,regional pressure relief and permeability increase was achieved in this study.

  20. How sorption-induced matrix deformation affects gas flow in coal seams: A new FE model

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H.B.; Liu, J.S.; Elsworth, D. [University of Western Australia, Nedlands, WA (Australia). School of Oil and Gas Engineering

    2008-12-15

    The influence of sorption-induced coal matrix deformation on the evolution of porosity and permeability of fractured coal seams is evaluated, together with its influence on gas recovery rates. The porosity-based model considers factors such as the volume occupied by the free-phase gas, the volume occupied by the adsorbed phase gas, the deformation-induced pore volume change, and the sorption-induced coal pore volume change. More importantly, these factors are quantified under in situ stress conditions. A cubic relation between coal porosity and permeability is introduced to relate the coal storage capability (changing porosity) to the coal transport property (changing permeability). A general porosity and permeability model is then implemented into a coupled gas flow and coal deformation finite element model. The new FE model was used to compare the performance of the new model with that of the Palmer-Mansoori model. It is found that the Palmer-Mansoori model may produce significant errors if loading conditions deviate from the assumptions of the uniaxial strain condition and infinite bulk modulus of the grains. The FE model was also applied to quantify the net change in permeability, the gas flow, and the resultant deformation in a coal seam. Model results demonstrate that the evolution of porosity and of permeability is controlled by the competing influences of effective stresses and sorption-based volume changes. The resulting sense of permeability change is controlled by the dominant mechanism.

  1. Layout and support design of a coal roadway in ultra-close multiple-seams

    Institute of Scientific and Technical Information of China (English)

    严红; 翁明月; 冯锐敏; 李伟康

    2015-01-01

    A roadway within ultra-close multiple-seams (RUCMSs) is one of the most difficult supported coal roadways to deal with in underground coal mines. This is usually due to the unknown stress distributions, improper roadway layout, and unreasonable support parameters. In order to solve this support problem and effectively save RUCMSs from frequent and abrupt disasters (such as serious deformation of the surrounding rock, roof cave ins, and coal side collapse), a comprehensive method is adopted here which includes theoretical analysis, numerical simulation, and field monitoring. A mechanical model was constructed to determine the stress distribution in the coal pillar after two sides of a longwall panel had been mined. Based on this model, the horizontal, vertical, and tangential stress equations for the plane below the floor of the upper-left coal pillar were deduced. In addition, a typical coal mine (the Jinggonger colliery, located in Shuozhou city, Shanxi province, China) with an average distance between its 9# and 11# coal seams of less than 8.0 was chosen to conduct research on the proper layout and reasonable support required for a typical coal roadway located within coal seam 11#. Using FLAC3D (Fast Lagrangian Analysis of Continua in 3-Dimensions) numerical software, eight schemes were designed with different horizontal distances (d) between the center lines of the coal pillar and the roadway in the lower coal seam (RLCS). The simulations and detailed analysis indicate that the proper distances required are between 22.5 and 27.5 m. A total of 20 simulation schemes were used to investigate the factors influencing the support provided by the key bolts (bolt length, spacing, distance between two rows, installation angle, and pre-tightening force). The results were analyzed and used to determine reasonable values for the support parameters. Field results show that the stability and strength of the RLCS can be effectively safeguarded using a combination of researched

  2. A 90 m-thick coal seam in the Lubstow lignite deposit (Central Poland): palynological analysis and sedimentary environment

    Energy Technology Data Exchange (ETDEWEB)

    Durska, E. [University of Warsaw, Warsaw (Poland). Faculty of Geology

    2008-07-01

    A 90 m-thick brown coal seam, the result of organic matter deposition in a fault-trough, is exploited in an open cast mine at Lubstow (Central Poland). Palynological analysis was conducted in order to determine which plants were the source of organic matter forming such a thick coal bed. The pollen spectrum is dominated by the gymnosperm pollen Inaperturopollenites, produced by trees closely related to the extant genera Taxodium and Glyptostrobus, the dominant constituents of swamp forests in SE North America and SE Asia today. However the lack of xylites and preserved tissues in the coal does not support the conception of a swamp forest as the peat-producing community. There is also significant percentage of angiosperm pollen in the coal, mainly from the groups: Castaneoideapollis, Tricolporopollenites exactus and T. pseudocingulum. The plants producing these pollen were probably the main constitutent of the peat-producing community. The community shows signs of a shrub swamp with local tree islands and a low water table. Evidence for this also includes the detrital type of coal, the lack of preserved plant tissues and the presence of fungal remains. The characteristics show the existence of aerobic zones at the time of peat production. The peat was probably derived from angiosperms. Dome-shaped forms in the upper part of the deposit are the remains of tree islands. As detritus accumulation is very on the surfaces of present-day tree islands, a similar rate of deposition may have taken place during peat production at Lubstow. This, combined with subsidence in the fault-through, explains the great thickness of the coal bed.

  3. The benefits of innovation In-Seam Seismic method in the coal mine condition at the Karvina Subbasin

    Czech Academy of Sciences Publication Activity Database

    Waclawik, Petr; Schott, W.

    Vol. 5. Ostrava: Ústav geoniky AV ČR, 2014 - (Koníček, P.; Souček, K.; Heroldová, N.). s. 49-50 ISBN 978-80-86407-49-4. [5th International Colloquium on Geomechanics and Geophysics. 24.06.2014-27.06.2014, Ostravice, Karolínka] Institutional support: RVO:68145535 Keywords : in-seam sesmic * ISS * coal seam * longwall panel Subject RIV: DH - Mining, incl. Coal Mining

  4. “Community perspectives of natural resource extraction: coal-seam gas mining and social identity in Eastern Australia”

    OpenAIRE

    Lloyd, D.; H. Luke; W.E. Boyd

    2014-01-01

    Using a recent case study of community reaction to proposed coal - seam gas mining in eastern Australia, we illustrate the role of community views in issues of natural resource use. Drawing on interviews, observations and workshops, the paper explores the anti - coal - seam gas social movement from its stages of infancy through to being a national debate linking community groups across and beyond Australia. Primary community concerns of inadequate commun...

  5. Selection of an Appropriate Mechanized Mining Technical Process for Thin Coal Seam Mining

    OpenAIRE

    Chen Wang; Shihao Tu

    2015-01-01

    Mechanized mining technical process (MMTP) related to the control method of the shearer is a vital process in thin coal seam mining operations. An appropriate MMTP is closely related to safety, productivity, labour intensity, and efficiency. Hence, the evaluation of alternative MMTP is an important part of the mining design. Several parameters should be considered in MMTP evaluation, so the evaluation is complex and must be compliant with a set of criteria. In this paper, two multiple criteri...

  6. IMPROVING METHODS OF MODELING CANAL WAVES PROPAGATION PROCESS IN COAL SEAMS

    OpenAIRE

    SMIRNOV YU.M.; КЕNZHIN B.М.

    2012-01-01

    There has been analyzed the principal methods of modeling the process of canal waves propagation in coal seams when carrying out mining geophysical studies. There has been established that the wave guide moving into the surface of the elastic half-space doesn’t practically change the main properties of the interferential waves propagating in them. There has been recommended to use Fourier integral describing the single pulse spectrum for studying the registered seismograms. There have been fo...

  7. All-age hospitalization rates in coal seam gas areas in Queensland, Australia, 1995–2011

    OpenAIRE

    Werner, Angela K.; Watt, Kerrianne; Cameron, Cate M; Vink, Sue; Page, Andrew; Jagals, Paul

    2016-01-01

    Background Unconventional natural gas development (UNGD) is expanding globally, with Australia expanding development in the form of coal seam gas (CSG). Residents and other interest groups have voiced concerns about the potential environmental and health impacts related to CSG. This paper compares objective health outcomes from three study areas in Queensland, Australia to examine potential environmentally-related health impacts. Methods Three study areas were selected in an ecologic study de...

  8. Effect of the computer fuzzy control on coal seam injection

    Institute of Scientific and Technical Information of China (English)

    SONG Hua-ling(宋华岭); YANG Jing-cai(杨景才); WANG Jin-li (王金力); WANG An(王安); LIU Shu-qin(刘淑芹); Cornelis Reiman

    2003-01-01

    To enhance the technology and efficiency of strata injection is a problem to be solved urgently. Because of effected by the rough and poor production conditions of mining and the changeable bearing condition of strata, the technological process of injection can not be controlled automatically.The fuzzy controlling technology of the coal strata injection is applied. This is the good way to ensure the effectiveness and efficiency of coal strata injection and to solve the current problems of production and safety in mining industry.

  9. Influence of Lithological Characters of Coal Bearing Formation on Stability of Roof of Coal Seams

    Institute of Scientific and Technical Information of China (English)

    孟召平; 彭苏萍; 李国庆; 黄为; 芦俊; 雷志勇

    2003-01-01

    Lithology is one of the important factors influencing the stability of roof of coal seams. In order to investigate this, the phenomenon of underground pressure and distribution of pressure were studied by using the local observation and simulation test with similar materials. The observation results show that the distance of initial weighting and periodic weighting of the mudstone roof is shorter than that of sandstone roofs. The sandstone roof with a high strength has a longer distance of initial weighting and periodic weighting, the abutment stress on the working face is big and the height of caving and fracture zone is high. The peak point of abutment stress in the sandstone roof is near to the working face and the pressure bump is inclined to occur. The result is contrary to that in case of the mudstone roof with a low strength. While in the transition zone of nipped sandstone, roof rock-mass is broken and is poor in stability, therefore, it is difficult to hold the roof.

  10. Pulsating hydraulic fracturing technology in low permeability coal seams

    Institute of Scientific and Technical Information of China (English)

    Wang Wenchao; Li Xianzhong; Lin Baiquan; Zhai Cheng

    2015-01-01

    Based on the difficult situation of gas drainage in a single coal bed of high gas content and low perme-ability, we investigate the technology of pulsating hydraulic pressure relief, the process of crank plunger movement and the mechanism of pulsating pressure formation using theoretical research, mathematical modeling and field testing. We analyze the effect of pulsating pressure on the formation and growth of fractures in coal by using the pulsating hydraulic theory in hydraulics. The research results show that the amplitude of fluctuating pressure tends to increase in the case where the exit is blocked, caused by pulsating pressure reflection and frictional resistance superposition, and it contributes to the growth of fractures in coal. The crack initiation pressure of pulsating hydraulic fracturing is 8 MPa, which is half than that of normal hydraulic fracturing;the pulsating hydraulic fracturing influence radius reaches 8 m. The total amount of gas extraction is increased by 3.6 times, and reaches 50 L/min at the highest point. The extraction flow increases greatly, and is 4 times larger than that of drilling without fracturing and 1.2 times larger than that of normal hydraulic fracturing. The technology provides a technical measure for gas drainage of high gas content and low permeability in the single coal bed.

  11. Petrographic and geochemical contrasts and environmentally significant trace elements in marine-influenced coal seams, Yanzhou mining area, China

    Science.gov (United States)

    Liu, Gaisheng; Yang, P.; Peng, Z.; Chou, C.-L.

    2004-01-01

    The Yanzhou mining area in west Shandong Province, China contains coals of Permian and Carboniferous age. The 31 and 32 seams of the Permian Shanxi Formation and seams 6, 15-17 of the Carboniferous Taiyuan Formation were analyzed for coal petrology, mineralogy and geochemical parameters. The parameters indicate that the coal is high volatile bituminous in rank. The coal is characterized by high vitrinite and low to medium inertinite and liptinite contents. These properties may be related to evolution of the coal forming environment from more reducing conditions in a marine influenced lower delta plain environment for the early Taiyuan coals to more oxidizing paleoenvironments in an upper delta plain for the upper Shanxi coal seams. The major mineral phases present in the coal are quartz, kaolinite, pyrite and calcite. Sulfur is one of the hazardous elements in coal. The major forms of sulfur in coal are pyritic, organic and sulfate sulfur. Pyritic and organic sulfur generally account for the bulk of the sulfur in coal. Elemental sulfur also occurs in coal, but only in trace to minor amounts. In this paper, the distribution and concentration of sulfur in the Yanzhou mining district are analyzed, and the forms of sulfur are studied. The sulfur content of the Taiyuan coal seams is considerably higher than that of the Shanxi coals. Organic sulfur content is positively correlated to total and pyritic sulfur. The vertical variation of Cu, Zn, Pb, As, Th, U and sulfur contents in coal seam 3 of the Shanxi Formation in the Xinglongzhuang mine show that all these trace elements, with the exception of Th, are enriched in the top and bottom plies of the seam, and that their concentrations are also relatively high in the dirt bands within the seam. The pyritic sulfur is positively correlated with total sulfur, and both are enriched in the top, bottom and parting plies of the seam. The concentrations of the trace elements are closely related to sulfur and ash contents. Most of

  12. Solution of underground mine gas emissions on surface of abandoned mining sites where steep deposited coal seams have been exploited

    International Nuclear Information System (INIS)

    The solution of uncontrolled gas emissions from abandoned underground coal mine sites in Ostrava-Karvina coal-field to surface ground in connection with old mine shafts and drifts and with old mining workings in horizontal and inclined coal seams has many forms. It varies according to geological and mining conditions and the disposition of the site surface. Since four years the gas emission risk has appeared in the area of former exploited vertical coal seams within the historical centre of Orlova town, which is protected by State Monument Protection office. A project based on such special nature of mining-geological and urban conditions was elaborated and already implemented. (authors)

  13. Investigation on displacement field characteristics of tunnel's surrounding rock and coal seam at FMTC face

    Institute of Scientific and Technical Information of China (English)

    XIE Guang-xiang; CHANG Ju-cai; YANG Ke

    2006-01-01

    The change rules of displacement field characteristics of coal seam and tunnel's surrounding rock were obtained by means of numerical simulation-FLAC3D and site observation, and according to engineering geology and exploitation technology of 1151 (3)fully mechanized top coal caving (FMTC) face in Xieqiao colliery. The research's results show that the top coal displacement on the top of FMTC face is apparently larger than those of the middle and the bottom, the top coal begins to move in the front of the face's wall, and the sub-level top coal-rock moves ahead of the Iow-level top coal-rock, the verticai displacement of top coal-rock increases gradually as the decreasing of distance to face.Top coal and overlying strata in vertical direction are always in compressed state in the front of face, then the top coal begins to separate from the overlying strata at the upside of face. The support loading at face is mainly the deformation pressure due to top coal and main roof's movement, and it is not suitable for the FMTC face with traditional support design. Surrounding rock movement of the face is of near-field effect, the surrounding rock deformation is acute greatly near to the face, the ideas of supporting design for the tailentry and headentry should be changed from loading control to deformation control.

  14. Numerical Study on 4-1 Coal Seam of Xiaoming Mine in Ascending Mining

    Directory of Open Access Journals (Sweden)

    Lan Tianwei

    2015-01-01

    Full Text Available Coal seams ascending mining technology is very significant, since it influences the safety production and the liberation of dull coal, speeds up the construction of energy, improves the stability of stope, and reduces or avoids deep hard rock mining induced mine disaster. Combined with the Xiaoming ascending mining mine 4-1, by numerical calculation, the paper analyses ascending mining 4-1 factors, determines the feasibility of ascending mining 4-1 coalbed, and proposes roadway layout program about working face, which has broad economic and social benefits.

  15. Hybrid Technology of Hard Coal Mining from Seams Located at Great Depths

    Science.gov (United States)

    Czaja, Piotr; Kamiński, Paweł; Klich, Jerzy; Tajduś, Antoni

    2014-10-01

    Learning to control fire changed the life of man considerably. Learning to convert the energy derived from combustion of coal or hydrocarbons into another type of energy, such as steam pressure or electricity, has put him on the path of scientific and technological revolution, stimulating dynamic development. Since the dawn of time, fossil fuels have been serving as the mankind's natural reservoir of energy in an increasingly great capacity. A completely incomprehensible refusal to use fossil fuels causes some local populations, who do not possess a comprehensive knowledge of the subject, to protest and even generate social conflicts as an expression of their dislike for the extraction of minerals. Our times are marked by the search for more efficient ways of utilizing fossil fuels by introducing non-conventional technologies of exploiting conventional energy sources. During apartheid, South Africa demonstrated that cheap coal can easily satisfy total demand for liquid and gaseous fuels. In consideration of current high prices of hydrocarbon media (oil and gas), gasification or liquefaction of coal seems to be the innovative technology convergent with contemporary expectations of both energy producers as well as environmentalists. Known mainly from literature reports, underground coal gasification technologies can be brought down to two basic methods: - shaftless method - drilling, in which the gasified seam is uncovered using boreholes drilled from the surface, - shaft method, in which the existing infrastructure of underground mines is used to uncover the seams. This paper presents a hybrid shaft-drilling approach to the acquisition of primary energy carriers (methane and syngas) from coal seams located at great depths. A major advantage of this method is the fact that the use of conventional coal mining technology requires the seams located at great depths to be placed on the off-balance sheet, while the hybrid method of underground gasification enables them to

  16. Estimation of Coal Bed Methane Potential of Coal Seams of Margherita Coal Field, Assam, India

    Directory of Open Access Journals (Sweden)

    Prasenjit Talukdar

    2015-06-01

    Full Text Available The rapid industrialization and growing energy needs have put a great stress on the conventional energy resources. This is even more concerning for a country like India which is a net importer of oil. To meet the ever increasing need for energy, it is essential that the search for unconventional energy is intensified. This paper deals with the estimation of coal bed methane potential of the Margherita Coal Field of Assam, India. For this purpose, eight coal samples were collected from Tirap O.C.P., Ledo UG Incline and Tikak O.C.P collieries of the Margherita coal field. Proximate analysis, megascopic study and finally qualitative analysis of these eight samples was undertaken. After analysis, the inferred reserves of CBM at Margherita Coalfield, was found to be in the range of 42.5-49.04 Billion Cubic Meter.

  17. TAKRAF surface mining equipment in the Greek Ptolomais brown coal basin

    Energy Technology Data Exchange (ETDEWEB)

    1983-06-01

    This paper enumerates heavy surface mining equipment and its technical specifications, delivered by TAKRAF in the German Democratic Republic to four brown coal surface mines at Kozani, in northern Greece. Machinery includes: an A/SUB/2 Rs-B boom spreader with a capacity of 4,500 m/sup 3//h, three coal storage yards (capacity 1 Mt) Ks-S 5,600 stackers and reclaimers (5,600 m/sup 3//h) for the Kardia power plant (4 x 300 MW); two SRs 2000 bucket wheel excavators (3,000 m/sup 3//h overburden, 1,700 m/sup 3//h coal) and four A/SUB/2Rs-B6700 boom spreaders (6,700 m/sup 3//h each) for the Ptolomais South surface mine, and a further five SRs 240 bucket wheel excavators (850 m/sup 3//h) for coal seam cleaning. Since 1982 three more Ks-S 5,600 stacker and reclaimers for a second coal storage yard (1.5 Mt) at the Aghios Dimitros power plant (2 x 300 Mw) are being assembled. For the fourth and latest brown coal surface mine, Amyntaion, two newly designed SRs 4000 bucket wheel excavators (7,600 m/sup 3//h) were ordered, which are being assembled and will enter operation by 1985.

  18. Interpretation of Coal-Seam Sequestration Data Using a New Swelling and Shrinkage Model

    Energy Technology Data Exchange (ETDEWEB)

    Siriwardane, H.J.; Smith, D.H.

    2006-10-01

    This paper deals with the influence of swelling and shrinkage of coal on the production of methane from, and sequestration of carbon dioxide in, a coalbed reservoir. A three-dimensional swelling and shrinkage model was developed. It is based on constitutive equations that account for coupled fluid pressure-deformation behavior of a porous medium that undergoes swelling and shrinkage. The swelling and shrinkage strains are computed on the basis of the amounts of different gases (e.g., CO2, CH4) sorbed or desorbed. The amounts of sorption and desorption are computed from measured isotherms with the aid of the Ideal Adsorbed Solution model for mixed gases. The permeability of the reservoir is modified according to the swelling-shrinkage model. The paper presents numerical results for the influence of swelling and shrinkage on reservoir performance during injection of carbon dioxide. The paper includes results from a number of examples, and analysis of a field injection into a coal seam at a site in the San Juan basin. Results show that with the incorporation of swelling and shrinkage into the analysis, it is possible to get a better history-match of production data. Results also show that coal swelling can reduce the injection volumes of carbon dioxide significantly. The interpretation of field data with the new swelling-shrinkage model shows that the coal swelling during carbon dioxide sequestration in coal-seams is an important factor that can influence field performance.

  19. Annual Change Detection by ASTER TIR Data and an Estimation of the Annual Coal Loss and CO2 Emission from Coal Seams Spontaneous Combustion

    Directory of Open Access Journals (Sweden)

    Xiaomin Du

    2014-12-01

    Full Text Available Coal fires, including both underground and coal waste pile fires, result in large losses of coal resources and emit considerable amounts of greenhouse gases. To estimate the annual intensity of greenhouse gas emissions and the loss of coal resources, estimating the annual loss from fire-influenced coal seams is a feasible approach. This study assumes that the primary cause of coal volume loss is subsurface coal seam fires. The main calculation process is divided into three modules: (1 Coal fire quantity calculations, which use change detection to determine the areas of the different coal fire stages (increase/growth, maintenance/stability and decrease/shrinkage. During every change detections, the amount of coal influenced by fires for these three stages was calculated by multiplying the coal mining residual rate, combustion efficiency, average thickness and average coal intensity. (2 The life cycle estimate is based on remote sensing long-term coal fires monitoring. The life cycles for the three coal fire stages and the corresponding life cycle proportions were calculated; (3 The diurnal burnt rates for different coal fire stages were calculated using the CO2 emission rates from spontaneous combustion experiments, the coal fire life cycle, life cycle proportions. Then, using the fire-influenced quantity aggregated across the different stages, the diurnal burn rates for the different stages and the time spans between the multi-temporal image pairs used for change detection, we estimated the annual coal loss to be 44.3 × 103 tons. After correction using a CH4 emission factor, the CO2 equivalent emissions resulting from these fires was on the order of 92.7 × 103 tons. We also discovered that the centers of these coal fires migrated from deeper to shallower parts of the coal seams or traveled in the direction of the coal seam strike. This trend also agrees with the cause of the majority coal fires: spontaneous combustion of coalmine goafs.

  20. Geochemistry of autochthonous and hypautochthonous siderite-dolomite coal-balls (Foord Seam, Bolsovian, Upper Carboniferous), Nova Scotia, Canada

    Science.gov (United States)

    Zodrow, E.L.; Lyons, P.C.; Millay, M.A.

    1996-01-01

    The 11-13 m thick Foord Seam in the fault-bounded Stellarton Basin, Nova Scotia, is the thickest seam from the Euramerican floral province known to contain coal-balls. In addition to the first discovery of autochthonous coal-balls in the Foord Seam, Nova Scotia, its shale parting also contains hypautochthonous coal-balls with histologically preserved plant structures. The coal-ball discovery helps fill a stratigraphic gap in coal-ball occurrences in the upper Carboniferous (Bolsovian) of Euramerica. The autochthonous and hypautochthonous coal-balls have a similar mineralogical composition and are composed of siderite (81-100%), dolomite-ankerite (0-19%), minor quartz and illite, and trace amounts of 'calcite'. Similar is also their permineralizing mineralogy, which consists of dolomite-ankerite and siderite. Their low pyrite content and carbonate mineralogy, and nonmarine origin, differentiates the Foord Seam coal-balls from other Euramerican coal-ball occurrences. A preliminary geochemical model, which is based on oxygen and carbon isotopic data, indicates that siderite in both the autochthonous and hypautochthonous coal-balls is of very early diagenetic (nonmarine) origin from 13C-enriched bicarbonate derived from bacterial methanogenesis of organic matter.

  1. An analysis of injury claims from low-seam coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, S.; Moore, S.; Dempsey, P.G. [NIOSH, Pittsburgh, PA (United States)

    2009-07-01

    The restricted workspace present in low-seam coal mines forces workers to adopt awkward working postures (kneeling and stooping), which place high physical demands on the knee and lower back. This article provides an analysis of injury claims for eight mining companies operating low-seam coal mines during calendar years 1996-2008. All cost data were normalized using data on the cost of medical care (MPI) as provided by the U.S. Bureau of Labor Statistics. Results of the analysis indicate that the knee was the body part that led in terms of claim cost ($4.2 million), followed by injuries to the lower back ($2.7 million). While the average cost per injury for these body parts was $13,100 and $14,400, respectively (close to the average cost of an injury overall), the high frequency of these injuries resulted in their pre-eminence in terms of cost. Analysis of data from individual mining companies suggest that knee and lower back injuries were a consistent problem across companies, as these injuries were each among the top five most costly part of body for seven out of eight companies studied. Results of this investigation suggest that efforts to reduce the frequency of knee and low back injuries in low-seam mines have the potential to create substantial cost savings.

  2. Relations between coal petrology and gas content in the Upper Newlands Seam, Central Queensland, Australia

    Science.gov (United States)

    Walker, R.; Glikson, M.; Mastalerz, Maria

    2001-01-01

    The Upper Newlands Seam in the northern Bowen Basin, Queensland Australia consists of six benches (A-F) that have different petrographic assemblages. Benches C and E contain relatively abundant inertodetrinite and mineral matter, as well as anomalously high reflectance values; these characteristics support a largely allochthonous, detrital origin for the C and E benches. Fractures and cleats in the seam show a consistent orientation of northeast-southwest for face cleats, and a wide range of orientations for fractures. Cleat systems are well developed in bright bands, with poor continuity in the dull coal. Both maceral content and cleat character are suggested to influence gas drainage in the upper Newlands Seam. A pronounced positive correlation between vitrinite abundance and gas desorption data suggests more efficient drainage from benches with abundant vitrinite. Conversely, inertinite-rich benches are suggested to have less efficient drainage, and possibly retain gas within pore spaces, which could increase the outburst potential of the coal. ?? 2001 Elsevier Science B.V. All rights reserved.

  3. Drilling coal seam outbursts where particle size matters

    Energy Technology Data Exchange (ETDEWEB)

    Gray, I. [Sigra Pty Ltd. (Australia)

    2009-10-01

    The paper is distilled from the ACARP report 'Coal mine outburst mechanisms, thresholds and predication techniques' originally written in 2006 and added to from recent direct experience of outburst conditions in Central Asian Mines. In an endeavour to provide a basis of prediction as to whether an outburst will occur it takes the approach of examining the total energy that may be released in an outburst. The sources of energy considered are the strain energy that may be released in failure of the coal and in the release of gas. Two modes of gas release are considered, one from pore space and one from diffusion. In the latter case a new model is developed to describe the potential energy release from diffusing particles. In the Australian context it is considered that the elements of energy release due to gas dominate. The critical factors that contributing to energy release in an outburst are: gas content/gas pressure; diffusion coefficient; sorption isotherm; particle size. The less critical factors are: free pore space; stress; and stiffness. 1 ref., 2 figs.

  4. Thick coal seam fully mechanized coal face moving method improvement%厚煤层综采工作面搬家方法改进研究

    Institute of Scientific and Technical Information of China (English)

    李燎; 王建

    2015-01-01

    针对晋华宫矿现阶段厚煤层综采工作面搬家方法,提出了高效安全的改进方案,提高了厚煤层综采工作面搬家速度及安全性,为厚煤层综采工作面搬家积累宝贵经验。%For thick seam fully mechanized coal face at the present stage moving method in jinhuagong coal mine, puts forward the effective safety improvement program, improve the thick coal seam fully mechanized coal face, moving speed, and safety for thick coal seam fully mechanized coal face moving accumulated valuable experience.

  5. Relaxation and gas drainage boreholes for high performance longwall operations in low permeability coal seams

    Energy Technology Data Exchange (ETDEWEB)

    Imgrund, Thomas [DMT GmbH und Co. KG, Essen (Germany); Bauer, Frank [Hazemag und EPR GmbH, Duelmen (Germany). Mining

    2013-06-15

    With an increasing depth of cover, gas emission control and gas outbursts prevention has become an increasingly important issue in coal mining. Deep multi-seam mining often requires operation in an environment characterised by a high gas content and gas pressure. Control of gas related risks has to be realised during heading and close to the longwall by proper risk assessment and flexible drilling schemes. These cover exploration and relaxation drilling, in-seam drilling for pre-drainage and cross measure drilling for drainage of roof and the floor gas emissions. DMT provides comprehensive solutions based on a scientific background. These solutions are engineered considering their technical feasibility. Hazemag Mining offers a large number of complete machinery including tools systems for the implementation of those solutions. (orig.)

  6. CO2 injection in a coal seam - Insights from the European CARBOLAB project with focus on water geochemical monitoring

    OpenAIRE

    Gal, Frédérick; Proust, Eric; Leynet, Aurélien

    2014-01-01

    The CARBOLAB project is funded by the European program RFCS (Research Fund for Coal and Steel). It gathers six partners from Spain, France and Poland. One of the main tasks of this project is to perform in-situ CO2 injection in a coal seam located at 464 m depth in the Montsacro pit, Asturias, Spain. Injection of CO2 in coal seams is one of the options for climate change mitigation but it presents lots of uncertainties and technical difficulties. Therefore work is needed to better constraint ...

  7. Explanation for peat-forming environments of coal seam 2 and 9-2 based on the maceral composition and aromatic compounds in the Xingtai coalfield, China

    Institute of Scientific and Technical Information of China (English)

    SUN Yu-zhuang; QIN Shen-jun; LI Yan-heng; LIN Ming-yue; DING Shu-li

    2009-01-01

    Maceral composition and aromatic compounds were determined on column samples to study the peat-forming environments of Permian coal seam 2 and Carbonifer-ous coal seam 9-2 from the Xingtai coalfield,China.The macerals were dominated by iner-tinite in seam 2 and by vitrinite in seam 9-2.Three maceral groups were selected as indi-cators of peat-forming environments.Two triangle diagrams were drawn based on the in-dicators to explicate the peat-forming environments of permian seam 2 and Carboniferous seam 9-2.The results indicate that the peat of carboniferous seam 9-2 formed dominantly in wet swamps,whereas the peat of Permian seam 2 formed dominantly in dry swamps and open moor environments.

  8. Strata behavior investigation for high-intensity mining in the water-rich coal seam

    Institute of Scientific and Technical Information of China (English)

    Ding Huande; Miao Xiexing; Ju Feng; Wang Xiulin; Wang Qingcang

    2014-01-01

    This paper describes a specific case of mining in a water-rich coal seam in western China. Water inrushes, roof caving and other disasters induced by intensive mining operation could pose great threats to the safety of coal mines. The strata behavior during the high-intensity extraction in the water-rich coal seam is analyzed by employing the numerical simulation method and in situ monitoring. The results show that about 10 m ahead of the workface, the front abutment pressure peaks is at 34.13 MPa, while the peak of the side abutment pressure is located about 8 m away from the gateway with the value of 12.41 MPa;the height of the fracture zone, the first weighting step and the cycle weighting step are calculated to be 45, 50 and 20.8 m, respectively; pressure distribution in the workface is characterized by that the vertical pressure in the center occurs earlier and is stronger than those on both ends. Then, the results above are verified by in situ measurement, which may provide a basis for safe mining under similar conditions.

  9. Research on forced gas draining from coal seams by surface well drilling

    Institute of Scientific and Technical Information of China (English)

    Wu Dongmei; Wang Haifeng; Ge Chungui; An Fenghua

    2011-01-01

    Surface drilling was performed at the Luling Coal Mine, in Huaibei, to shorten the period required for gas draining. The experimental study was designed to reduce the cost of gas control by efficiently draining gas from the upper protected layer. The structural arraignment and technical principles of pressure relief via surface drilling are discussed. Results from the trial showed that gas drained from the surface system over a period of 10 months. The total amount of collected gas was 248.4 million m3. The gas draining occurred in three stages: a growth period; a period of maximum gas production; and an attenuation period. The period of maximum gas production lasted for 4 months. During this time the methane concentration ranged from 60% to 90% and the average draining rate was 10.6 m3/min. Combined with other methods of draining it was possible to drain 70.6% of the gas from middle coal seam groups. The amount of residual gas dropped to 5.2 m3/ton, and the pressure of the residual gas fell to 0.53 MPa,thereby eliminating the outburst danger in the middle coal seam groups. The factors affecting pressure relief gas draining by surface drilling were analysed.

  10. Back-and-forth mining for hard and thick coal seams-research about the mining technology for fully mechanized caving working face of Datong Mine

    Institute of Scientific and Technical Information of China (English)

    JIN Zhi-xin; YU Hong; YU Bin; SONG Hua-ling

    2005-01-01

    The article introduced the key technology, mining process, and back-and-forth mining method for the caving working face of hard-thick coal seams in Datcng mine, and researched this innovations process, optimized the systemic design and working face outplay, tried to perfect the caving mining technology of hard-thick coal seams further.

  11. Time-Lapse Analysis of Methane Quantity in the Mary Lee Group of Coal Seams Using Filter-Based Multiple-Point Geostatistical Simulation

    OpenAIRE

    Karacan, C. Özgen; Ricardo A. Olea

    2013-01-01

    Coal seam degasification and its success are important for controlling methane, and thus for the health and safety of coal miners. During the course of degasification, properties of coal seams change. Thus, the changes in coal reservoir conditions and in-place gas content as well as methane emission potential into mines should be evaluated by examining time-dependent changes and the presence of major heterogeneities and geological discontinuities in the field. In this work, time-lapsed reserv...

  12. Recycling of coal seam gas-associated water using vacuum membrane distillation.

    Science.gov (United States)

    Heidarpour, Farideh; Shi, Jeffrey; Chae, So-Ryong

    2015-01-01

    Coal seam gas-associated water (CSGAW), which is a by-product of coal seam gas (CSG) production typically contains significant amounts of salts and has potential environmental issues. In this study, we optimized a bench-scale vacuum membrane distillation (VMD) process with flat-sheet hydrophobic polytetrafluoroethylene (PTFE) membranes for the treatment of synthetic CSGAW (conductivity = 15 mS/cm). To study performance of the VMD process, we explored the effects of feed temperature (T(f) = 60, 70, and 80°C), feed flow rate (V(f) = 60, 120, and 240 mL/min), and vacuum pressure (P(v) = 3, 6, and 9 kPa) on water permeability through the PTFE membrane in the VMD process. Under the optimum conditions (i.e. T(f) = 80°C, V(f) = 240 mL/min, P(v) = 3 kPa), water permeability and rejection efficiency of salts by the VMD process were found to be 5.5 L/m(2)/h (LMH) and 99.9%, respectively, after 2 h filtration. However, after 8 h operation, the water permeability decreased by 70% compared with the initial flux due to the formation of fouling layer of calcium, chloride, sodium, magnesium, and potassium on the membrane surface. PMID:26360750

  13. Managing produced water from coal seam gas projects: implications for an emerging industry in Australia.

    Science.gov (United States)

    Davies, Peter J; Gore, Damian B; Khan, Stuart J

    2015-07-01

    This paper reviews the environmental problems, impacts and risks associated with the generation and disposal of produced water by the emerging coal seam gas (CSG) industry and how it may be relevant to Australia and similar physical settings. With only limited independent research on the potential environmental impacts of produced water, is it necessary for industry and government policy makers and regulators to draw upon the experiences of related endeavours such as mining and groundwater extraction accepting that the conclusions may not always be directly transferrable. CSG is widely touted in Australia as having the potential to provide significant economic and energy security benefits, yet the environmental and health policies and the planning and regulatory setting are yet to mature and are continuing to evolve amidst ongoing social and environmental concerns and political indecision. In this review, produced water has been defined as water that is brought to the land surface during the process of recovering methane gas from coal seams and includes water sourced from CSG wells as well as flowback water associated with drilling, hydraulic fracturing and gas extraction. A brief overview of produced water generation, its characteristics and environmental issues is provided. A review of past lessons and identification of potential risks, including disposal options, is included to assist in planning and management of this industry. PMID:25783163

  14. Development of the first coal seam gas exploration program in Indonesia: Reservoir properties of the Muaraenim Formation, south Sumatra

    Energy Technology Data Exchange (ETDEWEB)

    Sosrowidjojo, I.B. [R and D Centre for Oil and Gas Technology, LEMIGAS, Jakarta (Indonesia); Saghafi, A. [CSIRO Energy Technology, P O Box 330, Newcastle, NSW, 2300 (Australia)

    2009-09-01

    The Late Miocene Muaraenim Formation in southern Sumatra contains thick coal sequences, mostly of low rank ranging from lignite to sub-bituminous, and it is believed that these thick low rank coals are the most prospective for the production of coal seam gas (CSG), otherwise known as coalbed methane (CBM), in Indonesia. As part of a major CSG exploration project, gas exploration drilling operations are being undertaken in Rambutan Gasfields in the Muaraenim Formation to characterize the CSG potential of the coals. The first stage of the project, which is described here, was designed to examine the gas reservoir properties with a focus on coal gas storage capacity and compositional properties. Some five CSG exploration boreholes were drilled in the Rambutan Gasfield, south of Palembang. The exploration boreholes were drilled to depths of {proportional_to} 1000 m into the Muaraenim Formation. Five major coal seams were intersected by these holes between the depths of 450 and 1000 m. The petrography of coal samples collected from these seams showed that they are vitrinite rich, with vitrinite contents of more than 75% (on a mineral and moisture free basis). Gas contents of up to 5.8 m{sup 3}/t were measured for the coal samples. The gas desorbed from coal samples contain mainly methane (CH{sub 4}) ranging from 80 to 93% and carbon dioxide (CO{sub 2}) ranging from 6 to 19%. The composition of the gas released into the production borehole/well is, however, much richer in CH{sub 4} with about 94 to 98% CH{sub 4} and less than 5% CO{sub 2}. The initial results of drilling and reservoir characterization studies indicate suitable gas recovery parameters for three of the five coal seams with a total thickness of more than 30 m. (author)

  15. Coal-ball floras of maritime Canada and palynology of the Foord seam: geologic paleobotanical and paleoecogical implications

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, P.C.; Zodrow, E.L.; Millay, M.A.; Dolby, G.; Gillis, K.S.; Cross, A.T. [US Geological Survey, Reston, VA (United States). National Center

    1997-01-01

    Coal balls in the Canadian Carboniferous System are known from the Clifton Formation (late Bolsovian) of New Brunswick and from the Foord seam (Stellarton Formation, late Bolsovian) of the Stellarton Basin of Nova Scotia. Coal balls from these two units are dominated by arborescent lycopods but ferns, seed ferns, calamiteans, and cordaiteans also occur. Baxter`s 1960 list of coal-ball plants from New Brunswick is updated. The palynomorphs and coal-ball plants of the Foord seam of the Stellarton Basin are illustrated and their paleoecology is discussed. Five genera of arborescent lycopods were present in the Foord swamp: Diaphorodendron, Paralycopodites, Lepidophloios, Sigillaria and Lepidodendron. The first three genera are represented in coal balls; the second two are also represented as compressions in the Foord seam; and all genera are represented in the spore assemblages from the Foord seam. The palynostratigraphy indicates that Sigillaria and Diaphorodendron were almost exclusively confined to the upper bench, whereas the other three genera were probably present in the Foord mire throughout its entire history. Palynomorphic changes in the Foord mire probably reflect gradual changes in wet and dry conditions.

  16. SULPHIDE MINERALIZATION IN UPPER WESTPHALIAN COAL SEAMS FROM THE EASTERN PART OF THE UPPER SILESIAN COAL BASIN

    Directory of Open Access Journals (Sweden)

    Lipiarski Ireneusz

    1997-10-01

    Full Text Available Morphologically diversified sulphide mineralization has been found in No. 301 and 302 coal seams (Westphalian B. The main sulphide is pyrite which forms veinlets cross-cutting the sedimentary fabrics of the coal, encrusts the cellular structures and intergrowths with oxysulphides. Two generations of pyrites were observed: the preceding and the following the oxysulphides. Pyrite composition is stoichiometric, rare admixtures are up to(in wt.%: Mn - 0.19, Co - 0.48, Ni - 0.42 and As - 1.41. Iron oxysulphides contain up to 35.06 wt.% oxygen. Their composition varies between FeS2O and FeS2O3. Increased contents of As (up to 1.46 wt.% and Pb (up to 0.96 wt.% were detected.

  17. Underground pressure appearance laws analysis for fully mechanized top coal slice caving on high-dipping thick coal seams

    Institute of Scientific and Technical Information of China (English)

    YANG Sheng-li; CAO Guang-ming; LI Fu-sheng

    2011-01-01

    Taking Adaohai Coal Mine as the example, underground pressure appearance laws of fully mechanized top coal slice caving on high-dipping and thick coal seams. Through site visit, theoretical analysis and discrete element calculation, the research shows that, as the mining deepens, underground stress of lower sublevels is more obvious and higher than that of upper sublevels and is higher in the air return roadway than that in the air intake roadway in the area that is near to the top coal.Because the top coal is thick and gangue is caved above the support, underground pressure to the working face is relatively gentle. Immediate roof will mainly fall down along the floor. Main roof and the rock bed above the main roof will move to the mined out area along the fault in the early stage and then fall down with the mined out area later. In addition, roof pressure mainly periodically appears in two directions along the trend and the dip.

  18. Brown coal, power plants, briquetes. The north of the Rhenish brown coal district; Braunkohle, Kraftwerke, Briketts. Der Norden des Rheinischen Braunkohlenreviers

    Energy Technology Data Exchange (ETDEWEB)

    Zenker, Peter

    2010-07-01

    The depiction of the history of the brown coal mining industry in the north of the Rhenish brown coal district suggests a description of this section of German industrial history in two independent chapters in the book under consideration. In the first part, the brown coal mining industry in Neurath (Federal Republic of Germany) with its briquette factories is described. The second part describes the lignite mining in Frimmersdorf (Federal Republic of Germany) with its brown coal power stations. Of course, the author of this book also elaborates on the production of peat, because the peat was the only energy supplier prior to brown coal available in these regions.

  19. Depillaring of total thickness of a thick coal seam in single lift using cable bolts:A case study

    Institute of Scientific and Technical Information of China (English)

    Kumar Rakesh; Mishra Arvind Kumar; Singh Arun Kumar; Singh Amit Kumar; Ram Sahendra; Singh Rajendra

    2016-01-01

    Explaining fundamentals of application of cable bolting for a thick seam depillaring, this paper summa-rizes the results of field studies conducted during adoption of this approach in more than fifteen panels of Madhusudanpur 7 pit and incline mine. Nearly 7.0 m thick Kajora top coal seam of this mine is developed on pillars along the floor horizon to an average height of 3.0 m, leaving a coal band of around 4.0 m along the roof. Analysis of procured core samples showed that roof strata are easily caveable with a caveability index value of around 2000 only. Easily caveable overlying strata and shallow depth of cover alleviated most of the expected strata mechanics problems of the thick seam mining. However, extraction of total thickness at shallow cover caused differential-subsidence and cracks on the surface. These manifestations were immediately tackled to avoid creation of a breathing path for spontaneous heating in the extracted area.

  20. Structure instability forecasting and analysis of giant rock pillars in steeply dipping thick coal seams

    Institute of Scientific and Technical Information of China (English)

    Xing-ping Lai; Huan Sun; Peng-fei Shan; Ming Cai; Jian-tao Cao; Feng Cui

    2015-01-01

    Structure stability analysis of rock masses is essential for forecasting catastrophic structure failure in coal seam mining. Steeply dipping thick coal seams (SDTCS) are common in the Urumqi coalfield, and some dynamical hazards such as roof collapse and min-ing-induced seismicity occur frequently in the coal mines. The cause of these events is mainly structure instability in giant rock pillars sand-wiched between SDTCS. Developing methods to predict these events is important for safe mining in such a complex environment. This study focuses on understanding the structural mechanics model of a giant rock pillar and presents a viewpoint of the stability of a trend sphenoid fractured beam (TSFB). Some stability index parameters such as failure surface dips were measured, and most dips were observed to be between 46° and 51°. We used a digital panoramic borehole monitoring system to measure the TSFB’s height (ΔH), which varied from 56.37 to 60.50 m. Next, FLAC3D was used to model the distribution and evolution of vertical displacement in the giant rock pillars;the re-sults confirmed the existence of a TSFB structure. Finally, we investigated the acoustic emission (AE) energy accumulation rate and ob-served that the rate commonly ranged from 20 to 40 kJ/min. The AE energy accumulation rate could be used to anticipate impeding seismic events related to structure failure. The results presented provide a useful approach for forecasting catastrophic events related to structure in-stability and for developing hazard prevention technology for mining in SDTCS.

  1. Investigations into the prediction and modelling of total sulphur in coal seams, German creek mines, Central Queensland

    International Nuclear Information System (INIS)

    Full text: The German Creek Formation contains five laterally persistent coal seam intervals known as the German Creek, Corvus, Tieri, Aquila and Pleiades in ascending order. The principal seam is the German Creek seam but the Aquila seam and, to a lesser extent, the Tieri seam have also been the focus of past open cut mining operations. The coal measures dip generally eastwards and the German Creek seam reaches depths of 600m to 800m at the eastern lease boundary. The majority of German Creek's production is from the German Creek seam, an ortho-bituminous, low ash, medium rank, hard coking coal, primarily for export. Most of the shallow coal in the German Creek sequence has been mined except in the north of the leases where thinner, poorer quality seams remain. Present day production is from three separate mines, German Creek Open-cut, Central and Southern Collieries. There is a systematic variation in rank across the German Creek mining lease, which is exemplified by a regular decrease in volatile matter in the coal from southwest to northeast. Because many of the coal's coking properties are governed by rank, there is a long-range reduction of coking parameters, such as fluidity and dilatation, towards the northeast. By comparison, the sulphur content of some coal seams can, on occasions, widely vary in both a vertical and lateral sense within and between seams, particularly near dykes and seam wash-out areas. This short-range variability creates problems in predicting the sulphur content of washed product coal, with the possibility of coal shipments to customers being rejected if sulphur levels exceed pre-defined limits. Therefore, if patterns in this variability could be determined and related to some geological property or process of formation of the coal seams, then areas of high sulphur might be predicted in advance of mining. The author instigated a background coal characterisation study, as it was seen as an integral part of ongoing investigations aimed

  2. Thermodynamic and kinetic processes associated with CO 2-sequestration and CO 2-enhanced coalbed methane production from unminable coal seams

    OpenAIRE

    Busch, Andreas

    2005-01-01

    The present thesis investigates the thermodynamic and kinetic processes associated with gas sorption (CO2, CH4) on coal. It is incorporated into a research field which studies CO2-sequestration in combination with CO2-enhanced coalbed methane production in unminable coal seams. This combination is regarded as a viable and promising option to reduce anthropogenic CO2-emissions. At the moment numerous world-wide research projects investigate the feasibility of this concept under different geolo...

  3. Assessing Connectivity Between an Overlying Aquifer and a Coal Seam Gas Resource Using Methane Isotopes, Dissolved Organic Carbon and Tritium

    OpenAIRE

    Iverach, Charlotte P.; Cendón, Dioni I.; Hankin, Stuart I.; David Lowry; Fisher, Rebecca E.; France, James L.; Nisbet, Euan G; Andy Baker; Kelly, Bryce F. J.

    2015-01-01

    Coal seam gas (CSG) production can have an impact on groundwater quality and quantity in adjacent or overlying aquifers. To assess this impact we need to determine the background groundwater chemistry and to map geological pathways of hydraulic connectivity between aquifers. In south-east Queensland (Qld), Australia, a globally important CSG exploration and production province, we mapped hydraulic connectivity between the Walloon Coal Measures (WCM, the target formation for gas production) an...

  4. CO2 sequestration in deep coal seams: experimental characterization of the fundamental underlying mechanisms

    Science.gov (United States)

    Pini, R.; Mazzotti, M.

    2012-04-01

    The process of injecting and storing carbon dioxide (CO2) into suitable deep geological formations, such as saline aquifers, (depleted) oil or gas reservoirs, and unmineable coal seams, is referred to as CO2 sequestration. In little more than a decade, this technology has emerged as one of the most important options for reducing CO2 emissions. Among the different options, unmineable coal seams are not as broadly distributed as saline aquifers or oil/gas reservoirs, but their peculiarity resides in the proven capacity of retaining significant amount of gas (mainly methane, CH4) for a very long time. Additionally, the injection of CO2 into the coal reservoir would enhance the recovery of this natural gas, a source of energy that will most likely play a key role in the power sector over the next 20 years from now. This process is called Enhanced Coal Bed Methane (ECBM) recovery and, as for enhanced oil recovery, it allows in principle offsetting the costs associated to the storage operation. A study was undertaken aimed at the experimental characterization of the fundamental mechanisms that take place during the process of injection and storage in coal reservoirs, namely adsorption and swelling (Pini et al 2010), and of their effects on the coal's permeability (Pini et al. 2009), the property that plays a dominant role in controlling fluid transport in a porous rock. An apparatus has been built that allows measuring the permeability of rock cores under typical reservoir conditions (high pressure and temperature) by the so-called transient step method. For this study, a coal core from the Sulcis coal mine in Sardinia (Italy) has been used. In the experiments, an inert gas (helium) was used to investigate the effects of the effective pressure on the permeability of the coal sample, whereas two adsorbing gases (CO2 and N2) to quantify those of adsorption and swelling. The experiments have been interpreted by a one-dimensional model that describes the fluid transport

  5. Significance of Coal Seam in Recognition of Sequence Boundaries and Systems Tract of the Jurassic in East Fukang Slope, Junggar Basin, China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The Jurassic in the East Fukang Slope can be divided into six sequences based on sequence stratigraphy by combining logging, core and seismic data. The indicators of sequence boundaries include unconformity, coal seams,change of spore and pollen abundance, scour surfaces and base conglomerate, change of logging curve and sedimentary facies. How to determine the location of the first flooding surfaces and the maximum flooding surface is the key step to divide the systems tract. There occurred a topographic slope break in the East Fukang Slope when the Jurassic was deposited, and therefore we can recognize the location of the first flooding surface and establish the sequence stratigraphic framework with the slope break in the study area. Coal seams regionally distributed are correlatable and isochronic, and record the termination of a depositional event or episode. So, the regional coal seam (more than 60percent coverage) can be used as the genetic stratigraphic sequence boundary, while locally distributed coal seam (less than 60 percent coverage) can be used as the systems tract boundary. The thick coal seams distributed regionally in the middle of the Badaowan Formation and the lower part of the Xishanyao Formation in the study area act as the sequence boundaries, while the thin and locally distributed coal seam acts as the systems tract boundary, which results in the correlation of the division of sequence stratigraphy of the Jurassic to the whole basin where coal seams are developed extensively.

  6. Improving the CO2 well injectivity and enhanced coalbed methane production performance in coal seams

    International Nuclear Information System (INIS)

    This paper reports on the performance comparison for different CO2-ECBM schemes in relatively thin unminable seams typical of Northern Appalachian coal basin using a horizontal well configuration. Numerical simulations based upon public-domain coalbed reservoir properties indicated that injection of pure CO2 is likely to result in only limited incremental methane recovery if any over primary recovery, due to the low injection rates that can be achieved. On the other hand, the presence of the nitrogen component in the injected gas stream is capable of improving the efficiency of enhanced methane recovery significantly without compromising the net CO2 injection rates, as a result of improved injectivity over pure CO2 injection. There is, however, a trade off between incremental methane recovery and produced gas purity due to early nitrogen breakthrough. (author)

  7. Coal seam gas water: potential hazards and exposure pathways in Queensland.

    Science.gov (United States)

    Navi, Maryam; Skelly, Chris; Taulis, Mauricio; Nasiri, Shahram

    2015-01-01

    The extraction of coal seam gas (CSG) produces large volumes of potentially contaminated water. It has raised concerns about the environmental health impacts of the co-produced CSG water. In this paper, we review CSG water contaminants and their potential health effects in the context of exposure pathways in Queensland's CSG basins. The hazardous substances associated with CSG water in Queensland include fluoride, boron, lead and benzene. The exposure pathways for CSG water are (1) water used for municipal purposes; (2) recreational water activities in rivers; (3) occupational exposures; (4) water extracted from contaminated aquifers; and (5) indirect exposure through the food chain. We recommend mapping of exposure pathways into communities in CSG regions to determine the potentially exposed populations in Queensland. Future efforts to monitor chemicals of concern and consolidate them into a central database will build the necessary capability to undertake a much needed environmental health impact assessment. PMID:24853090

  8. Coal seam gas-supply and impact on U.S. markets and Canadian producers

    International Nuclear Information System (INIS)

    The basic ways in which coalbed methane differs from natural gas are described. Coalbed methane is stored at a higher capacity in the coal seam, has a different production curve, and exploration costs are lower. Comparing a conventional gas well having 2 billion ft3 reserves with coalbed methane wells in the San Juan and Warrior basins, gas from the conventional well costs $1.90 per 1,000 ft3 and methane from the San Juan and Warrior wells costs $1.50 and $2.40 per 1,000 ft3 respectively. A 90 cent per 1,000 ft3 tax credit on coalbed methane reduces the two latter costs significantly and is without doubt the driving force behind the coalbed methane industry in some areas. Examples from the Warrior and San Juan basins are described to illustrate the technology driven economics of coalbed methane. Substantial improvements in gas production can be achieved by such means as multiple seam completion technologies, improved well stimulation, optimum well spacing, and the use of cavitation completion. Technically recoverable coalbed methane resources in the USA are estimated at 145 trillion ft3, concentrated in the western coal basins. At a wellhead price of $2 per 1,000 ft3, the economically recoverable potential is ca 13 trillion ft3. Examining future production potential, by developing new technologies or bringing more basins on stream, production could be increased to ca 3 billion ft3/d in the late 1990s. It is suggested that the increased volumes of coalbed methane have had minimal impact on gas prices. 9 figs., 12 tabs

  9. Slagging behavior of upgraded brown coal and bituminous coal in 145 MW practical coal combustion boiler

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, Katsuya; Pak, Haeyang; Takubo, Yoji [Kobe Steel, Ltd, Kobe (Japan). Mechanical Engineering Research Lab.; Tada, Toshiya [Kobe Steel, Ltd, Takasago (Japan). Coal and Energy Technology Dept.; Ueki, Yasuaki [Nagoya Univ. (Japan). Energy Science Div.; Yoshiie, Ryo; Naruse, Ichiro [Nagoya Univ. (Japan). Dept. of Mechanical Science and Engineering

    2013-07-01

    The purpose of this study is to quantitatively evaluate behaviors of ash deposition during combustion of Upgraded Brown Coal (UBC) and bituminous coal in a 145 MW practical coal combustion boiler. A blended coal consisting 20 wt% of the UBC and 80 wt% of the bituminous coal was burned for the combustion tests. Before the actual ash deposition tests, the molten slag fractions of ash calculated by chemical equilibrium calculations under the combustion condition was adopted as one of the indices to estimate the tendency of ash deposition. The calculation results showed that the molten slag fraction for UBC ash reached approximately 90% at 1,523 K. However, that for the blended coal ash became about 50%. These calculation results mean that blending the UBC with a bituminous coal played a role in decreasing the molten slag fraction. Next, the ash deposition tests were conducted, using a practical pulverized coal combustion boiler. A water-cooled stainless-steel tube was inserted in locations at 1,523 K in the boiler to measure the amount of ash deposits. The results showed that the mass of deposited ash for the blended coal increased and shape of the deposited ash particles on the tube became large and spherical. This is because the molten slag fraction in ash for the blended coal at 1,523 K increased and the surface of deposited ash became sticky. However, the mass of the deposited ash for the blended coal did not greatly increase and no slagging problems occurred for 8 days of boiler operation under the present blending conditions. Therefore, appropriate blending of the UBC with a bituminous coal enables the UBC to be used with a low ash melting point without any ash deposition problems in a practical boiler.

  10. Assessment of shrinkage-swelling influences in coal seams using rank-dependent physical coal properties

    Energy Technology Data Exchange (ETDEWEB)

    Balan, Huseyin Onur [Middle East Technical University, Ankara (Turkey); Gumrah, Fevzi [Middle East Technical University, Ankara (Turkey)]|[Alberta Research Council, Edmonton (Canada)

    2009-01-07

    Characterization of coal reservoirs and determination of in-situ physical coal properties related to transport mechanism are complicated due to having lack of standard procedures in the literature. By considering these difficulties, a new approach has been developed proposing the usage of relationships between coal rank and physical coal properties. In this study, effects of shrinkage and swelling (SS) on total methane recovery at CO{sub 2} breakthrough (TMRB), which includes ten-year primary methane recovery and succeeding enhanced coalbed methane (ECBM) recovery up to CO{sub 2} breakthrough, and CO{sub 2} sequestration have been investigated by using rank-dependent coal properties. In addition to coal rank, different coal reservoir types, molar compositions of injected fluid, and parameters within the extended Palmer and Mansoori (P and M) permeability model were considered. As a result of this study, shrinkage and swelling lead to an increase in TMRB. Moreover, swelling increased CO{sub 2} breakthrough time and decreased displacement ratio and CO{sub 2} storage for all ranks of coal. Low-rank coals are affected more negatively than high-rank coals by swelling. Furthermore, it was realized that dry coal reservoirs are more influenced by swelling than others and saturated wet coals are more suitable for eliminating the negative effects of CO{sub 2} injection. In addition, it was understood that it is possible to reduce swelling effect of CO{sub 2} on cleat permeability by mixing it with N{sub 2} before injection. However, an economical optimization is required for the selection of proper gas mixture. Finally, it is concluded from sensitivity analysis that elastic modulus is the most important parameter, except the initial cleat porosity, controlling SS in the extended P and M model by highly affecting TMRB. (author)

  11. Liptinite as an indicator of environmental changes during formation of coal seam No. 207 (Upper Silesia, Poland)

    Energy Technology Data Exchange (ETDEWEB)

    Jelonek, I.; Kruszewska, K.J.; Filipiak, P. [Faculty of Earth Sciences, University of Silesia, Bedzinska Street, 60, 41-200, Sosnowiec (Poland)

    2007-08-01

    The coal seam No. 207 was a subject of palynological and petrographic studies. According to the results of the vitrinite random reflectance measurements supplemented by moisture and calorific value determinations, the rank of this coal is matching the boundary between sub-bituminous and bituminous coals. The aim was to reconstruct the environmental conditions during the biochemical stage of seam formation, as well as the facies development throughout the seam profile. The maceral (incident and fluorescence mode) and microlithotype compositions (incident light) supplemented by palynological analyses, show that there were two main facies developments. In the authors opinion, they correspond with a phase of ombrogenous, raised bog marked by the presence of crassidurite with Densosporites variabilis and a wet-forest swamp phase represented by vitrite and clarite with more diverse spore assemblage including densospores. Other minor but distinctive sediments, a cannel layer and a reeds facies, both occurring in the lower part of the seam. Above the tonstein horizon, a dry forest type of sedimentation is recognized. (author)

  12. Novel pre-treatment of zeolite materials for the removal of sodium ions: potential materials for coal seam gas co-produced wastewater

    OpenAIRE

    Santiago, Oscar; Walsh, Kerry; Kele, Ben; Gardner, Edward; Chapman, James

    2016-01-01

    Coal seam gas (CSG) is the extraction of methane gas that is desorbed from the coal seam and brought to the surface using a dewatering and depressurisation process within the saturated coalbed. The extracted water is often referred to as co-produced CSG water. In this study, co-produced water from the coal seam of the Bowen Basin (QLD, Australia) was characterised by high concentration levels of Na+ (1156 mg/L), low concentrations of Ca2+ (28.3 mg/L) and Mg2+ (5.6 mg/L), high levels of salini...

  13. Geochemistry and Modes of Occurrence of Hazardous Trace Elements in the No.11 Coal Seam, Antaibao Surface Mine, Shanxi Province

    Institute of Scientific and Technical Information of China (English)

    SONG Dangyu; QIN Yong; WANG Wenfeng; ZHANG Junying; ZHENG Chuguang

    2007-01-01

    Concentrations of seventeen hazardous trace elements including As, Pb, Hg, Se, Cd, Cr, Co,Mo, Mn, Ni, U, V, Th, Be, Sb, Br and Zn in the No.11 coal seam, Antaibao surface mine, Shanxi Province were determined using Instrumental Neutron Activation Analysis (INAA), Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), Cold-Vapor Atomic Absorption Spectrometry (CV-AAS) and Graphite Furnace Atomic Absorption Spectrometry (GF-AAS).Comparisons with average concentrations of trace elements in Chinese coal show that the concentrations of Hg and Cd in the No. 11 coal seam, Antaibao surface mine are much higher. They may be harmful to the environment in the process of utilization. The variations of the trace elements contents and pyritic sulfur in vertical section indicated that: (a) the concentrations of As, Pb, Mn, and pyritic sulfur decrease from roof to floor; (b) the concentrations of Cr, Zn and Mo are higher in roof,floor and lower in coal seam; (c) the concentration of Br, Sb, and Hg are higher in coal seam and lower in roof and floor; (d) the concentrations of Mo, V, Th and Al vary consistently with the ash yield.Cluster analysis of trace elements, pyritic sulfur, ash yield and major elements, such as Al, Fe, P, Ca shows that: (a) pyritic sulfur, Fe, As, Mn, Ni, Be are closely associated and reflect the influence of pyrite; (b) Mo, Se, Pb, Cr, Th, Co, Ca and Al are related to clay mineral, which is the main source of ash; (c) U, Zn, V, Na, P maybe controlled by phosphate or halite; (d) Hg, Br, Sb and Cd may be mainly organic-associated elements which fall outside the three main groups. The concentration distribution characteristics of trace elements in coal seam and the cluster analysis of major and trace elements showed that the contents of trace elements in the No. 11 coal seam, Antaibao surface mine, are mainly controlled by detrital input and migration from roof and floor.

  14. A Combined Micro-CT Imaging/Microfluidic Approach for Understating Methane Recovery in Coal Seam Gas Reservoirs

    Science.gov (United States)

    Mostaghimi, P.; Armstrong, R. T.; Gerami, A.; Lamei Ramandi, H.; Ebrahimi Warkiani, M.

    2015-12-01

    Coal seam methane is a form of natural gas stored in coal beds and is one of the most important unconventional resources of energy. The flow and transport in coal beds occur in a well-developed system of natural fractures that are also known as cleats. We use micro-Computed Tomography (CT) imaging at both dry and wet conditions to resolve the cleats below the resolution of the image. Scanning Electron Microscopy (SEM) is used for calibration of micro-CT data. Using soft lithography technique, the cleat system is duplicated on a silicon mould. We fabricate a microfluidic chip using Polydimethylsiloxane (PDMS) to study both imbibition and drainage in generated coal structures for understating gas and water transport in coal seam reservoirs. First, we use simple patterns observed on coal images to analyse the effects of wettability, cleat size and distribution on flow behaviour. Then, we study transport in a coal by injecting both distilled water and decane with a rate of 1 microliter/ min into the fabricated cleat structure (Figure 1), initially saturated with air. We repeat the experiment for different contact angles by plasma treating the microfluidic chip, and results show significant effects of wettability on the displacement efficiency. The breakthrough time in the imbibition setup is significantly longer than in the drainage. Using rapid video capturing, and high resolution microscopy, we measure the saturation of displacing fluid with respect to time. By measuring gas and liquid recovery in the outlet at different saturation, we predict relative permeability of coal. This work has important applications for optimising gas recovery and our results can serve as a benchmark in the verification of multiphase numerical models used in coal seam gas industry.

  15. Impact of coal seam as interlayer on CO{sub 2} storage in saline aquifers: A reservoir simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Z.J.; Connell, L.D. [CSIRO Earth Science & Resource Engineering, Clayton, Vic. (Australia)

    2011-01-15

    Geological storage of CO{sub 2} is a viable option for the mitigation of greenhouse gas emissions. Two main reservoir types exist; porous formations such as saline aquifers or depleted oil or gas reservoirs and, of lesser importance in terms of storage capacity, coal or shale reservoirs. These reservoirs have distinct storage mechanisms; in the porous formations the CO{sub 2} is stored within the porosity by compression and/or dissolution in the formation fluid, whereas in coal or shale, the CO{sub 2} is primarily stored by adsorption. Geological storage scenarios exist where these two reservoir types could be present within a geological sequence and come into contact with migrating CO{sub 2}. In order to simulate this situation simulators are required which represent the mechanisms operating for both reservoir types. One aspect of the work presented in this paper involves further development of the coal seam gas reservoir simulator, SIMED 11, to include CO{sub 2} dissolution in formation waters and a more accurate Equation of State, the Span and Wagner model, to describe CO{sub 2} density. The second component of this paper involved investigating the potential impact that coal seams could have on CO{sub 2} storage in saline formations. A series of hypothetical cases are constructed to investigate the impact of coal seams as (1) a layer within the target aquifer above the injection point, (2) two layers separated by an aquifer above the injection point, (3) a layer in the target aquifer below the point of injection, and (4) a layer in the overburden. The results show that coal seams can have a significant impact on CO{sub 2} storage and migration behaviour by providing extra storage capacity and influencing the CO{sub 2} flow path both vertically and horizontally.

  16. Wide pillar roadway retained in the deep high gas coal seam

    Institute of Scientific and Technical Information of China (English)

    Pan; Liyou; Feng; Enhu; Zhao; Qingshou; Chen; Liqiang; Kong; Fanpeng

    2012-01-01

    According to the geological and mining conditions of deep high gas coal seam,this paper established the mechanical model of stope surrounding rock,and analyzed the stress distribution and deformation failure mechanism of working face and coal pillar.The research determined the arrangement mode that adjacent working faces retain wide pillar,and the reasonable support method of roadway that the combined support of roof and grouting combined together.The reasonable time of reinforced roadway was determined.Through analyzing the mechanical model of the ways of roadway supporting,this research drew the conclusions as follows:the combined support of roof and working slope improved the support strength and range of surrounding rock,optimized the support by adjusting the angle of anchor,and reached the support requirements by using cement grouting in working slope and chemical grout in roof.The technology was applied in 15104 working face of Baoan Mine,and obtained good results.

  17. Evolution of a mining induced fracture network in the overburden strata of an inclined coal seam

    Institute of Scientific and Technical Information of China (English)

    Wei; Xiujun; Gao; Mingzhong; Lv; Youchang; Shi; Xiangchao; Gao; Hailian; Zhou; Hongwei

    2012-01-01

    The geological conditions of the Pingdingshan coal mining group were used to construct a physical model used to study the distribution and evolution of mining induced cracks in the overburden strata.Digital graphics technology and fractal theory are introduced to characterize the distribution and growth of the mining induced fractures in the overburden strata of an inclined coal seam.A relationship between fractal dimension of the fracture network and the pressure in the overburden strata is suggested.Mining induced fractures spread dynamically to the mining face and up into the roof as the length of advance increases.Moreover,the fractal dimension of the fracture network increases with increased mining length,in general,but decreases during a period from overburden strata separation until the main roof collapses.It is a1so shown that overburden strata pressure plays an important role in the evolution of mining induced fractures and that the fractal dimension of the fractures increases with the pressure of the overburden.

  18. Coupled flow and geomechanical processes during enhanced coal seam methane recovery through CO{sub 2} sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Connell, L.D. [CSIRO Petroleum Resources, Ian Wark Laboratory, Clayton, Victoria (Australia); Detournay, C. [Itasca Consulting Group, Inc., Minneapolis, Minnesota (United States)

    2009-01-07

    The sensitivity of coal permeability to the effective stress means that changes in stress as well as pore pressure within a coal seam lead to changes in permeability. In addition coal swells with gas adsorption and shrinks with desorption; these sorption strains impact on the coal stress state and thus the permeability. Therefore the consideration of gas migration in coal requires an appreciation of the coupled geomechanical behaviour. A number of approaches to representing coal permeability incorporate the geomechanical response and have found widespread use in reservoir simulation. However these approaches are based on two simplifying assumptions; uniaxial strain (i.e. zero strain in the horizontal plane) and constant vertical stress. This paper investigates the accuracy of these assumptions for reservoir simulation of enhanced coalbed methane through CO{sub 2} sequestration. A coupled simulation approach is used where the coalbed methane simulator SIMED II is coupled with the geomechanical model FLAC3D. This model is applied to three simulation case studies assembled from information presented in the literature. Two of these are for 100% CO{sub 2} injection, while the final example is where a flue gas (12.5% CO{sub 2} and 87.5% N{sub 2}) is injected. It was found that the horizontal contrast in sorption strain within the coal seam caused by spatial differences in the total gas content leads to vertical stress variation. Thus the permeability calculated from the coupled simulation and that using an existing coal permeability model, the Shi-Durucan model, are significantly different; for the region in the vicinity of the production well the coupled permeability is greater than the Shi-Durucan model. In the vicinity of the injection well the permeability is less than that calculated using the Shi-Durucan model. This response is a function of the magnitude of the strain contrast within the seam and dissipates as these contrasts diminish. (author)

  19. An evaluation of deep thin coal seams and water-beating/resisting layers in the quaternary system using seismic inversion

    Institute of Scientific and Technical Information of China (English)

    XU Yong-zhong; HUANG Wei-chuan; CHEN Tong-jun; CUI Ruo-fei; CHEN Shi-zhong

    2009-01-01

    Non-liner wave equation inversion, wavelet analysis and artificial neural networks were used to obtain stratum parame-ters and the distribution of thin coal seams. The lithology of the water-bearing/resisting layer in the Quaternary system was also predicted. The implementation process included calculating the well log parameters, stratum contrasting the seismic data and the well logs, and extracting, studying and predicting seismic attributes. Seismic inversion parameters, including the layer velocity and wave impedance, were calculated and effectively used for prediction and analysis. Prior knowledge and seismic interpretation were used to remedy a dearth of seismic data during the inversion procedure. This enhanced the stability of the inversion method. Non-linear seismic inversion and artificial neural networks were used to interpret coal seismic lithology and to study the wa-ter-bearing/resisting layer in the Quaternary system. Interpretation of the 1-2 m thin coal seams, and also of the wa-ter-bearing/resisting layer in the Quaternary system, is provided. The upper mining limit can be lifted from 60 m to 45 m. The pre-dictions show that this method can provide reliable data useful for thin coal seam exploitation and for lifting the upper mining limit, which is one of the principles of green mining.

  20. Environmental impacts of brown coal surface mining and processing

    International Nuclear Information System (INIS)

    The proceedings contain 9 contributions, out of which 2 have been inputted in INIS. These are concerned with the impacts of mining in the North Bohemian Brown Coal Mining District on the air quality and public health, and with the effect of mined-out land reclamation on the environment. (M.D.). 8 tabs., 5 figs., 6 refs

  1. Draft Genome Sequence of Methanobacterium sp. Maddingley, Reconstructed from Metagenomic Sequencing of a Methanogenic Microbial Consortium Enriched from Coal-Seam Gas Formation Water

    OpenAIRE

    Rosewarne, Carly P.; Greenfield, Paul; Li, Dongmei; Tran-Dinh, Nai; Midgley, David J.; Hendry, Philip

    2013-01-01

    The draft genome of Methanobacterium sp. Maddingley was reconstructed from metagenomic sequencing of a methanogenic microbial consortium enriched from coal-seam gas formation water. It is a hydrogenotrophic methanogen predicted to grow using hydrogen and carbon dioxide.

  2. Draft Genome Sequence of Methanobacterium sp. Maddingley, Reconstructed from Metagenomic Sequencing of a Methanogenic Microbial Consortium Enriched from Coal-Seam Gas Formation Water.

    Science.gov (United States)

    Rosewarne, Carly P; Greenfield, Paul; Li, Dongmei; Tran-Dinh, Nai; Midgley, David J; Hendry, Philip

    2013-01-01

    The draft genome of Methanobacterium sp. Maddingley was reconstructed from metagenomic sequencing of a methanogenic microbial consortium enriched from coal-seam gas formation water. It is a hydrogenotrophic methanogen predicted to grow using hydrogen and carbon dioxide. PMID:23405289

  3. Development trends in the Lusatian brown coal mining industry

    International Nuclear Information System (INIS)

    Lusatia has lived on and with brown coal for over 200 years. Brown coal changed what was once a region in which forestry and agriculture predominated into an industrial region. Thanks to its good combustion properties and high energy yield brown coal very soon became known and popular. It was always the driving force for a rapid development which resulted in an economically sound and technically up-to-date industry in Lusatia. This powerful status of brown coal was however soon exploited for aims which were bound to lead to the downfall of two social structures (during the years from 1933 to 1990) by reason of a regime of unconditional autarchy. The economic and technical development thus initiated certainly brought many advantages, but it also had serious diadvantages. Constant increases in production, as a result of which planned rated outputs were intentionally disregarded, were the rule because production targets had to be met or exceeded. Economic inefficiency led to a scarcity of labour and a shortage of finances. Environmental aims had no priority since production was the absolute, primary objective. Consequently, this regime of economic autarchy ended in an one-way street as far as industry was concerned, a situation which was accompanied by an unexampled destruction of the natural basic living conditions and direct, threatening health hazards to man and nature. The year 1990 saw the beginning of the transition from planned controlled economy to free market economy. The reorganization of the former large combines as corporations was not however merely a formal change, but internally also represented a transformation. The brown coal mining industry manifested its new intention and determination to be economically competitive and unsubsidized in future, to operate in such a way as to be compatible with the environment and to exploit reserves carefully, as well as to render its activities socially compatible. (orig.)

  4. The adjusting mining technology of combining fully mechanized with individual prop, rotating, hilt, irregular form, and double unit face on thin coal seam of Tianchen Mine

    Institute of Scientific and Technical Information of China (English)

    SONG Hua-ling; WEN Guo-feng; LI Jin-ke

    2008-01-01

    Analyzed the situations and characteristics of thin coal seam mining and its mining technologies, and introduced the mining innovation technology used by Tianchen Coal Mine of Zhaozhuang Coal Company of China. This innovation technology combined the fully mechanized mining with individual props, and the working face of mining is over length, irregular form and double units. The rotational adjusting mining technology on thin coal seam is also practiced in this new mining technology. The detail technologies, such as outlays of working face and ways, mining methods, equipments of cutting, transporting and sporting, have been introduced. So that, using the synthetic and creative mining tech-nologies, Tianchen Coal Mine solves the mining problems of thin coal seam successfully.

  5. Modeling of Contaminant Migration through Porous Media after Underground Coal Gasification in Shallow Coal Seam

    Czech Academy of Sciences Publication Activity Database

    Soukup, Karel; Hejtmánek, Vladimír; Čapek, P.; Stanczyk, K.; Šolcová, Olga

    2015-01-01

    Roč. 140, DEC (2015), s. 188-197. ISSN 0378-3820 Grant ostatní: RFCS(XE) RFCR-CT-2011-00002 Institutional support: RVO:67985858 Keywords : underground coal gasification * transport phenomena modeling * transport parameters Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.352, year: 2014

  6. Membrane solutions for coal seam methane produced water : case history at Origin Energy, Spring Gully Gas Plant, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Wines, T. [Pall Corp., Port Washington, NY (United States); Blyth, G.; Chalmers, S. [Pall Australia, Melbourne (Australia); Karlapudi, R. [Pall Industrial Water, Port Washington, NY (United States)

    2009-07-01

    Coal seam methane is a significant and emerging source of energy that can be found in Australia, western Canada, the United States, China and India. However, the extraction of methane from coal seams has one particular problem whereby, in many cases, large volumes of water with high levels of dissolved salts are produced along with the gas. This produced water poses an environmental liability, but with proper treatment can be converted into an asset. This paper discussed the use of an integrated membrane system (IMS) consisting of microfiltration coupled with reverse osmosis filtration. A case history at Origin Energy was evaluated where pilot testing was first conducted and later followed by a commercial installation treating nine million liters per day, creating a purified water product that can be used for industrial processes as well as irrigation or discharge into the environment. The paper also presented lessons learned from the pilot phase and explained the experience of the full scale operation demonstrating the advantages of this newly applied technology for coal seam methane production. The IMS system has met Origin Energy's requirements for producing high quality water, and has continued to operate effectively, producing treated water that is well within the Queensland Environmental Protection Agency's guidelines. 6 refs., 1 tab., 11 figs.

  7. Functional composition of humates of brown coal and their stimulating activity

    International Nuclear Information System (INIS)

    Present article is devoted to functional composition of humates of brown coal and their stimulating activity. The results of researches of functional composition of brown and weathered coals and their activity as a growth-promoting factor for agricultural crops were considered. The composition of coals was studied. It was found that application of humates of brown coal is a very important factor for complex rehabilitation of soils and for application in agriculture.

  8. Methanolobus zinderi sp nov., a methylotrophic methanogen isolated from a deep subsurface coal seam

    Energy Technology Data Exchange (ETDEWEB)

    Doerfert, S.N.; Reichlen, M.; Iyer, P.; Wang, M.Y.; Ferry, J.G. [Penn State University, University Park, PA (United States)

    2009-05-15

    A methanogenic organism from the domain Archaea (SD1{sup T}) was isolated from saline water released from a coal seam located 926 m below the surface via a methane-producing well near Monroe, Louisiana, USA. Growth and methanogenesis were supported with methanol, monomethylamine, dimethylamine or trimethylamine, but not with dimethylsulfide, formate, acetate or H{sub 2}/CO{sub 2}. Cells grew in high-salt minimal medium but growth was stimulated with yeast extract or tryptone. Cells were single, non-motile, irregular coccoids 0.5-1.0 {mu} m in diameter and the cell wall contained protein. Conditions for the maximum rate of growth were 40-50{sup o}C, 0.2-0.6 M NaCl, 100- {ge} 200 mM MgCl{sub 2}, and pH 7.0-8.0. The G + C content of the genomic DNA was 42 {+-} 1 mol%. A comparison of 16S rRNA gene sequences indicated that strain SD1{sup T} was most closely related to Methanolobus oregonensis DSM 5435{sup T} with 96% gene sequence similarity. It is proposed that strain SD1{sup T} represents a novel species, Methanolobus zinderi sp. nov. The type strain is SD1{sup T} (=ATCC BAA-1601P{sup T}=DSM 21339{sup T}).

  9. Variable frequency of pulse hydraulic fracturing for improving permeability in coal seam

    Institute of Scientific and Technical Information of China (English)

    Li Quangui; Lin Baiquan; Zhai Cheng; Ni Guanhua; Peng Shen; Sun Chen; Cheng Yanying

    2013-01-01

    Variable frequency, a new pattern of pulse hydraulic fracturing, is presented for improving permeability in coal seam. A variable frequency pulse hydraulic fracturing testing system was built, the mould with triaxial loading was developed. Based on the monitor methods of pressure sensor and acoustic emission, the trials of two patterns of pulse hydraulic fracturing of single frequency and variable frequency were carried out, and at last fracturing mechanism was analyzed. The results show that the effect of variable frequency on fracture extension is better than that of single frequency based on the analysis of macro-scopic figures and AE. And the shortage of single frequency is somewhat remedied when the frequency is variable. Under variable frequency, the pressure process can be divided into three stages: low fre-quency band, pressure stability band and high frequency band, and rupture pressure of the sample is smaller than that of the condition of single frequency. Based on the Miner fatigue theory, the effect of different loading sequences on sample rupture is discussed and the results show that it is better to select the sequence of low frequency at first and then high frequency. Our achievements can give a basis for the improvement and optimization of the pulse hydraulic fracturing technology.

  10. Chemical variability of groundwater samples collected from a coal seam gas exploration well, Maramarua, New Zealand.

    Science.gov (United States)

    Taulis, Mauricio; Milke, Mark

    2013-03-01

    A pilot study has produced 31 groundwater samples from a coal seam gas (CSG) exploration well located in Maramarua, New Zealand. This paper describes sources of CSG water chemistry variations, and makes sampling and analytical recommendations to minimize these variations. The hydrochemical character of these samples is studied using factor analysis, geochemical modelling, and a sparging experiment. Factor analysis unveils carbon dioxide (CO(2)) degassing as the principal cause of sample variation (about 33%). Geochemical modelling corroborates these results and identifies minor precipitation of carbonate minerals with degassing. The sparging experiment confirms the effect of CO(2) degassing by showing a steady rise in pH while maintaining constant alkalinity. Factor analysis correlates variations in the major ion composition (about 17%) to changes in the pumping regime and to aquifer chemistry variations due to cation exchange reactions with argillaceous minerals. An effective CSG water sampling program can be put into practice by measuring pH at the wellhead and alkalinity at the laboratory; these data can later be used to calculate the carbonate speciation at the time the sample was collected. In addition, TDS variations can be reduced considerably if a correct drying temperature of 180 °C is consistently implemented. PMID:23199455

  11. Atmospheric radon, CO2 and CH4 dynamics in an Australian coal seam gas field

    Science.gov (United States)

    Tait, D. R.; Santos, I. R.; Maher, D. T.

    2013-12-01

    Atmospheric radon (222Rn), carbon dioxide (CO2), and methane concentrations (CH4) as well as carbon stable isotope ratios (δ13C) were used to gain insight into atmospheric chemistry within an Australian coal seam gas (CSG) field (Surat Basin, Tara region, Queensland). A˜3 fold increase in maximum 222Rn concentration was observed inside the gas field compared to outside of it. There was a significant relationship between maximum and average 222Rn concentrations and the number of gas wells within a 2 km to 4 km radius of the sampling sites (n = 5 stations; p gas field related to point sources (well heads, pipelines, etc.) and diffse soil sources due to changes in the soil structural and hydrological characteristics. A rapid qualitative assessment of CH4 and CO2 concentration, and carbon isotopes using a mobile cavity ring-down spectrometer system showed a widespread enrichment of both CH4 and CO2 within the production gas field. Concentrations of CH4 and CO2 were as high as 6.89 ppm and 541 ppm respectively compared average concentrations of 1.78 ppm (CH4) and 388 ppm (CO2) outside the gas field. The δ13C values showed distinct differences between areas inside and outside the production field with the δ13C value of the CH4 source within the field matching that of the methane in the CSG.

  12. The effect of zeolite treatment by acids on sodium adsorption ratio of coal seam gas water.

    Science.gov (United States)

    Wang, Xiaoyu; Ozdemir, Orhan; Hampton, Marc A; Nguyen, Anh V; Do, Duong D

    2012-10-15

    Many coal seam gas (CSG) waters contain a sodium ion concentration which is too high relative to calcium and magnesium ions for environment acceptance. Natural zeolites can be used as a cheap and effective method to control sodium adsorption ratio (SAR, which is a measure of the relative preponderance of sodium to calcium and magnesium) due to its high cation exchange capacity. In this study, a natural zeolite from Queensland was examined for its potential to treat CSG water to remove sodium ions to lower SAR and reduce the pH value. The results demonstrate that acid activated zeolite at 30%wt solid ratio can reduce the sodium content from 563.0 to 182.7 ppm; the pH from 8.74 to 6.95; and SAR from 70.3 to 18.5. Based on the results of the batch experiments, the sodium adsorption capacity of the acid-treated zeolite is three times greater than that of the untreated zeolite. Both the untreated and acid-treated zeolite samples were characterized using zeta potential, surface characterization, DTA/TG and particle size distribution in order to explain their adsorption behaviours. PMID:22841594

  13. Deformation effect of lateral roof roadway in close coal seams after repeated mining

    Institute of Scientific and Technical Information of China (English)

    Xie Jianlin; Xu Jialin; Wang Feng; Guo Jiekai; Liu Donglin

    2014-01-01

    This paper analyzed the deformation mechanism in lateral roof roadway of the Ding Wu-3 roadway which was disturbed by repeated mining of close coal seams Wu-8 and Wu-10 in Pingdingshan No. 1 Mine. To determine the strata disturbance scope, the strata displacement angle was used to calculate the protection pillar width. A numerical model was built considering the field geological conditions. In simulation, the mining stress borderline was defined as the contour where the induced stress is 1.5 times of the original stress. Simulation results show the mining stress borderline of the lateral roadway extended 91.7 m outward after repeated mining. Then the original stress increased, deforming the road-way of interest. This deformation agreed with the in situ observations. Moreover, the strata displacement angle changed due to repeated mining. Therefore, reselection of the displacement angle was required to design the protective pillar width. Since a constant strata displacement angle was used in traditional design, the proposed method was beneficial in field cases.

  14. Thick Coal Seam coal movement law studies measured top%厚煤层综放工作面顶煤运移规律实测研究

    Institute of Scientific and Technical Information of China (English)

    牛建忠

    2015-01-01

    为了掌握晋煤集团赵庄二号井厚煤层综放工作面顶煤运移规律,以首个综采工作面1304工作面为工程背景,运用深基点位移法进行现场实测。结果表明:顶煤始动点随煤层位的不同而变化,顶煤层位越高始动点位置越超前,顶煤运移始动点发生在煤壁前方15~20m位置;顶煤从始动点至煤壁位移量远大于煤壁至顶煤冒落的距离;工作面顶煤运移煤壁前以水平运移为主,工作面煤壁后方以垂直运移为主。研究结果为确定合理的放煤工艺参数,提高顶煤回收率提供参考。%In order to grasp the Shanxi Coal zhaozhuang II wells Thick Coal Seam Top Coal shift law, the first fully mechanized coal face to face in 1304 as engineering background, deep-site basis points measured using the displacement method. The results show that:the beginning of the top coal seam bit fixed point with different changes, the higher the top seam bit more ahead of the initiating point, the top coal initiating point shift occurred in the coal wall in front of 15~20m position;top coal from initiating point to the coal wall displacement is much larger than the amount of coal wall to top coal caving distance;former top coal face in the wall to move the horizontal transport of coal-based, face the wall behind the vertical transport of coal-based. The results for the determination of reasonable caving process parameters, increase the top coal recovery rate reference.

  15. Efficient direct coal liquefaction of a premium brown coal catalyzed by cobalt-promoted fumed oxides

    Energy Technology Data Exchange (ETDEWEB)

    Trautmann, M.; Loewe, A.; Traa, Y. [Stuttgart Univ. (Germany). Inst. of Chemical Technology

    2013-11-01

    The search for alternatives in the fuel sector is an important technological challenge. An interim solution could be provided by direct coal liquefaction. Hydrogen economy and the lack of an efficient catalyst are the main obstacles for this process. We used a premium German brown coal with a high H/C molar ratio of 1.25 and nanostructured cobalt catalysts to improve the efficiency of direct coal liquefaction. We were able to recover and recycle the catalyst efficiently and reached good brown coal conversions and oil yields with single-stage coal liquefaction. The oil quality observed almost reached that of a conventional crude oil considering higher heating value (HHV), H/C molar ratio and aliphatic content. (orig.)

  16. Removal of humic substances from water by brown coal sorbents

    Energy Technology Data Exchange (ETDEWEB)

    E.V. Veprikova; A.V. Rudkovskii; M.L. Shchipko [Russian Academy of Sciences, Krasnoyarsk (Russian Federation). Institute of Chemistry and Chemical Technology, Siberian Branch

    2007-12-15

    Brown coal sorption materials with high activity toward humic substances were prepared using a larger scale laboratory unit with a spouted-bed system. The effect of thermal treatment conditions on the sorption properties of these materials was studied. It was found that the sorption activity of the resulting samples toward humates was closely related to the limiting sorption volume of the materials with respect to benzene.

  17. Brown coal coke in biological waste water cleaning

    International Nuclear Information System (INIS)

    Biological sewage plants working by the activated sludge process are often confronted by the following problems: the formation of expanded bubbles, lack of decomposition performance, unstable operation and insufficient excess sludge dewatering. In the former East Germany, there is also the problem of too little nitrificaion/denitrification, caused by obsolete plant. The use of brown coal coke guarantees efficient cleaning of waste water. (orig.)

  18. Empirical-analytical method for evaluating the pressure distribution in the hard coal seams

    Institute of Scientific and Technical Information of China (English)

    KABIESZ Józef; MAKóWKA Janusz

    2009-01-01

    At present, numerical modelling of distributions of many rock mass characteristics plays more and more important role in many geomechanical questions. In the issues related to seismic and rockburst hazards, the analyses of distributions of stress component values in the rock strata are performed, similarly as those of deformation parameters of the strata. To do this, commercial computer programs are used which function on the basis of the finite element-, separate element-, finite difference-, boundary element methods, or individually designed computer programs. They enable to obtain information, unattainable with other methods, being of importance for further concluding on those hazards. The programs based on applying those methods have contributed to important progress and development of science in the domain of analyzing and predicting the hazards. To this end, the commercial computer programs are used that are based on the methods of: finite elements, separate elements, finite differences, boundary elements, etc., or on individually developed computer programs. They enable to obtain information, unavailable using other methods, being of vital importance for further concluding on these hazards. The programs based on these methods have contributed to essential progress and development of science in the field of analysing and predicting the hazards. Apart from their obvious advantages, they have many drawbacks that hinder their practical, routine application. To allow making these type of analyses, without the necessity of constructing complicated models and knowing the detailed geomechanical parameters of rocks, together with laborious computation using a high-rank computer hardware, an analytical-empirical method has been developed at Central Mining Institute, Poland, to make prediction (modelling) of the distribution of pressure values (vertical component of stress) in SIGMAZ coal seams. It is based on geophysical measurements, generalized for the conditions of

  19. Reserve estimation method for Afsin-Elbistan Collolar brown-coal district

    Energy Technology Data Exchange (ETDEWEB)

    Celebi, N.; Erarslan, K.; Pasamehmetoglu, A.G. (Middle East Technical University, Ankara (Turkey). Dept. of Mining Engineering)

    A coal deposit evaluation system developed for reserve estimation at the Afsin-Elbistan Collolar coal deposit in Turkey is described. The thick coal seam has a highly irregular and undilating bottom and therefore the reserve estimation requires prior determination of the pit bottom especially if bucket wheel excavators are used. The coal evaluation system described includes compositing, gridding and reserve estimation facilities and takes into account the economic value of the pit and the pit bottom evaluation. 11 figs., 2 tabs.

  20. Geochemical Characteristics of Trace Elements in the No. 6 Coal Seam from the Chuancaogedan Mine, Jungar Coalfield, Inner Mongolia, China

    Directory of Open Access Journals (Sweden)

    Lin Xiao

    2016-03-01

    Full Text Available Fourteen samples of No. 6 coal seam were obtained from the Chuancaogedan Mine, Jungar Coalfield, Inner Mongolia, China. The samples were analyzed by optical microscopic observation, X-ray diffraction (XRD, scanning electron microscope equipped with an energy-dispersive X-ray spectrometer (SEM-EDS, inductively coupled plasma mass spectrometry (ICP-MS and X-ray fluorescence spectrometry (XRF methods. The minerals mainly consist of kaolinite, pyrite, quartz, and calcite. The results of XRF and ICP-MS analyses indicate that the No. 6 coals from Chuancaogedan Mine are higher in Al2O3, P2O5, Zn, Sr, Li, Ga, Zr, Gd, Hf, Pb, Th, and U contents, but have a lower SiO2/Al2O3 ratio, compared to common Chinese coals. The contents of Zn, Sr, Li, Ga, Zr, Gd, Hf, Pb, Th, and U are higher than those of world hard coals. The results of cluster analyses show that the most probable carrier of strontium in the coal is gorceixite; Lithium mainly occurs in clay minerals; gallium mainly occurs in inorganic association, including the clay minerals and diaspore; cadmium mainly occurs in sphalerite; and lead in the No. 6 coal may be associated with pyrite. Potentially valuable elements (e.g., Al, Li, and Ga might be recovered as byproducts from coal ash. Other harmful elements (e.g., P, Pb, and U may cause environmental impact during coal processing.

  1. Direct measurement of oxygen in brown coals and carbochemical products by means of fast neutron analysis

    International Nuclear Information System (INIS)

    Analyses of elemental oxygen by means of fast neutron activation permit high-accuracy measurements of oxygen concentrations in East German brown coal; this applies to run-of-mine brown coal as well as to demineralized brown coal. The relative error was 4% in the first case and 2% in the latter case. Pre-washing with 1n ammonium acetate solution permits direct analyses of the oxygen bonded to the coal minerals. The method is applicable to other carbonaceous materials, e.g. coal ashes, solid hydrogenation residues, cokes, coal extracts, asphaltenes, oils, etc., at oxygen concentrations of 1-50%. (orig.)

  2. Rheological Behaviors of Bio-degradable Drilling Fluids in Horizontal Drilling of Unconsolidated Coal Seams

    Directory of Open Access Journals (Sweden)

    Cai Jihua

    2011-06-01

    Full Text Available In China, horizontal drilling techniques have been widely used in the exploration of coalbed methane (CBM. The drill-in fluids, especially in unconsolidated coal seams, are typically comprised of cellulose polymers, xanthan polymers and guar gums. However, testing and experience have shown that insufficient degradation of filter cakes resulting from even this “clean” drill-in fluids can significantly impede flow capacity at the wellbore wall. Past approaches to minimizing the damage have been the application of strong acids or oxidative breakers systems. They are often only marginally successful, particularly when applied in extended length intervals. Therefore, this paper introduced an engineered technique incorporating non-toxic, environment friendly and economically attractive bio-degradable drilling fluids (BDF.Extensive lab tests were conducted to evaluate the effects of substrate (polymer type, substrate concentration, enzyme type and enzyme concentration on the viscosity breaking behaviors of BDFs. We got the conclusions as follows. (1 Power Law model was the best model to matching the rheological properties of BDFs; (2 Compared with konjak, the degradations of Na-CMC and guar gum were easier to be controlled; (3 In the degradation of CMC by enzyme SE-1, the optimal weight concentration ratio of CMC to SE-1 was 3 to 1; (4 Of the three enzymes, enzyme SE-2 had the highest activity and could be used to degrade polymer in shorter time; (5 Higher enzyme concentration could speed up the degradation reaction; (6 Viscosity breaking times fluctuating from 13.5 hours to 74.5 hours and viscosity breaking ratios varying from 20% to 100% could be achieved by modifying the formulations of BDFs.

  3. Inferring Hydraulic and Fracture Properties of a Fracked Coal Seam Aquifer by Using GLUE Uncertainty Analysis using TOUGH2 reservoir simulator

    Science.gov (United States)

    Willgoose, G. R.; Askarimarnani, S. S.

    2014-12-01

    Coal seam gas (also called coal bed methane) is a form of natural gas that occurs in some coal seams. In the coal seam gas industry, hydraulic fracturing is performed to enhance the extraction of the gas from the coal seam. This paper presents flow simulation results for a fractured coal seam and its associate production well, and an investigation of the well piezometric head drawdown curves resulting from hydraulic pumping tests. The aim is to infer the hydraulic and fracture properties of the coal and associated well, such as length, width, conductivity of fractures, and the proportion of the water and gas contained in the coal seam. For this purpose the TOUGH2/EOS7C numerical simulator is applied. It is capable of modelling multiphase flow in fractured and porous system. The EOS7C is an "equation of state" module for TOUGH2 that is used to model the methane dissolved and free gas multiphase component. The Wingridder grid generator has been used to generate the 2D, 3D and MINCE (multiple interacting continua) grids for TOUGH2. The simulation results provide some constraints on hydraulic and fracture properties. However, there is still have significant uncertainty. In order to assess the uncertainty and increase our knowledge of the hydraulic properties, uncertainty analysis using the Generalized Likelihood Uncertainty Estimation (GLUE), which is a Monte-Carlo methodology, is applied. We will discuss how the Monte-Carlo uncertainty analyses is used to infer the properties of a hydraulically fractured well from pump test data. One major outcome of this work will be the development of a fast and routine method for assessing the post-development performance and safety of a production gas well, and to provide reassurance that the fracking that has actually occurred in the field is within design parameters.

  4. Non-harmonious deformation controlling of gob-side entry in thin coal seam under dynamic pressure

    Institute of Scientific and Technical Information of China (English)

    Kegong Fan; Hongguang Liang; Chishuai Ma; Chuanwei Zang

    2014-01-01

    The behavior of gob-side entry under dynamic pressure is totally different from the one driven after the movement of overlying strata above the adjacent coalface goaf. The gob-side entry will experience severe roof lateral structural adjustments caused by adjacent coalface mining. Thus the deformation and failure characteristics of narrow coal pillar along the gob should be carefully considered. On the basis of the data of the gob-side entry obtained in a thin coal seam under dynamic pressure, the measures to reinforce the narrow coal pillar are put forward. In addition, the non-harmonious controlling of the rock structures and non-equilibrium gob-side entry deformation is proposed to avoid potential failure. Field practices show that the supporting problems of the gob-side entry under dynamic pressure can be well addressed, which could be used in other similar mining cases.

  5. Sensitivity of detection of fugitive methane emissions from coal seam gas fields

    Science.gov (United States)

    Feitz, A. J.; Berko, H.; Wilson, P.; Jenkins, C.; Loh, Z. M.; Etheridge, D.

    2013-12-01

    There is increasing recognition that minimising methane emissions from the oil and gas sector is a key step in reducing global greenhouse gas emissions in the near term. Atmospheric monitoring techniques are likely to play an important future role in measuring the extent of existing emissions and verifying emission reductions. They can be very suitable for monitoring gas fields as they are continuous and integrate emissions from a number of potential point and diffuse sources that may vary in time. Geoscience Australia and CSIRO Marine & Atmospheric Research have collected three years of continuous methane and carbon dioxide measurements at their atmospheric composition monitoring station ('Arcturus') in the Bowen Basin, Australia. Methane signals in the Bowen Basin are likely to be influenced by cattle production, landfill, coal production, and conventional and coal seam gas (CSG) production. Australian CSG is typically 'dry' and is characterised by a mixed thermogenic-biogenic methane source with an absence of C3-C6+ alkanes. The range of δ13C isotopic signatures of the CSG is similar to methane from landfill gas and cattle emissions. The absence of standard in-situ tracers for CSG fugitive emissions suggests that having a comprehensive baseline will be critical for successful measurement of fugitive emissions using atmospheric techniques. In this paper we report on the sensitivity of atmospheric techniques for the detection of fugitive emissions from a simulated new CSG field against a three year baseline signal. Simulation of emissions was performed for a 1-year period using the coupled prognostic meteorological and air pollution model TAPM at different fugitive emission rates (i.e. estimates of <1% to up to 10% of production lost) and distances (i.e. 10 - 50 km) from the station. Emissions from the simulated CSG field are based on well density, production volumes, and field size typical of CSG fields in Australia. The distributions of the perturbed and

  6. Numerical modeling of Gondwana coal seams in India as coalbed methane reservoirs substituted for carbon dioxide sequestration

    International Nuclear Information System (INIS)

    India has recently witnessed the production of coalbed methane (CBM) on a commercial scale. The analysis of Garg and Shukla (2009) summarizes that initial carbon dioxide storage opportunities should be ventured in CBM sector where the effective cost of the process is partly lowered due to enhanced recovery of methane. This research work was carried out to understand and establish the technical feasibility of CO2 driven enhanced CBM recovery in Indian coals. A regional scale underground coal seam/block was modeled using a commercial reservoir simulator, COMET3. It was found that approximately 218 Mm3 of CO2 can be sequestered in place of 74 Mm3 of CH4 produced from the chosen dimensions of coal block. The changes in fracture gas saturation, matrix CO2 concentration and matrix CH4 concentration with space and time were monitored. Eventually, the numerical values for peak saturation at certain time intervals have been reported. This study is an initial technical estimate for CO2 driven ECBM (enhanced coalbed methane) at a regional scale in India. The results are expected to prove useful not only to reduce India's contribution to greenhouse gases emission into the atmosphere but also to partially meet with the growing energy demand by enhanced recovery of methane from deep, unminable coal seams. -- Highlights: ► Critical numerical simulation of storage of CO2 in coal vis-à-vis capture of natural gas. ► Approximately 218 Mm3 of CO2 can be sequestered in the chosen dimensions of Gondwana coal block. ► A total of 74 Mm3 of CH4 can be produced for the period of study (4000 days). ► Monitoring matrix gas saturation, fracture CO2-CBM saturation with space and time. ► A brief review on possible CO2 sinks in India.

  7. 保护层开采被保护层卸压增透效果的应用研究%Effect of protective seam mining on pressure relief and permeability enhancement of protected coal seam

    Institute of Scientific and Technical Information of China (English)

    冯拥军; 周玉军; 张喜传

    2014-01-01

    In view of the coal seam occurrence condition and geological condition of the west-ern region of Henan Province,the gas pressure releasing and drainage in protective coal seam was designed and the drilling design was investigated. In addition,the gas parameters and the dis-placement of roof and floor of B1 coal seam were determined. The research results showed that after the protective seam mining,coal seam gas pressure was decreased from the original 0.9 MPa to 0.12 MPa,the original gas content was reduced from the previous 6.52 m3/t to 3.1 m3/t,the expansion deformation of roof and floor reached 20.6 ‰,and the coal seam permeability coefficient was increased 810 times,so that the outburst danger at No. 12112 working face of B1 coal seam was eliminated in the pressure released area.%针对豫西煤田煤层赋存情况及地质状况,设计了被保护层的卸压抽采方案及考察钻孔,对瓦斯基础参数和二1煤层的煤层顶底板移近量进行了测定.研究结果表明,二1煤层在受到保护层开采后,煤层瓦斯压力由原始的0.9 MP a降为0.12 MP a ,原始瓦斯含量由以前的6.52 m3/t降为3.1 m3/t,顶底板膨胀变形量达到20.6‰,煤层透气性系数增大了810倍,在卸压区内完全消除了二1煤层12112工作面的突出危险性.

  8. “Community perspectives of natural resource extraction: coal-seam gas mining and social identity in Eastern Australia”

    Directory of Open Access Journals (Sweden)

    D. Lloyd

    2014-01-01

    Full Text Available Using a recent case study of community reaction to proposed coal - seam gas mining in eastern Australia, we illustrate the role of community views in issues of natural resource use. Drawing on interviews, observations and workshops, the paper explores the anti - coal - seam gas social movement from its stages of infancy through to being a national debate linking community groups across and beyond Australia. Primary community concerns of inadequate community consultation translate into fears regarding potential impacts o n farmland and cumulative impacts on aquifers and future water supply, and questions regarding economic, social and environmental benefits. Many of the community activists had not previously been involved in such social action. A recurring message from aff ected communities is concern around perceived insufficient research and legislation for such rapid industrial expansion. A common citizen demand is the cessation of the industry until there is better understanding of underground water system interconnectiv ity and the methane extraction and processing life cycle. Improved scientific knowledge of the industry and its potential impacts will, in the popular view, enable better comparison of power generation efficiency with coal and renewable energy sources and better comprehension of the industry as a transition energy industry . It will also enable elected representatives and policy makers to make more informed decisions while developing appropriate legislation to ensure a sustainable future.

  9. Enrichment of Radon and Carbon Dioxide in the Open Atmosphere of an Australian Coal Seam Gas Field

    OpenAIRE

    Tait, Douglas R.; Santos, Isaac R.; Maher, Damien T.; Cyronak, Tyler J.; Davis, Rachael J.

    2013-01-01

    Atmospheric radon (222Rn) and carbon dioxide (CO2) concentrations were used to gain insight into fugitive emissions in an Australian coal seam gas (CSG) field (Surat Basin, Tara region, Queensland). 222Rn and CO2 concentrations were observed for 24 h within and outside the gas field. Both 222Rn and CO2 concentrations followed a diurnal cycle with night time concentrations higher than day time concentrations. Average CO2 concentrations over the 24-h period ranged from ∼390 ppm at the control s...

  10. Organic geochemistry of the Lower Suban coal seam, South Sumatra Basin, Indonesia: Palaeoecological and thermal metamorphism implications

    Energy Technology Data Exchange (ETDEWEB)

    Amijaya, H.; Schwarzbauer, J.; Littke, R. [University of Aachen, Aachen (Germany)

    2006-07-01

    Hydrocarbons extracted from the Tertiary age coals from the Lower Suban seam, South Sumatra Basin, Indonesia have been investigated using gas chromatography (GC) and combined gas chromatography/mass spectrometry (GC/MS). Low rank (vitrinite-huminite reflectance about to 0.41-0.45%) coals from the Tambang Air Laya mine represent different maceral assemblages of an ideal succession of ombrogenous palaeo-peat development in a vertical section. High rank coals (vitrinite reflectance about to 1.42-5.18%) from the Suban mine have been thermally metamorphosed by an andesitic intrusion. Variations in the distributions of n-alkanes, isoprenoids and saturated and aromatic biomarkers in the low rank coals reflect variations in local source input and palaeomire conditions. Terpenoid biomarkers, such as cadinane- and eudesmane-type sesquiterpenoids and oleanane- and ursane-type triterpenoids, indicate the predominance of angiosperm plants in the palaeomire, particularly Dipterocarpaceae. The distribution of hopanoids is affected by the organic facies of the coal and their maturity, and correlates with the palaeomire evolution as derived from petrological studies. Close to the igneous intrusion, rapid thermal stress has destroyed most of the biomarkers, but variations in n-alkane distributions, attributable to palaeomire conditions, remain. Reversals in the trends for molecular parameters based on aliphatic hydrocarbons (n-alkane distribution and pristane/phytane ratio) and aromatic hydrocarbons (methyl phenanthrenes) with coal rank are observed.

  11. Numerical simulation and experiment analysis of improving permeability by deep-hole presplitting explosion in high gassy and low permeability coal seam

    Institute of Scientific and Technical Information of China (English)

    CAI Feng; LIU Ze-gong; LIN Bai-quan; LI Wei

    2009-01-01

    Created a new damage model for explosive for LS-DYNA3D, taking advantage of the Taylor method aimed at the high gassy and low permeability coal seam, and nu-merically simulated and analyzed the deep-hole presplitting explosion. The entire process of explosion was represented, including cracks caused by dynamic pressure, transmission and vibration superposition of stress waves, as well as cracks growth driven by gas gen-erated by explosion. The influence of the cracks generated in the process of explosion and the performance of improving permeability caused by the difference of interval between explosive holes were analyzed. A reasonable interval between explosive holes of deep-hole presplitting explosions in high gassy and low permeability coal seams was proposed, and the resolution of gas drainage in high gassy and low permeability coal seam was put forward.

  12. Chemical composition of asphaltenes from thermal dissociation of brown coal

    Energy Technology Data Exchange (ETDEWEB)

    Evstaf' ev, S.N.; Denisova, T.I.; Tuturina, V.V.

    1987-07-01

    Investigates chemical composition of asphaltenes and preasphaltenes separated from liquid products of thermal dissociation of Azeisk deposit brown coal in tetralin. Asphaltenes and preasphaltenes represent a mixture of mainly aromatic compounds containing bi- and tri-cyclic aromatic fractions differing by length of aliphatic substituents and by distribution of oxygen-containing functional groups. Describes tests carried out at 300-420 C in autoclaves using 0.1-0.3 mm coal particles and tetralin containing decalin (2.8%) and naphthalene (5.2%). Establishes that asphaltenes soluble in acetone are represented by low-molecular saturated compounds; about 60% of oxygen in asphaltenes and preasphaltenes is attached to ethereal and heterocyclic structure groups. 10 refs.

  13. Suitable layout of gate roads related to slice mining in an ultra-thick unstable coal seam

    Institute of Scientific and Technical Information of China (English)

    Fan Gangwei; Zhang Dongsheng; Zhou Lei

    2011-01-01

    We determined a suitable gate road layout in slice mining in an ultra-thick unstable coal seam,using theoretical analysis and numerical calculations.Based on plasticity theory in terms of limiting equilibrium,the width of chain pillar in the upper slice was calculated to be 18 m.The stress distribution in the chain pillar after the upper slice was mined out was described with numerical simulation.The extent of the effect of stress on the upper chain pillar on the lower solid coal was obtained on the basis of an elastic solution of a distributed force loaded on a half-plane.Three layout designs for lower gate roads were proposed and a stability factor was introduced to analyze the stability of the lower pillar with numerical calculation.Gate road translation was determined as the most suitable layout method,which maximizes the extraction rate on the basis of the pillar stability.

  14. Analysis of alternatives for using cable bolts as primary support at two low-seam coal mines

    Institute of Scientific and Technical Information of China (English)

    Esterhuizen Gabriel S; Tulu Ihsan B

    2016-01-01

    Cable bolts are sometimes used in low-seam coal mines to provide support in difficult ground conditions. This paper describes cable bolting solutions at two low-seam coal mines in similar ground conditions. Both mines used support systems incorporating cable bolts as part of the primary support system. Two original cable bolt based support systems as well as two modified systems are evaluated to estimate their ability to prevent large roof falls. One of the support systems incorporated passive cable bolts, while the other used pre-tensioned cable bolts. The results and experience at the mines showed that the mod-ified systems provided improved stability over the original support systems. The presence of the cable bolts is the most important contribution to stability against large roof falls, rather than the details of the support pattern. It was also found that a heavy steel channel can improve the safety of the system because of the‘sling’ action it provides. Additionally, the analysis showed that fully-grouted rebar bolts load much earlier than the cable bolts, and pre-tensioning of the cable bolts can result in a more uniform distribution of loading in the roof.

  15. A reactive transport modelling approach to assess the leaching potential of hydraulic fracturing fluids associated with coal seam gas extraction

    Science.gov (United States)

    Mallants, Dirk; Simunek, Jirka; Gerke, Kirill

    2015-04-01

    Coal Seam Gas production generates large volumes of "produced" water that may contain compounds originating from the use of hydraulic fracturing fluids. Such produced water also contains elevated concentrations of naturally occurring inorganic and organic compounds, and usually has a high salinity. Leaching of produced water from storage ponds may occur as a result of flooding or containment failure. Some produced water is used for irrigation of specific crops tolerant to elevated salt levels. These chemicals may potentially contaminate soil, shallow groundwater, and groundwater, as well as receiving surface waters. This paper presents an application of scenario modelling using the reactive transport model for variably-saturated media HP1 (coupled HYDRUS-1D and PHREEQC). We evaluate the fate of hydraulic fracturing chemicals and naturally occurring chemicals in soil as a result of unintentional release from storage ponds or when produced water from Coal Seam Gas operations is used in irrigation practices. We present a review of exposure pathways and relevant hydro-bio-geo-chemical processes, a collation of physico-chemical properties of organic/inorganic contaminants as input to a set of generic simulations of transport and attenuation in variably saturated soil profiles. We demonstrate the ability to model the coupled processes of flow and transport in soil of contaminants associated with hydraulic fracturing fluids and naturally occurring contaminants.

  16. Induced drill-spray during hydraulic slotting of a coal seam and its influence on gas extraction

    Institute of Scientific and Technical Information of China (English)

    Shen Chunming; Lin Baiquan; Zhang Qizhi; Yang Wei; Zhang Lianjun

    2012-01-01

    Hydraulic slotting can induce drill spray in a gassy,low permeability coal seam.This then influences subsequent gas extraction.This paper describes the drill spray phenomenon from a mechanical perspective and analyzes the effects of water jet damage during slotting.A simulation of the stresses around the drill hole and slot was prepared using FLAC-3D code.It helps explain the induction of drill spray during hydraulic slotting.The stress concentration around the bore increases as the diameter of the hole increases.As the hole enlarges the variation in stress also increases,which introduces an instability into the coal.This allows easy breaking and removal of the coal.Destruction of the coal structure by the water jet is the major factor causing drill spray.Energy stored as either strain or gas pressure is released by the water jet and this causes the coal to fracture and be expelled from the hole.Field tests showed the effect on gas extraction after slotting with drill spray.The concentration of gas increases after drilling.Compared to conventional techniques,the hydraulic slotted bore gives a gas concentration three times higher and has an effective range twice as far.This makes the gas extraction process more efficient and allows reduced construction effort.

  17. Data base for the analysis of compositional characteristics of coal seams and macerals. Part 7. Petrographic variation due to depositional setting of the lower Kittanning seam, western Pennsylvania. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Allshouse, S.D.; Davis, A.

    1984-01-01

    Detailed megascopic and microscopic petrographic analyses were conducted on samples of the Lower Kittanning seam from western Pennsylvania. Relationships were sought between the paleoenvironmental setting of the coal swamp and the vertical and lateral variability of lithotypes, maceral composition and vitrinite types. Megascopically, the four samples collected from the freshwater facies of the seam are similar in appearance and relative lithotype composition, and display no distinct vertical zonations. The sample from the marine-influenced central portion of the basin (PSOC-1340) possesses a marked vertical zonation into a bright lower zone and a dull upper zone. The lower zone is similar in appearance to the freswater samples. Detailed microscopic analyses revealed that the vertical zonation of PSOC-1340 is apparent in both the maceral and vitrinite type composition. No similar zonation is apparent in the microscopic analysis of the four freshwater facies samples. Similarities between the lower zone of PSOC-1340 and the whole seam of the freshwater samples are most apparent in the vitrinite-type analysis. The lower zone of PSOC-1340 and the whole seam from the freshwater facies are considered to be laterally equivalent coal types. The dull upper zone of PSOC-1340 is considered to have formed in response to a major change in the paleoenvironment of the swamp, probably a marine transgression. 49 references, 25 figures, 15 tables.

  18. The Outburst Risk as a Function of the Methane Capacity and Firmness of a Coal Seam

    Science.gov (United States)

    Wierzbicki, Mirosław; Skoczylas, Norbert

    2014-12-01

    In most coal basins that are currently being exploited, gas and rock outbursts pose a considerable safety threat. The risk of their occurrence is frequently assessed by means of a parameter known as the methane capacity of coal. In a lot of countries, the evaluation of the mechanical properties of coal is conducted by means of another parameter: the firmness of coal. Due to the laboratory investigations and in situ observations carried out by the authors of this paper, it was possible to determine a function space in which the outburst risk can be described as a function of the methane capacity and firmness of a coal seam. This, in turn, made it possible to link the "gas factor" to the "mechanical factor", and thus provide a more comprehensive risk analysis. Wyrzuty gazów i skał stanowią duże zagrożenie w większości obecnie eksploatowanych zagłębi węglowych. Bardzo często wykorzystywanym parametrem oceny stanu zagrożenia wyrzutowego jest zawartość metanu w węglu. W wielu krajach do oceny mechanicznych parametrów węgla wykorzystuje się zwięzłość. Autorzy przeprowadzili badania laboratoryjne polegające na prowokacjach wyrzutów w skali laboratoryjnej. Jako materiał badawczy wykorzystane zostały brykiety węglowe. W trakcie badań wstępnych ustalona została zależność pomiędzy porowatością brykietów, a ich zwięzłością f oraz pomiędzy ciśnieniem nasycania metanem, a wskaźnikiem intensywności desorpcji dP. Pozwoliło to na przygotowywanie eksperymentów o kontrolowanych parametrach gazowych (wskaźnik intensywności desorpcji) oraz wytrzymałościowych (zwięzłość). Opracowana została metoda kontrolowania intensywności prowokacji wyrzutu poprzez określenie tempa spadku ciśnienia gazu przed czołem brykietu. Dzięki temu dla siatki parametrów f-dP możliwe było poszukiwanie minimalnej, skutecznej intensywności prowokacji wyrzutu. Znormalizowana wartość stałej czasowej spadku ciśnienia przed czołem brykietu powoduj

  19. Pyrolysis of Compositions of Mixtures of Combustible Shales and Brown Coals Deposited in Belarus

    Science.gov (United States)

    Lishtvan, I. I.; Dudarchik, V. M.; Kraiko, V. M.; Belova, Yu. V.

    2013-11-01

    This paper presents the results of investigating the pyrolysis of compositions of mixtures of brown coals and combustible shales in a close-packed and a moving layer and the yield dynamics of the pyrolysis gas and resin. A comparative analysis of the quality of pyrolysis products obtained from combustible shales and brown coal and from their mixtures has been performed.

  20. A sequential approach to control gas for the extraction of multi-gassy coal seams from traditional gas well drainage to mining-induced stress relief

    International Nuclear Information System (INIS)

    Highlights: • The gas reservoirs characteristics are measured and analyzed. • A sequential approach to control gas of multi-gassy coal seams is proposed. • The design of gas drainage wells has been improved. • The utilization ways of different concentrations of gas production are shown. - Abstract: As coal resources become exhausted in shallow mines, mining operations will inevitably progress from shallow depth to deep and gassy seams due to increased demands for more coal products. However, during the extraction process of deeper and gassier coal seams, new challenges to current gas control methods have emerged, these include the conflict between the coal mine safety and the economic benefits, the difficulties in reservoirs improvement, as well as the imbalance between pre-gas drainage, roadway development and coal mining. To solve these problems, a sequential approach is introduced in this paper. Three fundamental principles are proposed: the mining-induced stress relief effect of the first-mined coalbed should be sufficient to improve the permeability of the others; the coal resource of the first-mined seams must be abundant to guarantee the economic benefits; the arrangement of the vertical wells must fit the underground mining panel. Tunlan coal mine is taken as a typical example to demonstrate the effectiveness of this approach. The approach of integrating surface coalbed methane (CBM) exploitation with underground gas control technologies brings three major benefits: the improvement of underground coal mining safety, the implementation of CBM extraction, and the reduction of greenhouse gas emissions. This practice could be used as a valuable example for other coal mines having similar geological conditions

  1. Geochemistry of the late Permian No. 30 coal seam, Zhijin Coalfield of Southwest China: influence of a siliceous low-temperature hydrothermal fluid

    International Nuclear Information System (INIS)

    This paper describes the influence of siliceous low-temperature hydrothermal fluid on the elemental concentrations and mineralogical characteristics of the late Permian anthracitic (Ro,max=3.58%) coal seam (No. 30) from the Zhijin Coalfield in western Guizhou Province, SW China. Coal samples were examined using instrumental neutron activation analysis, inductively coupled plasma-mass spectroscopy, inductively coupled plasma-atomic emission spectrometry, X-ray fluorescence, powder X-ray diffraction, scanning electron microscopy equipped with energy-dispersive X-ray, and isotope analysis. The modes of occurrence of elements were determined using a sequential chemical extraction procedure. The studies indicate that the No. 30 coal seam has a very high content of veined quartz (vol. 9.4%), whose isotope values of δ30Si and δ18O are 0.6 per mille and 15.4 per mille, respectively, indicating that the quartz originated from siliceous low-temperature hydrothermal fluid (formation temperature 160-220 deg. C) rather than detrital material of terrigenous origin or magmatic hydrothermal inputs. Results of scanning electron microscopy equipped with energy-dispersive X-ray and sequential chemical extraction procedure show that the veined quartz is the dominant source of Fe, Cu, U, Pd, Pt and Ir, which are as high as 2.31%, 356, 8, 2.1, 2.43, and 0.006 μg/g in this coal seam, respectively. The studies have also found that elements, such as Fe and Cu are mainly in the veined quartz and they do not occur as sulfides in this coal seam, in sharp contrast to many other coal seams in China. The geochemical and mineralogical anomalies of the coal are attributed to the siliceous low-temperature hydrothermal fluid

  2. Fossil rubber in brown coal deposits: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Mahlberg, P.G.; Stoerr, M. (Indiana University, Bloomington (USA))

    1989-01-01

    Fossil rubber strands of middle Eocene from Geiseltal and Harpke brown coal deposits in the GDR are angiospermous remains of the branched nonarticulated laticifer cell. The cis-1,4-polyisoprene rubber was cribriform in appearance indicating possibly that it polymerized around protoplasmic components during fossilization. Cell morphology and thermal analyses of rubber hydrocarbons indicate that the deposits were not subjected to high pressure or temperatures during fossilization. The similarity of profiles for hydrocarbons extractable only from the rubber indicates their presence in the original living cell and identifies the samples to be derived from the same species. Sulfur accumulated nearly all as organic sulfur to higher levels in the rubber than in the gel. Morphological and chemical data show the laticifer to be a highly specialized cell already in the Eocene and provide new insight for interpreting the age of Angiosperms. Presence of predominantly organic sulfur with greater deposition in rubber than gel indicates the unique environmental condition related to sulfur deposition and provides the basis for a better understanding of sulfur fixation in brown coal. 23 refs., 12 figs., 2 tabs.

  3. Modelling of a coal seam of the deposit Đurđevik (BiH) by means of 2D reflection seismic imaging

    Science.gov (United States)

    Arsenović, Siniša; Urošević, Milovan; Sretenović, Branislav; Cvetkov, Vesna; Životić, Dragana

    2016-06-01

    A low cost 2D reflection seismic survey was used to map the continuity of the main seams as well as the numerous faults at the Đurđevik sub-bituminous coal deposit (BiH). A 24-channel seismic data acquisition system was available for this survey. The natural high reflectivity of the coal seams and a favourable geometry of seismic profiles enabled the identification and correlation of major faults across the area. Rugged terrain presented challenges to both data acquisition and processing. Stacks of acceptable quality were obtained only after the application of surface consistent statics and careful application of multi-channel filtering. A set of recorded 2D lines was interpreted in a 3D environment. Inferred structural elements disrupting the seam continuity were identified and were in agreement with available drilling results and mine workings. The result of this work was used to reduce mining hazards and also to help optimise mine planning.

  4. 大采高夹矸煤层片帮机理%The Spalling Mechanism in Large Mining Height Tonstein Coal Seam

    Institute of Scientific and Technical Information of China (English)

    张建生

    2012-01-01

    With the research technique of the compressive stress experiment in laboratory, theoretical analysis and the field measure- ment, taking the actual production of large mining height working face in Hedong coal mine as background, the spalling mechanism in working face of large mining height tonstein coal seam has been studied. The research indicated that the single axle compressive strength of non - coupling superposition specimens is larger than the pure coal sample intensity without tonstein, and the deformation a- mount is smaller than pure coal sample. The theory analysis of the coal wall spalling model indicated that the main influencing factors for the coal wall stability is the coal seam'whole height, under the same external force condition, more higher of the coal seam height is, more easier of the coal wall instability is, the tonstein layers reduce the overall thickness of coal seam effectively, the spalling degree of the working face is obviously small. The rib spalling phenomenon of the tonstein coal seam mainly occured in the upside position of the 10^# coal seam in Hedong coal mine, the rib spalling area is not big, and the influence degree is also small.%采用实验室内试块压力实验、理论分析及现场实测相结合的研究方法,以河东煤矿大采高工作面生产实际为背景,对大采高夹矸煤层工作面片帮作用机理进行分析。研究表明:夹矸及薄煤块不耦合叠加试件单轴抗压强度较不含夹矸的纯煤样强度有所增大,而变形量较纯煤样变形有所减小;煤壁片帮模型理论分析表明,煤层整体高度对煤壁稳定性影响较大,在相同外力条件下,高度越大,煤壁越容易失稳,夹矸层有效减小煤层整体厚度,工作面分层片帮严重程度明显较小;河东煤矿夹矸煤层片帮现象主要发生在10^#煤层靠上部位置,片帮面积不大,影响程度较小。

  5. JV Task 109 - Risk Assessment and Feasibility of Remedial Alternatives for Coal Seam at Garrison, North Dakota

    Energy Technology Data Exchange (ETDEWEB)

    Jarda Solc

    2008-01-01

    The Energy & Environmental Research Center (EERC) conducted an evaluation of alternative technologies for remediation of hydrocarbon-contaminated coal seam, including impacted soils and groundwater in Garrison, North Dakota. Geotechnical characteristics of the impacted fractured coal seam provide for rapid off-site contaminant transport, with the currently identified impacted zone covering an area of about 40 acres. Regardless of the exposure mechanism (free, dissolved, or vapor phase), results of laboratory tests confirmed secondary release of gasoline-based compounds from contaminated coal to water reaching concentrations documented from the impacted areas. Coal laboratory tests confirmed low risks associated with spontaneous ignition of gasoline-contaminated coal. High contaminant recovery efficiency for the vacuum-enhanced recovery pilot tests conducted at three selected locations confirmed its feasibility for full-scale remediation. A total of 3500 gallons (13.3 m{sup 3}) of contaminated groundwater and over 430,000 ft{sup 3} (12,200 m{sup 3}) of soil vapor were extracted during vacuum-enhanced recovery testing conducted July 17-24, 2007, resulting in the removal of about 1330 lb (603 kg) of hydrocarbons, an equivalent of about 213 gallons of product. The summary of project activities is as follows: (1) Groundwater and vapor monitoring for existing wells, including domestic wells, conducted on a monthly basis from December 12, 2006, to June 6, 2007. This monitoring activity conducted prior to initiation of the EERC field investigation was requested by NDDH in a letter dated December 1, 2006. (2) Drilling of 20 soil borings, including installation of extraction and monitoring wells conducted April 30-May 4 and May 14-18, 2007. (3) Groundwater sampling and water-table monitoring conducted June 11-13, 2007. (4) Evaluation of the feasibility of using a camera survey for delineation of mining voids conducted May 16 and September 10-11, 2007. (5) Survey of all wells

  6. 远距离保护层开采煤层渗透特性及瓦斯抽采技术研究%Study on permeability characteristic of coal seam and gas extraction techniques in coal mining with long distance protection coal seam

    Institute of Scientific and Technical Information of China (English)

    王文; 李化敏; 高保彬; 李东印

    2014-01-01

    依据平顶山矿区某矿的丁、戊组煤层(间距90m)的地质条件,采用实验室试验、数值模拟和现场试验相结合的方式,对远距离下保护层开采煤层渗透特征及瓦斯抽采技术展开探讨。运用自制的煤-气耦合系统进行了大尺寸煤样的加载试验,试验将煤样加载及裂隙发展分原生微孔隙压密阶段、煤样的弹性变形阶段、膨胀破坏阶段和峰后的破坏阶段四阶段,卸载后煤样孔隙不闭合,渗透系数仍能保持高位运行;并对现场丁组煤的卸压区域进行参数测试,卸压效果明显,煤层透气性系数增加720~1550倍,卸压范围内的煤层煤与瓦斯突出危险性消除;根据对被保护层裂隙场形成分析,提出了煤与瓦斯共采中卸压瓦斯抽采钻孔抽采最佳时机,实现了戊组煤开采与丁组煤瓦斯抽采在时间、空间上的有序配合。%According to the geological conditions of Ding group coal seams and Wu coal group seams( the separation distance of them was 90 meters) in Pingdingshan mine area, the characteristics of coal seam permeability and the gas extraction techniques with the influence of long distance protection coal seam were studied by adopting various methods including laboratory tests, numerical simulation, as well as field tests.The loading tests on the large di-mension coal samples were conducted by the self-developed coal-gas coupling system.It showed that there are four stages in the coal sample loading and fracture development process, including primary micropore pressurization stage, coal sample elastic deformation stage, drum-expansion destruction stage and post-peak destruction stage.In addition, the micro pores in the sample are not closed and the permeability coefficient is still high after unloading. Field tests on parameters in the destressed zone of Ding seams revealed that the effect of pressure relief was obvi-ous, the permeability coefficient of coal seam

  7. THE ISSUE OF BROWN COAL QUALITY ON THE BASIS OF PHYSICOCHEMICAL PARAMETERS

    OpenAIRE

    Škvarekova, Erika; Kozakova, L'ubica

    2011-01-01

    Coal is expected to remain the dominant fuel for electricity generation in the Slovak republic for a considerable time in the future. Mining of lignite and brown coal is necessary for security and stabilizes the electricity systems of this republic through the heat power Nováky (ENO). Coal combustion processes represent a significant potential for contamination of environmental components. The elemental composition of coal from the mine Cígeľ showed that coal contains variable amount of arsen...

  8. Assessment of Geogenic Contaminants in Water Co-Produced with Coal Seam Gas Extraction in Queensland, Australia: Implications for Human Health Risk

    OpenAIRE

    William Stearman; Mauricio Taulis; James Smith; Maree Corkeron

    2014-01-01

    Organic compounds in Australian coal seam gas produced water (CSG water) are poorly understood despite their environmental contamination potential. In this study, the presence of some organic substances is identified from government-held CSG water-quality data from the Bowen and Surat Basins, Queensland. These records revealed the presence of polycyclic aromatic hydrocarbons (PAHs) in 27% of samples of CSG water from the Walloon Coal Measures at concentrations <1 µg/L, and it is likely th...

  9. Gas Control Technology of Coal Mining in Upper Protective Seam of Contiguous Outburst Seams Group%近距离突出煤层群上保护层开采瓦斯治理技术

    Institute of Scientific and Technical Information of China (English)

    刘震; 李增华; 杨永良; 唐一博; 季淮君

    2012-01-01

    In combination with the mining conditions of the upper protective seam in Qingdong Mine, the FLAC3D software was applied to the simulation of the floor pressure releasing law in the upper protective seam mining. The study results showed that the pressure released gas emission rate of the protected seam was 30. 0% -36. 5%. After the upper protective seam mined, the in-situ ground stress of the protected seam would be reduced from i0. 5 N i0. 8 Mpa to I. 0 ~ 1.5 Mpa. The initial pressure released location in the protected seam would be 40 - 50 m to the coal mining face. According to the study results, stereo gas control technology with roof rock roadway in coal layer, bedding drainage, a roof high level gas drainage gateway, tubing buried at the up corner, downward borehole through strata with fracturing in the air retuning gateway in the upper protective seam was set up. The engineering application showed that the pressure re- leased gas would account for 86. 8% of the total gas emission of the coal mining face, the gas emission rate of the protected seam was 30. 4% and the initial pressure releasing location of the protected seam was the location that the coal mining face advanced at 40 m.%结合青东煤矿上保护层开采条件,采用FLAC3D软件模拟了上保护层开采底板卸压规律。研究结果表明:被保护煤层卸压瓦斯涌出率为30.0%~36.5%;上保护层开采后被保护煤层原始地应力由10.5~10.8 MPa降低为1.0~1.5 MPa;被保护煤层初始卸压位置为工作面回采至40~50m。根据研究结果制定了顶板岩巷穿层钻孔、顺层预抽、顶板高抽巷、上隅角埋管及上保护层回风巷下向穿层增裂钻孔的立体瓦斯治理技术。工程应用表明,卸压瓦斯占工作面瓦斯涌出总量的86.8%,被保护煤层瓦斯涌出率为30.4%,被保护煤层初始卸压位置为工作面回采至40 m位置。

  10. Estimating Effective Seismic Anisotropy Of Coal Seam Gas Reservoirs from Sonic Log Data Using Orthorhombic Buckus-style Upscaling

    Science.gov (United States)

    Gross, Lutz; Tyson, Stephen

    2015-04-01

    Fracture density and orientation are key parameters controlling productivity of coal seam gas reservoirs. Seismic anisotropy can help to identify and quantify fracture characteristics. In particular, wide offset and dense azimuthal coverage land seismic recordings offers the opportunity for recovery of anisotropy parameters. In many coal seam gas reservoirs (eg. Walloon Subgroup in the Surat Basin, Queensland, Australia (Esterle et al. 2013)) the thickness of coal-beds and interbeds (e.g mud-stone) are well below the seismic wave length (0.3-1m versus 5-15m). In these situations, the observed seismic anisotropy parameters represent effective elastic properties of the composite media formed of fractured, anisotropic coal and isotropic interbed. As a consequence observed seismic anisotropy cannot directly be linked to fracture characteristics but requires a more careful interpretation. In the paper we will discuss techniques to estimate effective seismic anisotropy parameters from well log data with the objective to improve the interpretation for the case of layered thin coal beds. In the first step we use sonic log data to reconstruct the elasticity parameters as function of depth (at the resolution of the sonic log). It is assumed that within a sample fractures are sparse, of the same size and orientation, penny-shaped and equally spaced. Following classical fracture model this can be modeled as an elastic horizontally transversely isotropic (HTI) media (Schoenberg & Sayers 1995). Under the additional assumption of dry fractures, normal and tangential fracture weakness is estimated from slow and fast shear wave velocities of the sonic log. In the second step we apply Backus-style upscaling to construct effective anisotropy parameters on an appropriate length scale. In order to honor the HTI anisotropy present at each layer we have developed a new extension of the classical Backus averaging for layered isotropic media (Backus 1962) . Our new method assumes layered

  11. Characteristics and stability of slope movement response to underground mining of shallow coal seams away from gullies

    Institute of Scientific and Technical Information of China (English)

    Zhang Dongsheng; Fan Gangwei; Wang Xufeng

    2012-01-01

    Underground pressure is abnormal during mining of shallow coal seams under gullies.We studied gully slope movements,subject to underground mining,with physical simulation and theoretical analysis.The rules disclose that the slope rock slides horizontally in response to mining in the direction of gullies and rotates reversely with the appearance of a polygon block in mining away from gullies.We focused our attention on the case of mining away from a gully.We built a mechanical model in terms of a polygon block hinged structure and investigated the variation of horizontal thrust and shear force at the hinged point in relation to the rotation angle under different fragmentations.The Sliding-Rotation instability conditions of the polygon block hinged structure are presented based on the analyses of sliding instability and rotation instability.These results can serve as a theoretical guide for roof control during mining away from gullies in a coalfield defined by gullies.

  12. Water inrush evaluation of coal seam floor by integrating the water inrush coefficient and the information of water abundance

    Institute of Scientific and Technical Information of China (English)

    Shi Longqing; Qiu Mei; Wei Wenxue; Xu Dongjing; Han Jin

    2014-01-01

    The method of singular coefficient of water inrush to achieve safety mining has limitation and one sidedness. Aiming at the problem above, large amounts of data about water inrush were collected. Then the data, including the maximum water inrush, water inrush coefficient and water abundance in aquifers of working face, were processed by the statistical analysis. The analysis results indicate that both water inrush coefficient and water abundance in aquifers should be taken into consideration when evaluating the danger of water inrush from coal seam floor. The prediction model of safe-mining evaluation grade was built by using the support vector machine, and the result shows that this model has high classifica-tion accuracy. A feasible classification system of water-inrush safety evaluation can be got by using the data visualization method which makes the implicit support vector machine models explicit.

  13. Data and facts on brown and hard coal. Status quo and perspectives. Background

    International Nuclear Information System (INIS)

    This publication reports on the contribution of brown and hard-coal power plants to gross electricity production, quoting a total of 45.2% for 2013. CO2 emissions from hard coal rose continuously from 2011 to 2013, largely due to a growing electricity export surplus. By contrast, CO2 emissions from brown coal power plants decreased slightly, in spite of more electricity being produced from brown coal. This can be explained by the replacement of a number of old power plants with new, more efficient ones in the course of 2012 and 2013. From an environmental viewpoint brown and hard coal carry a heavy burden as energy resources. Their specific characteristics and special features are thus covered in a separate part of the report, giving due consideration to aspects of energy economy, general economy and environmental issues.

  14. Gas drainage from different mine areas:optimal placement of drainage systems for deep coal seams with high gas emissions

    Institute of Scientific and Technical Information of China (English)

    Ping Lu; Ping Li; Jian Chen; Chuijin Zhang; Junhua Xue; Tao Yu

    2015-01-01

    The techniques of stress relief mining in low-permeability coal seams and pillarless gob side retained roadway entry using Y-type ventilation and gas drainage systems were developed to control gas outbursts and applied successfully. However, as the mining depth increasing, parts of the gas drainage system are not suitable for mines with high gas emissions. Because larger mining depths cause higher ground stresses, it becomes extremely difficult to maintain long gob side roadways. The greater deformation suffered by the roadway is not favorable for borehole drilling for continuous gas drainage. To solve these problems, Y-type ventilation and gas drainage systems installed from a roof roadway were designed for drainage optimization. This system was designed based on a gas-enrichment zone analysis developed from mining the 11-2 coal seam in the Zhuji Mine at Huainan, Anhui Province, China. The method of Y-type gas extraction from different mine areas was applied to the panel 1112(1) in the Zhuji Mine. The absolute gas emission rate was up to 116.3 m3/min with an average flow of 69.1 m3/min at an average drainage concentration of nearly 85%. After the Y-type method was adopted, the concentration of gas in the return air was 0.15%–0.64%, averaging 0.39%with a ventilation rate of 2100–2750 m3/min. The gas management system proved to be efficient, and the effective gas control allowed safe production to continue.

  15. A SWOT ANALYSIS OF NEW INVESTMENTS IN BROWN COAL DEPOSITS IN POLAND

    OpenAIRE

    Ziętera, Anna, Monika

    2014-01-01

    The purpose of this article is to present factors determining the effectiveness of new investments in brown coal deposits. It discusses the weak and strong points of brown coal mining in Poland, as well as opportunities and risks in its development. The strong point is that Poland has abundant resources of lignite and the opportunity lies in the rising demand for energy. The weak point is that brown coal emits large amounts of CO2 and risk is perceived in that the EU tightens up its policy on...

  16. Assessing Connectivity Between an Overlying Aquifer and a Coal Seam Gas Resource Using Methane Isotopes, Dissolved Organic Carbon and Tritium

    Science.gov (United States)

    Iverach, Charlotte P.; Cendón, Dioni I.; Hankin, Stuart I.; Lowry, David; Fisher, Rebecca E.; France, James L.; Nisbet, Euan G.; Baker, Andy; Kelly, Bryce F. J.

    2015-11-01

    Coal seam gas (CSG) production can have an impact on groundwater quality and quantity in adjacent or overlying aquifers. To assess this impact we need to determine the background groundwater chemistry and to map geological pathways of hydraulic connectivity between aquifers. In south-east Queensland (Qld), Australia, a globally important CSG exploration and production province, we mapped hydraulic connectivity between the Walloon Coal Measures (WCM, the target formation for gas production) and the overlying Condamine River Alluvial Aquifer (CRAA), using groundwater methane (CH4) concentration and isotopic composition (δ13C-CH4), groundwater tritium (3H) and dissolved organic carbon (DOC) concentration. A continuous mobile CH4 survey adjacent to CSG developments was used to determine the source signature of CH4 derived from the WCM. Trends in groundwater δ13C-CH4 versus CH4 concentration, in association with DOC concentration and 3H analysis, identify locations where CH4 in the groundwater of the CRAA most likely originates from the WCM. The methodology is widely applicable in unconventional gas development regions worldwide for providing an early indicator of geological pathways of hydraulic connectivity.

  17. Pico-nano bubble column flotation using static mixer-venturi tube for Pittsburgh No. 8 coal seam

    Institute of Scientific and Technical Information of China (English)

    Peng Felicia F.; Yu Xiong

    2015-01-01

    The flotation process is a particle-hydrophobic surface-based separation technique. To improve the essential flotation steps of collision and attachment probabilities, and reduce the step of detachment probabilities between air bubbles and hydrophobic particles, a selectively designed cavitation venturi tube combined with a static mixer can be used to generate very high numbers of pico and nano bubbles in a flotation column. Fully embraced by those high numbers of tiny bubbles, hydrophobic particles readily attract the tiny bubbles to their surfaces. The results of column flotation of Pittsburgh No. 8 seam coal are obtained in a 5.08 cm ID and 162 cm height flotation column equipped with a static mixer and cavitation venturi tube, using kerosene as collector and MIBC as frother. Design of the experimental procedure is combined with a statistical two-stepwise analysis to determine the optimal operating conditions for maximum recovery at a specified grade. The effect of independent variables on the responses has been explained. Combustible material recovery of 85–90% at clean coal product of 10–11%ash is obtained from feed of 29.6%ash, with a much-reduced amount of frother and collector than that used in conventional column flotation. The column flotation process utilizing pico and nano bubbles can also be extended to the lower limit and upper limit of particle size ranges, minus 75 lm and 300–600 lm, respectively, for better recovery.

  18. Assessing Connectivity Between an Overlying Aquifer and a Coal Seam Gas Resource Using Methane Isotopes, Dissolved Organic Carbon and Tritium.

    Science.gov (United States)

    Iverach, Charlotte P; Cendón, Dioni I; Hankin, Stuart I; Lowry, David; Fisher, Rebecca E; France, James L; Nisbet, Euan G; Baker, Andy; Kelly, Bryce F J

    2015-01-01

    Coal seam gas (CSG) production can have an impact on groundwater quality and quantity in adjacent or overlying aquifers. To assess this impact we need to determine the background groundwater chemistry and to map geological pathways of hydraulic connectivity between aquifers. In south-east Queensland (Qld), Australia, a globally important CSG exploration and production province, we mapped hydraulic connectivity between the Walloon Coal Measures (WCM, the target formation for gas production) and the overlying Condamine River Alluvial Aquifer (CRAA), using groundwater methane (CH4) concentration and isotopic composition (δ(13)C-CH4), groundwater tritium ((3)H) and dissolved organic carbon (DOC) concentration. A continuous mobile CH4 survey adjacent to CSG developments was used to determine the source signature of CH4 derived from the WCM. Trends in groundwater δ(13)C-CH4 versus CH4 concentration, in association with DOC concentration and (3)H analysis, identify locations where CH4 in the groundwater of the CRAA most likely originates from the WCM. The methodology is widely applicable in unconventional gas development regions worldwide for providing an early indicator of geological pathways of hydraulic connectivity. PMID:26530701

  19. The prospects of hard and brown coal in Poland and in the European Union

    Energy Technology Data Exchange (ETDEWEB)

    Gawlik, Lidia; Majchrzak, Henryk; Mokrzycki, Eugeniusz; Uliasz-Bochenczyk, Alicja

    2010-09-15

    Poland possess significant reserves of hard and brown coal and is an important producer of these fuels, for that reason coal has a dominant position in Polish energy balance. The government document describing energy policy of Poland up to the year 2030 treats Polish coal as an stabilizer of national energy safety. The progress in clean coal technologies development is a key element to determine the role of Polish coal both in Polish and EU economy. The possibilities of prospective use of coal pointing at the main direction of clean technology development has also been discussed in the paper.

  20. Effects of caving-mining ratio on the coal and waste rocks gangue flows and the amount of cyclically caved coal in fully mechanized mining of super-thick coal seams

    Institute of Scientific and Technical Information of China (English)

    Zhang Ningbo; Liu Changyou; Pei Mengsong

    2015-01-01

    Aimed at determining the appropriate caving–mining ratio for fully mechanized mining of 20 m thick coal seam, this research investigated the effects of caving–mining ratio on the flow fields of coal and waste rocks, amount of cyclically caved coal and top coal loss by means of numerical modeling. The research was based on the geological conditions of panel 8102 in Tashan coal mine. The results indicated the loose coal and waste rocks formed an elliptical zone around the drawpoint. The ellipse enlarged with decreasing caving–mining ratio. And its long axis inclined to the gob gradually became vertical and facil-itating the caving and recovery of top coal. The top coal loss showed a cyclical variation;and the loss cycle was shortened with the decreasing in caving–mining ratio. Moreover, the mean squared error (MSE) of the amount of cyclically caved coal went up with increasing caving–mining ratio, indicating a growing imbalance of amount of cyclically caved coal, which could impede the coordinated mining and caving operations. Finally it was found that a caving–mining ratio of 1:2.51 should be reasonable for the conditions.

  1. Organic petrology and geochemistry of the Carboniferous coal seams from the Central Asturian Coal Basin (NW Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Piedad-Sanchez, Noe; Martinez, Luis; Izart, Alain; Elie, Marcel [UMR G2R/7566, Geologie et Gestion des Ressources Minerales et Energetiques, Faculte des Sciences, Universite Henri Poincare, Nancy 1, BP-239, Boulevard des Aiguillettes, Vandoeuvre-les-Nancy Cedex 54506 (France); Suarez-Ruiz, Isabel [Instituto Nacional del Carbon (CSIC), C/ Francisco Pintado Fe, 26, Ap. Co., 73, Oviedo 33011 (Spain); Keravis, Didier [Institut des Sciences de la Terre (ISTO), CNRS-Universite d' Orleans, Batiment Geosciences, BP 6759, Orleans 45067 (France)

    2004-03-23

    This paper presents for the first time a petrological and geochemical study of coals from the Central Asturian Coal Basin (North Spain) of Carboniferous (Pennsylvanian), mainly of Moscovian, age. A paleoenvironmental approach was used, taking into account both petrographic and organic geochemical studies. Vitrinite reflectance (R{sub r}) ranges from 0.5% to 2.5%, which indicates a high volatile bituminous to semianthracite and anthracite coal rank. The coal samples selected for paleoenvironmental reconstruction are located inside the oil-gas-prone phase, corresponding to the interval between the onset of oil generation and first gas generation and efficient expulsion of oil. This phase is represented by coals that have retained their hydrocarbon potential and also preserved biomarker information. Paleodepositional reconstruction based on maceral and petrographic indices points to a swamp environment with vitrinite-rich coal facies and variable mineral matter content. The gelification index (GI) and groundwater influence index (GWI) indicate strong gelification and wet conditions. The biomarkers exhibit a high pristane/phytane ratio, suggesting an increase in this ratio from diagenetic processes, and a high diterpanes ratio. This, in turn, would seem to indicate a high swamp water table and a humid climate. The maximum point of coal accumulation occurred during the regressive part of the Late Moscovian sequence and in the most humid climate described for this period of time in the well-known coal basins of Europe and North America.

  2. Petrologic and geochemical characteristics of Seam 9-3 and Seam 2, Xingtai Coalfield, Northern China

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yuzhuang [Hebei Institute of Architectural Science and Technology, Hebei, 056038 Handan (China); Puettmann, W. [Johann Wolfgang Goethe-Universitaet Frankfurt, FB 17 Geowissenschaften-Umweltanalytik, Georg-Voigt-Str. 14, D-60054 Frankfurt am Main (Germany); Kalkreuth, W. [Instituto de Geociencias, Universidade Federal do Rio Grande do Sul, Av. Benito Goncalves, 9500, 91501-970 , Rio Grande do Sul, Porto Alegre (Brazil); Horsfield, B. [ICG-4, Forschungszentrum Juelich, Juelich (Germany)

    2002-04-01

    Six samples of Carboniferous (Mississippian-Pennsylvanian) coal (Seam 9-3) and 11 samples of Permian coal (Seam 2) from the Xingtai Coalfield were studied by petrological and organic geochemical methods. Both seams show different petrological and geochemical compositions. In Seam 9-3 of the Carboniferous age, the predominant maceral is vitrinite (83%) whereas in Seam 2 of Permian age, inertinite predominates (45%). 'Barkinite' was found with an average content 1% only in Seam 2. Sixty-four different aromatic compounds were identified by gas chromatography (GC)/mass spectrometry (MS) analysis of solvent extracts (Extr) of both seams. Abundant polyaromatic sulfur hydrocarbons (PASH) were determined in coal samples from Seam 9-3, while they are very low in samples from Seam 2. 1,2,5-Trimethylnaphthalene and 1,2,5,6-tetramethylnaphthalene contents are much higher in Seam 2, while 2-methylfluorene contents are higher in Seam 9-3. Cadalene was found in Seam 2 with a high content of 94 mg/kg coal but was not detected in samples from Seam 9-3. This might indicate a different floral contribution to the sedimentary organic matter. All petrologic and geochemical results indicate that Seam 2 formed in a more oxidized environment compared with Seam 9-3.

  3. Utilization of heat pumps in the brown coal industry

    Energy Technology Data Exchange (ETDEWEB)

    Strehlau, R.

    1981-09-01

    This paper points out fields for possible energy recovery by heat pumps in the area of brown coal surface mines. It is stated that surface mine ground water from a depth of 80 m has a constant temperature of 10 to 11 C. The theoretical heat content of cooling 170,000 m/SUP/3/h of drainage water of all GDR surface mines from 10 C to 5 C is calculated to amount to 9 million MWh. Research is therefore being conducted on recovering heat from mine drainage and mine surface waters for use as space heating in buildings and installations of surface mines, which are at present electrically heated. Further sources of heat which are being examined for possible heat pump employment are heat generating plants and large surface mine machinery. Studies have been carried out by TAKRAF on determining feasibility and economic benefit of using waste heat from engine and transmission mechanisms of heavy surface mining equipment. Results of a further study on utilizing waste heat from a large transformer station show that a direct heat recovery system is definitely more efficient than employing a heat pump system, but only in the case of a transformer average load higher than 60%. (2 refs.)

  4. 泉店煤矿近距离煤层群联合开采方式的实现%Realization of Close Distance Coal Seam United Mining Way in Quan-dian Coal Mine

    Institute of Scientific and Technical Information of China (English)

    曹品伟

    2012-01-01

    In order to realize close distance coal seam united mining, analyzes the relationship between exploration coal seam mining rock bottom plate moves and advance break section. The close coal seam groups united mining common dislocation model is proposed. The reasonable dislocation computing formula is given out from theory. This method can avoid unreasonable setting distance of up and low coal seam, which causes abnormal exploration.%为实现近距离煤层联合开采,分析了开采工作面采动岩层底板移动与超前破坏区间相互作用的关系,提出了近距离煤层群联合开采常规错距开采模型。从理论上给出近距离煤层群联合开采下的工作面合理错距计算公式,避免因上、下煤层工作面间距设置不合理,造成上下采场不能正常开采的情况。

  5. Numerical simulation of top coal moving regularity about fully mechanical top coal caving of thick coal seam with gangue%含夹矸厚煤层综放开采顶煤运移规律数值模拟

    Institute of Scientific and Technical Information of China (English)

    陈海波; 吴祥业; 董玉书

    2012-01-01

    This paper builds on thick coal seam of geological conditions and occurrence status of Fuli coal mine in Hegang and describes the use of RFPA^2D numerical simulation software to simulate the mov- ing regularity of -450 south 18 -2 working face, with different gangue thickness 0.5, 1.0, 1.5 m re- spectively. The results show that the upper top coal has larger vertical displacement than the lower in mining process, and the starting point of the lower top coal is more distant than that of the upper top coal from working face. With certain strength of gangue and coal seam, top coal in the working face shows the moving regularity and the degree of crushing, depending on gangue thickness, the top coal with 1.0 m gangue thickness gives a greater displacement and better crushing than that with 0. 5 m or 1.5 m. The re- search could provide a better basis for the caving process of thick coal seam with gangue in fully mecha- nized top coal caving.%根据鹤岗富力矿合中位厚夹矸煤层地质条件及煤的赋存状况,应用RFPA^2D数值模拟软件分别对-450南18-2工作面含0.5、1.0、1.5m厚夹矸开采煤体的运移情况进行数值模拟。结果表明,采动过程中,上部顶煤垂直方向的位移量均大于下部,而下部顶煤始动点距工作面的距离均大于上部。夹矸层强度与煤层强度既定情况下,工作面顶煤的运移规律及破碎程度均与含夹矸层的厚度相关。含1.0m厚夹矸顶煤总位移量大于含0.5、1.5m厚夹矸顶煤总位移量;合1.0m厚夹矸顸煤比含0.5、1.5m厚夹砰顶煤破碎充分。该研究为含夹矸条件下厚煤层综放开采冒放工艺的确定提供了依据。

  6. Novel pre-treatment of zeolite materials for the removal of sodium ions: potential materials for coal seam gas co-produced wastewater.

    Science.gov (United States)

    Santiago, Oscar; Walsh, Kerry; Kele, Ben; Gardner, Edward; Chapman, James

    2016-01-01

    Coal seam gas (CSG) is the extraction of methane gas that is desorbed from the coal seam and brought to the surface using a dewatering and depressurisation process within the saturated coalbed. The extracted water is often referred to as co-produced CSG water. In this study, co-produced water from the coal seam of the Bowen Basin (QLD, Australia) was characterised by high concentration levels of Na(+) (1156 mg/L), low concentrations of Ca(2+) (28.3 mg/L) and Mg(2+) (5.6 mg/L), high levels of salinity, which are expected to cause various environmental problems if released to land or waters. The potential treatment of co-produced water using locally sourced natural ion exchange (zeolite) material was assessed. The zeolite material was characterized for elemental composition and crystal structure. Natural, untreated zeolite demonstrated a capacity to adsorb Na(+) ions of 16.16 mEq/100 g, while a treated zeolite using NH4 (+) using a 1.0 M ammonium acetate (NH4C2H3O2) solution demonstrated an improved 136 % Na(+) capacity value of 38.28 mEq/100 g after 720 min of adsorption time. The theoretical exchange capacity of the natural zeolite was found to be 154 mEq/100 g. Reaction kinetics and diffusion models were used to determine the kinetic and diffusion parameters. Treated zeolite using a NH4 (+) pre-treatment represents an effective treatment to reduce Na(+) concentration in coal seam gas co-produced waters, supported by the measured and modelled kinetic rates and capacity. PMID:27247868

  7. Rapid quality control for coal seams by gamma ray transmission technique

    CERN Document Server

    Raja-Sekhar, N; Nageswara-Rao, A S

    1999-01-01

    The quality of coal expressed as useful heat value (UHV) depends on various parameters such as fixed carbon, volatiles, ash and moisture. These factors have been assessed and the detailed dependence of UHV on these parameters has been studied for samples of coal from a local mine. The samples were subjected to collimated low energy gamma beams and correlation was obtained between the attenuation coefficient and UHV. The method is reliable, fast and non-destructive and can be used in the field for estimating UHV.

  8. Application of principal-component analysis to the interpretation of brown coal properties

    Energy Technology Data Exchange (ETDEWEB)

    Tesch, S.; Otto, M. [TU Bergakademie, Freiberg (Germany). Institute for Analytical Chemistry

    1995-07-01

    The characterization of coal properties using principal-component analysis is described. The aim is to obtain correlations between a large number of chemical and technological parameters as well as FT-i.r. spectroscopic data. A database on 44 brown coals from different deposits was interpreted. After computation of the principal components, scatterplots and component-weight plots are presented for the first two or three principal components. The overlap of the component-weights plot and the scatterplot (biplot) shows how it is possible to classify brown coals by means of selected characteristics. 14 refs., 6 figs., 1 tab.

  9. Quality characteristics of Greek brown coals and their relation to the applied exploitation and utilization methods

    Energy Technology Data Exchange (ETDEWEB)

    C. Papanicolaou; M. Galetakis; A.E. Foscolos [Institute of Geology and Mineral Exploration, Athens (Greece)

    2005-02-01

    Brown coal exploitation in Greece is of primary interest because it is an abundant domestic energy resource that contributes more than 70% in total electricity production. Greek brown coals present challenging and diverse technological characteristics, which should be studied to design and manage efficiently the mining, as well as, the operation of nearby power stations. The present study focuses on the organic and inorganic properties, as well as the mineralogy of the most-prominent Greek coal basins and their importance to mine planning, as well as to power station design and a productive working operation. 49 refs., 9 figs., 7 tabs.

  10. Quantitative relation between the macromolecular characteristics of brown coal and its reactivity in conversion with tetralin

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, P.N.; Kuznetsova, L.I.; Bimer, J.; Salbut, P.; Gruber, R.; Brodzki, D. [Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk (Russian Federation)

    1997-01-01

    The reactivity of Kansk-Achinsk brown coal in thermochemical conversion with tetralin is a linear function of the network flexibility, which is primarily controlled by ionic cross-linking with carboxylate bridges via polyvalent cations such as Ca{sup 2+}. Selective chemical pretreatments were used to modify specific oxygen functionalities. This allowed better defined correlations with coal characteristics to be evaluated and the principal structural units responsible for coal behaviour to be identified. 24 refs., 3 figs., 7 tabs.

  11. Dissolved radon and uranium in groundwater in a potential coal seam gas development region (Richmond River Catchment, Australia).

    Science.gov (United States)

    Atkins, Marnie L; Santos, Isaac R; Perkins, Anita; Maher, Damien T

    2016-04-01

    The extraction of unconventional gas resources such as shale and coal seam gas (CSG) is rapidly expanding globally and often prevents the opportunity for comprehensive baseline groundwater investigations prior to drilling. Unconventional gas extraction often targets geological layers with high naturally occurring radioactive materials (NORM) and extraction practices may possibly mobilise radionuclides into regional and local drinking water resources. Here, we establish baseline groundwater radon and uranium levels in shallow aquifers overlying a potential CSG target formation in the Richmond River Catchment, Australia. A total of 91 groundwater samples from six different geological units showed highly variable radon activities (0.14-20.33 Bq/L) and uranium levels (0.001-2.77 μg/L) which were well below the Australian Drinking Water Guideline values (radon; 100 Bq/L and uranium; 17 μg/L). Therefore, from a radon and uranium perspective, the regional groundwater does not pose health risks to consumers. Uranium could not explain the distribution of radon in groundwater. Relatively high radon activities (7.88 ± 0.83 Bq/L) in the fractured Lismore Basalt aquifer coincided with very low uranium concentrations (0.04 ± 0.02 μg/L). In the Quaternary Sediments aquifers, a positive correlation between U and HCO3(-) (r(2) = 0.49, p gas, establishing radon and uranium concentrations in overlying aquifers comprises an important component of baseline groundwater investigations. PMID:26867097

  12. Enrichment of radon and carbon dioxide in the open atmosphere of an Australian coal seam gas field.

    Science.gov (United States)

    Tait, Douglas R; Santos, Isaac R; Maher, Damien T; Cyronak, Tyler J; Davis, Rachael J

    2013-04-01

    Atmospheric radon ((222)Rn) and carbon dioxide (CO2) concentrations were used to gain insight into fugitive emissions in an Australian coal seam gas (CSG) field (Surat Basin, Tara region, Queensland). (222)Rn and CO2 concentrations were observed for 24 h within and outside the gas field. Both (222)Rn and CO2 concentrations followed a diurnal cycle with night time concentrations higher than day time concentrations. Average CO2 concentrations over the 24-h period ranged from ~390 ppm at the control site to ~467 ppm near the center of the gas field. A ~3 fold increase in maximum (222)Rn concentration was observed inside the gas field compared to outside of it. There was a significant relationship between maximum and average (222)Rn concentrations and the number of gas wells within a 3 km radius of the sampling sites (n = 5 stations; p gas field related to both point (well heads, pipelines, etc.) and diffuse soil sources. Radon may be useful in monitoring enhanced soil gas fluxes to the atmosphere due to changes in the geological structure associated with wells and hydraulic fracturing in CSG fields. PMID:23444905

  13. The Coal-Seq III Consortium. Advancing the Science of CO2 Sequestration in Coal Seam and Gas Shale Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Koperna, George [Advanced Resources International Inc., Arlington, VA (United States)

    2014-03-14

    The Coal-Seq consortium is a government-industry collaborative that was initially launched in 2000 as a U.S. Department of Energy sponsored investigation into CO2 sequestration in deep, unmineable coal seams. The consortium’s objective aimed to advancing industry’s understanding of complex coalbed methane and gas shale reservoir behavior in the presence of multi-component gases via laboratory experiments, theoretical model development and field validation studies. Research from this collaborative effort was utilized to produce modules to enhance reservoir simulation and modeling capabilities to assess the technical and economic potential for CO2 storage and enhanced coalbed methane recovery in coal basins. Coal-Seq Phase 3 expands upon the learnings garnered from Phase 1 & 2, which has led to further investigation into refined model development related to multicomponent equations-of-state, sorption and diffusion behavior, geomechanical and permeability studies, technical and economic feasibility studies for major international coal basins the extension of the work to gas shale reservoirs, and continued global technology exchange. The first research objective assesses changes in coal and shale properties with exposure to CO2 under field replicated conditions. Results indicate that no significant weakening occurs when coal and shale were exposed to CO2, therefore, there was no need to account for mechanical weakening of coal due to the injection of CO2 for modeling. The second major research objective evaluates cleat, Cp, and matrix, Cm, swelling/shrinkage compressibility under field replicated conditions. The experimental studies found that both Cp and Cm vary due to changes in reservoir pressure during injection and depletion under field replicated conditions. Using laboratory data from this study, a compressibility model was developed to predict the pore-volume compressibility, Cp, and the matrix compressibility, Cm, of coal and shale, which was applied to

  14. New approach to brown coal pricing using internal rate of return methodology

    International Nuclear Information System (INIS)

    Highlights: • We showed that brown coal is the substitute for black coal only at the time of the investment decision. • We compiled the model used in a calculation of the economically justified price for the productive and extractive component. • The resulting economically justified price is on a par with the current black coal price. • The proposed methodological approach is applicable to solve similar tasks not only in the energy sector. - Abstract: Brown coal is one of the dominant local strategic raw materials in Europe, used, to a large extent, in the power-generating industry. The current situation, where the price of gas and electricity precludes the efficient use of gas sources, leads to the extraction of older sources, chiefly brown coal ones. In tandem with a turning away from nuclear power, brown coal is experiencing a renaissance and the issue of brown coal price setting is, and will be, relevant. This paper deals with a proposal of a new method for determining the base price, consisting of defining the reference fuel chain for electricity and heat production based on brown coal. It builds on the notion that the degree of risk of the involved parties should be reflected in the modified amount of revenue per capital invested. The resulting price is then an economically justified price which encourages a respect for the specific features of the market in question and set the base price of the commodity in a way that is acceptable for both the extractive and the productive components of the fuel chain

  15. Simulation research on the influence of eroded primary key strata on dynamic strata pressure of shallow coal seams in gully terrain

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhiqiang; Xu Jialin; Zhu Weibing; Shan Zhenjun

    2012-01-01

    In Huojitu Coal Mine of Shendong mining area,the dynamic strata pressure (DSP) accidents occurred when the working faces passed the gully terrain,Focusing on this problem,we used physical simulation experimental method to thoroughly study the influence of eroded overlying primary key strata (PKS) in the gully terrain on DSP of shallow coal seams in this paper.The result show that when mining activities took place in the uphill section of shallow coal seams in gully terrain and the PKS were eroded,the blocks could not form stable bond-beam structures since the horizontal force of PKS blocks in adjacent sloping surfaces were relatively small.The sliding instability of blocks caused rapid increase of the load on the sub-key strata (SKS) blocks,which resulted into coal slide and roof fall as well as sharp drop of active columns.This led to DSP phenomenon.When the PKS blocks were intact,there was no DSP phenomenon to enable blocks provide certain horizontal force to maintain stable bond-beam structure.The simulation results were verified by the mining practices of working face 21306 crossing the gully terrain in the Huojitu Coal Mine.

  16. Determination of indices and critical values of gas parameters of the first gas outburst in a coal seam of the Xieqiao Mine

    Institute of Scientific and Technical Information of China (English)

    Ou Jianchun; Liu Mingju; Zhang Chunru; Liu Yanwei; Wei Jianping

    2012-01-01

    Based on the important role in mine safety played by parameters of the first gas outburst,we propose a method of combining historic data,theoretical analysis and experimental research for the purpose of critical values of gas parameters of the first gas outburst in a coal seam of the Xieqiao Mine.According to a characteristic analysis and a summary of the rules ofcoal and gas outbursts in the No.8 coal seam ofa Huainan mine,we have investigated their effect on coal and gas outbursts in terms such as ground stress,gas,and coal structure.We have selected gas parameters and determined the critical values of each of the following indices:gas content as 7.7 m3/t,tectonic coal as 0.8 m thick,the absolute gas emission as 2 m3/min,the rate of change as 0.7 m3/min,the gas desorption index of a drilling chip K1 as 0.26 ml/(g min1/2) and the values of desorption indexes △h2 as 200 Pa.From a verification of the production,the results indicate that application of each index and their critical values significantly improve the level of safety in the production process,relieve the burden upon the mine,save much labor and bring clear economic benefits.

  17. Impact of thermal processes on CO2 injectivity into a coal seam

    International Nuclear Information System (INIS)

    The objective of this study is to investigate how thermal gradients, caused by CO2 injection, expansion and adsorption, affect the permeability and adsorption capacity of coal during CO2 sequestration. A new permeability model is developed in which the concept of elastic modulus reduction ratio is introduced to partition the effective strain between coal matrix and fracture. This model is implemented into a fully coupled mechanical deformation, gas flow and heat transport finite element simulator. To predict the amount of CO2 sequested, the extended Langmuir sorption model is used, with parameters values taken from the literature. The coupled heat and gas flow equations, are solved in COMSOL using the finite element method. The simulation results for a constant volume reservoir demostrate that thermal strain acts to significantly reduce both CO2 injectivity and adsorption capacity. These impacts need to be considered in the calculation of the optimum injection rate and the total sequestration capacity.

  18. Analysis and Application of Coal Seam Seismic Waves for detection of Abandoned Mines

    OpenAIRE

    Yancey, Daniel Jackson

    2006-01-01

    It is not uncommon for underground coal mining to be conducted in the proximity of abandoned underground mines that are prone to accumulate water, methane or other toxic gases, and are often either poorly mapped or without good surface survey control. Mining into such abandoned voids poses a great safety risk to personnel, equipment, and production from inundation or toxic/explosive gas release. Often, surface or underground drilling is employed to detect the mine void and e...

  19. Performance Analysis of Fractured Wells with Stimulated Reservoir Volume in Coal Seam Reservoirs

    OpenAIRE

    Yu-long Zhao; Lie-Hui Zhang; Guo-Qing Feng; Bo-Ning Zhang; Bo Kang

    2016-01-01

    CoalBed Methane (CBM), as one kind of unconventional gas, is an important energy resource, attracting industry interest in research and development. Using the Langmuir adsorption isotherm, Fick’s law in the matrix and Darcy flow in cleat fractures, and treating the Stimulated Reservoir Volume (SRV) induced by hydraulic fracturing as a radial composite model, the continuous linear source function with constant production is derived by the methods of the Laplace transform and Duhamel theory. Ba...

  20. Forward modeling to improve seismic reflection energy of a protective coal seam based on Zoeppritz equation

    Institute of Scientific and Technical Information of China (English)

    TAO Wen-peng; DONG Shou-hua; LI Yang

    2008-01-01

    In seismic exploration for coal, seismic waves are very difficult to transmit downward because of high velocity protec-tive layers, making the reflection information very hard to receive above ground. Based on the Snell law and the Zoeppritz equation, we studied the relationship between the incidence angle and reflection seismic wave energy using a forward model of level media. The result shows that the seismic wave energy has a sudden increase at the critical angle. Based on the energy propagation rule, using big offset to receive the seismic wave energy under a protective layer can effectively reduce its protection effect.

  1. Fly ash formation and sulphation during the combustion of brown coal

    Energy Technology Data Exchange (ETDEWEB)

    Domazetis, G. (and others)

    1987-12-01

    This report presents an overview of investigations into the fly ash formation and sulphation process that occurs when brown coal is burnt. A code has been developed to simulate the chemistry of ash formation. The results of this project show that for the coals considered the chemistry of sodium species in a coal flame is central to the ash formation and fouling. Aluminium based additives have been tested on two Loy Yang coals. The tests show that the additives exert a pronounced influence on ash formation, probably via changes in the heterogeneous condensation of sodium compounds.

  2. Brown coal phaseout NRW. Which coal mining amounts are necessary from an energy point of view and are possible with respect to climate policy?

    International Nuclear Information System (INIS)

    The study on the brown coal phaseout in NRW covers the following issues: scope of the study, targets on a federal level and review of actual scenario calculations; brown coal demand in Garzweiler in the different scenarios; climate policy targets in Nordrhein-Westfalen; feasibility in the frame of energy production.

  3. Algal growth and community structure in a mixed-culture system using coal seam gas water as the water source.

    Science.gov (United States)

    Buchanan, Jessica J; Slater, Frances R; Bai, Xue; Pratt, Steven

    2013-01-01

    Coal seam gas (CSG) is being touted as a transition fuel as the world moves towards low-carbon economies. However, the development of CSG reserves will generate enormous volumes of saline water. In this work, we investigate the potential of using this saline water to support mass algae production. Water and brine from a CSG water treatment facility (1.6 and 11.6 g total dissolved solids per litre (TDS L(-1)) respectively) were inoculated with algal biomass from freshwater and seawater environments and supplemented with nutrients in open, fed-batch reactors. Significant algal growth was recorded, with maximum specific growth rates in CSG water and CSG brine of 0.20 +/- 0.05 d(-1) and 0.26 +/- 0.04 d(-1) respectively. These maximum specific growth rates were equal to or greater than specific growth rates in deionized water and seawater diluted to the same salinity. However, algal growth lag time in CSG brine was between 7 and 9 times longer than in other waters. Microscopy and terminal-restriction fragment length polymorphism (T-RFLP) were used to monitor community structure in the reactors. The same few algal species dominated all of the reactors, except for the CSG brine reactor at day 15. This result indicates that conditions in CSG brine select for different species of algae compared to seawater of the same salinity and other waters tested. The findings suggest that mass algae production in CSG water is feasible but algae community composition may be a function of CSG water chemistry. This has implications for the downstream use of algae. PMID:23837320

  4. A laboratory instrument for determination of ash in brown coal and some results of its testing

    International Nuclear Information System (INIS)

    A computer controlled laboratory instrument for the determination of ash as well as calcium and iron oxides in brown coals has been developed. It consists of a measuring head, control unit and printing device. Its principle of operation is based on XRF and scattering of the low energy X-rays from a Pu-238 source. Algorithms of the operation, software and design of the instrument are described. Some results of its testing are provided. The instrument is designed for the application in laboratories of power plants and brown coal mines. 6 refs., 5 figs., 1 tab. (author)

  5. Refinement of brown coal in fluidized bed reactors - use of the results for the energy management

    International Nuclear Information System (INIS)

    The proof of the positive properties of the plants for various applications which have been described so far, have led to the plan to take the high temperature Winkler process and the fluidized bed drying process with internal waste heat recovery as a basis for the combined power plant/demonstration plant for brown coal. Fluidization systems which are based on the developments in Germany have also been applied in foreign countries. A HTW-plant for the gasification of peat in Finland and a brown coal drying plant in Australia should be especially mentioned. (orig./DG)

  6. Hydrocarbon structure in primary tar of Kansk-Achinsk brown coal

    Energy Technology Data Exchange (ETDEWEB)

    Platonov, V.V.; Klyavina, O.A.; Kasimtseva, T.V.; Ivleva, L.N.; Tabolenko, N.V.; Mazurov, V.V.

    1987-07-01

    Develops method for separating primary hydrocarbons from low temperature carbonization tar of Berezovsk brown coal in conditions which exclude high-temperature pyrolysis of vapor-gas products, and makes it possible to isolate concentrates of triterpanes, steranes, azulenes, flavonoids and terpenes. Compounds obtained were analyzed using infrared and ultraviolet spectroscopy, chromoto-mass-spectrometry, spectral, emissive and functional analysis, cryoscopy, thin-layer and capillary chromatography. Characteristics of eluates obtained are given. Assumes that cellular polyamantine structure together with long polymethylene and isoprene bonds play an important role in maintaining bituminous-waxy complex in brown coal. 15 refs.

  7. Performance Analysis of Fractured Wells with Stimulated Reservoir Volume in Coal Seam Reservoirs

    Directory of Open Access Journals (Sweden)

    Yu-long Zhao

    2016-01-01

    Full Text Available CoalBed Methane (CBM, as one kind of unconventional gas, is an important energy resource, attracting industry interest in research and development. Using the Langmuir adsorption isotherm, Fick’s law in the matrix and Darcy flow in cleat fractures, and treating the Stimulated Reservoir Volume (SRV induced by hydraulic fracturing as a radial composite model, the continuous linear source function with constant production is derived by the methods of the Laplace transform and Duhamel theory. Based on the linear source function, semi-analytical solutions are obtained for a fractured vertical well producing at a constant production rate or constant bottom-hole pressure. With the help of the Stehfest numerical algorithm and computer programing, the well test and rate decline type curves are obtained, and the key flow regimes of fractured CBM wells are: wellbore storage, linear flow in SRV region, diffusion flow and later pseudo-radial flow. Finally, we analyze the effect of various parameters, such as the Langmuir volume, radius and permeability in the SRV region, on the production performance. The research results concluded in this paper have significant importance in terms of the development, well test interpretations and production performance analysis of unconventional gas.

  8. The natural radioactivity in vicinity of the brown coal mine Tusnica - Livno, BiH

    International Nuclear Information System (INIS)

    Coal mine Tusnica is located in South-West part of Bosnia and Herzegovina in the municipality Livno. Coal mine Tusnica consists of two surface coal mines. The first one is brown coal surface deposit called Drage and second one is lignite deposit called Table. The brown coal deposit shows increased levels of natural radionuclides. The highest absorbed dose rate is recorded in the center of the surface coal mine Tusnica-Drage (500 nGy h-1) as result of the increased content of uranium and radium in coal (average specific activity of U-238 is 623 ± 23 Bq kg-1 and Ra-226 is 1191 ± 5 Bq kg-1). Levels of natural radionuclides in the vicinity of the surface deposit Drage in agricultural soil (about 3 km of the centre mine) are slightly increased due to the use of the coal ash and coal dust for fertilization of the land (U-238 is 142 ± 11 Bq kg-1 and Ra-226 is 197 ± 2 Bq kg-1). Obtained results in soil-plant-animal products chain does not show significantly increased levels of natural radionuclides due to the fact that mentioned radionuclides, in general, have a low transfer factors in soil-plant-animal products chain. (author)

  9. Assessment of Geogenic Contaminants in Water Co-Produced with Coal Seam Gas Extraction in Queensland, Australia: Implications for Human Health Risk

    Directory of Open Access Journals (Sweden)

    William Stearman

    2014-09-01

    Full Text Available Organic compounds in Australian coal seam gas produced water (CSG water are poorly understood despite their environmental contamination potential. In this study, the presence of some organic substances is identified from government-held CSG water-quality data from the Bowen and Surat Basins, Queensland. These records revealed the presence of polycyclic aromatic hydrocarbons (PAHs in 27% of samples of CSG water from the Walloon Coal Measures at concentrations <1 µg/L, and it is likely these compounds leached from in situ coals. PAHs identified from wells include naphthalene, phenanthrene, chrysene and dibenz[a,h]anthracene. In addition, the likelihood of coal-derived organic compounds leaching to groundwater is assessed by undertaking toxicity leaching experiments using coal rank and water chemistry as variables. These tests suggest higher molecular weight PAHs (including benzo[a]pyrene leach from higher rank coals, whereas lower molecular weight PAHs leach at greater concentrations from lower rank coal. Some of the identified organic compounds have carcinogenic or health risk potential, but they are unlikely to be acutely toxic at the observed concentrations which are almost negligible (largely due to the hydrophobicity of such compounds. Hence, this study will be useful to practitioners assessing CSG water related environmental and health risk.

  10. Effect of utlrasonics on reduction-oxidation properties of Kansk-Achinsk brown coal humic substances

    Energy Technology Data Exchange (ETDEWEB)

    Kandelaki, G.I.; Aleksandrov, I.V.; Kamneva, A.I.

    1988-09-01

    Carries out complex assessment of reduction-oxidation properties of humic acids obtained from brown coal, and establishes effect of ultrasonic treatment on changes in redox characteristics during storage. The investigations into redox properties of potassium humate solutions included the study of chemical activity of preparations separated from Kansk-Achinsk brown coal with various oxidation characteristics. Discusses tests carried out into the dynamics of reduction-oxidation potential changes during storage. States that reduction-oxidation systems in potassium humates separated from ultrasonically treated coal differ in chemical activity to those in humates separated from coal without ultrasonic treatment and indicates that oxidizing potential parameters chacterize redox properties of humic substances. Shows that spontaneous increase in reduction-oxidation potential of humate solutions occurs regardless of humate separation methods. 11 refs.

  11. Hydrochemical evolution within a large alluvial groundwater resource overlying a shallow coal seam gas reservoir.

    Science.gov (United States)

    Owen, Daniel D R; Cox, Malcolm E

    2015-08-01

    A combination of multivariate statistical techniques, simple hydrochemical mixing models and inverse geochemical modelling was used to investigate the major hydrochemical evolutionary pathways of a large alluvial aquifer, the upper Condamine River alluvium, south-east Queensland, Australia. Hydrochemical similarities between alluvium and sedimentary bedrock groundwater imply some mixing between alluvial and sedimentary bedrock aquifers, but spatial assessment showed that this was localised around outcrops of sedimentary bedrock in upstream areas. Within the alluvium, a distinct shift towards a low salinity Na-HCO3 water type and a brackish Na-HCO3-Cl water type was obvious in two separate locations. Both of these water types are unique to the alluvium, and inverse modelling shows that they can evolve via a combination of in situ alluvial processes, including diffuse recharge of rainfall or river water or the evolution of basalt-derived groundwater via gypsum dissolution plagioclase weathering, cation exchange and some carbonate precipitation/dissolution. The evolution of these water types is potentially influenced by overlying sodic alkaline soils, and often is associated with a source of sulfate. Evapotranspiration is the dominant salinization process in the alluvium and increases in calcium cations during salinization indicate that brackish Na-HCO3-Cl groundwater in the underlying Walloon Coal Measures are unlikely to have a major influence on salinization in the alluvium. The most saline water types observed were endemic to shallow zones of the alluvium where evapotranspiration is likely. Results demonstrate that a combination of multivariate statistics and inverse geochemical modelling can be successfully used to delineate hydrochemical pathways in complex hydrogeological settings where a range of environmental and anthropogenic factors may be influencing the evolution of water types with similar hydrochemical compositions. PMID:25863513

  12. Current planning of agricultural priority areas in conjunction with the recultivation of brown coal opencast mines in the Rhineland brown coal mining area

    International Nuclear Information System (INIS)

    In the Rhineland brown coal mining area the brown coal is won by the opencast method. Brown coal mining operations entail an enchroachment on the land over large areas, and in this connection most of the areas involved were previously cultivated intensively for agricultural purposes and very highly productive. The areas in question certainly become agricultural areas again when recultivation commences, but because of the increasing obligation to comply with the present concepts of nature and landscape preservation new demands are made as regard the landscape, and these demands for the most part are to the detriment of agriculture. In the matter of recultivation the companies operating mines therefore endeavour, already in the stage of drafting final plans, to reach an agreement in particular with the most important representatives of public interests and thus also with agricultural authorities as regards the development of the landscape. The difficult nature of this co-ordinatin process is illustrated inter alia by the example of the planning and construction of mine roads and tracks, a potential development feature which has a considerable influence on the overall structure of a landscape. (orig.)

  13. Economic efficiency of brown coal mine ''Konin'' in market economy conditions

    International Nuclear Information System (INIS)

    The economic situation of ''Konin'' brown coal mine located in Central Poland is analysed. The main problem of the mine is the coal price which is still regulated despite market economy. It causes many difficulties and therefore a change of energy policy is postulated. The basic economic results for 1993 as well as prognosis of investment costs up to 2020 are given. The changes of management system and the strategy planning training are also described. 2 ills, 1 tab

  14. Study on Remained Gas Content Calculation in Protected Coal Seam%被保护煤层残余瓦斯含量计算的探讨

    Institute of Scientific and Technical Information of China (English)

    朱红青; 潘凤龙; 王宁; 冯世梁

    2012-01-01

    被保护煤层的残余瓦斯含量是瓦斯治理的一项重要基本参数,也是考察其保护效果的一项基本指标。基于被保护煤层卸压瓦斯的运移规律,利用煤质工业分析值及瓦斯吸附实验,并结合Langmuir公式对残余瓦斯含量计算,得出被保护煤层残余瓦斯含量的计算方法。%Remained gas content is an important basic parameter of gas control in protected coal seam,which is also a basic index to assess its protective effects.The calculation of remained gas content is based on moving law of pressure-relief gas in protected coal seam,it makes use of coal quality industry analysis value and gas adsorption experiment,combined with Langmuir formula.Finally,the calculation method of remained gas content can be obtained.

  15. Overview of the influence of syn-sedimentary tectonics and palaeo-fluvial systems on coal seam and sand body characteristics in the Westphalian C strata, Campine Basin, Belgium

    Science.gov (United States)

    Dreesen, Roland; Bossiroy, Dominique; Dusar, Michiel; Flores, R.M.; Verkaeren, Paul

    1995-01-01

    The Westphalian C strata found in the northeastern part of the former Belgian coal district (Campine Basin), which is part of an extensive northwest European paralic coal basin, are considered. The thickness and lateral continuity of the Westphalian C coal seams vary considerably stratigraphically and areally. Sedimentological facies analysis of borehole cores indicates that the deposition of Westphalian C coal-bearing strata was controlled by fluvial depositional systems whose architectures were ruled by local subsidence rates. The local subsidence rates may be related to major faults, which were intermittently reactivated during deposition. Lateral changes in coal seam groups are also reflected by marked variations of their seismic signatures. Westphalian C fluvial depositional systems include moderate to low sinuosity braided and anastomosed river systems. Stable tectonic conditions on upthrown, fault-bounded platforms favoured deposition by braided rivers and the associated development of relatively thick, laterally continuous coal seams in raised mires. In contrast, rapidly subsiding downthrown fault blocks favoured aggradation, probably by anastomosed rivers and the development of relatively thin, highly discontinuous coal seams in topogenous mires.

  16. Emission Factors of Pollutants from the Combustion of Brown Coal in Domestic Appliances

    Czech Academy of Sciences Publication Activity Database

    Hopan, F.; Horák, J.; Dej, M.; Krpec, K.; Šyc, Michal; Ocelka, T.; Tomšej, T.; Pekárek, Vladimír

    Vol. 71. -: -, 2009, 000715-718. [International Symposium on Halogenated Persistent Organic Pollutants (Dioxin 2009) /29./. Beijing (CN), 23.08.2009-28.08.2009] R&D Projects: GA MŽP(CZ) SP/1A2/116/07 Institutional research plan: CEZ:AV0Z40720504 Keywords : emission factor * small sources * brown coal Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  17. Do stable carbon isotopes of brown coal woods record changes in Lower Miocene palaeoecology?

    NARCIS (Netherlands)

    Poole, I.J.; Dolezych, M.; Kool, J.; Burgh, J. van der; Bergen, P.F. van

    2006-01-01

    Stable carbon isotope ratios of fossil wood from the Miocene brown coal deposits in former East Germany are compared with palaeobotanical and sedimentological data to test the use of stable isotopes in determining palaeoenvironment. Significant differences in the chemical composition of samples from

  18. Application of overburden stripping complexes at brown coal surface mines in the GDR

    Energy Technology Data Exchange (ETDEWEB)

    Drebenstadt, K.

    1987-12-01

    In the GDR, brown coal provides 70% of primary energy and 20% of chemical feedstocks. Annual brown coal consumption in power plants is 120 Mt. The present annual output of 310 Mt will be increased to 330-335 Mt in 1990. In order to extract 1 t of brown coal it was necessary to drain 5.2 m/sup 3/ water and to remove 4.2 m/sup 3/ overburden in 1985. In 2000 these numbers will increase to 9-10 m/sup 3/ and 6.3 m/sup 3/ respectively. About 50% of brown coal fields have resources under 100 Mt which does not justify application of overburden conveyor bridges. Mobile, console type stripping complexes present essential advantages, e.g. mobility, selective excavation, capability of overcoming slopes, reliability and efficiency. Stripping complexes used in the USSR and those manufactured by TAKRAF are reviewed. A complex with a capacity of 14,000 m/sup 3//h consisting of an SRs bucket wheel excavator and ARs spreader will be put into operation at the Bitterfeld mine in the near future. The LFG-1 laser type equipment for monitoring position of the bucket wheel is described.

  19. Study of thermal reactivity of brown coal tars from rapid and slow pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Teubel, J.; Rast, A.; Schmiers, H.; Scholze, S. (Bergakademie, Freiberg (German Democratic Republic))

    1990-01-01

    Analyzes differences in properties of brown coal tars produced from coal of the same deposit, but using either rapid or slow pyrolysis. Samples of rapid pyrolysis tar originated from laboratory fluidized bed carbonization; the slow pyrolysis tar came from industrial brown coal coking. The study showed that rapid pyrolysis tar has a high thermal reactivity in the 400 C temperature range. Obtained pitch from thermal tar treatment has a high content of asphaltenes and benzene insoluble compounds. Electrode coke produced by carbonization of this pitch had an unfavorable microstructure and is unsuitable for graphitization. Secondary pyrolysis is therefore required to gain rapid pyrolysis pitch comparable in properties to pitch from industrial slow pyrolysis. 4 refs.

  20. Mapping the hydraulic connection between a coalbed and adjacent aquifer: example of the coal-seam gas resource area, north Galilee Basin, Australia

    Science.gov (United States)

    Jiang, Zhenjiao; Mariethoz, Gregoire; Schrank, Christoph; Cox, Malcolm; Timms, Wendy

    2016-07-01

    Coal-seam gas production requires groundwater extraction from coal-bearing formations to reduce the hydraulic pressure and improve gas recovery. In layered sedimentary basins, the coalbeds are often separated from freshwater aquifers by low-permeability aquitards. However, hydraulic connection between the coalbed and aquifers is possible due to the heterogeneity in the aquitard such as the existence of conductive faults or sandy channel deposits. For coal-seam gas extraction operations, it is desirable to identify areas in a basin where the probability of hydraulic connection between the coalbed and aquifers is low in order to avoid unnecessary loss of groundwater from aquifers and gas production problems. A connection indicator, the groundwater age indictor (GAI), is proposed, to quantify the degree of hydraulic connection. The spatial distribution of GAI can indicate the optimum positions for gas/water extraction in the coalbed. Depressurizing the coalbed at locations with a low GAI would result in little or no interaction with the aquifer when compared to the other positions. The concept of GAI is validated on synthetic cases and is then applied to the north Galilee Basin, Australia, to assess the degree of hydraulic connection between the Aramac Coal Measure and the water-bearing formations in the Great Artesian Basin, which are separated by an aquitard, the Betts Creek Beds. It is found that the GAI is higher in the western part of the basin, indicating a higher risk to depressurization of the coalbed in this region due to the strong hydraulic connection between the coalbed and the overlying aquifer.

  1. Investigations on the fouling behaviour of Rhenish brown coals in lignite-fired power plants

    International Nuclear Information System (INIS)

    In lignite-fired power plants high fouling in heat exchangers can be observed while firing Rhenish brown coals rich in sodium and poor in silicon content. These sulphatic and oxidic deposits reduce the heat transfer and can cause plant damage. It is assumed that fouling is caused by ash softening and partial melting of alkaline phases. The objective of this dissertation is to provide a better understanding of the fouling processes in lignite-fired boilers through experimental analysis using the ashes of different Rhenish brown coals and synthetic ash mixtures. In order to estimate the agglomeration potential of the brown coal ashes and synthetic ash mixtures, measurements of shear properties and impedance spectroscopy were performed. Furthermore, exposure tests in air and flue gas were conducted in the temperature range between 600 to 1,200 C to evaluate the influence of different parameters on the crystalline phase compounds and microstructures of the brown coal ashes and synthetic ash mixtures. The exposed samples were compared among each other and with corresponding ash deposits produced in a micro combustion chamber. Another aim of this dissertation is to verify the occurrence of NaOH melt in fouling processes. For this purpose impedance spectroscopy with a special probe was performed in the pilot power plant Niederaussem while firing sodium enriched fouling coal. This research indicates the importance of non-silicate bonded sodium and calcium in fouling processes. The higher their contents are, the higher is the fouling potential of the brown coal. Although the occurrence of NaOH in the boiler can not be directly proven by impedance spectroscopy, the experimental results indicate that it plays an important role in fouling. However, this research shows that silicates reduce the fouling potential of the ashes. Shear property measurements, impedance spectroscopy and the calculation of Na/Si and Ca/Si ratios of 450 C-ashes are applicable methods to predict the

  2. Petrographic and geochemical characterization of pale and dark brown coal from Yunnan Province, China

    Energy Technology Data Exchange (ETDEWEB)

    Ming, Q.; Xilin, R.; Dazhong, T.; Jian, X.; Wolf, M. [Aachen University, Aachen (Germany). Lehrstuhl fuer Geologie, Geochemie und Lagerstaetten des Erdoels und der Kohle

    1994-01-01

    Fifteen lignite samples from the province of Yunnan were analysed by organic petrography and geochemistry. Twelve of the samples represent the very pale (yellow) Baipao coal, the other three were normal coals of a medium brown colour. The Baipao coal consists mainly of mineral-bituminous groundmass, whereas the normal coal is characterised by well-preserved tissues derived from gymnosperm wood. Up to 190 mg/g C{sub org} of extract is extractable from the Baipao coal; only 63 mg/g C{sub org} from the normal coal. The n-alkaline fraction of the Baipao coal extract consists of high amounts of hopanes and shows the predominance of nor-abietane within the diterpenoids present. The first group of compounds points to intensive bacterial activity, while the second compound indicates not only that gymnosperms are present but also that a relatively oxygen-rich environment existed at the time of deposition. From the petrographic and organic geochemical characteristics it is concluded that the Baipao coal was formed from the same plant source material as the normal coal, but underwent stronger decay. 22 refs., 11 figs., 2 plates, 8 tabs.

  3. Upgrading of brown coal by slurry-dewatering; Kattan no yuchu dassui ni yoru clean kotai nenryo no seizo

    Energy Technology Data Exchange (ETDEWEB)

    Okuma, O.; Shimizu, T.; Inoue, T.; Shigehisa, T.; Deguchi, T.; Katsushima, S. [Kobe Steel, Ltd., Kobe (Japan)

    1996-10-28

    This paper describes an outline of solid fuel production process from brown coal and the investigation results of its elemental techniques. Dried coal is produced by this process which consists of a dewatering of crushed brown coal in oil-based solvent, a solid and liquid separation of slurry, and a remained oil recovery by heating. This process is characterized by the higher thermal efficiency compared with usual drying and the restraint of spontaneous combustion of product coal. It was revealed that solid fuel with low moisture, low ash, low sulfur, and suppressed spontaneous combustion property can be produced from Australian brown coal through this process. From the comparison between kerosene and fuel oil A, it was confirmed that the oil content during dewatering was smaller and the oil recovery by heating was easier by using a solvent with lower boiling point. It was also confirmed that the spontaneous combustion property can be suppressed using small amount of asphalt by solving asphalt in the solvent and adsorbing asphalt on the surface of brown coal. From these results, low rank coals including brown coal, which are difficult to use, are expected to be used as clean coal with low ash and low sulfur through this process. 2 refs., 7 figs., 2 tabs.

  4. Research on prevention and control technology of rock burst in close distance coal seams mining%近距离煤层开采冲击地压防治技术研究

    Institute of Scientific and Technical Information of China (English)

    刘鹏; 曲延伦; 刘宝亮

    2015-01-01

    The distance between the upper No. 3 coal seam and lower No.3 coal seam of Na-ntun Coal Mine was 2-1 3 m,strong mine earthquakes affected by the first breakage of extra thick red bed occurred in upper No. 3 coal seam,and the mine earthquakes caused rock burst disasters in working face,moreover,strong mine earthquakes also occurred in the mining of lower No. 3 coal seam. The caving and moving laws of overlying rock stratum in the mining of lower No. 3 coal seam were analysed,and the mechanism of mine earthquake triggered by the mining of lower No. 3 coal seam was worked out. On the basis of the mechanism,through optimizing mining ar-rangement and roadway support parameters and decreasing the disturbance of mining on rock burst danger area were adopted,which ensured safety in production of protective coal seam and realized safety mining.%南屯煤矿的3上、3下煤层间距2~13 m,3上煤层开采中受巨厚红层初次断裂影响引发强矿震,并诱发采场形成冲击灾害,且在3下煤层开采中仍发生强矿震。分析了开采3下煤层上覆岩层的冒落和移动规律,得出3下煤层采动引发矿震的机理。依据矿震诱发冲击机理,通过采取优化采面开采布局、减小采动对冲击危险区扰动和优化巷道支护体参数等措施,有效地保证了被解放层采场的作业安全,实现了安全开采。

  5. Spontaneous combustion characteristics and control technology of steeply inclined coal seam%急倾斜煤层自然发火特点及控制技术

    Institute of Scientific and Technical Information of China (English)

    孙启海; 王业常

    2015-01-01

    福兴煤矿现开采的急倾斜煤层多采用伪倾斜柔性掩护支架采煤法,由于前期开采经验不足,工作面搬家频繁,采空区多次出现自燃征兆,安全生产形势较为严峻。通过近几年的不断探索和总结,制定了有效的安全防范技术措施,从而大大降低了煤层自然发火几率,确保了矿井安全生产。%Fuxing coal use the false inclined lfexible shield mining method in mining steeply inclined coal seam, due to the lack of experience of working face mining, frequent moving, occurred repeatedly the signs of coal spontaneous combustion in gob, production safety situation is more severe, in recent years through the continuous exploration and summary, developed the security and effective technical measures, which greatly reduces the risk of spontaneous combustion of coal, and ensures the safety of mine production.

  6. Hydrochemical processes in a shallow coal seam gas aquifer and its overlying stream–alluvial system: implications for recharge and inter-aquifer connectivity

    International Nuclear Information System (INIS)

    Highlights: • Major ions and isotopes used to study inter-aquifer mixing in a shallow CSG setting. • Considerable heterogeneity in the water composition of the coal-bearing aquifer. • Rapid recharge of the coal-bearing aquifer through highly fractured igneous rocks. • Potential mixing between the coal-bearing aquifer and downstream alluvial aquifer. • Need to consider the seasonal influences on inter-aquifer mixing in CSG settings. - Abstract: In areas of potential coal seam gas (CSG) development, understanding interactions between coal-bearing strata and adjacent aquifers and streams is of highest importance, particularly where CSG formations occur at shallow depth. This study tests a combination of hydrochemical and isotopic tracers to investigate the transient nature of hydrochemical processes, inter-aquifer mixing and recharge in a catchment where the coal-bearing aquifer is in direct contact with the alluvial aquifer and surface drainage network. A strong connection was observed between the main stream and underlying alluvium, marked by a similar evolution from fresh Ca–Mg–HCO3 waters in the headwaters towards brackish Ca–Na–Cl composition near the outlet of the catchment, driven by evaporation and transpiration. In the coal-bearing aquifer, by contrast, considerable site-to-site variations were observed, although waters generally had a Na–HCO3–Cl facies and high residual alkalinity values. Increased salinity was controlled by several coexisting processes, including transpiration by plants, mineral weathering and possibly degradation of coal organic matter. Longer residence times and relatively enriched carbon isotopic signatures of the downstream alluvial waters were suggestive of potential interactions with the shallow coal-bearing aquifer. The examination of temporal variations in deuterium excess enabled detection of rapid recharge of the coal-bearing aquifer through highly fractured igneous rocks, particularly at the catchment

  7. THE OHIO RIVER VALLEY CO2 STORAGE PROJECT - PRELIMINARY ASSESSMENT OF DEEP SALINE RESERVOIRS AND COAL SEAMS

    Energy Technology Data Exchange (ETDEWEB)

    Michael J. Mudd; Howard Johnson; Charles Christopher; T.S. Ramakrishnan, Ph.D.

    2003-08-01

    This report describes the geologic setting for the Deep Saline Reservoirs and Coal Seams in the Ohio River Valley CO{sub 2} Storage Project area. The object of the current project is to site and design a CO{sub 2} injection facility. A location near New Haven, WV, has been selected for the project. To assess geologic storage reservoirs at the site, regional and site-specific geology were reviewed. Geologic reports, deep well logs, hydraulic tests, and geologic maps were reviewed for the area. Only one well within 25 miles of the site penetrates the deeper sedimentary rocks, so there is a large amount of uncertainty regarding the deep geology at the site. New Haven is located along the Ohio River on the border of West Virginia and Ohio. Topography in the area is flat in the river valley but rugged away from the Ohio River floodplain. The Ohio River Valley incises 50-100 ft into bedrock in the area. The area of interest lies within the Appalachian Plateau, on the western edge of the Appalachian Mountain chain. Within the Appalachian Basin, sedimentary rocks are 3,000 to 20,000 ft deep and slope toward the southeast. The rock formations consist of alternating layers of shale, limestone, dolomite, and sandstone overlying dense metamorphic continental shield rocks. The Rome Trough is the major structural feature in the area, and there may be some faults associated with the trough in the Ohio-West Virginia Hinge Zone. The area has a low earthquake hazard with few historical earthquakes. Target injection reservoirs include the basal sandstone/Lower Maryville and the Rose Run Sandstone. The basal sandstone is an informal name for sandstones that overlie metamorphic shield rock. Regional geology indicates that the unit is at a depth of approximately 9,100 ft below the surface at the project site and associated with the Maryville Formation. Overall thickness appears to be 50-100 ft. The Rose Run Sandstone is another potential reservoir. The unit is located approximately 1

  8. Environmental policy in brown coal mining in accordance with the precautionary measures principle and polluter pays principle

    International Nuclear Information System (INIS)

    The precautionary measures principle and the polluter pays principle in brown coal mining are discussed. Ground water subsidence and landscape destruction are local or regional problems and thus easily detectable. If damage cannot be avoided, its authors are known and will pay. In spite of all this, the German brown coal industry is well able to compete on the world market with others who don't care about the environmental damage they may cause. (orig./HS))

  9. Properties of the solid thermolysis products of brown coal impregnated with an alkali

    Energy Technology Data Exchange (ETDEWEB)

    Yu.V. Tamarkina; L.A. Bovan; V.A. Kucherenko [National Academy of Sciences of Ukraine, Donetsk (Ukraine). Litvinenko Institute of Physicoorganic and Coal Chemistry

    2008-08-15

    The mechanism of formation of a porous active carbon framework is considered, and the properties of the solid thermolysis products of brown coal (Aleksandriisk deposit, Ukraine) with potassium hydroxide are studied. The yields of the solid thermolysis products and potassium humates, the rate of the interaction of the solid thermolysis products with KOH at 700-900{sup o}C, the specific surface areas, the adsorption capacities for methylene blue and iodine, and the specific activities of surface areas are determined under variation of the KOH/coal ratio KOH < 18 mol/kg and temperature (110-900{sup o}C).

  10. Palynostratigraphy of the Erkovtsy field of brown coal (the Zeya-Bureya sedimentary basin)

    Energy Technology Data Exchange (ETDEWEB)

    Kezina, T.V.; Litvinenko, N.D. [Amur State University, Blagoveshchensk (Russian Federation)

    2007-08-15

    The Erkovtsy brown coal field in the northwestern Zeya-Bureya sedimentary basin (129-130{sup o}E, 46-47{sup o}N) is structurally confined to southern flank of the Mesozoic-Cenozoic Belogor'e depression. The verified stratigraphic scheme of the coalfield sedimentary sequence is substantiated by palynological data on core samples from 18 boreholes sampled in the course of detailed prospecting and by paleobotanical analysis of sections in the Yuzhnyi sector of the coalfield (data of 1998 by M.A. Akhmetiev and S.P. Manchester). Sections of the Erkovtsy, Arkhara-Boguchan, and Raichikha brown-coal mines are correlated. Stratigraphic subdivisions distinguished in the studied sedimentary succession are the middle and upper Tsagayan subformations (the latter incorporating the Kivda Beds), Raichikha, Mukhino, Buzuli, and Sazanka formations.

  11. The trace fossil Asthenopodichnium lithuanicum isp nov from Late Neogene brown-coal deposits, Lithuania

    Energy Technology Data Exchange (ETDEWEB)

    Uchman, A.; Gaigalas, A.; Melesyte, M.; Kazakauskas, V. [Jagiellonian University, Krakow (Poland). Inst. of Geological Science

    2007-07-01

    A new freshwater ichnospecies of Asthenopodichnium Thenius, A. lithitanicton, is distinguished by its pouch-like shape with a J-shaped limb that is distinctly wider than the remaining part of the pouch. It was produced in a stiffground at the top of a mineral-rich brown-coal layer of Neogene age by a suspension feeder forming pouch-like domichnial cavities. Mayfly larvae may perhaps be considered as candidates for its tracemaker. Other arthropods (amphipods, isopods) are also possibilities. The brown-coal layer was exposed during the Neogene by river erosion, was colonized by the tracemaker (locally two colonization events took place) and in the Pliocene covered by distal crevasse and river channel sands.

  12. Fly ash formation and sulphation during the combustion of brown coal

    Energy Technology Data Exchange (ETDEWEB)

    Domazetis, G.; Lovelace, P. (State Electricity Commission of Victoria, Melbourne, Vic. (Australia))

    1988-02-01

    This report deals with the extension of the NERDDP project 'Fly Ash Formation and Sulphation during the combustion of Brown Coal', completed in 1987, and describes improvements in the computer code SCCOFF, which simulates the chemical kinetics of brown coal combustion. Modification of SCCOFF has improved its user interface, allowed time-temperature profiles and constant pressure conditions to be included in SCCOFF's numerical integration routines, calculates sulphuric acid dewpoints, and combustion heat relase profiles. A sensitivity analysis of hypothetical sodium silicate reactions has been carried out. The results show that the extent and rate of formation of sodium silicate is not critically dependent on the rate constants of the proposed reaction scheme. The formation of sodium sulphate however, shows great sensitivity to the rate of sodium silicate formation. It is planned to produce an engineering version of SCCOFF. This can be accomplished through collaboration with research groups in the United States.

  13. Distribution of sulfur and pyrite in coal seams from Kutai Basin (East Kalimantan, Indonesia): Implications for paleoenvironmental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Widodo, Sri [Department of Mining Engineering, Moslem University of Indonesia, Jln. Urip Sumoharjo, Makassar (Indonesia); Oschmann, Wolfgang [Institute of Geosciece, J.W. Goethe-University, Altenhoeferallee 1, D-60438 Frankfurt a.M. (Germany); Bechtel, Achim; Sachsenhofer, Reinhard F. [Department of Applied Geoscience and Geophysics, University of Leoben, Peter-Tunner-Str.5, A-8700 Leoben (Austria); Anggayana, Komang [Department of Mining Engineering, Bandung Institute of Technology, Jln. Ganesa 10, I-40132 Bandung (Indonesia); Puettmann, Wilhelm [Institute of Atmospheric and Environmental Sciences, Dapartment of Analytical Enviromental Chemistry, J.W. Goethe-University, Altenhoeferallee 1, D-60438 Frankfurt a.M. (Germany)

    2010-03-01

    Thirteen Miocene coal samples from three active open pit and underground coal mines in the Kutai Basin (East Kalimantan, Indonesia) were collected. According to our microscopical and geochemical investigations, coal samples from Sebulu and Centra Busang coal mines yield high sulfur and pyrite contents as compared to the Embalut coal mine. The latter being characterized by very low sulfur (< 1%) and pyrite contents. The ash, mineral, total sulfur, iron (Fe) and pyrite contents of most of the coal samples from the Sebulu and Centra Busang coal mines are high and positively related in these samples. Low contents of ash, mineral, total sulfur, iron (Fe) and pyrite have been found only in sample TNT-32 from Centra Busang coal mine. Pyrite was the only sulfur form that we could recognize under reflected light microscope (oil immersion). Pyrite occurred in the coal as framboidal, euhedral, massive, anhedral and epigenetic pyrite in cleats/fractures. High concentration of pyrite argues for the availability of iron (Fe) in the coal samples. Most coal samples from the Embalut coal mine show lower sulfur (< 1 wt.%) and pyrite contents as found within Centra Busang and Sebulu coals. One exception is the coal sample KTD-38 from Embalut mine with total sulfur content of 1.41 wt.%. The rich ash, mineral, sulfur and pyrite contents of coals in the Kutai Basin (especially Centra Busang and Sebulu coals) can be related to the volcanic activity (Nyaan volcanic) during Tertiary whereby aeolian material was transported to the mire during or after the peatification process. Moreover, the adjacent early Tertiary deep marine sediment, mafic igneous rocks and melange in the center of Kalimantan Island might have provided mineral to the coal by uplift and erosion. The inorganic matter in the mire might also originate from the ground and surface water from the highland of central Kalimantan. (author)

  14. State of the eyes in welders of Division M-5, Brown Coal Mine in Belchatow

    Energy Technology Data Exchange (ETDEWEB)

    Gos, R.; Stepien, J.; Horowski, P.

    1984-01-01

    Sight organ impairments have been compared in a group of M-5 Division welders, Brown Coal Mine in Belchatow, and control group of randomly selected administration workers. In the group of welders statistically more frequent were degenerative changes in the eye macula, melanomatosis and conjunctivitis. Those with changes in the area of the macua lutea and melanosis conjunctivae should undergo periodic ophthalmological control (dispensary groups).

  15. 煤层稳定性的定性与定量评价%Qualitative and Quantitative Evaluation on Coal Seam Stability

    Institute of Scientific and Technical Information of China (English)

    李建芳

    2014-01-01

    Coal seam stability is one of main geological factors influencing mines. Any changes of the seams will directly impact production, such as branching, thickening, and thinning. Traditional qualitative evaluation differs from person to person and is difficult to mark the boundary. The paper, taking Shennan'ao Mine as an example, applies mixed qualitative and quantitative methods in the stability evaluation, which is more scientific and reasonable.%煤层稳定性是影响煤矿的主要地质因素之一,煤层发生分叉、增厚、变薄等变化,直接影响煤矿的正常生产。仅以传统的定性方式评价会因人而异,难以区分界限,文章以申南凹煤矿为例,运用定性与定量结合方法对可采煤层的稳定性评价,使煤层稳定性的评价更加科学合理。

  16. Data base for the analysis of compositional characteristics of coal seams and macerals. Final report - Part 10. Variability in the inorganic content of United States' coals: a multivariate statistical study

    Energy Technology Data Exchange (ETDEWEB)

    Glick, D.C.; Davis, A.

    1984-07-01

    The multivariate statistical techniques of correlation coefficients, factor analysis, and cluster analysis, implemented by computer programs, can be used to process a large data set and produce a summary of relationships between variables and between samples. These techniques were used to find relationships for data on the inorganic constituents of US coals. Three hundred thirty-five whole-seam channel samples from six US coal provinces were analyzed for inorganic variables. After consideration of the attributes of data expressed on ash basis and whole-coal basis, it was decided to perform complete statistical analyses on both data sets. Thirty variables expressed on whole-coal basis and twenty-six variables expressed on ash basis were used. For each inorganic variable, a frequency distribution histogram and a set of summary statistics was produced. These were subdivided to reveal the manner in which concentrations of inorganic constituents vary between coal provinces and between coal regions. Data collected on 124 samples from three stratigraphic groups (Pottsville, Monongahela, Allegheny) in the Appalachian region were studied using analysis of variance to determine degree of variability between stratigraphic levels. Most variables showed differences in mean values between the three groups. 193 references, 71 figures, 54 tables.

  17. Research in cleaning water-walls of the TP-45 boiler with water during combustion of Angren brown coal

    Energy Technology Data Exchange (ETDEWEB)

    Zagrutdinov, R.Sh.; Shpakovich, E.Ya.; Guzenko, S.I.; Timofeev, A.P.; Perevezentsev, V.P.; Vasil' ev, V.V.

    1982-08-01

    With the growth of the electric power industry, great significance is placed on combustion of low-grade coals in large deposits with infavorable properties. Angren brown coal is an inexpensive low-grade fuel with 20-22% dry ash. During its combustion in steam generators with a radiant heat surface associated deposits are formed. Research on the problem of preventing slag formation on heating surfaces during the combustion of Angren brown coal is discussed. The use of water to clean these surfaces is also discussed.

  18. 近距离煤层重复采动上覆岩层"两带"高度的探测%Close Distance Coal Seam of Repeated Mining Exploration Moves Overburden Height "Two Belts"

    Institute of Scientific and Technical Information of China (English)

    武书泉

    2015-01-01

    Five mining area mining lower coal group 14#、15#、16# coal seam,the upper 2#、6# coal seam min-ing,mined out area is large with water,through field exploration 15# coal seam working face mining and drill-ing,summed up the lower coal group 14#、15# coal repeated mining overlying strata "two belts" development al-titude 14# coal,15# coal stack of caving zone height 15.86 to 16.06m,superimposed pilot water fractured zone height of 57.45 ~ 57.56m.In order to provide the basis for the prevention and control of water in the upper part of the coal mining area,the safe mining of the working face is ensured.%矿井五采区开采下组煤14#、15#、16#煤层,其上部2#、6#煤层已开采,采空区面积大,采空区内有积水.通过在15#煤层工作面开采前后施工钻孔,进行现场探测,总结出下组煤14#、15#煤层重复采动上覆岩层"两带"发育高度,即14#煤、15#煤叠加垮落带高度为15.86~16.06m,叠加导水裂缝带高度为57.45~57.56m,为下组煤开采防治上部采空区积水,提供了依据,保证了工作面安全开采.

  19. 高瓦斯突出煤层组井筒快速揭煤关键技术%The key technology of uncovering coal quickly on the shaft in the outburst coal seam group with high gas

    Institute of Scientific and Technical Information of China (English)

    吴爱军; 程国军; 王法凯

    2015-01-01

    The first auxiliary shaft of Panyidong project department is served for minting area above-850m ,it will cross the high gas and outburst group be made of 13-1coal and 12coal . The In order to accelerate uncovering coal safely ,a number of new technology of outburst prevention were adopted by Project department :At first ,the coal seam gas pressure has been rapidly determined used the method of high gas inflation;At the same time ,the self-developed corer was used to achieve complete coal-core ,and the specific information of coal seam were mastered .After the uncovered coal has been verified and has no outburst ,large diameter drillings were constructed by the expansion slot hole and were used to speed up the gas emissions . After a series of rigorous organization and tight construction ,the whole process of uncovering coal is in less than 20 days ,and nearly a third of the time was shorten compared with conventional process ,a win-win situation of the economic and security benefits are gained .%潘一东项目部第一副井主要是服务于-850m以上的开采水平,该井筒要穿越13-1煤与12煤组成的高瓦斯突出煤层组,为了实现安全快速的揭煤,该项目部根据现场的实际情况,采用了多项新技术实施防突措施:首先使用高压充气法快速测定了煤层瓦斯压力,与此同时利用自行研制的取芯器实现完整钻取煤芯,掌握了煤层具体信息;在验证所揭煤层无突出危险性后,再利用扩槽钻头施工大直径的钻孔以加快瓦斯的排放。经过一系列严密组织和紧张施工,整个揭煤过程不到20天,较常规工艺缩短了近1/3的时间,取得了经济效益和安全效益的双赢。

  20. Effect of dispersing and stabilizing additives on rheological characteristics of the upgraded brown coal water mixture

    Energy Technology Data Exchange (ETDEWEB)

    Umar, Datin Fatia; Muta' alim [Research and Development Center for Mineral and Coal Technology, Jalan Jenderal Sudirman No. 623 Bandung 40211 (Indonesia); Usui, Hiromoto; Komoda, Yoshiyuki [Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501 (Japan)

    2009-04-15

    Upgraded brown coal water mixture (UBCWM) preparation by using an Indonesian upgraded coal produced by upgraded brown coal (UBC) process, was carried out to study the effect of dispersing and stabilizing additives on rheological behavior of the UBCWM. Three kinds of anionic dispersing additives, naphthalene sulfonic formaldehyde condensate (NSF), poly (meth) acrylate (PMA) and poly styrene sulfonic acid (PSS) and three kinds of stabilizing additives, carboxyl methyl cellulose (CMC), rhansam gum (S-194) and gellan gum (S-60) were used in this study. Results indicate that the addition of NSF 0.3 wt.% together with S-194 0.01 wt.% is effective in preparing UBCWM with good slurryability and stability, based on its rheological characteristics with the apparent viscosity at shear rate of 100 s{sup -} {sup 1} and yield stress at zero point of shear rate. The rheological behavior of all of the UBCWM that prepared, exhibits non-Newtonian Bingham plastic. From the economical point of view, the price of S-194 is expensive. On the other hand, CMC is cheap and abundant. Therefore, the addition of CMC 0.01 wt.% together with NSF 0.3 wt.% is also effective in preparing UBCWM with good fluidity and stability. (author)

  1. Influence of reaction parameters on brown coal-polyolefinic plastic co-pyrolysis behavior

    Energy Technology Data Exchange (ETDEWEB)

    Sharypov, V.I.; Beregovtsova, N.G.; Kuznetsov, B.N. [Institute of Chemistry and Chemical Technology SB RAS, K.Marx Str. 42, 660049 Krasnoyarsk (Russian Federation); Cebolla, V.L. [Instituto de Carboquimica, CSIC, Miguel Luesma, 4, 50015 Zaragoza (Spain); Collura, S.; Finqueneisel, G.; Zimny, T.; Weber, J.V. [Laboratoire de Chimie et Applications, Universite de Metz, rue V.Demange, 57500 Saint-Avold (France)

    2007-03-15

    Co-processing of polyolefinic polymers with Kansk-Achinsk (Russia) brown coal was investigated by thermogravimetry (TG) and autoclave pyrolysis under argon and hydrogen pressure in catalytic conditions (or not). Gas chromatography-mass spectrometry (GC-MS) and high performance thin layer chromatography (HPTLC) were used to analyze the distillate products. Some synergistic effects indicate chemical interaction between the products of thermal decomposition of coal and plastic. In co-pyrolysis under H{sub 2} a significant increasing of coal conversion degree as a function of polymer amount in feedstock was found. Simultaneously the coal promoted formation of distillate products from polymers. Some alkyl aromatic and O-containing substances were detected in co-pyrolysis fraction boiling in the range 180-350 C, indicating interactions between coal and plastic. Iron containing ore materials, modified by mechanochemical treatment, demonstrated a catalytic activity in hydropyrolysis process. In catalytic conditions, increases of the mixtures conversion degree by 9-13 wt.%, of distillate fraction yields by 1.2-1.6 times and a decrease of olefins and polycyclic components were observed. (author)

  2. Study on Coal and Rock Pressure Releasing Effect of Protected Seam Mining Under Long Distance%远程下保护层开采煤岩卸压效应研究

    Institute of Scientific and Technical Information of China (English)

    程详; 赵光明

    2011-01-01

    基于保护层开采覆岩移动破坏特征,分析了远程下保护层开采煤岩卸压的可行性,采用FLAC2D数值模拟软件对被保护煤层的应力分布特征、煤厚变形规律、水平位移规律、卸压范围及卸压角进行了研究。结果表明:下保护层开采时,断裂带高度已发育到被保护层,煤层产生膨胀变形,生成大量的次生裂隙,使被保护煤层产生不同程度的卸压,同时水平位移的产生也有利于煤层透气性增加。在走向方向上,被保护层向保护层采空区方向内错约30 m,煤层进入稳定膨胀变形区,走向有效卸压角的大小为66°左右。研究结果应用于工程实践后,淮南某矿13-1煤层瓦斯压力由原来的4.4 MPa变为卸压后的0.7 MPa,煤层透气性系数增大了1 061倍,表明该方法是较好的区域性防突措施。%Based on the overburden strata movement and failure features of the protected seam mining,the paper had an analysis on the feasibility of the coal and rock pressure releasing in the protected seam mining under long distance.The FLAC2D numerical simulation software was applied to the study on the stress distribution features of the protected seam,seam thickness variation law,the horizontal displacement law,the pressure releasing scope and the pressure releasing angle.The results showed that during the underneath protective seam mining,the height of the crack zone was developed to the protected seam,swelling deformations were occurred in the seam,great secondary cracks were occurred and thus different pressure releasing were occurred in the protected seam.Meanwhile,the horizontal displacement occurred would be favorable to improve the permeability of the seam.On the strike direction,the protected seam was moved about 30 m to the direction of the goaf of the protective seam.The protected seam was in the stable swelling deformation zone and the effective pressure releasing angle in the strike was about 66°.After the study

  3. Investigations concerning the mechanism of action of brown-coal coke particles in aerobic biological waste water treatment

    International Nuclear Information System (INIS)

    At the start of this work experience with the use of brown coal coke in the activated sludge process was lacking entirely. It therefore was necessary to carry through preliminary experiments in order to practically test the effect of Grown-coal coke. In two technical-scale experiments and a pilot test, very good results were obtained with the application of brown-coal coke to activated sludge. These, and previously published results, permitted to evolve moodel concepts of the mechanism of action of coal, especially brown coal coke, in activated sludge. According to these concepts the coal particles act as buffers and a temporary adsorbent of oxygen and waste water constituents. This in turn stimulates the colonization of the surface with microorganisms. In order to corroborate these model concepts, the - adsorption and desorption of solved oxygen to coal in a watery medium and - the effect of coal over a longer period of time were investigated. The results in essence confirm the model concepts. (UWa)

  4. Medullosalean fusain trunk from the roof rocks of a coal seam: Insight from FTIR and NMR (Pennsylvanian Sydney Coalfield, Canada)

    Energy Technology Data Exchange (ETDEWEB)

    Zodrow, Erwin L. [Palaeobotanical Laboratory, Cape Breton University, Sydney, Nova Scotia (Canada); Mastalerz, Maria [Indiana Geological Survey, Indiana University, 611 North Walnut Grove, Bloomington, IN 47405-2208 (United States); Werner-Zwanziger, Ulrike [Department of Chemistry, Dalhousie University, Halifax, Nova Scotia (Canada); D' Angelo, Jose A. [Instituto Argentino de Nivologia, Glaciologia y Ciencias Ambientales (IANIGLA), CCT-CONICET-Mendoza, Avda. Ruiz Leal s/n Parque Gral. San Martin (5500) Mendoza (Argentina); Area de Quimica, Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Centro Universitario - M5502JMA - Mendoza (Argentina)

    2010-05-01

    Reported for the first time from the Sydney Coalfield, Canada, is a fragmentary fusain (R{sub o} = 2.51%) specimen, 41 cm long, of a medullosalean trunk or massive petiole that originated from the roof rocks of the banded bituminous Hub Seam (R{sub o} {proportional_to} 0.65%). Megascopic characteristics of the flat-preserved specimen include an irregular-cracked fusain surface with secretinite-rodlet structures and sclerenchymatous strands some of which still embedded in the shaly matrix, and locally preserved vitrain (R{sub o} 0.69%). Co-occurrence with a compression flora composed virtually of only the seed-fern taxon Macroneuropteris scheuchzeri (Hoffmann) is noted. The goal of this study is to provide a framework for the phytophysicochemical taphonomic history which includes the perspective on vitrinite/fusinite relationship, formation of fusinite, and on the significance the only fusinized identifiable plant-fossil specimen in the Sydney Coalfield. We use state-of-the-art solid-state FTIR, {sup 13}C, {sup 1}H NMR CP/MAS techniques, and standard reflected-light microscopy and SEM methods as investigative tools. Results indicate that the fusinite is characterized by long and narrow xylem fibers, without fungal signals, and cell structures infilled with pyrite and carbonate. FTIR spectra of the fusinite and secretinite are similar particularly in respect to high absorbance of aromatic and low absorbance of aliphatic compounds, and absorbance of Si-O functionalities relating to kaolinite. {sup 13}C NMR experiments with direct carbon excitation quantify the aromatic to aliphatic ratio as being 20 {+-} 3:1. As part of the taphonomic history, the evidence favors a hot, > 400 C, directional surface-fueled flame palaeofire of local extent that charred trunks of growing arborescent seed ferns on only one side, and that these trunks were transported to comprise part of the roof rocks of the Hub Seam. (author)

  5. Sequestration of carbon dioxide by indirect mineralization using Victorian brown coal fly ash

    International Nuclear Information System (INIS)

    Highlights: ► The indirect CO2 mineralization by brown coal fly ash has been tested. ► A large CO2 capture capacity of fly ash under mild conditions was achieved. ► The kinetic analysis confirmed a fast reaction rate with low activation energy. ► The fly ash based capture process is highly efficient and cost-effective. - Abstract: The use of an industry waste, brown coal fly ash collected from the Latrobe Valley, Victoria, Australia, has been tested for the post-combustion CO2 capture through indirect minersalization in acetic acid leachate. Upon the initial leaching, the majority of calcium and magnesium in fly ash were dissolved into solution, the carbonation potential of which was investigated subsequently through the use of a continuously stirred high-pressure autoclave reactor and the characterization of carbonation precipitates by various facilities. A large CO2 capture capacity of fly ash under mild conditions has been confirmed. The CO2 was fixed in both carbonate precipitates and water-soluble bicarbonate, and the conversion between these two species was achievable at approximately 60 °C and a CO2 partial pressure above 3 bar. The kinetic analysis confirmed a fast reaction rate for the carbonation of the brown coal ash-derived leachate at a global activation energy of 12.7 kJ/mol. It is much lower than that for natural minerals and is also very close to the potassium carbonate/piperazine system. The CO2 capture capacity of this system has also proven to reach maximum 264 kg CO2/tonne fly ash which is comparable to the natural minerals tested in the literature. As the fly ash is a valueless waste and requires no comminution prior to use, the technology developed here is highly efficient and energy-saving, the resulting carbonate products of which are invaluable for the use as additive to cement and in the paper and pulp industry.

  6. Moessbauer investigations of iron containing catalysts used for hydrogenation of brown coal at high pressure

    International Nuclear Information System (INIS)

    The changes of the composition of added iron compounds are investigated in catalytic brown coal hydrogenation at high pressure by Moessbauer spectroscopy. The liquid yields are enhanced in dependence on both the vacancy content of the obtained pyrrhotite (FexS) and the dispersity of the active component. Iron compounds on carrier material are shown to be more efficient in the hydrogenation process than directly imposed iron sulfate due to pyrrhotite with lower iron content and the high dispersity of the active iron phase. Moessbauer spectroscopy is proved to represent a sensitive analytical method to characterize changes of iron containing phases in the course of hydrogenation process. (author)

  7. The use of mixed waste polymers in thermal treatment with brown coal

    Czech Academy of Sciences Publication Activity Database

    Kříž, Vlastimil; Bičáková, Olga; Machač, P.

    Ostrava: Vysoká škola báňská - TU Ostrava, 2010 - (Fečko, P.; Čablík, V.), s. 137-141 ISBN 978-80-248-2208-2. [International Conference on Environment and Mineral Processing /14./. Ostrava (CZ), 03.06.2010-05.06.2010] R&D Projects: GA ČR(CZ) GA105/07/1407 Institutional research plan: CEZ:AV0Z30460519 Keywords : brown coal * waste polymers * gasification Subject RIV: DM - Solid Waste and Recycling

  8. Influence of additives on the increase of the heating value of Bayah’s coal with upgrading brown coal (UBC) method

    Energy Technology Data Exchange (ETDEWEB)

    Heriyanto, Heri [Chemical Engineering of University Sultan AgengTirtayasa, Indonesia Email: herfais@yahoo.com (Indonesia); Widya Ernayati, K.; Umam, Chairul; Margareta, Nita

    2015-12-29

    UBC (upgrading brown coal) is a method of improving the quality of coal by using oil as an additive. Through processing in the oil media, not just the calories that increase, but there is also water repellent properties and a decrease in the tendency of spontaneous combustion of coal products produced. The results showed a decrease in the water levels of natural coal bayah reached 69%, increase in calorific value reached 21.2%. Increased caloric value and reduced water content caused by the water molecules on replacing seal the pores of coal by oil and atoms C on the oil that is bound to increase the percentage of coal carbon. As a result of this experiment is, the produced coal has better calorific value, the increasing of this new calorific value up to 23.8% with the additive waste lubricant, and the moisture content reduced up to 69.45%.

  9. Influence of additives on the increase of the heating value of Bayah’s coal with upgrading brown coal (UBC) method

    International Nuclear Information System (INIS)

    UBC (upgrading brown coal) is a method of improving the quality of coal by using oil as an additive. Through processing in the oil media, not just the calories that increase, but there is also water repellent properties and a decrease in the tendency of spontaneous combustion of coal products produced. The results showed a decrease in the water levels of natural coal bayah reached 69%, increase in calorific value reached 21.2%. Increased caloric value and reduced water content caused by the water molecules on replacing seal the pores of coal by oil and atoms C on the oil that is bound to increase the percentage of coal carbon. As a result of this experiment is, the produced coal has better calorific value, the increasing of this new calorific value up to 23.8% with the additive waste lubricant, and the moisture content reduced up to 69.45%

  10. Stress transfer between multi-seam longwall mines

    OpenAIRE

    Ganguli, Rajive

    1995-01-01

    The future of most underground coal mining in the USA will entail the extraction of coal under multi-seam mining conditions. Mine design in such an environment will require the accurate prediction of stress transfer between adjacent seams. The available knowledge on criteria controlling stress transfer has been exhaustively reviewed and critical factors affecting multi-seam mining investigated. Young's Moduli of rock layers, thickness of rock layers, number of these layers a...

  11. Power technology complex for production of motor fuel from brown coals with power supply from NPPs

    International Nuclear Information System (INIS)

    With the present-day challenge of efficient use of low-grade coals and current restructuring of coal industry in the Russian Federation, it is urgent to organise the motor fuel production by the synthesis from low grade coals and heavy petroleum residues. With this objective in view, the Institute of Physics and Power Engineering of RF Minatom and Combustible Resources Institute of RF Mintopenergo proposed a project of a standard nuclear power technology complex for synthetic liquid fuel (SLF) production using fast neutron reactors for power supply. The proposed project has two main objectives: (1) Engineering and economical optimization of the nuclear power supply for SLF production; and (2) Engineering and economical optimization of the SLF production by hydrogenisation of brown coals and heavy petroleum residues with a complex development of advanced coal chemistry. As a first approach, a scheme is proposed with the use of existing reactor cooling equipment, in particular, steam generators of BN-600, limiting the effect on safety of reactor facility operation at minimum in case of deviations and abnormalities in the operation of technological complex. The possibility to exclude additional requirements to the equipment for nuclear facility cooling was also taken into account. It was proposed to use an intermediate steam-water circuit between the secondary circuit sodium and the coolant to heat the technological equipment. The only change required for the BN-600 equipment will be the replacement of sections of intermediate steam superheaters at the section of main steam superheaters. The economic aspects of synthetic motor fuel production proposed by the joint project depend on the evaluation of integral balances: thermal power engineering, chemical technology, the development of advanced large scale coal chemistry of high profitability; utilisation of ash and precious microelements in waste-free technology; production of valuable isotopes; radical solution of

  12. Effect of structural alteration on the macromolecular properties of brown and bituminous coals, quantitative relationships to the hydrogenation reactivity with tetralin

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, P.N.; Kuznetsova, L.I. [Inst. of Chemistry and Chemico-Metallurgical Processes, Krasnoyarsk (Russian Federation); Bimer, J.; Salbut, P.D. [Inst. of Organic Chemistry, Warszawa (Poland); Gruber, R. [Univ. de Metz (France)

    1996-12-31

    The mobility of macromolecular network has been found to be the fundamental property of both brown and bituminous coals governing the reactivity for hydrogenation with tetralin. In Kansk-Achinsk brown coal, this was primarily affected by carboxylate cross-linking via polyvalent cations like Ca.

  13. An annular-furnace boiler for the 660-MW power unit for ultrasupercritical parameters intended for firing brown slagging coals

    Science.gov (United States)

    Serant, F. A.; Belorutskii, I. Yu.; Ershov, Yu. A.; Gordeev, V. V.; Stavskaya, O. I.; Katsel, T. V.

    2013-12-01

    We present the main technical solutions adopted in designing annular-furnace boilers intended for operation on brown coals of the prospective Maikubensk open-cast mine in Kazakhstan as part of 660-MW power units for ultrasupercritical steam conditions. Results from 3D modeling of combustion processes are presented, which clearly show the advantages furnaces of this kind have over a traditional furnace in burning heavily slagging brown coals. The layout of the main and boiler auxiliary equipment in the existing boiler cell of the 500-MW power unit at the Ekibastuz GRES-1 district power station is shown. Appropriate attention is paid to matters concerned with decreasing harmful emissions.

  14. Degassification and methane drainage in thick and vertical coal seams worked by horizontal sublevel caving method; Drenaje y Desgasificacion de Grisu en Capas de Carbon Potentes y Verticales, Explotadas por subniveles Horizontales con sutiraje

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The present trend of the working in spanish coal underground mines is directed towards the utilization, if the deposit characteristics permit it, of mining method by horizontal sublevels with caving. The application of this method involves an important coal volume in specific situations inside the workings cycle (shots, roof cavings, workings beginning, etc). Therefore, those considerable quantities of coal put into circulation, joined to high firedamp concentration desorbable of coal seam, produce in a instantaneous way large volumes of firedamp in the mine atmosphere with the consequent associated risk for the mine people, the stoppage of the works and its evacuation. These aforementioned risks could be avoided, or at least decreased to a great extent, through a methane capture before its circulation in openings caused by the mining works or by draining from accumulation rooms. During the last years, basically in EU countries, some researches have been accomplished about previous Degassification and methane capture in longwall faces of horizontal seams. In these researches have been studied the methane capture both from surface and from underground. In sublevel caving workings, substantially different from longwall faces workings, the techniques and capture systems utilized in the first one are not applicable to the second. The field works and measurements of this project have been mainly carried out in two mining companies located at the north of Spain, the Mina la Camocha S. A. and the S. A. Hullera Vasco Leonesa. Many methane capture tests by means of boreholes in coal seam have been carried out to determine the influence that capture boreholes exert in degassification of coal panel. Otherwise, many firedamp drainage tests in accumulation rooms have been also carried out, and a small-scale system that makes possible the capture in safe conditions have been defined and tested. (Author)

  15. EPR- study of paramagnetic features of brown coal from Kiyakty coal deposit after mechanic activation and electron irradiation

    International Nuclear Information System (INIS)

    Full text: It is known that prospected coal resources exceed, at least by order of magnitude, petroleum reserves decreasing steeply at last time as a result of world oil consumption rise. In this connection the manufacture of different liquid products from coal, especially brown coal, is issue of the day. Liquid fuel yield depends on physical-chemical characteristics and their changes owing to preliminary chemical, mechanical and radiation treatment. In this paper some results of paramagnetic characteristic study of Kiyakty deposit coal as initial one as after its mechanical treatment and electron irradiation are presented. It is discovered that in Kiyakty coal there are, at least, two fractions differed in EPR line width and concentration of free radical states they contained. First fraction has EPR line width ΔH1=4-5 Oe and mean free radical states concentration N1= 2.4·1017 sp/g. For samples of second fraction the EPR line width ΔH2= 6.6-7.2 Oe and N2= 1.8·1018 sp/g are typical. Thus, in the second fraction the EPR line width and free radical states concentration are greater than in the first case. Besides free radical states in coal EPR signals were found from trivalent iron ions with g-factor approximated 2 and with g=4.3. It the signals with g=4.3, are practically identical for both fractions, their concentrations are neighbour and line width is ΔH1= 250 Oe, then for the lines near g=2.0 situation is markedly different. For the first fraction ΔH1= 800 Oe whereas for the second case two signals in this g-factor range are observed. The first signal has line width ΔH1= 550 Oe and g=l .97, the second is more wide with ΔH1= 1000 Oe and g=2.02. We cannot discover significant dependence of free radical states concentration on mechanic activation time. Obviously, life times of complementary free radical states generated in process of coal activation are very low. As Fe3+ ions, for both fractions it is observed intensity growth of their signals with mechanic

  16. Three-dimensional numerical simulation of methane drainage by high-level drill holes in a lower protective coal seam with a‘‘U’’ type face

    Institute of Scientific and Technical Information of China (English)

    Xingkui Liu; Shuzhao Yang

    2014-01-01

    Different drill-hole positions may produce different drainage results in low protective coal seams. To inves-tigate this possibility, a 3D stope model is established, which covers three kinds of drill holes. The FLUENT computational fluid mechanics software is used to solve the mass, momentum and species conservation equations of the model. The spatial distributions of oxygen and methane was obtained by calculations and the drainage results of different drill-hole positions were compared. The results show that, from top to bottom, methane dilution by oxygen weakens gradually from the intake to the return side, and methane tends to float; methane and oxygen distribute horizontally. The high-level crossing holes contribute to better methane drainage and a greater level of control. Around these holes, the methane density decreases dramatically and a ‘‘half circle’’ distribution is formed. The methane density decreases on the whole, but a proportion of the methane moves back to deep into the goaf. The research findings provide theoretical grounds for methane drainage.

  17. Brown coal phaseout NRW. Which coal mining amounts are necessary from an energy point of view and are possible with respect to climate policy?; Braunkohleausstieg NRW. Welche Abbaumengen sind energiewirtschaftlich notwendig und klimapolitisch moeglich?

    Energy Technology Data Exchange (ETDEWEB)

    Bauknecht, Dierk; Hermann, Hauke; Ritter, David; Vogel, Moritz; Winger, Christian

    2015-04-15

    The study on the brown coal phaseout in NRW covers the following issues: scope of the study, targets on a federal level and review of actual scenario calculations; brown coal demand in Garzweiler in the different scenarios; climate policy targets in Nordrhein-Westfalen; feasibility in the frame of energy production.

  18. Study on the Failure Characteristics of Coal Seam Floor in Xinglongzhuang Coal Mine%兴隆庄煤矿煤层底板破坏特征研究

    Institute of Scientific and Technical Information of China (English)

    赵连涛; 岳尊彩; 于旭磊; 张光明; 张蕊

    2012-01-01

    Taking the condition of fully - mechanized working face in Xinglongzhuang coal mine as background, using mutual authenti- cation method of numerical simulation and live ultrasound imaging test, a comprehensive comparative study on the failure characteristics of coal seem floor under the mining is made. The numerical simulation indicats that the vertical stress is "saddle - shaped" distribution and the shear stress is roughly "butterfly - shaped" distribution in the workface. Field measurement studies show that the fracture de- velopment is obvious within the 16 m range under the seam floor of 10302 mechanized caving face, but the fracture development is rela- tively less exceed the range of 16 m. The depth of defoimation failure of coal seam floor is 16 m by the comprehensive analysis, and the results provide a reference for safety mining and mine water disaster control of Xinglongzhuang coal mine under the same condition.%以兴隆庄煤矿10302综放工作面开采实际为背景,采用数值模拟和现场超声成像测试相互验证的方法.对采动条件下煤层底板破坏特征进行综合对比研究。数值模拟研究表明,工作面垂直应力呈“马鞍形”分布,剪应力大致呈“蝶状”分布;现场超声成像探测表明,10302综放工作面煤层底板下16m范围内裂隙发育较为明显,但16n,以后裂隙发育相对较少;综合分析得出该面采动底板变形破坏深度为16m,研究结果为兴隆庄煤矿煤炭资源安全开采及矿井水害防治提供参考依据。

  19. 倾斜煤层水力压裂起裂压力计算模型及判断准则%Initiation pressure calculation model and judgment criterion for hydraulic fracturing of inclined coal seam

    Institute of Scientific and Technical Information of China (English)

    程亮; 卢义玉; 葛兆龙; 丁红; 钟定云

    2015-01-01

    As for the problem of ambiguous mechanism of crack initiation in inclined coal seam, it leads to a blind increase in water pressure or water injection rate to enhance the coal seam permeability during hydraulic fracturing in underground coal mines.In this paper, the stress state around the fracturing boreholes is analyzed using the in-situ stress coordinate conversion, then a model is established using the maximum tension stress (MTS) theory to calculate the initiation parameters of the borehole rocks. The influences of in-situ stress and coal seam inclination on the hydraulic fracturing initiation pressure and locations in underground coal mines are investigated using the model. The field test is conducted at Tonghua coal mine of Chongqing Songzao Coal and Electricity Co. Ltd. .The results show that: according to the stress state in fracturing area, the crack initiation pressure increases along with the increasing coal inclination. With the increase in the coal inclination, initiation location moves to the strike direction. The results in field test are consistent with the calculated result which is that initiation pressure increases along with increasing coal inclination. It verfies the feasibility of the calculation model.%针对目前倾斜煤层起裂机制不明确,导致水力压裂时盲目升高压力或增大注水量来增加煤层透气性的问题,根据最大拉应力理论,分析真实环境下倾斜煤层压裂钻孔周围应力状态,建立压裂钻孔周围煤岩体起裂压力计算模型及判断准则,并在重庆松藻煤电公司同华煤矿进行了验证,结果表明,根据实测压裂区域地应力状态,起裂压力随煤层倾角增大而增大,钻孔起裂位置随煤层倾角增大逐渐向走向方向偏转;现场试验起裂压力与理论计算相符,随煤层倾角增大而增大,从而验证了计算模型的正确性。

  20. Data preparation for digital modelling of the coal seams in the South Moravian Lignite Coalfield (Czech part of the Vienna Basin)

    International Nuclear Information System (INIS)

    In the contribution data preparation for digital modelling and assessing the Kyjov Seam (Pannonian, zone B of the Vienna Basin stratigraphy) and the Dubnany Seam (Pannonian, zone F) is presented. The seams occur partly as unit seam and partly as seam split in up to four benches. Almost 3000 holes were drilled in the area in the last 50 years. Data about lithological logs, laboratory results and other measurements were gathered, uniformed, and stored in digital database. Input data for modelling, which were the thickness and average values of analytical parameters in set thickness in each data point (drill hole), were derived from the primary data stored in database by designed software. The thickness was defined in five ways in each drill hole. Firstly as the geological thickness to model natural geometry of the seam and secondly as deposit thickness to model only part of the seam with required quality. Deposit thickness was defined in four variants according to limit parameter of maximal average ash content value of 50, 40, 35, and 30 % in the seam in borehole. (authors)

  1. Thermodynamic Characteristics of Adsorption-Desorption of Methane in 3# Coal Seam of Sihe

    OpenAIRE

    Dongmin Ma; Jianchang Zhang; Jianping Bai; Hui Zhang

    2014-01-01

    A series of methane adsorption-desorption isotherm experiments on anthracite of No. 3 Sihe coal mine were conducted at 20°C, 25°C, 30°C, 35°C and 40°C respectively. Based on Clausius-Clapeyron equation, isosteric heat of adsorption and maximum heat of adsorption has been calculated. These calculations indicate that the maximum heat of adsorption in process of elevated pressure (adsorption) and lowered stress (desorption) is 23.31 KJ/mol and 24.02 KJ/mol, so it belongs to physical adsorption. ...

  2. 石门揭露突出煤层冻结温度场数值模拟研究%Research on numerical simulation of freezing temperature field in uncovering outburst coal seam in cross-cut

    Institute of Scientific and Technical Information of China (English)

    谢雄刚; 冯涛

    2011-01-01

    Aiming at a new-presented outburst-proof method by injecting liquid and freezing in uncovering coal seam in cross-cut in this paper,with the ANSYS numerical simulation software,according to the operation parameters in the work face of uncovering coal seam at No.2 cross-cut of-400 m level in Longjiashan Mine,the authors established the numerical simulation calculation model of the temperature field in freezing section,analyzed its expand nephogram in different period,decided the effective range,average temperature,closure time of ice zone and expand velocity.The simulation shows that the more near to the freezing center,the more fast the temperature of the No.6 coal seam will decline.At the same time,the temperature in coal seam of frozen tubes in center cross-section and vertical-section is lowest.After 35~40 days,reached the frozen control temperature of-15 ℃ for outburst-proof.The No.6 coal in freezing zone is strong enough to prevent coal and gas outburst.The feasibility of injecting liquid and freezing as a new outburst-proof method was proved.%针对新提出的石门揭煤注液冻结防突方法,根据龙家山煤矿-400 m水平2号石门揭煤工作面施工参数,应用ANSYS数值模拟软件,建立了石门揭煤冻结温度场数值模拟计算模型,分析了不同时期冻结区温度扩展云图,得出不同冻结时间冻结区有效范围、平均温度、交圈时间及温度扩展速度。数值模拟表明:距离中心越近,冻结区煤层温度下降越快;相同冻结时间,竖向中排冻结管断面和横向中排冻结管断面处煤层温度最低。该石门揭煤工作面需要35~40 d冻结时间来满足-15℃煤层控制温度的防突工程要求。证明石门揭煤注液冻结防突技术是可行性的。

  3. Analysis of brown coal fly-ash using X-ray photoelectron spectroscopy

    Science.gov (United States)

    Ersez, T.; Liesegang, J.

    1991-08-01

    The surface chemical composition of brown coal ash particles formed during combustion has been determined using the surface-sensitive technique of X-ray photoelectron spectroscopy (XPS). Samples taken from furnace heat exchanger tube surfaces were in both powder and aggregate form. Other samples were obtained directly using 1 cm 2 steel coupons on a sample holder designed for insertion into flue gases in an experimental furnace. This allowed comparison of the XPS analyses between the fly-ash samples so acquired. After initial XPS characterization, samples were subjected to rare-gas ion (Ar +) sputtering for depth profiling purposes. The XPS technique was thus used to detect any sputter-induced composition changes or to observe any difference between the surface and bulk compositions of the ash. It was also observed that certain steels used for heat exchanger piping may well be pre-disposed to aluminosilicate fouling due to their intrinsic Al content.

  4. Sequestration of carbon dioxide by indirect mineralization using Victorian brown coal fly ash.

    Science.gov (United States)

    Sun, Yong; Parikh, Vinay; Zhang, Lian

    2012-03-30

    The use of an industry waste, brown coal fly ash collected from the Latrobe Valley, Victoria, Australia, has been tested for the post-combustion CO(2) capture through indirect minersalization in acetic acid leachate. Upon the initial leaching, the majority of calcium and magnesium in fly ash were dissolved into solution, the carbonation potential of which was investigated subsequently through the use of a continuously stirred high-pressure autoclave reactor and the characterization of carbonation precipitates by various facilities. A large CO(2) capture capacity of fly ash under mild conditions has been confirmed. The CO(2) was fixed in both carbonate precipitates and water-soluble bicarbonate, and the conversion between these two species was achievable at approximately 60°C and a CO(2) partial pressure above 3 bar. The kinetic analysis confirmed a fast reaction rate for the carbonation of the brown coal ash-derived leachate at a global activation energy of 12.7 kJ/mol. It is much lower than that for natural minerals and is also very close to the potassium carbonate/piperazine system. The CO(2) capture capacity of this system has also proven to reach maximum 264 kg CO(2)/ton fly ash which is comparable to the natural minerals tested in the literature. As the fly ash is a valueless waste and requires no comminution prior to use, the technology developed here is highly efficient and energy-saving, the resulting carbonate products of which are invaluable for the use as additive to cement and in the paper and pulp industry. PMID:22326240

  5. Practices to control rock burst in deep coal mines of Upper Silesian coal basin and their applicability for Disergarh seam of Raniganj coalfield

    Czech Academy of Sciences Publication Activity Database

    Koníček, Petr; Souček, Kamil; Staš, Lubomír; Singh, R.; Sinha, A.

    New Dehli: ISRM, Indian National Group of International Society for Rock Mechanics, Central Board of Irrigation and Power, 2010 - (Sharma, K.; Ramamurthy, T.; Kanjlia, V.; Gupta, A.), s. 1-16 ISBN N. ISSN N. [ISRM International Symposium 2010 and Asian Rock Mechanics Symposium /6./. New Dehli (IN), 23.10.2010-27.10.2010] R&D Projects: GA ČR GA105/08/1625 Institutional research plan: CEZ:AV0Z30860518 Keywords : rock burst * Upper Silesian coal basin * Raniganj coalfield Subject RIV: DH - Mining, incl. Coal Mining

  6. Coal Seam Methane Pressure as a Parameter Determining the Level of the Outburst Risk - Laboratory and in Situ Research / Ciśnienie Złożowe Jako Parametr Określający Stan Zagrożenia Wyrzutami Metanu I Skał - Badania Laboratoryjne I Kopalniane

    Science.gov (United States)

    Skoczylas, Norbert

    2012-12-01

    Scarcity of research focusing on the evaluation of the coal seam methane pressure as a parameter determining the outburst risk makes it difficult to assess the value for which the level of this risk increases considerably. It is obvious that, apart from the gas factor, the evaluation of the threat should also take into account the strength factor. The research presented in this paper attempted at estimating the level of the outburst risk on the basis of the coal seam methane pressure value and firmness of coal. In this work, the author seeks to present both the relevant laboratory research and the measurements carried out in mines.

  7. Groundwater methane in relation to oil and gas development and shallow coal seams in the Denver-Julesburg Basin of Colorado.

    Science.gov (United States)

    Sherwood, Owen A; Rogers, Jessica D; Lackey, Greg; Burke, Troy L; Osborn, Stephen G; Ryan, Joseph N

    2016-07-26

    Unconventional oil and gas development has generated intense public concerns about potential impacts to groundwater quality. Specific pathways of contamination have been identified; however, overall rates of contamination remain ambiguous. We used an archive of geochemical data collected from 1988 to 2014 to determine the sources and occurrence of groundwater methane in the Denver-Julesburg Basin of northeastern Colorado. This 60,000-km(2) region has a 60-y-long history of hydraulic fracturing, with horizontal drilling and high-volume hydraulic fracturing beginning in 2010. Of 924 sampled water wells in the basin, dissolved methane was detected in 593 wells at depths of 20-190 m. Based on carbon and hydrogen stable isotopes and gas molecular ratios, most of this methane was microbially generated, likely within shallow coal seams. A total of 42 water wells contained thermogenic stray gas originating from underlying oil and gas producing formations. Inadequate surface casing and leaks in production casing and wellhead seals in older, vertical oil and gas wells were identified as stray gas migration pathways. The rate of oil and gas wellbore failure was estimated as 0.06% of the 54,000 oil and gas wells in the basin (lower estimate) to 0.15% of the 20,700 wells in the area where stray gas contamination occurred (upper estimate) and has remained steady at about two cases per year since 2001. These results show that wellbore barrier failure, not high-volume hydraulic fracturing in horizontal wells, is the main cause of thermogenic stray gas migration in this oil- and gas-producing basin. PMID:27402747

  8. Development and application of reservoir models and artificial neural networks for optimizing ventilation air requirements in development mining of coal seams

    Energy Technology Data Exchange (ETDEWEB)

    Karacan, C. Oezgen [National Institute for Occupational Safety and Health (NIOSH) Pittsburgh Research Laboratory Pittsburgh, PA 15236 (United States)

    2007-11-22

    In longwall development mining of coal seams, planning, optimizing and providing adequate ventilation are very important steps to eliminate the accumulation of explosive methane-air mixtures in the working environment. Mine operators usually try to supply maximum ventilation air based on the capacity of the system and the predicted need underground. This approach is neither economical nor safer as ventilation capacity may decrease in time depending on various mining and coalbed parameters. Thus, it is important to develop better engineered approaches to optimize mine ventilation effectiveness and, therefore, to ensure a safer work environment. This study presents an approach using coalbed methane reservoir modeling and an artificial neural network (ANN) design for prediction and optimization of methane inflows and ventilation air requirements to maintain methane concentrations below statutory limits. A coalbed reservoir model of a three-entry development section, which is typical of Pittsburgh Coalbed mines in the Southwestern Pennsylvania section of Northern Appalachian Basin, was developed taking into account the presence and absence of shielding boreholes around the entries against methane inflow. In the model, grids were dynamically controlled to simulate the advance of mining for parametric simulations. Development and application of artificial neural networks as an optimization tool for ventilation requirements are introduced. Model predictions are used to develop, train, and test artificial neural networks to optimize ventilation requirements. The sensitivity and applications of proposed networks for predicting simulator data are presented and discussed. Results show that reservoir simulations and integrated ANN models can be practical and powerful tools for predicting methane emissions and optimization of ventilation air requirements. (author)

  9. Groundwater methane in relation to oil and gas development and shallow coal seams in the Denver-Julesburg Basin of Colorado

    Science.gov (United States)

    Sherwood, Owen A.; Rogers, Jessica D.; Lackey, Greg; Burke, Troy L.; Osborn, Stephen G.; Ryan, Joseph N.

    2016-01-01

    Unconventional oil and gas development has generated intense public concerns about potential impacts to groundwater quality. Specific pathways of contamination have been identified; however, overall rates of contamination remain ambiguous. We used an archive of geochemical data collected from 1988 to 2014 to determine the sources and occurrence of groundwater methane in the Denver-Julesburg Basin of northeastern Colorado. This 60,000-km2 region has a 60-y-long history of hydraulic fracturing, with horizontal drilling and high-volume hydraulic fracturing beginning in 2010. Of 924 sampled water wells in the basin, dissolved methane was detected in 593 wells at depths of 20–190 m. Based on carbon and hydrogen stable isotopes and gas molecular ratios, most of this methane was microbially generated, likely within shallow coal seams. A total of 42 water wells contained thermogenic stray gas originating from underlying oil and gas producing formations. Inadequate surface casing and leaks in production casing and wellhead seals in older, vertical oil and gas wells were identified as stray gas migration pathways. The rate of oil and gas wellbore failure was estimated as 0.06% of the 54,000 oil and gas wells in the basin (lower estimate) to 0.15% of the 20,700 wells in the area where stray gas contamination occurred (upper estimate) and has remained steady at about two cases per year since 2001. These results show that wellbore barrier failure, not high-volume hydraulic fracturing in horizontal wells, is the main cause of thermogenic stray gas migration in this oil- and gas-producing basin. PMID:27402747

  10. 近距离下煤层综采工作面侧向支承压力分布研究%Study on Lateral Support Pressure Distribution of Fully Mechanized Coal Mining Face in the Contiguous Lower Seams

    Institute of Scientific and Technical Information of China (English)

    张小康; 何峰

    2012-01-01

    In order to determine a rational width of the sectional coal pillar in fully mechanized coal mining face in seam closed distance to below seam in Mugua Mine, based on the mine pressure and strata control theory, a mechanics model of a broken delta block structure in lateral strata was established. The cracking length of the main roof along the coal mining face forward direction and the lateral cracking span calculated was 11.9 m individually. The cracking location of the delta block structure in the coal seam was 11.5 m. Meanwhile the numerical simulation method was applied to establish a 3D mechanics model of the coal mining face. With the coal mining face moving for- ward, the lateral support pressure peak of the gateway was 20 MPa, the max stress concentrated was 2. 55 and the plastic zone was about 10 m. The site detection showed when the rational width of the sectional coal pillar was 16 ~ 18 m, the mining gateway would be less affected by the mining operations of the fully mechanized coal mining face.%为确定木瓜煤矿近距离下煤层综采工作面区段煤柱的合理宽度,基于矿山压力与岩层控制理论,建立了侧向岩层断裂的三角块结构力学模型,计算出基本顶沿工作面推进方向断裂长度和沿侧向断裂跨度均为11郾 9 m,三角块结构在煤体中的断裂位置为11郾 5 m;同时应用数值模拟的方法,建立采场三维力学模型,得出随采场推进巷道侧向支承压力峰值为20 MPa、应力集中系数最大为2郾 55、塑性区范围为10 m左右。经现场检验,区段煤柱的合理宽度为16 ~18 m时,回采巷道受综采工作面采动影响较小

  11. Occurrence and transformation of phyllocladanes in brown coals from Nograd Basin, Hungary

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, G.; Hazai, I.; Grimalt, J.; Albaiges, J.

    1987-08-01

    Phyllocladanes are the major components of the lipid extracts of two series of brown coals from the Nograd Basin (Northern Hungary). In this basin coalification was induced by thermal stress of volcanic origin which determined the isomeric composition of these compounds. Depending on the degree of maturation the 16..cap alpha..(H)-isomer decreases in abundance relative to the more geochemically stable 16..beta..(H)-isomer, the presumed equilibrium ratio being 0.3. Laboratory thermal degradation experiments have confirmed the feasibility of this transformation, showing that phyllocladene and isophyllocladene are intermediate products of the process. Variable amounts of retene and simonellite are also found, but no evidence is obtained of abietane-type precursors. Nevertheless, a close relationship of the retene-phyllocladane ratio with maturity, represented by the H/C ratio, is observed. As an explanation, it is suggested the thermally induced formation of retene from phyllocladanes, simonellite being an intermediate of the proposed reaction. Further evidence for this hypothesis has been obtained from laboratory simulation experiments. Finally, the presumed isomerization and aromatization rates of these diterpenoids have been compared for the series of samples, pointing to a promising tool for assessing the geochemical history of coal basins. 57 refs., 6 figs., 2 tabs.

  12. Occurrence and transformation of phyllocladanes in brown coals from Nograd Basin, Hungary

    Science.gov (United States)

    Alexander, Gabor; Hazai, Istvan; Grimalt, Joan; Albaigés, Joan

    1987-08-01

    Phyllodactanes are the major components of the lipid extracts of two series of brown coals from the Nograd Basin (Northern Hungary). In this basin coalification was induced by thermal stress of volcanic origin which determined the isomeric composition of these compounds. Depending on the degree of maturation the 16α(H)-isomer decreases in abundance relative to the more geochemically stable 16β(H)-isomer, the presumed equilibrium ratio being 0.3. Laboratory thermal degradation experiments have confirmed the feasibility of this transformation, showing that phyllocladene and isophyllocladene are intermediate products of the process. Variable amounts of retene and simonellite are also found, but no evidence is obtained of abietane-type precursors. Nevertheless, a close relationship of the retene-phyllocladane ratio with maturity, represented by the H/C ratio, is observed. As an explanation, it is suggested the thermally induced formation of retene from phyllocladanes, simonellite being an intermediate of the proposed reaction. Further evidence for this hypothesis has been obtained from laboratory simulation experiments. Finally, the presumed isomerization and aromatization rates of these diterpenoids have been compared for the series of samples, pointing to a promising tool for assessing the geochemical history of coal basins.

  13. 煤体注水难易性评价的可拓物元模型与应用%Extensible matter-element model and application of difficulty assessment on water infusion for coal seam

    Institute of Scientific and Technical Information of China (English)

    邱进伟; 刘泽功; 戴广龙; 刘健; 唐明云

    2014-01-01

    Based on the matter-element theory and entropy theory of extenics,a model of extensible matter-element model for evaluating difficulty of water infusion for coal seam was established. In order to determine the weight rati-os on difficulty of water infusion for coal seam,the method of entropy weight was adopted. Five major index factors such as cranny viability,porosity,wet rim angle,hardness of coal,and saturation moisture increment were regar-ded as the discriminant factors. The grading standard and index threshold range on difficulty of water infusion for coal seam were established,namely establishing classical field matter elements and extensional matter elements. The proposed model was applied in five actual water infusion cases. The results fitted well with the actual situation. Therefore,the extenics method is feasible for difficulty assessment of water infusion for coal seam. It is simple, convenient and practical by comparing with the traditional method,and can be applied in similar engineering.%基于可拓学的物元理论和熵原理,构建了煤体注水难易性评价的可拓物元模型,引入熵权法确定煤体注水难易性的权系数。选取裂隙发育程度、孔隙率、煤体湿润边角、煤的硬度和饱和水分增值五个指标作为评判因子,并确定煤体注水难易性分级标准和指标阀值范围,即构建了经典域物元和节域物元。利用建立的模型对五个工程实例进行综合评价,应用研究结果表明:评判结果与工程实际情况吻合良好。因此,可拓学评价方法应用于煤体注水难易性评价是可行的,与传统评价方法相比,具有计算简单、便捷实用,易于在同类工程中推广应用。

  14. 煤巷掘进过程煤层瓦斯运移规律的数值模拟%Numerical simulation on gas migration law during tunnel excavation in thick coal seam

    Institute of Scientific and Technical Information of China (English)

    贾真真; 冯涛

    2015-01-01

    研究煤巷掘进过程中瓦斯运移规律对瓦斯灾害防治具有重要的意义。本文构建了瓦斯流动的固气耦合模型,应用 RFPA_GASFLOW 软件对煤巷掘进过程瓦斯运移进行数值模拟。研究表明,煤巷掘进过程中,掘进巷道周围产生瓦斯渗流场,瓦斯压力梯度等值线呈轴对称分布并随着巷道的掘进向前移动;掘进工作面前方和掘进巷道两帮煤壁内的瓦斯压力的变化规律相同,瓦斯压力在渗流场内呈抛物线分布,瓦斯压力梯度在巷道附近最大,并逐渐增加至煤层初始瓦斯压力,采掘作业只对巷道周围一定范围内的瓦斯压力有影响;随着煤壁暴露时间的增加,巷道周围煤层中的瓦斯压力和瓦斯流量逐渐降低,最终趋于稳定。%The study of gas migration law during tunnel excavation in thick coal seam is of important significance for preventing gas disasters.A coupling model between coal and gas is constructed,and then gas migration law during tunnel excavation in thick coal seam is simulated by means of RFPA software.Results show that the gas seepage field appears around the roadway during tunnel excavation in thick coal seam,gas pressure gradient is axis symmetry and moves forward with the tunnel excavation;the change of gas pressure before working face and in roadway wall are the same,the gas pressure distribution is parabolic in the gas seepage field, the gas pressure gradient around the roadway is largest,and then it gradually increases to the initial gas pressure. With the increase of exposure time of roadway wall,gas pressure and gas flow in the coal seam around the roadway gradually decreases,and finally tends to be stable.

  15. Study on Influence of Coal Seam Water Infusion Pressure upon Infusion Effect%煤层注水压力对注水效果的影响研究

    Institute of Scientific and Technical Information of China (English)

    骆大勇

    2014-01-01

    分析了注水压力在煤层注水中的作用,对试验煤矿掘进工作面煤层注水进行了数值模拟,得出煤层注水压力与压裂过程中煤体破裂程度之间的变化关系。运用模拟结果对试验煤矿工作面的注水压力进行优化,取得了较好的效果。为选择适当的煤层注水压力提供了一种方法。%In this paper, analysis was made on effect of water pressure in coal seam water infusion, numerical simulation was carried out on the seam water infusion in a heading face in the experimental mine, and the variation relation between the water infusion pressure and the coal breaking degree in the fracturing process was obtained. The simulated results were used to optimize the water infusion pressure in the coal face of the mine, better effect was achieved. This thus provided a method for the selection of the appropriate infusion pressure.

  16. 煤层注水压力对注水效果的影响研究%Study on Influence of Coal Seam Water Infusion Pressure upon Infusion Effect

    Institute of Scientific and Technical Information of China (English)

    骆大勇

    2014-01-01

    分析了注水压力在煤层注水中的作用,对试验煤矿掘进工作面煤层注水进行了数值模拟,得出煤层注水压力与压裂过程中煤体破裂程度之间的变化关系。运用模拟结果对试验煤矿工作面的注水压力进行优化,取得了较好的效果。为选择适当的煤层注水压力提供了一种方法。%In this paper, analysis was made on effect of water pressure in coal seam water infusion, numerical simulation was carried out on the seam water infusion in a heading face in the experimental mine, and the variation relation between the water infusion pressure and the coal breaking degree in the fracturing process was obtained. The simulated results were used to optimize the water infusion pressure in the coal face of the mine, better effect was achieved. This thus provided a method for the selection of the appropriate infusion pressure.

  17. Research on Ascending Mining of NO.4-1 Coal Seam in Xiaoming Mine%晓明矿4-1#煤层上行开采研究

    Institute of Scientific and Technical Information of China (English)

    刘军; 张宏伟; 冯家元; 刘日成; 马会安

    2011-01-01

    针对晓明矿地质条件,综合运用关键层理论、围岩平衡法、“三带”法、数值分析压巷道探查等方法分析了7#煤层回采后上覆围岩活动规律,确定了上部4-1#煤层的底板下沉量、煤体破坏程度及煤层应力状态以及煤层的连续性和完整性.综合理论分析、数值分析及现场探查结果,判定4-1#煤层上行开采是可行的,并提出回采设计方案,为晓明矿及类似务件矿井进行上行开采提供了参考.%According to the geological conditions of Xiaoming Mine,the key strata theory,surrounding rack equilibrium method,three zones method,numerical analysis and roadway exploration are used to analyze moving rule of .surrounding rock overlying NO. 7 coal seam after mined it. Floor linkage,broken degree,continuity ,integrity and the stress condition of NO.4-1 coal seam are determined. From the result of theoretical Analysis,numerical simulation calculation and exploration,ascend mining feasibility of NO.4-1 coal seam is determined,with its mining design scheme proposed. References for ascend mining in Xiaoming Mine or one's geological conditions being similar to it can be gotten from these.

  18. Numerical Analysis of the Influence to Coal Seam Roof of Tectonic Stress%构造应力对煤层顶板稳定性影响的数值分析

    Institute of Scientific and Technical Information of China (English)

    张鑫; 潘恺; 武志德

    2012-01-01

    Seam roof failure is common disaster in coal mine production ; the stability prediction of roof is the key techni- cal measures for prevention and control of roof fall accidents ; tectonic stress is one of the important factors to the stability of roof. By using FLAC3D software. The distortion destroy characteristic of coal seam roof in undermining process and the move- ment law of coal seam roof under different lateral pressure in the influence of tectonic stress are analysed in this paper. It can be concluded that the roof failure extends from the middle of the bottom of the stratified rock upwardly, under certain condi- tions, with the horizontal tectonic stress increase, the shift of roof rock layers will decrease and the destroy zone will reduce.%煤层顶板垮落是煤矿生产常见的灾害,煤层顶板稳定性预测是防治顶板事故的关键技术措施。构造应力是影响煤层顶板稳定性的重要因素之一。利用FLAC3D软件,分析在构造应力的影响下煤层项板在采动过程中的变形破坏特征,以及不同侧压条件下煤层顶板的移动规律。结果表明,顶板破坏在岩梁中部是由下向上发展的,在一定的条件下,随着水平构造应力的增大,顶板破坏范围逐步减小,顶板岩层的位移逐步减小。

  19. Application Researches on Coal Seam Interface Interpolation Based on Moving Fitting Method%移动拟合法在煤层界面插值中的应用研究

    Institute of Scientific and Technical Information of China (English)

    刘光伟; 白润才; 朱志宇

    2011-01-01

    In order to reach the best approximation of coal seam when establishing 3D geological model,a new method is proposed to interpolate its interface based on moving fitting. Optimization choice for parameters is selected in the different occurrence condition of coal seams and the distribution features of primary data, with interpolation accuracy enhanced by improving morbid equations. The coal seam interpolation is realized by a mine borehole, which is determined kernel by cross-validation and 3D displayed by AutoCAD. Strong data support for the geology model construction is provided.%为了在构建三维矿床模型过程中,形成最佳逼近的煤层界面模型,将移动拟合法引入到煤层界面插值中.根据煤层的赋存条件以及原始采样数据的分布特点提出了参数优化选择的有效方法度适用条件,并通过数学方法改善病态矩阵,使待估区域中的插值结果精度更高.以某矿的煤层界面数据为样本,通过交叉检验确定权函数,进行空间插值以及三维可视化,比较真实地反映了矿床的基本特征,为矿床地质模型的建立提供了有力的数据支撑.

  20. Methane production from coal seams and CO2 uptake capability of the Mecsek mountain range, Hungary; Die Methangewinnung aus Kohlefloezen und das CO{sub 2}-Aufnahmevermoegen des Mecsek-Gebirges in Ungarn

    Energy Technology Data Exchange (ETDEWEB)

    Varga, Z.N. [Univ. Miskolc (Hungary); Lakatos, I. [Forschungsinstitut der angewandten Chemie (Hungary); Foeldessy, J.; Toth, J.; Fodor, B.; Csecsei, T. [Ungarischer Geologischer Dienst, Rotaqua KFT (Hungary)

    2006-06-15

    Methane from the Mecsek mountain range coal seams is of vast economic importance. Modified geological models focusing on zones of enhanced permeability may be useful in the development of practicable winning technologies. High gas volumes are assumed in stowed material, which may be recovered by a simple technology. There is a power station in the vicinity which produces waste gases that may be used for injection, so the Mecsek region offers promising conditions for CO2 CBM production. The same power plant is also a potential consumer of the recovered methane. (orig.)

  1. Nature of olefins and carboxyl groups in an Australian brown coal resin

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M.A.; Collin, P.J.; Vassallo, A.M.; Russell, N.J.

    1984-01-01

    The chemical structure of the resin from an Australian soft brown coal (Yallourn) has been investigated by cross-polarization nuclear magnetic resonance spectroscopy with magic angle spinning (/sup 13/C CP MAS NMR). Some additional solution /sup 1/H and /sup 13/C data were also obtained. Solid-state experiments were performed with and without a delay period before data acquisition. The resulting free induction decays were Fourier transformed with respect to acquisition time and delay period to produce two-dimensional solid-state spectra. Assignments made from the spectra clearly demonstrate that the gross chemical structure of the Yallourn resin is best described as a polymerized diterpenoid with one axial carboxylic group and two double bonds. One double bond is trisubstituted, the other is monosubstituted. After consideration of various mechanisms for polymerization of diterpenoid units during biogenesis and coalification, it was concluded that polymerization occurs at the C/sub 15/ carbon atoms in the diterpenoids without cyclization of the methylene units at C/sub 8/. 26 references.

  2. Chemical evolution of Miocene wood: Example from the Belchatow brown coal deposit, central Poland

    Science.gov (United States)

    Drobniak, A.; Mastalerz, Maria

    2006-01-01

    Miocene conifer wood samples from the Belchatow brown coal deposit in Poland were studied in order to discuss a range of chemical variations that occur as a result of biochemical coalification. Petrographic analysis, ultimate analysis, electron microprobe technique, and FTIR spectroscopy were used in this study. Our data show several progressive trends in functional groups distribution that take place during the wood transformation from group 1 to group 4, such as an overall increase in aromaticity, an increase in lignin/cellulose ratio, and an increase in oxygen functionalities. Other observations include an increase in aliphatic stretching and bending functionalities from groups 1 to 3; followed by a decrease in the wood of group 4; appearance of aliphatic out-of-plane bands in group 3 and increase in group 4; an increase in CH2/CH3 in group 4 compared to the other groups; and decrease in O-H groups in group 4 compared to other groups. These observations, together with other chemical and petrological observations, indicate that the progressive elimination of cellulose and modification of lignin are dominant processes of the wood transformation. ?? 2005 Elsevier B.V. All rights reserved.

  3. Numerical simulation study on roof failure process in steep-inclined coal seam with RFPA%急倾斜煤层顶板垮落过程的RFPA数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    温彦良; 常来山; 张宏伟

    2011-01-01

    Take example for 15 coal seam of Chang' gouyu mine, RFPA2D software is used to simulate roof failure process of steep-inclined coal seam with working face moving forwards. Research results indicate that roof supporting pressure of workface is decreased as the roof failure range increased. There exists first weighting and periodic weighting during roof failure process, but strata behavior is not obvious during periodic weighting. Synchronously with the increase of mining depth, floor begins to failure with low depth. Research results have Significance to safe productivity of mine.%以长沟峪矿15槽煤层为例,用RFPA2D软件模拟了急倾斜煤层顶板随工作面推进的垮落过程.研究结果表明,工作面顶板岩体支承压力随顶板冒落范围增大而降低;急倾斜煤层顶板垮落过程中,存在初次来压和周期来压现象,但周期来压期间矿压显现不明显.同时,随采深加大,煤层底板开始出现相应破坏,但破坏深度较小.研究结果,对矿山的安全生产有重要指导意义.

  4. The analysis of antireflection range in coal seam hydraulic fracturing%本煤层水压致裂增透范围分析

    Institute of Scientific and Technical Information of China (English)

    赵源; 曹树刚; 李勇; 覃乐

    2015-01-01

    在理论分析水压致裂起裂机理和起裂方向的基础上,应用煤岩损伤破裂过程渗流-应力耦合分析系统,对5种不同地应力条件下的本煤层水压致裂过程进行模拟,得到了煤体的起裂方向、起裂压力和扩展压力.研究发现:侧压系数λ<1时,煤体基本沿垂直方向起裂,起裂压力和扩展压力呈逐步增长的趋势;λ>1 时,煤体的起裂方向为水平,起裂压力和扩展压力表现出平缓降低的趋势;在λ=1时,运用3种屈服准则进行了对比分析,得到了不同判别准则下的最小起裂水压.通过对λ=1.2时的受力状态进行深入分析,提出了压裂增透范围为宏观裂隙区、微裂隙贯通区、微裂隙产生区(受拉区)和原生裂隙扰动区(压应力恢复区)之和;利用数值图像处理得到的增透面积增长趋势符合二次函数的关系.%Based on the theoretical analysis of crack initiation mechanism and crack direction of hy-draulic fracturing, the hydraulic fracturing process of coal seam under five different in-situ stress situa-tions has been simulated by using the seepage-stress coupling analysis system of coal and/or rock dam-age & fracture process, and hence, the crack initiation direction, initial pressure and expansion pressure have been obtained. Studies have found that, the crack direction is vertical, with the initial pressure as well as the expansion pressure presenting as gradual increasing trend when the lateral pressure coeffi-cientλ<1. When the lateral pressure coefficientλ>1, the crack direction is horizontal, with the initial pressure and the expansion pressure presenting as gradually decreasing trend. When the lateral pressure coefficientλ=1, by carrying out three different kinds of yield criterion contrastive analysis, the minimum initial pressure are respectively obtained under the different kinds of yield criterion. Through the further stress analysis, i.e., when coefficientλ=1.2, studies have proposed

  5. 薄煤层综采数字化无人工作面技术研究与应用%Research and Application of Fully Mechanized and Digitalized Unmanned Coal Mining Face in Thin Seam

    Institute of Scientific and Technical Information of China (English)

    王巨光

    2012-01-01

    为实现薛村矿薄煤层94702综采工作面数字化无人开采,根据该工作面地质条件,介绍了采煤机、液压支架、刮板输送机三机设备选型过程;设计并实现了采煤机位置检测、记忆截割自动调高、运行状态实时监控以及液压支架电液控制系统的自动控制等功能。结果表明:通过采用合理的采煤方法和回采工艺,综采数字化无人工作面开采技术安全可靠,可实现自动完成割煤、移架、推移刮板输送机和顶板支护等生产流程。%In order to realize a digitalized unmanned mining of No. 94702 fully mechanized coal mining face in thin seam of Xuecun Mine, according to the geological conditions of the coal mining face, the paper introduced the equipment selection process of the coal shearer, hydraulic powered supports and scraper conveyor. The location detection of the coal shearer, the automatic height adjustment of the memory cutting, the real time monitoring and control of the operation status, the automatic control of the hydraulic powered support electric and hydraulic control system and other functions were designed and realized. The results showed that with the rational coal mining method and the coal mining technique, the mining technology of the fully mechanized digitalized unmanned coal mining face was safety and reliable and could automatically realize the coal cutting, powered support moving forward, scraper conveyor and roof support and other production process.

  6. Problems in stabilizing the quality of brown coal fuel for powerful state regional electric power plants. Zadachi stabilizatsii kachestva burougol'nogo topliva dlya moshchykh GRES

    Energy Technology Data Exchange (ETDEWEB)

    Varshavskiy, A.M.

    1984-01-01

    The change in the structure of the fuel balance of thermal electric power plants over the last decades is examined. The growing role of brown coals for coal dust combustion at the present time is shown. Data are cited which characterize the Kansko Achinskiy fuel and energy complex, the deposit of brown coal and the specifications on the quality of the coal. Characteristic to this are thick, complexly structured coal strata of high strength with substantial fluctuations in ash content, moisture level and heat creating capability. The powerful energy producing units of thermal electric power plants require a quite uniform fuel quality. The existing GOST 11717-78 insufficiently regulates the specifications for the quality of fuel for state regional electric power plants (GRES) which come from the different open pits of the Kansko Achinskiy basin. It is proposed that the coal be averaged and ground within the concentrating plant by means of cutting excavators and that corrections to the GOST be introduced.

  7. Draining surface mines in the Dnepr coal basin and environmental protection

    Energy Technology Data Exchange (ETDEWEB)

    Rudnev, E.N.; Spivak, O.A.; Ustinov, S.A.

    1984-11-01

    Mine draining methods used in the Morozovsk and Protopopovsk brown coal surface mines in the Dnepr basin are discussed. Water bearing strata situated above and below coal seams are characterized: types of aquifers, influx rate, filtration properties of rock layers adjacent to coal seams. The following mine draining methods are used in the coal mines: draining from the ground surface by a system of long boreholes, use of underground workings for mine draining, use of trenches situated at the bottom of surface mines. Effects of mine draining on surface water (rivers) and on agriculture in the vicinity of the surface mines are evaluated. The following methods for water pollution control recommended for the coal mines are comparatively evaluated: use of waterproof screens (e.g. layers of clay) for prevention of water leaks from water tanks and water channels used for mine draining, widespread use of long boreholes for mine draining, reducing content of mineral matter in waste water from mine draining.

  8. CO2 adsorption properties of char produced from brown coal impregnated with alcohol amine solutions.

    Science.gov (United States)

    Baran, Paweł; Zarębska, Katarzyna; Czuma, Natalia

    2016-07-01

    Carbon dioxide (CO2) emission reduction is critical to mitigating climate change. Power plants for heating and industry are significant sources of CO2 emissions. There is a need for identifying and developing new, efficient methods to reduce CO2 emissions. One of the methods used is flue gas purification by CO2 capture through adsorption. This study aimed to develop CO2 adsorbent out of modified brown coal impregnated with solutions of first-, second-, and third-order amines. Low-temperature nitrogen adsorption isotherms and CO2 isotherms were measured for the prepared samples. The results of experiments unexpectedly revealed that CO2 sorption capacity decreased after impregnation. Due to lack of strait trends in CO2 sorption capacity decrease, the results were closely analyzed to find the reason for the inconsistencies. It was revealed that different amines represent different affinities for CO2 and that the size and structure of impregnating factor has influence on the CO2 sorption capacity of impregnated material. The character of a support was also noticeable as well for impregnation results as for the affinity to CO2. The influence of amine concentration used was investigated along with the comparison on how the theoretical percentage of the impregnation on the support influenced the results. The reaction mechanism of tertiary amine was taken into consideration in connection to no presence of water vapor during the experiments. Key findings were described in the work and provide a strong basis for further studies on CO2 adsorption on amine-impregnated support. PMID:27317051

  9. Similar Material Simulation Experiment on Overburden Rock Movement of Close-distance Coal Seams%近距离煤层覆岩移动相似材料模拟

    Institute of Scientific and Technical Information of China (English)

    郭从军; 南存全; 王东

    2015-01-01

    In order to study the law of overburden rock movement and bed separation development in close distance coal seams,the movement of overburden rock when downward mining of close distance coal seams is simulated through similar material simulation experiment. The digital image correlation method is applied to measure displacement points and obtain displacement data of the measured points. The cluster analysis is used to classify the measured points and obtain the specific scope of the three zones under mining influence. According to the analysis on the displacement process of measured point,it has a feature of conti-nuity and mutability. The expansion of the mining influence scope is in lateral spreading and vertical extension;When lower coal seam is explored,the maximal displacement point is behind the shortening distance of working face. Bed separation during upper coal seam mining is transformed into caving at lower coal seam mining. By analyzing the extension of the bed separation,it is con-cluded that the direction of the bed separation is in vertical and horizontal extension,and experiences the process of development-expansion-mutation-close. It is found that the bed separation rate curve of the row and column survey line is in double-humped shape. On row survey line,the causes for bed-separation rate curve,peak point size relations,and position change are analyzed,it is concluded that the peak point of the upper rock stratum are in internal displacement with that the lower rock stratum,the peak point nears to the fracture line,and the trough is located in the middle of goaf. From bed separation rate curve of the column sur-vey line,it is obtained that the peak point is in bed separation. The closed area of bed separation is on the left of peak,and the development area is on the right. The trough on the right side of peak point is the position of key stratum;Peaks discontinuously moves and leaps to the right with coal seam mining. The discriminant method for

  10. 特厚煤层大采高综放开采机采高度的确定与影响%Determination and influence of cutting height of coal by top coal caving method with great mining height in extra thick coal seam

    Institute of Scientific and Technical Information of China (English)

    王国法; 庞义辉; 刘俊峰

    2012-01-01

    In order to determine the cutting height of coal on top caving with great mining height, the influence of dif- ferent cutting height on the support working resistance, the top-coal caving rules and the coal wall stability were stud- ied based on theoretical analysis and numerical simulation method. The results show that the ratio of mining height to caving height, coal wall stability, mine pressure appeared, top coal recovery rate and equipment investment should be fully considered to determine the cutting height. The support requires strength, top coal recovery rate, coal wall spalling positively correlate with the cutting height, which is not a linear relation. Due to the influence of top coal geological conditions and recovery rate, the rate of coal wall spalling large mining height fully-mechanized in the condition of the in top coal caving with great mining height is larger than same cutting height. The top coal caving with great mining height is a breakthrough, and is a new effective way to achieve safe and efficient mining in extra thick coal seam.%为了确定大采高综放开采合理的机采高度,基于理论分析与数值模拟计算方法,研究了不同机采高度对支架工作阻力、顶煤冒放规律、煤壁稳定性的影响。研究结果表明:大采高综放开采机采高度的确定应充分考虑采放比、煤壁稳定性、矿压显现、顶煤采出率及设备投资等。支架所需支护强度、顶煤采出率、煤壁片帮程度与机采高度成正相关性,但并不是简单的线性关系。由于受顶煤赋存条件及采出率等因素影响,相同采高大采高综放开采煤壁片帮几率要高于大采高综采。大采高综放开采是煤炭开采技术的新突破,是实现特厚煤层安全高效开采的有效途径。

  11. Rehabilitation of residual pits in post-mining area: a goal of Czech brown coal opencast mining industry

    International Nuclear Information System (INIS)

    The closure of surface brown coal mines is a complex process with many specific considerations. In the Czech Republic a special project was proposed to analyze the types of environmental disturbance generated by surface mining operations and suggest procedures for the affected areas. It also aims to propose rehabilitation techniques for residual pits, considering their future use for recreational or development purposes. A Chabarovice mine case study demonstrates how to solve the problem of water flooding and utilization of the future residual lake. 2 figs

  12. 倾斜煤层防水煤岩柱尺寸留设的技术优化研究%Research on reasonable size of waterproof pillar in mining inclined coal seam

    Institute of Scientific and Technical Information of China (English)

    王志强; 陈超凡; 王磊; 李鹏飞; 郭晓菲; 高运

    2013-01-01

    采用传统方法对4#煤层需要留设的防水煤岩柱尺寸进行计算,分析结果认为传统方法对于倾斜煤层防水煤柱中央弹性核区存在重复计算的问题,因此造成留设的防水煤柱尺寸偏大。为了改善传统方法存在的弊端,在保证安全的前提下对4#煤层屈服区尺寸进行计算并考虑覆岩移动角度的影响,得到设计方法优化后的防水煤岩柱尺寸。为了进一步提高采区回采率,综合分析煤柱留设的共性问题,提出巷道布置的优化方案。研究结果表明,设计优化后留设防水煤柱的尺寸仅为原方法的42.42%,综合起坡段带来的三角煤损结合防水煤岩柱尺寸,优化后的煤炭损失仅为原方法煤炭损失的45.42%,按照采区设计的推进长度计算,相邻工作面之间可多采出煤炭资源近1.58 Mt。另外,优化方案中起坡段回采工艺可以改善工作面倾角大带来的设备稳定性的问题。%In the study, we calculated the pillar size of 4# coal seam with the traditional method, the analysis result showed that repeated calculation was existed in calculation of the central elastic area of the waterproof pillar in inclined seam, which results in oversized waterproof pillar left. In order to im-prove the disadvantages of traditional methods, in the premise of ensuring safety, we calculated the yield zone size of 4# seam, considered the impact of the overburden rock moving angle and we obtained the reasonable waterproof pillar size after the design method had been optimized. In order to further im-prove the recovery rate in the mining area, we comprehensively analyzed the common problems of coal pillar design and proposed optimization. Findings showed that the size of waterproof coal pillars after the design was optimized is only 42.42%of the size calculated in traditional method. Integrated the tri-angle coal loss of the slope segment and combined with a waterproof coal pillar size, coal

  13. The influence of brown coal exploitation in Poland on the groundwater pollution as determined by isotopic analyses of sulphate

    International Nuclear Information System (INIS)

    This research deals with pollution impact on natural water resources in the industrial area of Belchatow, central Poland, where a large brown coal deposit is exploited and the coal is burned in an electric power plant. To trace the sources of groundwater pollutants the stable isotope analysis of oxygen and sulphur in sulphates was applied. The mass-spectrometric analysis was performed on SO42- samples from numerous wells and piezometres in the excavation area. By repetitive sampling performed in November 1994, May 1995 and December 1996 significant changes of SO42- concentration and sulphur and oxygen isotopic ratios in several sites were recorded. The interpretation of isotope ratios allowed us to recognize three groups of sulphates: (1) from the leaching of Permian salt dome, (2) produced by the leaching of soluble sulphates from an ash pool and (3) produced by oxidation of natural sulphides in water-bearing rocks. (author)

  14. Characteristics of thrust nappe structures and coal seam forecast in the western part of Shiguai basin%石拐盆地西段逆冲构造及找煤方向预测

    Institute of Scientific and Technical Information of China (English)

    王怀

    2011-01-01

    为寻找潜在的煤炭资源,通过对石拐盆地西段地表及地下构造特征的分析,认为大青山逆冲推覆构造的前缘应为F10断层组;地表的长汉沟组等地层是从3 km外的南部推覆而来的外来岩层;深部的五当沟组一段主含煤地层基本未受推覆构造影响,且该地层应比其地表位置更向南;盆地南缘的二叠系下应有未受推覆构造影响的原生煤层.%In order to search for potential coal resources, by analysis of the surface and underground structure characteristics in the western part of Shiguai basin, it is considered that the front of Daqingshan thrust nappe should be F10 fault group. Surface Changhangou Formation etc. Is allochthonous strata moved 3 km away from the south. The deep main coal-bearing strata, the first member of Wudanggou Formation, is almost not affected by nappe structures. The first member of Wudanggou Formation should be more southern than its surface position. Native coal seams not effected by nappe structures should exist below Permian strata in the south of the basin.

  15. 薄煤层开采条件下地面建筑物移动变形观测%On observation of moving and deforming of surface building under mining the thin coal seam

    Institute of Scientific and Technical Information of China (English)

    张建全; 来兴平; 廖国华; 姜青山

    2001-01-01

    兖州矿区杨村煤矿火药库下采煤是该矿首次进行的建筑物下采煤试验研究项目.本文主要介绍该矿在薄煤层开采条件下地面建筑物所受到的采动损坏程度以及用对比法分析地表移动与房屋变形的关系,同时也分析研究了该矿具体地质采矿条件下地表岩层移动的一般规律.%It is the first time that the Yang village mine has excavated coal under powder storeroom. The damage level of buildings disturbed by mining in the thin coal seam has been introduced. The authors use antithesis to analyze the relationship between the moving of the surface and the damage of buildings,and discuss the normal principles of the moving of the surface ground under the specific geological and coal mining situation.

  16. “三软”煤层机采工作面端头支护技术%Support technology about “Three Soft” coal seam machinery mining face end

    Institute of Scientific and Technical Information of China (English)

    孙光中; 田坤云; 关鹏云

    2013-01-01

      针对“三软”煤层工作面上下端头处围岩变形特点及对支护结构的要求,分析了现有端头支护方式及优缺点,设计了步移式支护架结构及其技术参数,步移式支护架主要分为前部、中部和后部.理论计算了步移式支护架上载荷大小为2807.35 kN,通过实测分析,支架上平均载荷值2238 kN,为额定载荷的46.6%,上下端头处围岩最大变形量为197 mm,为安全生产提供了保证,为“三软”煤层端头支护提供了理论及技术依据.%About "three soft" coal seam face end up and down ‘s surrounding rock deformation characteristics and the requirements of the supporting structure, analysis the existing face end support way’s advantages and disadvantages, designed the step moving type support frame structure and technical parameters, Step shift retaining bracket are mainly divided into the front, middle and back.The theoretical loading on step moving type support is 2 807.35 kN. By field measurement analysis, average loading value is 2 238 kN, for 46.6 % of the rated load, and the maximum roof-to-floor convergence is 197 mm. Step shift type support frame played a good control effect of surrounding rock of face end and down,For the "three soft" coal seam end support provides the theoretical and technical basis.

  17. Autochthonous microbe-assisted phytoremediation of brown coal mine overburden soil

    Science.gov (United States)

    Hamidović, Saud; Teodorović, Smilja; Lalević, Blažo; Karličić, Vera; Jovanović, Ljubinko; Kiković, Dragan; Raičević, Vera

    2015-04-01

    One of the largest brown coal mines in Bosnia and Herzegovina (BiH), Kakanj, has been exploited for over a hundred years. As a consequence of decades of exploitation, severe biocenosis disturbance and degradation of the entire ecosystem have occurred, resulting in overburden soil formation. A significant challenge in remediation of degraded mining areas is difficulty in creating conditions favorable for vegetation growth. Thus, numerous remediation technologies have focused on increasing soil nutrient composition, as well as the number and activity of plant growth-promoting bacteria (PGPB), given that they stimulate host plant growth by increasing the availability of essential nutrients (phosphorus, nitrogen, manganese, iron), producing phytohormones, and providing protection from pathogens. The main objective of this research was to characterize autochthonous plant and microbial overburden communities and access their ability to restore these contaminated soils. Phytocenological analysis of vegetation and plant species was performed according to Flora Europaea (2001), from 2011 - 2013. Our results show that plant species were not detected at mine overburden soil in 2011. However, we detected presence of a single plant species, Amaranthus albus L., in 2012. Further, we recorded the presence of five families (Amaranthaceae, Chenopodiaceae, Convolvulaceae, Poaceae and Polygonaceae) in 2013. Microbial abundance and enzymatic activity were also examined during the same period. The diversity of microbial populations in the first year was rather small. Two Bacillus spp., B. simplex and a B. cereus group member, indigenous to mine overburden were isolated and identified using standard macroscopic and microscopic, as well as molecular techniques (Hamidovic et al., submitted). Phosphate solubilizing activity of bacteria was tested on National Botanical Research Institute's phosphate growth medium (1999). Production of ammonia was determined in peptone water with Nessler

  18. 综采工作面过上层煤集中煤柱动载矿压控制技术%Dynamic Mine Strata Pressure Control Technology of Fully-Mechanized Coal Mining Face Passing Through Concentrated Coal Pillars in Above Seam

    Institute of Scientific and Technical Information of China (English)

    陈苏社

    2014-01-01

    为解决近距离煤层群下层煤综采工作面过上层煤集中煤柱时压架的问题,以大柳塔煤矿活鸡兔井12306综采工作面为研究对象,分析其过上层煤集中煤柱期间的矿山压力规律、支架工作阻力、动载矿压显现特征,据此分析动载矿压显现的原因为工作面悬顶距离过长,周期来压步距较大,导致基本顶大面积垮落与集中煤柱边界覆岩铰接结构失稳的载荷同时作用于工作面支架上,对工作面支架形成了冲击载荷,支架立柱下缩1.2~1.5 m,形成剧烈的动载矿压。据此提出主要采取工作面调斜、调整周期来压、加大支架工作阻力、提高安全阀开启压力、加快推进速度以及采用合理的采高等技术措施,预防了综采工作面压架事故,保证矿井安全生产。%In order to solve the powered support crushed problem when a fully-mechanized coal mining face in a low seam of contiguous seams passing through concentrated coal pillars in above seam,taking No.12306 fully-mechanized coal mining face in Huojitu Mine Shaft of Daliuta Mine as a study object,the paper had an analysis on the mine strata pressure law,powered support working resistance and mine dynamic strata behavior features when the coal mining face passed through the concentrated coal pillars in above seam.According to the analysis,the causes of the dynamic strata behavior would be overlong suspended roof distance of the coal mining face and a large periodic strata weighting step.Thus a large area main roof falling and lost stability of the overburden strata jointing structure in the concentrated coal pillar boundary were affected on the powered supports in the coal mining face,made an impact load on the powered supports in the coal mining face,the legs of the powered support were drawn back with 1.2~1.5 m and serious dynamic mine strata pressure occurred.The technical measures of the tilt control of the coal mining face,adjustment of the periodic strata

  19. 石门揭露突出煤层冻结温度场的实验研究%Experimental study of freezing temperature field in uncovering outburst coal seam in cross-cut

    Institute of Scientific and Technical Information of China (English)

    冯涛; 谢雄刚; 刘河清

    2011-01-01

    针对新提出的石门揭煤注液冻结防突方法,设计了室内水泥槽模型煤体冻结实验,分析了注液冻结后水泥槽中煤体温度、物理力学性能与冻结时间的关系。实验表明:槽中煤体形成以冻结管中心为圆心、半径为R沿径向随时间扩展的冻煤圆柱。槽中煤、瓦斯和水三相体最终变成坚硬冻结体,极大提高了其抗压强度和弹性模量等力学性能。实验论证了注液冻结石门揭煤工作面冻结区的形成,距离冻结管越近,煤体温度越低,最终能降到石门揭煤防突工程所需的-15℃煤层控制温度。%Aiming at a new-presented proof-outburst method by injecting liquid and freezing in uncovering coal seam in cross-cut,designed the coal freezing experimentation in cement trough model,analyzed the relation between the coal temperature,mechanical property and freezing time.Through the coal freezing experimentation in cement trough model,it shows that the freezing section,whose radius is R,is revolved around the freezing tube centre.The formed frozen coal column is patulous with the freezing time.The coal,gas,and water in the trough is frozen into the firm freezing structure finally,so the uniaxial compression strengths and elastic modulus of coal models and the other mechanical property are greatly increased.Through the experiment it proved the formation of freezing area in the cross-cut working face.The more near to the freezing tube,the more low the coal temperature is,reaching to the frozen control temperature of-15 ℃ for proof-outburst.

  20. A Systematic Analysis of Coal Accumulation Process

    Institute of Scientific and Technical Information of China (English)

    CHENG Aiguo

    2008-01-01

    Formation of coal seam and coal-rich zone is an integrated result of a series of factors in coal accumulation process. The coal accumulation system is an architectural aggregation of coal accumulation factors. It can be classified into 4 levels: the global coal accumulation super-system, the coal accumulation domain mega.system, the coal accumulation basin system, and the coal seam or coal seam set sub-system. The coal accumulation process is an open, dynamic, and grey system, and is meanwhile a system with such natures as aggregation, relevance, entirety, purpose-orientated, hierarchy, and environment adaptability. In this paper, we take coal accumulation process as a system to study origin of coal seam and coal-rich zone; and we will discuss a methodology of the systematic analysis of coal accumulation process. As an example, the Ordos coal basin was investigated to elucidate the application of the method of the coal accumulation system analysis.

  1. Test with Rhein brown coal in 1-liter oven and fourth report on neutralization of coal and precipitants

    Energy Technology Data Exchange (ETDEWEB)

    Reitz

    1942-10-12

    A 1.5 liter sump oven, without stirrer, was used for preparation of Rhein coal with different grinding oils. Partial neutralization of the coal, by mixing sulfuric acid or sulfates with wet coal before drying, was sought. Oven precipitation was reduced by addition of street tar (high middle oil content) and Bruex tar (up to 350/sup 0/C) as well as by a mixture of Estonian slate tar oil and anthracitic tar oil in ratio of 80:20, but there was chalk-coke residue similar to caviar found when the oven was disassembled. Fifty percent neutralization of the coal by sulfuric acid as opposed to untreated coal gave some reduced vaporization and lower asphalt content. Iron sulfate catalyst also gave good results; magnesium sulfate, somewhat less. Though not unequivocally, H/sub 2/SO/sub 4/ and FeSO/sub 4/ both apparently reduced precipitants. A mixture of magnesium sulfate with iron sulfate gave less favorable results over all. Untreated coal with the previous catalysts produced the undesirable caviar-precipitants. The results of the tests were questionable since exactness in components, viscosity, and other problems hindered reproducing the tests consistently. 2 tables.

  2. Study on strengthening control mechanism with support and cable for roadway in“three-soft”coal seam during deep mining%深部“三软”煤巷棚-索强化控制机理研究

    Institute of Scientific and Technical Information of China (English)

    荆升国; 王其洲; 陈杰

    2014-01-01

    In response to the problem of the unstability of the“three-soft”coal roadways caused by se-rious deformation despite the repeated reinforcement of it in Zhengzhou mining area, the characteristics of “three-soft” coal seam occurrence, stress environment and the causes of the unstability have been analyzed. On this basis, the strengthening control mechanism with support and cable has been proposed. In this supporting system, on one hand, the bearing capacity and stability of support are improved by the supporting resistance from the cable. On the other hand, the shear deformation of creep coal seam is ef-fective controlled by higher supporting resistance of support. In addition, the bearing capability of coal seam is also developed, which makes the collaborative bearing of the support, cable and surrounding rock possible, and according to the mechanical calculation, the primary and secondary parts to be strengthened and the reasonable determination of the cable prestress are indicated. After the application of support and cable strengthening technology in 31041 haulage roadway of Chaohua mine, conver-gence of two sides in the roadway are controlled less than 300 mm during the impact of working face mining, and convergence between roof and floor are controlled less than 400 mm, which can control effectively the deformation of deep“three-soft”coal roadway.%针对郑州矿区深部“三软”煤巷变形严重,服务期间屡次扩修仍无法稳定的问题,分析了“三软”煤层赋存特点、深部应力环境及巷道失稳原因;提出棚-索强化控制理念,利用锚索提供的支护阻力提高支架的结构稳定性和承载能力,通过支架提供高支护阻力控制蠕变煤体剪胀变形和发挥深部稳定煤体的承载性能,实现支架-锚索-围岩协同承载;并根据力学计算结果指出支架结构的主、次关键强化部位及锚索预应力的合理确定。棚-索强化控制技术在超化煤矿31041

  3. Experimental Study on the Movement and Deformation of Rock Strata Between Coal Seams in the Coal Mining Above Gob Area%采空区上覆煤层开采层间岩层移动变形实验研究

    Institute of Scientific and Technical Information of China (English)

    冯国瑞; 任亚峰; 王鲜霞; 栗继祖; 康立勋

    2011-01-01

    To guarantee safety and high productivity of the left-over coal seam mining above gob area,and considering the importance of the movement and deformation of rock strata between coal seams, we use similar simulation experiment to study the movement and deformation rules of rock strata in the same horizontal layer and vertical measuring position in the mining process. The results show that original three zones of the lower coal seam develop upwards and a controlling stratum presents duo to the mining operation of upper coal seam above gob area. Additionally, the deformed basins are formed among the rock strata, and the strata under the controlling stratum appear subsidence basin, while the strata above the controlling stratum appear fractal basin. Meanwhile, the subsidence of the strata in the same level moves asymmetrically as a whole as the working face advances. During the process of movement and deformation, the strata above the controlling stratrum move continuously, while the strata under the controlling stratum move discontinuously.%为了安全高效开采采空区上覆煤层,基于其层间岩层移动变形问题的重要性,采用相似模拟实验的方法研究了采空区上覆煤层开采层间岩层相同水平层位与竖直层位岩层的移动变形情况.结果表明,采空区上覆煤层开采使下部煤层开采的原“三带”均向上位扩展,并出现了层间岩层控制层;采空区上覆煤层开采层间岩层出现变形盆地,在控制层以下的岩层出现下沉盆地,而控制层以上的岩层出现分形盆地;同一层位岩层下沉随工作面推进呈现整体移动的偏态性,在移动变形过程中,控制层以上的岩层移动变形呈现连续性的特点,控制层以下的岩层移动变形呈现突变性的特点.

  4. The practice of fully-mechanized coal mining for belt of fault in steeply dipping seam%大倾角条件下综采工作面过断层回采实践

    Institute of Scientific and Technical Information of China (English)

    张帅

    2012-01-01

    In fully mechanized working, the faul is very prone to cause spalling and roof falling accident, especially in the qualita- tive difference of fault and steeply dipping seam , the more difficult conditions bring great pressure and more difficulties to the safety production, gequan coal mine, through long and short range of chemical grouting and strengthening measures of fully - mechanized coal mining technology , realizing the Safety mining and passing the belt of fault successful, avoiding the Fully mecha- nized moving and roof accidents, acquiring the precious experience and practice.%综采工作面遇断层时,极容易出现片帮、冒顶等顶板事故,尤其是在落差大于采高、大倾角工作面等困难条件下,给安全生产带来巨大的压力和困难,葛泉矿通过长短距离注浆加固、严格的回采工艺措施,实现了大倾角条件下综采工作面顺利通过大落差断层,避免了工作面搬家,杜绝了顶板事故,取得了宝贵的现场经验。

  5. Feasibility Analysis of Ascending Mining on Slope Thin Coal Seam at Short Range%近距离倾斜薄煤层上行开采可行性分析

    Institute of Scientific and Technical Information of China (English)

    刘聪; 邱阳; 刘天龙

    2015-01-01

    In order to ensure the security of ascending mining,this paper analyze and verify the move-ment rules of surrounding rocks while mining based on the related theories and numerical simulation ac-cording to the present mining situation and occurrence of coal seam of Si Mian Mining area in Hua Ping County.Finally practice proves that ascending mining in Si Mian coal area is reasonable in economy and techniques is feasible,which could provide reference for similar mines.%为安全有效地进行上行开采,根据华坪县思棉煤矿煤层赋存条件及开采现状,利用理论分析和数值模拟对其进行分析验证,研究其上行开采顶板的围岩运动规律,通过工程实践证明思棉煤矿上行开采经济上合理,技术上可行。

  6. Comparative study of cogasification and co-combustion of communal sewage sludge in brown coal fuelled plants; Vergleich der Mitvergasung und Mitverbrennung kommunaler Klaerschlaemme in braunkohlegefeuerten Anlagen

    Energy Technology Data Exchange (ETDEWEB)

    Schiffer, H.P.; Bierbaum, K.; Adlhoch, W.; Thomas, G. [Rheinbraun AG, Koeln (Germany)

    1996-12-31

    Co-combustion and cogasification of sewage sludge in brown coal fuelled plants are compared, and an economic assessment is made. (ABI) [Deutsch] Die Mitverbrennung und Mitvergasung von Klaerschlamm in braunkohlegefeuerten Anlagen werden verglichen und auf ihre Wirtschaftlichkeit hin untersucht. (ABI)

  7. A new approach to precious metals recovery from brown coals: Correlation of recovery efficacy with the mechanism of metal-humic interactions

    Science.gov (United States)

    Bratskaya, Svetlana Yu.; Volk, Alexandra S.; Ivanov, Vladimir V.; Ustinov, Alexander Yu.; Barinov, Nikolay N.; Avramenko, Valentin A.

    2009-06-01

    The presence of gold and platinum group elements (PGE) in low-rank brown coals around the world has promoted interest in the industrial exploitation of this alternative source of precious metals. However, due to low efficacy of the methods traditionally used for the processing of mineral ores, there exists a high demand for new strategies of precious metal recovery from refractory carbonaceous materials that could significantly increase the economic potential of gold- and PGE-bearing organic resources. Here we discuss the possibility of gold and PGE recovery from alkaline extracts of brown coals using the difference in colloidal stability of bulk organic matter and its fractions enriched with precious metals. This approach enables one to avoid complete oxidation or combustion of brown coals prior to gold recovery, to minimize organic content in gold concentrate, and to obtain a valuable by-product - humic extracts. Using gold-bearing brown coals from several deposits located in the South Far East of Russia, we show that up to 95% of gold can be transferred to alkaline extracts of humic acids (HA) and up to 85% of this gold can be recovered by centrifugation at pH 4.0-6.0, when only 5-15% of HA precipitated simultaneously. We have shown that the high efficacy of gold recovery can be attributed to the occurrence of fine-dispersed elemental gold particles stabilized by HA, which differ significantly in colloidal stability from the bulk organic matter and, thus, can be separated by centrifugation.

  8. Retrofitting brown-coal-fired power plants in the new Federal Laender with flue gas desulfurization systems as exemplified by the Jaenschwalde power plant (3000 megawatts)

    International Nuclear Information System (INIS)

    Brown-coal-fired power plants continuing in operation in the new Federal laender must be retrofitted with flue-gas desulfurization systems in accordance with the ordinance on large furnaces. One such plant is the Jaenschwalde power station, for which the author describes the retrofitting concept as well as the design, process steps and most important components of the desulfurization system. (orig.)

  9. Conversion of nitrogen compounds and tars obtained from pre-composted pig manure pyrolysis, over nickel loaded brown coal char

    International Nuclear Information System (INIS)

    Fuel gas production and nitrogen transformation during pig manure pyrolysis from room temperature to 900 °C are investigated. The catalytic decomposition of the derived volatiles is also studied. Ammonia, HCN and N2 were obtained as the main N-containing gases. Ammonia was mainly emitted below 700 °C, which corresponds to 24.8 wt% of the nitrogen in the manure. Hydrogen cyanide and N2 gases obviously formed at temperatures above 700 °C, while the HCN concentration was as low as one ninth that of NH3 and one fifth of the concentration of nitrogen even at 900 °C. Thermal cracking of the pyrolysis volatiles produced little NH3, but noticeably increased HCN formation. When the prepared nickel-loaded brown coal char (LY-Ni) was added to the second part of the reactor (second stage) as a catalyst, most of the N-containing species in the volatiles converted into N2 gas. It suggests that LY-Ni has high catalytic activity for the conversion of N-containing compounds. Significant quantities of light fuel gases (H2, CO and CH4) were also generated. Compared with sand, 5.8 times (H2 and CO) the amount of gases was produced with the LY-Ni char at 650 °C. Decomposition of the manure volatiles depends on the catalyst temperature. Total product gases approximately doubled in yield when the catalyst temperature increased from 450 to 550 °C, and the volatiles conversion (based on carbon balance of the manure volatiles) increased from 72.4 wt% to 92.0 wt%. At 600–700 °C, the volatiles conversions stabilized at high levels of 96.7–98.2 wt%. -- Highlights: •The main N-containing gases from pig manure pyrolysis were NH3, HCN and N2. •Thermal cracking for the pig manure volatiles promoted HCN formation noticeably, and did little effect on NH3. •A nickel-loaded brown coal char converted the N in the pig manure volatiles mostly into N2 gas. •Light fuel gases, such as H2, CO and CH4, were significantly generated under the prepared nickel-loaded brown coal char

  10. 特厚煤层综放工作面区段煤柱合理宽度研究%Study on Rational Width of Sectional Coal Pillar Applied to Fully-Mechanized Top Coal Caving Mining Face in Ultra Thick Seam

    Institute of Scientific and Technical Information of China (English)

    兰奕文

    2014-01-01

    针对塔山矿特厚煤层综放工作面与回采巷道对头施工过程中面临的区段煤柱合理宽度留设、回采动压影响范围确定等问题,采用理论分析、数值模拟及现场应力实测等手段对特厚煤层综放采场覆岩断裂结构、区段煤柱应力分布及区段煤柱合理宽度进行研究。采空区一侧煤体应力,应力剧烈影响范围30~35 m。煤柱应力现场实测表明,相邻工作面回采期间应力沿煤柱宽度大致呈单峰型、非对称分布,应力高峰区距8210回风巷21~30 m、距8208采空区8~17 m,采空区顶板运动稳定滞后距离120~130 m。结果表明,塔山矿特厚煤层综放面对头施工条件下留设38 m煤柱是安全的,从煤柱应力分布角度分析煤柱宽度可减小至30~32 m。%According to the sectional coal pillar rational width applied,mining dynamic influence scope determination and other problems occurred in a face to face construction process of fully-mechanized top coal caving mining face and a mining gateway in ultra thick seam of Tashan Mine,the theoretical analysis,numerical simulation,site stress measurement and other means were applied to study the breaking structure of an overburden strata,stress distribution of the sectional coal pillar and rational width of the sectional coal pillar. The stress in one side of the coal seam in the goaf had a serious influence scope of 30~35 m.The site measurement of the coal pillar stress showed dur-ing a mining period of an adjacent coal mining face,along the coal pillar width,the stress was in a unimodal asymmetric distribution,stress peak zone had a distance of 21~30 m to No.8210 air retuning gateway and had a distance of 8~17 m to No.8208 goaf and the roof move-ment in the goaf was stabilized with a delay distance of over 120~130 m.The study results showed that under the condition of the face to face to construction of the fully-mechanized top coal caving mining face in ultra thick seam of Tashan

  11. Study on dumping mechanism of hydraulic powered support in fully mechanized wall of deep inclined soft coal seam%大倾角松软煤层综放支架倾倒机理研究

    Institute of Scientific and Technical Information of China (English)

    孟建喜

    2012-01-01

    In the fully mechanized caving face of large inclination soft thick coal seam, there is a comparatively large gap between the articulated hydraulic front spar bracket, while the top coal in middle and upper part of the face crushing more fully and leak more easily. Top-bracket lost their jobs resistance and dump in the process of moving , which is more serious when roof pressure increases. Measures such as laying of metal mesh stents at the top of the frame,moving support with pressure on and rubbing the top,pseudo-helical arrangement of working face, moving support from the bottom of working face, controlling mining height, top-down one-way cutting coal, bottom-up and two mining caving with one leaking, increasing anti-inverted jack,can effectively prevent the occurrence of the dumping.%在大倾角松软厚煤层综放工作面中,由于铰接式前梁的液压支架之间存在较大缝隙,同时工作面中上部顶煤破碎较充分,导致顶煤冒漏,支架失去工作阻力,在移架过程中易发生倾倒,并在顶板来压期间倾倒加剧.支架顶部铺设金属网、带压擦顶移架、伪斜布置工作面、从下至上移架、控制采高、自上而下单向割煤、自下而上和两采一放的放煤方式、增加防倒千斤顶等措施可有效避免倒架的发生.

  12. 湖南煤矿复杂煤层条件下实施综采对策%Countermeasure on practicing fully-mechanized mining technology under complicated seam conditions in Hunan coal mines

    Institute of Scientific and Technical Information of China (English)

    李青锋

    2014-01-01

    Taking Hunan coal mines practicing fully -mechanized mining technology as the engineering background,the paper analyzes problems of practicing fully -mechanized mining technology and proposes the countermeasures of solving these problems,which originate from coal mining technology conditions,middle -small geological exploration technology,mining roadways layout of complicated seam,roadways fast driving technology,excavating fully -mechanized mining technology through the fault and fast moving technique of working faces.Results show that the coal faces which are successful practiced conventional machine mining technology can be completely practiced fully-mechanized mining technology,and that it is worthy of support from several aspects such as policy and fund.%以湖南煤矿实施综合机械化开采工艺为工程背景,从煤矿开采技术条件、中小型地质构造探测技术、复杂煤层回采巷道布置、巷道快速掘进技术、综采过断层技术、采面快速搬家技术等方面分析了湖南煤矿复杂煤层条件下实施综合机械化采煤工艺存在的问题,并提出了解决这些问题的对策。研究结果表明,在现已成功实施普通机械化采煤工艺的采煤工作面是完全可以实施综合机械化采煤工艺的,值得从政策、资金等方面予以支持。

  13. Entry roof truss-bolt system test under the gob of contiguous seams

    Institute of Scientific and Technical Information of China (English)

    LIAN Chuan-jie; XU Wei-ya; WANG Ya-jie

    2007-01-01

    Roof bolt support system has been widely applied in the No.7.9 seam in Caozhuang coal mine.However,it has not been able to be applied in the NO.10-2 seam since the small interburden(2m)between NO.9 and NO.10-2 seam.The NO.9 and NO.10-2 seams are contiguous seams.The NO.9 seam has been mined out and the NO.10-2 seam will be mined under the gob of the NO.9 seam.The roof strata of the NO.10-2 seam may have been weakened and fractured due to the shear failure caused by the NO.9 seam mining activities.The steel beam sets spaced at 0.8 m have been used to support the entry of the NO.10-2 seam.In order to speed up the advance rate and cut entry development cost,a test area,using roof bolt in conjunction with truss-system,was successfully conducted.This paper presents the support system design,application of designed system,and the test results.Test results provide a cheaper,quicker,and safer way to support entry for the No.10-2 seam.

  14. Slagging and fouling characteristics of seam 32/33, Panian coalfield, Semirara Island, Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Stella Marris Limos-Martinez; Koichiro Watanabe [Kyushu University, Fukuoka (Japan). Department of Earth Resources Engineering, Graduate School of Engineering

    2006-02-01

    Twenty samples of seam 32/33, the main seam of Panian coalfield in Semirara Island, Antique Province, Philippines, were collected from a borehole drilled at the northeastern edge of the coalfield. The samples were analyzed to characterize the coal geochemistry of the seam and understand why the coals of Semirara Island exhibit a high tendency for slagging and fouling despite its low average ash content. Analysis of the slagging and fouling characteristics of this seam is important because it supplies five electric power utilities and several cement plants in the Philippines. Proximate analyses and vitrinite reflectance measurements designate the rank of the seam as sub-bituminous C, based on ASTM coal classification. H/C versus O/C ratios indicate that the seam is made up largely of huminite, denoting early stages of coalification. Chemical analysis of the ash reveals high contents of Na, Mg, Fe, Ca, Ba and Sr. The strongly negative correlation of these elements with the ash content indicates an organic affinity of the chemical elements of the seam. Owing to enrichment in alkali and alkali-earth elements, slagging and fouling indices indicate that the seam has medium to high propensity for slagging and a severe tendency for fouling. The detrimental characteristics of coal feedstock from Panian mine is mitigated by modifications to the boiler design and operational conditions and by blending with coals imported from Indonesia, China and Australia. 31 refs., 6 figs., 3 tabs.

  15. Steep-dipping Coal Seam Mined-out Area Foundation Stability Study in Dahuangshan Mine Area, Xuzhou%徐州大黄山矿区急倾斜煤层采空区地基稳定性研究

    Institute of Scientific and Technical Information of China (English)

    张国堂; 杨定明; 孙晖

    2015-01-01

    依托某工程项目,分析了研究区工程地质条件和岩层受力破坏机理。依据简便计算参数和易于确定的原则,将急倾斜煤层实际开采空间转化为“滑移空间”,分析研究区地表沉陷问题,利用“滑移空间”计算参数,将单个任意形状开采工作面顺煤层走向划分为若干矩形工作面,并将其各点引起的预测下沉值按叠加原理进行叠加计算,获得采空区多个不规则形状工作面的地表沉降量。根据计算结果绘制地表变形参数的等值线图,并依据相关规范、标准评价地表残余变形对地基稳定性的影响,在综合考虑多项因素影响的前提下,对研究区进行分区,给出了各分区地表稳定性和建筑适宜性。%Based on an engineering project has analyzed study area engineering geological condition and stressed strata failure mecha⁃nism. According to facility computational parameters and easy to determine principles, translated steep-dipping coal seam actual min⁃ing space into“sliding space”, analyzed study area surface subsidence issue. Using“sliding space”computational parameters, an indi⁃vidual arbitrarily shaped working face along the coal seam strike divided into several rectangular working faces, predicted subsidence of each point has been superimposed based on superposition principle, thus obtained many mined-out area irregularly shaped working face surface subsidence. Then isogram of surface deformation parameters plotted based on computed results. And based on relevant codes and standards have assessed impacts from surface residual deformation on foundation stability. After overall consideration of mul⁃tiple impacting factors, carried out study area partitioning, and gave out surface stability and construction adaptability of each subzones.

  16. 含断层煤层底板损伤破坏演化数值模拟及微震监测研究%Modeling and microseismic monitoring of damage and failure evolution of faulty coal seam floor

    Institute of Scientific and Technical Information of China (English)

    陆银龙; 王连国

    2013-01-01

    Based on the elastic damage mechanics theory, a piecewise linear and elastic damage constitutive model incorporating the residual strengths under different confining pressures was constructed, and the model parameters were determined by general triaxial compression and split tension tests. In addition, taking the geology conditions in one mine as engineering background, the damage and failure evolution characteristics of faulty coal seam floor during the mining process were simulated, after the established damage model programmed by MATLAB being embedded into COMSOL. The results show that when the working face moves to the top zones of fault, the active zones of fault will connect with the failure zones in floor induced by mining, which dramatically increases the failure depth of floor, reduces the water isolating properties of the aquifuge, and increases water-inrush possibility. Finally, the high-precision microseismic monitoring technique was employed to monitor the dynamic failure characteristics of the coal seam floor, and the monitoring results are basically in agreement with the numerical results.%基于弹性损伤力学理论,建立了考虑不同围压下岩石残余强度的分段线性弹性损伤本构模型,利用岩石常规三轴压缩实验和劈裂实验确定了损伤模型的基本参数.以某矿井工程地质条件为背景,采用MATLAB软件编程将损伤本构模型嵌入到COMSOL软件中,对工作面推进过程中含断层煤层底板的损伤破坏演化规律进行了数值模拟研究.结果表明,当工作面回采至断层区域附近时,断层带活化区将与开采造成的底板破坏区相连接,显著地增大了底板的破坏深度,削弱了隔水层的隔水性能,增加了底板突水的可能性.采用高精度微地震监测仪对煤层底板破坏范围进行了现场动态监测,监测结果与数值模拟结果基本吻合.

  17. 厚煤层小煤柱巷道采掘交锋应力变化规律研究%Research on Change Rule of Roadway Tunneling and Mining Stress in Thick Coal Seam Small Pillar

    Institute of Scientific and Technical Information of China (English)

    王震

    2014-01-01

    以晋华宫矿12-3#层5107巷为研究对象,利用FLAC3D软件模拟研究了厚煤层在留设小煤柱时采掘交锋过程中围岩的应力变化规律。结果表明:采掘交锋前,第一应力在顶底角形成了小范围的应力集中,最大值为12 MPa,第二应力由巷道表面向深部逐渐增加,在煤帮深处达到最大;采掘交锋后,巷道浅部围岩第一主应力增量波动较大,巷道顶板上部及靠煤柱侧的顶角,第一应力均有不同程度的增加,最大增量达到4.78 MPa,而第二应力基本没增加,反而有不同程度的降低。%Takes No.12 -3 layer of 5 107 roadway in Jinhuagong coal mine as research object,utilizes FLAC3D software simulation researches the stress change rule of surrounding rock in the process of tunneling and mining when small coal pillar is establishes in thick coal seam,the result shows that before tunneling and mining,the major princi-pal stress forms small range of stress concentration in the corner of roof and floor,the maximum is 12 MPa,the third principal stress gradually increases from roadway surface to the deep,reaches maximum in the depths of coal side.Af-ter tunneling and mining,the major principal stress increment of roadway shallow surrounding rock have a larger fluc-tuation,the major principal stress of roadway roof upside and top corner on the side of coal pillar have different de-grees of augment,the biggest increment reaches 4.78 MPa,but the third principal stress almost have no increase,on the contrary have different degrees of decrease.

  18. Draft Genome Sequence of Bacillus pumilus Fairview, an Isolate Recovered from a Microbial Methanogenic Enrichment of Coal Seam Gas Formation Water from Queensland, Australia

    OpenAIRE

    Vockler, Cassandra J.; Greenfield, Paul; Tran-Dinh, Nai; Midgley, David J.

    2014-01-01

    Despite its global abundance, Bacillus pumilus is poorly studied. The Fairview strain was obtained from a methanogenic anaerobic coal digester. The draft genome sequence was 3.8 Mbp long and contained 3,890 protein-coding genes. Like the SAFR-032 strain, it includes B. pumilus-specific proteins that likely confer enhanced resistance to environmental stresses.

  19. Draft Genome Sequence of Bacillus pumilus Fairview, an Isolate Recovered from a Microbial Methanogenic Enrichment of Coal Seam Gas Formation Water from Queensland, Australia.

    Science.gov (United States)

    Vockler, Cassandra J; Greenfield, Paul; Tran-Dinh, Nai; Midgley, David J

    2014-01-01

    Despite its global abundance, Bacillus pumilus is poorly studied. The Fairview strain was obtained from a methanogenic anaerobic coal digester. The draft genome sequence was 3.8 Mbp long and contained 3,890 protein-coding genes. Like the SAFR-032 strain, it includes B. pumilus-specific proteins that likely confer enhanced resistance to environmental stresses. PMID:24744330

  20. Determining the effect of a stope line on the seams situated above and below using measurements of electrical resistance, from the example of research in the Murck hard coal mine

    Energy Technology Data Exchange (ETDEWEB)

    Czekaj, A.; Jaskowski, S.

    1979-01-01

    It is known that stoping work in one of the seams of a formation causes changes in the tension of the rock mass along the line (edge) of the stope in other higher and lower seams in an area up to several dozen meters thick. Results are described of research on the effect of the stope edge under conditions of the Murck nongas well at three gently dipping seams (with interseams of 30-40 m and 130-150 m), using the method of measuring the electrical resistance of side rock in development workings at underworked and overworked seams.

  1. Research on coal seam pulse high pressure water injection technology in fully mechanized working face%综采工作面煤层脉动高压注水技术研究

    Institute of Scientific and Technical Information of China (English)

    贾本红

    2015-01-01

    为了煤矿综采工作面粉尘率得到有效降低,采用脉动高压注水与静压注水技术相结合的方法对煤层进行注水,使得煤层具有较好的增水率;同时,呼吸性粉尘浓度、非呼吸性粉尘浓度和总粉尘浓度均得到了较大幅度降低,为改善工作人员工作环境和煤矿企业安全高效生产奠定了良好基础。%in order to effectively reduced the dust rate fully mechanized face, using the method combined with pulse high pressure water injection and static pressure water injection technology, which improve the seam moisture content, at the same time, concentration of respiratory dust, non respirable dust and total dust concentration were greatly reduced, laid a good foundation for improving the working environment and staff of coal mine safety and efifcient production.

  2. Integrated drying and gasification: technology for power generation from brown coal and biomass

    International Nuclear Information System (INIS)

    The fact that 2% of Australia's electricity generation needs to be derived from new renewable energy sources by the year 2010 limits the fuel/energy options in the short term, simply from the sheer size of the undertaking, namely some 9000 GWh of electricity is required from new renewables alone. Realistically, this target can only be achieved by using biomass as the major fuel/energy source. The increasing government, scientific and community pressures to reduce greenhouse gas emissions has focussed particular emphasis on the use of renewable fuels for electricity and heating applications. Various biomass fuels such as agricultural residues, forestry wastes and special energy crops have been targeted as sources. Small and large- scale tests have been conducted in various combustion and gasification equipment facilities especially in Europe and to a lesser extent in Australia. Several operational issues, e.g. chloride removal, slagging, need further resolution. A major factor in the introduction of biomass gasification is the comparative cost with existing coal-fired facilities for producing electricity. However, co-firing of biomass with coal appears to be a less costly option. Nonetheless, biomass gasification technologies are being actively demonstrated and show enhanced efficiency. The IDGCC process is designed to produce electricity at low cost and high efficiency from low-rank coals. These high moisture coals are available at low cost in many countries and their use would reduce imports of black coal or other fuels. The process has been shown to operate successfully at the 10 MW scale and the technology is ready to be applied to a commercially scale plant in the 120 to 400 MW scale plants. The drying and gasification part of IDGCC, i.e. IDG, is a suitable means of preparing biomass for co-firing in existing boiler plant, with advantages in simplifying fuel size reduction and in keeping undesirable inorganic constituents out of the boiler

  3. 无煤柱开采保护层实现倾向连续、充分卸压的实验研究%Experimental research on realizing inclined successive and sufficient pressure-relief in pillarless protective coal seam mining

    Institute of Scientific and Technical Information of China (English)

    王志强; 周立林; 月煜程; 张立海; 张政; 赵科成; 赵景礼

    2014-01-01

    研究基于实现被保护层倾向充分、连续卸压的下保护层开采展开。分析与实验表明,保护层工作面长度、层间距、卸压边界线与留设煤柱造成的远距离被保护层倾向无法实现卸压、近距离被保护层倾向存在高应力区域或者卸压不充分区域,无法实现被保护层倾向的安全、连续开采。在此基础上,提出使用无煤柱布置被保护层回采工作面,接续工作面回采时上覆岩层的运动与首采工作面形成一个整体,实现了倾斜方向的连续开采长度,覆岩的采动程度更加充分,被保护层在裂隙带中的层位相对降低,卸压程度更加充分,因此无煤柱开采实现了被保护层倾向的充分、连续卸压。结合实际工程背景,综合回采率和巷道工程量考虑,煤2采用无煤柱开采方案比原方案增加回采利润2.84亿元;与5 m小煤柱沿空掘巷相比,减少岩巷工程费用计600万元,增加回采利润1.4亿元。%The research in this paper was conducted based on realizing inclined sufficient and succes-sive pressure-relief in lower protected coal seam mining. The results show that due to the length of coal face, interval between layers, borderline of pressure-relief and coal pillar layout, the pressure-relief in the inclination of the distant protected coal seam can’t be realized, and the high stress zones or insuffi-cient pressure-relief zones may exist in the close protected seam. The safe and successive mining of protected seam can’t be realized. On this basis, the pillarless face layout in protected seam was proposed. Thus, the overlying strata movement during the successive face mining may integrate with that of the first mining face, the inclined successive mining length can be enlarged, and the mining degree of the overburden strata is more sufficient. So, the horizon of the protected seam in the fractured zone is rela-tively lower, which means the pressure

  4. Effects of lithium iodide doping on devolatilization characteristics of brown coals; Yoka lithium no tenka ga kattan no kanetsu henka katei ni oyobosu eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Muraoka, J.; Kumagai, H.; Hayashi, J.; Chiba, T. [Hokkaido University, Sapporo (Japan)

    1996-10-28

    In order to discuss effects of lithium iodide (LiI) doping on condensation structure of brown coals during heating, spectral changes were measured by using an in-situ FT-IR. It was found that the LiI doping accelerates weight reduction due to heating, and the doping effect is affected by coal structure. Both of Loy Yang (LY) coal and its LiI doped coal (DLY) had absorption intensity of the FT-IR spectra decreased with rising temperature, and the absorption center belonging to an OH group shows different shifts between the LY and DLY coals. This indicates that the LiI doping has affected the change in hydrogen bonding patterns associated with heating. Both of South Banko (SB) and LY coals had the absorption spectral intensity in the OH group decreased as the weight reduction (conversion) rate increased. Reduction in the OH groups associated with heating is caused by volatilization and condensation reaction in light-gravity fraction. However, in the case of equal conversion rate, the LiI doped coal shows higher spectral intensity than the original coal, with the LiI doping suppressing reduction in the OH groups. It appears that the doping suppresses the condensation reaction between the OH groups. 2 refs., 6 figs., 1 tab.

  5. An investigation of the effectiveness of blending (averaging) brown coal for state regional electric power plants (GRES). Issledovaniye effektivnosti usredneniya burykh ugley dlya GRES

    Energy Technology Data Exchange (ETDEWEB)

    Varshavskiy, A.M.

    1985-01-01

    The variability of the ash content of coal effects the specific expenditure of fuel by a state regional electric power plant for producing electric power. The studies were conducted at the Aleksandriyskiy thermal power plant (TeTs) number three and at the Zaporozhye, Yermakovskiy and Nazarovskiy state regional thermal power plants. It is established that a reduction in the mean square deviation of the hourly volumes of coal from 3 to 0.5 leads to a savings of 3.2 to 3.8 percent of coal and 2.4 to 2.9 percent brown coal. Regression equations are acquired. Correlation factors are calculated which do not exceed 0.7 percent of the reliable association between indicators.

  6. Investigations of coprocessing of a hydrothermally pretreated brown coal with petroleum feedstocks. Untersuchungen zur gemeinsamen Hydrierung einer hydrothermal vorbehandelten Braunkohle mit mineraloelstaemmigen Anmischoelen

    Energy Technology Data Exchange (ETDEWEB)

    Argirusis, C.

    1992-01-01

    It is the aim of the experiments to modify a Merseburg brown coal through hydroghermal pretreatment at three temperatures in the subcritical range (250, 300 and 350 degrees centigrade). The influence of pretreatment is to be analyzed. By means of vacuum distillation of the vacuum residue Arabian-Mix at three temperatures (190, 225 and 300 degrees centigrade) and constant low pressure of 6 x 10[sup 2] bar six petroleum-based feedstocks are to be produced. In total seven petroleum-based feedstocks are employed together with the initial vacuum residue. The original coal and the three pretreated coal grades are investigated for their suitability for coprocessing with the seven petroleum feedstocks. The hydrogenating and liquefaction behavior of the pretreated coals is particularly interesting. Simutaneously the influence of the petroleum feedstocks on coprocessing is examined; in particular distillation residues and the original vacuum residue. (orig./HS)

  7. Naturally occurring radionuclides in brown coal and copper shale mining waste and its impact on landscape mitigation

    International Nuclear Information System (INIS)

    are still not sufficient investigations to optimise existing conventional water treatment methods methods. Furthermore for the treatment of heavy metal and radionuclide contaminated water by permeable reactive walls only short term experiences are existing. According to actual prognoses the lifetime of the reactive material can be estimated to be only about 10 to 15 years. The life time of reactive materials has recently been estimated to In our study one main topic was to evaluate the level of naturally occurring radioactivity in brown coal and copper shale mining wastes. The other main topic was the development of concepts for the improvement of long term effectiveness of passive water treatment systems and for feasibility tests for natural attenuation and in situ bioprecipitation of heavy metals and radionuclides as remediation methods for radioactive contaminated waste waters. (author)

  8. Brown coal. Energy source of yesterday or a future chance for the Lausitz region; Braunkohle. Energietraeger von gestern oder Zukunftschance fuer die Lausitz

    Energy Technology Data Exchange (ETDEWEB)

    Klocek, Gert [Vattenfall Europe Mining AG, Cottbus (Germany). Tagebauplanung; Ketzmer, Wolfgang [Vattenfall Europe Mining AG, Cottbus (Germany). Referat Grunddaten Bergbau

    2009-09-15

    The economic development of the region Lausitz-Spreewald (Federal Republic of Germany) is a main topic of activity for Vattenfall Europe Mining AG (Cottbus, Federal Republic of Germany). An essential component of the strategy ''Innovative energy region Lausitz-Spreewald'' is the long-term concept of mining industry and power plant. The emphasis of this concept is the development of the CCS technology (CCS: Carbon Capture and Storage). Important topics are: Climate-neutral conversion of brown coal to electricity; Development of the energy economical know-how; Use of further sources of energy. Use of wind energy on recultivation areas, production of fermentation gas from biomass for power generation as well as the fixation of carbon dioxide by micro algae belong to this. Brown coal has a firm place in the energy mix.

  9. 特厚煤层综放开采地表沉陷规律实测研究%Research on Actual Measurement of Surface Subsidence Law for Fully-Mechanized Top Coal Caving in Extra Thick Seam

    Institute of Scientific and Technical Information of China (English)

    高超; 徐乃忠; 刘贵; 倪向忠

    2014-01-01

    为研究近浅埋深、中厚基岩、特厚煤层综放开采地表沉陷规律,在东坡煤矿914工作面地表建立地表移动观测站进行了观测。经对测得的数据分析,得到一套完整的地表沉陷预计参数和角量参数,分析了该地质采矿条件下角量参数与动态变形特征。结果表明:东坡煤矿下沉系数、水平移动系数、主要影响角正切、开采影响传播角分别为0.74、0.25、2.95、86.5°;在特厚煤层综放开采条件下,地表移动的初始期较短,活跃期内地表下沉速度大,移动剧烈,地表下沉量占总下沉量的比例大。在近浅埋深、中厚基岩条件下,特厚煤层综放开采地表沉陷规律具有其特殊性。%In order to study law of surface subsidence under situation of shallow buried depth,medium thick bedrock and extra thick seam using fully-mechanized top coal caving method,an observation station was established on surface above No. 914 Working Face of Dongpo Coal Mine.By analyzing the measured data,a set of complete prediction parameters for surface subsidenceand angular parameters were ob-tained. Under this geology and mining condition,the authors studied its mobile angle parameters and the dynamic deformation characteris-tics. The results showed that the subsidence factor was 0. 74,the displacement factor was 0. 25,the major influence tangent angle was 2. 95,and the main influence spread angle was 86.5°. It is concluded that under this situation,the initial period is short;the active period of surface subsidence velocity is large and moves violently,and subsidence in the active period occupies a high ratio of the total movement period. Under situation of shallow buried depth and medium thick bedrock,law of surface subsidence for extra thick seam using fully mechanized top coal caving method has its particularity.

  10. Surrounding rock control optimal design of large section roadway in soft coal seam%大断面软煤层大巷围岩控制优化设计

    Institute of Scientific and Technical Information of China (English)

    刘锦荣; 康庆涛

    2013-01-01

    Affected by complicated factors such as large section, low strength of coal mass, high in-situ stress, rich water roof and Mudstone floor characterized by rheological, swelling and softening property, the roadway in Ma Jialiang Mine soft coal seam encounters heavy rock surrounding support problems of roof sag and floor heave. Consequently, the safe and orderly production was affected seriously. Taking the main air return way as a primary research object, the paper has studied the law of surrounding rock deformation and failure, reasonable section size and shape, support parameters and floor heave control method by means of field measurement, theoretical analysis, numerical simulation and so on. The re-search shows that micro cambered arch roof, drain-pipe installed in roof, inverted-arch floor, net and bolt support of whole section are the optimum combination of section form and support scheme. The field application tells that the optimized air return way surrounding deformation can be controlled effec-tively, which meets the requirements of keeping it stable for a long period. The achievements of this re-search will offer useful data for large section roadway support in soft coal seam.%受煤体强度低、水平地应力大、顶板赋存富含水层及泥岩底板稳定性差等多因素影响,麻家梁煤矿大断面软弱煤层大巷遇到顶板下沉、底鼓严重的难题,严重影响矿井的安全生产。以回风大巷为主要研究对象,采用现场实测、理论分析、数值模拟等方法,对巷道的围岩变形破坏规律、合理断面形式、底鼓控制方法及合理支护参数进行研究。经研究确定回风大巷顶板采用微弧拱形,增加顶板排水管,底板采用反底拱的结构形式,全断面采用锚网索联合支护。现场应用表明,经优化设计后的回风大巷能有效控制围岩变形,满足矿井大巷保持长期稳定的要求。研究结果对大断面软弱煤层大巷的支护设计具有借鉴意义。

  11. Estimation of Population Size of Dentaria Enneaphyllos in the Vicinity of the Bełchatów Brown Coal Mine and the Attempt of its Metaplantation

    OpenAIRE

    Kurowski, Józef; Koczywąs, Ewelina; Pieńkowski, Michał

    2012-01-01

    The impact of anthropopressure on the flora in the vicinity of the Bełchatów Brown Coal Mine in Central Poland has been substantially strong. Consequently, certain changes in habitat conditions have been observed, leading to a decline in particular species stands. Mechanical damage, as well as the mine and power plant expansion have contributed to further species decline in the area. Ex situ conservation, e.g. metaplantation from native to secondary localities seems an efficient method of ens...

  12. Degradation Mechanism in a Direct Carbon Fuel Cell Operated with Demineralised Brown Coal

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Degradation mechanism studied for demineralised coal in a direct carbon fuel cell. • Diffusion limited processes dominate the electrode polarisation losses in pure N2. • Major fuel cell performance loss occurred due to loss of carbon/anode contacts. • The anode retained its phase structure with minor other phases formed in operation. - Abstract: The performance of a demineralised and devolatilised coal from the Morwell mine in the Latrobe Valley, Victoria, has been investigated in a direct carbon fuel cell (DCFC) operated at 850 °C. The focus of the investigation has been on understanding degradation issues as a function of time involving a sequence of electrochemical impedance spectroscopy and voltage-current characteristic. Diffusion limited processes dominate the electrode polarisation losses in pure N2 atmosphere, however, these decrease substantially in the presence of CO2 as the anode chamber purge gas, due to in situ generation of fuel species by the reaction of CO2 with carbon. Post-mortem analysis of anode by SEM and XRD revealed only a minor degradation due to its reduction, particle agglomeration as well as the formation of small quantity of new phases. However, major fuel cell performance degradation (increase of ohmic resistive and electrode polarisation losses) occurred due to loss of carbon/anode contacts and a reduction in the electron-conducting pathways as the fuel was consumed. The investigations revealed that the demineralised coal char can be used as a viable fuel for DCFC, however, further developments on anode materials and fuel feed mechanism would be required to achieve long-term sustained performance

  13. Adsorption of NO, SO{sub 2} and light hydrocarbons on activated Greek brown coals

    Energy Technology Data Exchange (ETDEWEB)

    Papanicolaou, C. [Institute of Geology and Mineral Exploration, Messoghion 70, Athens 11527 (Greece); Pasadakis, N.; Dimou, D.; Foscolos, A.E. [Department of Mineral Resources Engineering, Technical University Crete, Chania, Crete (Greece); Kalaitzidis, S.; Papazisimou, S. [Department of Geology, University of Patras, Rio-Patras, 26500 (Greece)

    2009-01-31

    Twenty-eight samples of peat, peaty lignites and lignites (of both matrix and xylite-rich lithotypes) and subbituminous coals have been physically activated by pyrolysis. The results show that the surface area of the activated coal samples increases substantially and the higher the carbon content of the samples the higher the surface area. The adsorption capacity of the activated coals for NO, SO{sub 2}, C{sub 3}H{sub 6} and a mixture of light hydrocarbons (CH{sub 4}, C{sub 2}H{sub 6}, C{sub 3}H{sub 8} and C{sub 4}H{sub 10}) at various temperatures was measured on selected samples. The result shows a positive correlation between the surface area and the gas adsorption. In contrast, the gas adsorption is inversely correlated with the temperature. The maximum recorded adsorption values are: NO = 8.22 x 10{sup -} {sup 5} mol/g at 35 C; SO{sub 2} = 38.65 x 10{sup -} {sup 5} mol/g at 60 C; C{sub 3}H{sub 6} = 38.9 x 10{sup -} {sup 5} mol/g at 35 C; and light hydrocarbons = 19.24 x 10{sup -} {sup 5} mol/g at 35 C. Adsorption of C{sub 3}H{sub 6} cannot be correlated with either NO or SO{sub 2}. However, there is a significant positive correlation between NO and SO{sub 2} adsorptions. The long chain hydrocarbons are preferentially adsorbed on activated lignites as compared to the short chain hydrocarbons. The results also suggest a positive correlation between surface area and the content of telohuminite maceral sub-group above the level of 45%. (author)

  14. Biosorption of Fe, Al and Mn of acid drainage from coal mine using brown seaweed sargassum sp. in continuous process

    International Nuclear Information System (INIS)

    The acid mine drainage (AMD) are leaches as result of a coal mining running, it have low ph and high concentrations of heavy metals that convert them in strong polluter; with the purpose of reduce its concentration, a continuous biosorption system was designed by removing heavy metals from drainages using a cheap biosorbent material. The brown seaweed was pre-treatment with solutions 0,1 N of NaOH, Ca(OH)2 NaCl, CaCl2, NaSO4 y H2SO4 for to study the effect on biosorption process; the removal percentage were determined, which are better than 80% with the exception of pre-treatment with H2SO4 who cancel the algae sorption capacity. The seaweed was packed in plastic mesh and polyester tulle in the shape of a rectangular prism; there isn't effect on the biosorption process by using this packet. The continuous biosorption process was studied in two units of operation: a packed-bed flow-through sorption column and an horizontal vessel like a canal with baffles, which treated adequately 3,5 and 4,71 of AMD respectively, using in each one of them 100 g of algae. The burning of algae was studied like an alternative for the problem of handling of residual algae. The ashes kept the metals removed from AMD, furthermore keep stable too by the attack of solutions of different pH

  15. Occupational exposure to rubber vulcanization products during repair of rubber conveyor belts in a brown coal mine.

    Science.gov (United States)

    Gromiec, Jan P; Wesołowski, Wiktor; Brzeźnicki, Sławomir; Wróblewska-Jakubowska, Krystyna; Kucharska, Małgorzata

    2002-12-01

    Several hundred chemical compounds were found in workroom environments in the rubber industry, but most of the published exposure data relate to the production of tyres; information from the "non-tyre" sections are very limited, if any. This study was carried out to identify chemical substances and measure their air concentrations in the repair shop of a brown coal mine in which damaged rubber conveyor belts were repaired. GC-MS and HPLC analysis of stationary air samples resulted in identification of aliphatic and aromatic hydrocarbons to C12, PAHs, alcohols, phenols, ketones, heterocyclic nitrogen and sulfur compounds. Quantitative evaluation of occupational exposure included determination of organic compound vapours collected on charcoal (GC-MSD), polycyclic aromatic hydrocarbons (HPLC), N-nitrosoamines and other amines (GC-NPD) and DNPH derivatives of aldehydes (HPLC) in the breathing zone of workers representing all job titles. The concentrations of investigated compounds were very low. Carcinogenic substances: N-nitrosoamines, benzene, PAHs were not present in workroom air in concentrations exceeding limits of detection of the analytical methods being applied; concentrations of methylisobutylketone, tetrachloroethylene, naphtha, aromatic hydrocarbons, phthalates and aldehydes were much lower than the respective occupational exposure limit values. The results indicate much lower exposure than that reported in the production of tyres and other fabricated rubber products. PMID:12509065

  16. Systematic solutions for thick seam mining

    Energy Technology Data Exchange (ETDEWEB)

    Zitz, A.

    1986-06-01

    Room and pillar method and rib pillar extraction in thick seams are analysed for non European coal mining and available equipment, the resulting weaknesses are shown - The analysis forms the basis for the development of the model of an integrated machinery system, consisting of excavating machine, continuous transport system and fully mechanised mobile support. Because the continuous conveyor system still remains to be put to underground tests, comprehensive results from applications of other system components only are available. They are the basis for improvement and source of efficiency improvement of the mentioned mining methods. (orig./MOS). With 21 figs.

  17. 极破碎顶板松软煤层支架选型及抱采工艺实践%Practices on Hydraulic Powered Support Selection and Holding Mining Technology Applied to Seam with Extreme Broken Roof and Soft Coal

    Institute of Scientific and Technical Information of China (English)

    倪建明; 李桂臣

    2012-01-01

    In order to solve the problems of the coal mining wall spalling and the roof falling at the front of the powered support in the coal mining face in an extreme broken and soft seam, taking the fully mechanized top coal caving mining in No. 9 extreme broken and soft seam as an engineering background, the paper analyzed the features of the conventional fully mechanized top coal caving mining technique. In combination with the site engineering practices, a study on a holding mining top coal caving mining technique with non beam distance was conducted. The features would be that with the length expansion of the powered support beam, thus a coal mining operation could be con- ducted under the non beam end distance. The expansion beam with a distance of 800 mm could ensure the pilot support. With the spade plate to level the top coal and the powered supports moved forward with pressures, the coal wall spalling could be applied for coal mining. According to the echnioue feafures, the rational three machines matched technology was provided for the coal mining technique and applied to the industrial trial in Luling Mine under the special geological conditions. The coal production of the coal mining face could be reached at 100 000 t per month with good benefits.%为解决极破碎松软厚煤层工作面煤壁片帮和架前端冒顶难题,以芦岭煤矿极松软9煤综放开采为工程背景,分析了传统综放开采工艺特点,结合现场工程实践,研究了无梁端距抱采放项煤工艺,其特点是通过加长顶梁实现无梁端距条件下采煤,设置800mm伸缩梁保证超前支护,借助铲煤板铲平顶煤,带压移架,充分利用煤壁片帮进行采煤。针对此工艺特点,提出了该回采工艺合理的“三机”配套技术,并在芦岭煤矿特定地质条件下开展工业性试验,煤炭月产量达10万t,效果良好。

  18. Mechanical behavior investigation for floor rock stratum in the water-rich coal seam%含水煤层底板岩层力学性质分析:以小纪汗煤矿为例

    Institute of Scientific and Technical Information of China (English)

    李海龙; 白海波; 钱宏伟; 马丹; 许静

    2016-01-01

    在陕北榆林小纪汗煤矿实际建井开采过程中发现了煤层为矿井主充水含水层这种特殊的水文地质现象,为对这种特殊现象下底板岩层的力学性质进行分析,对现场底板岩样进行岩石矿物成分测试、岩石膨胀性测试及水作用下岩石强度弱化规律测试等一系列试验研究。研究发现:1)小纪汗煤矿煤层为裂隙含水层,且为矿井主充水含水层,底板岩层长时间受水侵蚀,岩体易于软化、变形,易造成岩层裂隙扩展及其稳定性破坏;2)底板岩样中含蒙脱石、伊利石等膨胀性矿物是底板岩层膨胀变形的微观影响因素;3)底板岩样浸水膨胀变形经过急速膨胀—变形缓慢—变形结束3个阶段,岩样浸水2 h 内的膨胀变形已占总变形量73.3%,浸水2~12 h,变形量占总变形量的24.7%,浸水12 h 后,试样基本不变形;4)岩样与水作用后其单轴抗压强度、弹性模量、劈裂抗拉强度随饱水时间的延长、含水率的增大而不断降低,总体呈指数关系递减;5)岩样浸水12 h后,岩石单轴抗压强度、弹性模量及抗拉强度降低值占总衰减值分别为71.6%,72.3%和65.4%,煤层裂隙水对底板岩层的侵蚀软化作用明显。%One special hydrogeologic phenomenon was found when building well drilling for Xiaoji-han mine located in Yulin city, north of Shaanxi province. The coal seam is a main aquifer to the geo-logic structure of the nearby area. Different tests including rock mineral composition test for floor rock samples, rock expansion test and the rock strength test under water pressure have been applied to find out the mechanical properties of the floor rock stratum under this special hydrogeologic phenomenon. The following conclusions have been drawn: 1) The coal seam of Xiaojihan mine is found out to be a fracture aquifer as well as a main aquifer. The floor rock has been exposed to water erosion for a long time, which

  19. 松软突出煤层钻孔护壁力学作用机理分析%Analysis of Mechanism of Borehole Wall Protection in Soft Coal Seams with Outburst Threat

    Institute of Scientific and Technical Information of China (English)

    王永龙; 翟新献; 孙玉宁

    2012-01-01

    Borehole wall protection technology is an effective tool to prevent the soft coal seam borehole collapse. Based on discusses of technical principles of borehole wall protection methods, combined with elasto - plastic surrounding rock and support theory, borehole wall protection mechanics model was created, by using numerical analysis method, under different internal stress the parameters were analyzed, such as stress in coal body around borehole, and deformation changes regulation. The research results showed that with the internal stress increase within the borehole wall, borehole deformation shows decreasing trend, the peak position of maximum principal stress σ1 moves to the left, plastic loosen area shows shrinking trend; curve corresponding to the secondary principal stress σ3 moves up; stress concentration phenomenon surrounding the borehole shows growth trend. Based on the analysis of mechanical effect mechanism of borehole wall protection, application of borehole wall protection technology can effectively reduce or prevent borehole from deformation, and borehole collapse, so as to ensure the maximum slagging space in borehole, which is conducive to construction of deeper gas drainage borehole.%为了解决松软突出煤层钻进问题,提高钻进深度,为了有效阻止松软煤层抽采钻孔塌孔的情况,在讨论了不同钻孔护壁方法的技术原理的基础上,结合弹塑性“围岩-支护”理论,建立钻孔护壁力学模型,采用数值分析的方法,分析钻孔在不同内压条件下,钻孔周围煤体应力、变形量变化规律.研究结果表明,伴随孔壁内压增大,钻孔变形量呈减小趋势,最大主应力σ1峰值位置左移,塑性松动区呈缩小趋势;次主应力σ3对应曲线整体上移,钻孔周边的应力集中现象有增长趋势.通过钻孔护壁力学作用机理分析,应用钻孔护壁技术,可有效减小或阻止钻孔变形,预防塌孔,保证钻孔的最大排渣空间,有利于施工较深的瓦斯抽采钻孔.

  20. 德国IGOR煤液化工艺及云南先锋褐煤液化%IGOR PROCESS OF DIRECT COAL LIQUEFACTION AND XIANFENG BROWN COAL LIQUEFACTION IN IT

    Institute of Scientific and Technical Information of China (English)

    李克健; 史士东; 李文博

    2001-01-01

    In this paper, IGOR process of direct coal liquefaction in Germany and experimental results of Xianfeng brown coal in 200 kg/d PDU of IGOR process in Germany are introduced. Compared with other direct coal liquefaction processes, IGOR process is characterized with higher throughout of coal hydrogenation reactor, higher integration degree and higher quality of oils. The results of Xianfeng coal tested in 200 kg/d PDU of IGOR process in Germany showed IGOR process marched Xianfeng brown coal well with 53% of oil yield, 2 mg/kg and 17 mg/kg of N and S contents. Qualified 0# diesel oil can be produced from Xianfeng coal oil with simple distillation and qualified 90# lead free gasoline can be produced from it with reforming step.%介绍了德国IGOR煤直接液化工艺和云南先锋褐煤在IGOR工艺200 kg/d的PDU装置的试验结果. 与其它煤直接液化工艺相比, IGOR工艺具有煤直接液化反应器的空速高、系统集成度高和油品质量好的特点. 云南先锋褐煤在IGOR工艺200 kg/d的PDU装置上的试验结果表明, 先锋褐煤是适宜IGOR煤液化的煤种, 得到的油收率为53%, 油品中氮和硫的含量分别为2 mg/kg和17 mg/kg.煤液化油经过简单蒸馏可得到合格的0#柴油,经过重整可得到合格的90#无铅汽油.

  1. “三软”煤层综采面上端头及超前段自移式抬棚的研究与实施%“ThreeSoft”CoalSeamFullyMechanizedFaceEndandLeadParagraph Self-movingResearchandImplementationoftheRoof

    Institute of Scientific and Technical Information of China (English)

    邓小磊

    2013-01-01

    嵩山煤矿在“三软”煤层综采面上端头及超前段压力大、单体柱易钻底的不利条件下,通过研究与实施自移式抬棚支护技术,成功地解决了“三软”煤层综采面上端头及超前段支护难的问题,最终实现了安全、有效的稳定支护。%Songshan coal mine in “three soft” coal seam fully mechanized mining face end and advanced section of the column to the bottom of the drill pressure, monomer adverse conditions, through the research and implementation of the move type “shed supporting technology, successfully solve the” three soft “coal seam fully mechanized face the upper end of the head and lead paragraph, the difficulty of supporting, finally realize the stability of the safe and effective support.

  2. Laser Seam welding method

    International Nuclear Information System (INIS)

    The present invention provides a laser seam welding method for welding spacers to be used in nuclear fuel assemblies at a stable quality. Namely, the laser seam welding method comprises irradiating, while moving, laser beams to a portion to be welded. In this case, data of the shapes and characteristics of the portion to be welded are inputted to restrict the range of the welding of the portion to be welded. The power, moving speed, distance to a focal point and energy of the laser beams are controlled in the midway of the range for the welding. Then, a welding nugget having a shape defined to a portion to be welded can be formed thereby enabling to keep the portion to be welded to stable quality. As a result, failed welding can be eliminated, and strength of joint can be guaranteed. In addition, auxiliary products of portions to be welded, for example, springs are not failed by laser beams. As a result, satisfactory spacers can be provided. (I.S.)

  3. The 2000/60/EC Water Framework Directive and the Flooding of the Brown Coal Meirama Open Pit (NW Spain)

    Science.gov (United States)

    Delgado, J.; Juncosa, R.

    2009-04-01

    Coal mining in Galicia (NW Spain) has been an important activity which came to an end in December, 2007. Hence, for different reasons, the two large brown coal mines in Galicia (the As Pontes mine, run by ENDESA GENERACIÓN, and the Meirama mine, owned by Lignitos de Meirama, S.A., LIMEISA), have started closure procedures, both of which are considering the flooding of the mine pits to create two large lakes (~8 km2 in As Pontes and ~2 km2 in Meirama). They will be unique in Galicia, a nearly lake-free territory. An important point to consider as regards the flooding of the lignite mine pits in Galicia is how the process of the creation of a body of artificial water will adapt to the strict legal demands put forth in the Water Framework Directive. This problem has been carefully examined by different authors in other countries and it raises the question of the need to adapt sampling surveys to monitor a number of key parameters -priority substances, physical and chemical parameters, biological indicators, etc.- that cannot be overlooked. Flooding, in both cases consider the preferential entrance into the mine holes of river-diverted surface waters, in detriment of ground waters in order to minimize acidic inputs. Although both mines are located in the same hydraulic demarcation (i.e. administrative units that, in Spain, are in charge of the public administration and the enforcement of natural water-related laws) the problems facing the corresponding mine managers are different. In the case of Meirama, the mine hole covers the upper third part of the Barcés river catchment, which is a major source of water for the Cecebre reservoir. That reservoir constitutes the only supply of drinking water for the city of A Coruña (~250.000 inhabitants) and its surrounding towns. In this contribution we will discuss how mine managers and the administration have addressed the uncertainties derived from the implementation of the Water Framework Directive in the particular case of

  4. Bare face red-brown bricks manufactured with fly ash from the Narcea (Asturias Coal Power Plan

    Directory of Open Access Journals (Sweden)

    Ayesta, G.

    1999-12-01

    Full Text Available Fly ash, from the Coal Power Plant of Narcea (Asturias, has been used to determine its possible use as a raw material in the bare face red-brown brick manufacture. The correct mould of a ceramic material demands a paste with an adequate plasticity. So, the optimum compositions of humidity, lubricant (talc and binder (white dextrin have been investigated. The samples were made by compressing paste into a mould using varying values of pressure and boiling temperature once the cooling speed had been established. Finally, the cooked pieces were submitted to trials demanded by the Basic Construction Norm, to see if they met the required specifications concerning Water Absorption, Suction, Contraction, Resistance to Freezing, Efflorescence and Compressive Strength.

    Se caracterizan las cenizas volantes de la Central Térmica del Narcea (Asturias para determinar su utilización como materia prima en la obtención de ladrillos cara vista. El moldeo correcto de una pieza cerámica exige trabajar una pasta con una adecuada plasticidad, para ello se investiga cuál ha de ser la composición óptima de la misma, en cuanto a: humedad, cantidad de lubricante (talco y de ligante (dextrina blanca. El conformado de las piezas o ladrillos se realiza por prensado, utilizando distintos valores de presión, así como la temperatura de cocción, una vez establecida la velocidad de enfriamiento. Finalmente, las piezas cocidas se someten a los ensayos exigidos por la Norma Básica de Edificación, para ver si cumplen las especificaciones requeridas en cuanto a: Absorción de agua. Succión, Contracción, Heladicidad, Eflorescencia y Resistencia a la compresión.

  5. Desulfurization and oxidation behavior of ultra-fine CaO particles prepared from brown coal; Kattan wo mochiite choseishita CaO chobiryushi no datsuryu tokusei to sanka tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Benjamin, G.; Roman, M.; Yamazaki, Y.; Abe, H.; Harano, Y.; Takarada, Y. [Gunma University, Gunma (Japan). Faculty of Engineering

    1996-10-28

    The effect of reaction temperature and oxygen concentration on the desulfurization and oxidation behavior of ion-exchanged brown coal by Ca as new desulfurizing agent was studied. In experiment, Yallourn coal was used for ion- exchange, and limestone produced in Tochigi prefecture was also used for comparative study. Ca-exchanged brown coal was prepared by agitating coal in Ca(OH)2 slurry for 24 hours. The desulfurization behavior of a desulfurizing agent was obtained by measuring H2S and sulfur compounds in outlet gas of a reactor, and the oxidation behavior by measuring SO2 emission in outlet gas after oxidation reaction. As the experimental result, CaO produced from Ca-exchanged brown coal offered the extremely high activity to desulfurization reaction in a temperature range of 850-950{degree}C as compared with limestone. Although the oxidation behavior was dependent on oxidation temperature and oxygen concentration, CaS obtained from Ca-exchanged brown coal was more rapidly converted to CaSO4 than limestone. 3 refs., 8 figs., 2 tabs.

  6. Recultivation of brown coal dumping grounds as an element of safety during and after forming process on the example of ''Turow'' mine

    International Nuclear Information System (INIS)

    The growth of vegetation at the dumps of brown coal mine ''Turow'' has been determined as a result of the survey. The intensity of the soil-formative process occurring in initial soil at the forestations is closely related to water circulation system formed in ecosystem. The volume of water stored in studied dumps was approx. 300 m3/ha what gives the total water volume of 240000 m3 for area of forestation (800 ha). The results show that the forestation decreases the quantity of eroded material and gives an effective protection against erosion. (author). 5 refs

  7. 基于Watch-dog的嵌入式煤层注水多级保护系统设计%Design of Coal Seam Water Infusion Multi-level Embedded Protection System Based on Watchdog

    Institute of Scientific and Technical Information of China (English)

    施伟; 李丽丽

    2011-01-01

    In view that the existing automatic control system for coal seam water infusion can not work stably for a long time in some conditions of the mining area because of its limited anti-interference ability, a embedded protection system composed of multi-level watchdogs is designed. A four-tier protection measure is provided by the system. The level of protection is escalated according to the severity of failures. When the control system hardware and software failures occur, different watchdogs start different protection measures to make the system return to normal, including electromagnetic interference or deadlock. In circuit design of the protection system, the following three factors are taken full account:the independence of watchdog timers,the fail-safe feature and the real-time feature,use the watchdogs at all levels with a minimum of soft wares and hard wares in order to reduce system redundancy. Being applied to a number of water infusion automatic control systems,The stability and reliability of the original systems have been effectively improved to be with high value of application and promotion.%针对现有煤层注水自动控制系统因抗干扰能力有限,无法在部分条件恶劣的采区长时间稳定工作的实际情况,设计了采用多级看门狗组成的嵌入式保护系统.本系统提供了四个级别的保护措施,根据故障严重程度,保护级别逐步升级,在控制系统出现软硬件故障后,包括出现电磁干扰或死锁现象后,不同看门狗启动不同保护措施,使系统恢复正常.在保护系统电路设计中充分考虑了看门狗定时器的独立性、故障安全性和作用实时性三方面因素,各级看门狗用最少的软件及硬件实现,降低了系统冗余.本设计在多个注水自动控制系统的改造实践中应用,有效地提高了原系统的稳定性、可靠性,具有很强的应用和推广价值.

  8. Seam 2 Web Development LITE

    CERN Document Server

    Salter, David

    2011-01-01

    Packed with illustrations and examples, this book will make the task of improving your Seam application simple and straightforward. This book is for Java EE application developers who have a Seam web application set up and ready to go, and are looking for information on the key areas of Seam that this book covers. You will need a basic understanding of Java EE and also to be aware of EJB3, although you do not need to know it in any detail. Experience with JBoss AS would be great, but all you really need is to be comfortable using any application server. Knowledge of AJAX and JavaScript would a

  9. The certification of the gross calorific value and mass fractions of ash, C, H, N, S, Cl, major elements and trace elements in three coal materials: ERM®-EF411 (hard coal), ERM®-EF412 (brown coal) and ERM®-EF413 (furnace coke)

    OpenAIRE

    Linsinger, Thomas; Raffaelli, Barbara; OOSTRA Albert

    2013-01-01

    This report describes the production of ERM-EF411, ERM-EF412 and ERM-EF413, three coal materials certified for proximates and trace elements. The materials have been produced following ISO Guide 34:2009. Industial hard coal, brown coal and furnace coke were obtained, dried, milled (ERM-EF411 and ERM-EF413) and filled into aluminium laminated sachets. Between-unit homogeneity were quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006. Wit...

  10. 王家山煤矿急倾斜煤层综放设备选型及回采工艺%Equipment Selection and Mining Technique of Fully Mechanized Top Coal Caving Mining in Steep Inclined Seam of Wangjiashan Mine

    Institute of Scientific and Technical Information of China (English)

    杨吉文

    2011-01-01

    In order to determine the matched equipment selection of the hydraulic powered support, coal shearer and face conveyor and the safety reliable mining technique for the fully mechanized strike top coal caving mining in the steep inclined seam, according to the steep inclined seam deposit conditions and the mining technical features in Wangjiashan Mine, a 3D numerical simulation was applied to analyze the stressed process of the surrounding rock and the powered supports in the coal mining face and analyze the failure deformation features of the roof and top coal. In combination with the anti falling down and anti sliding requirements of the equipment applied in the coal mining face, the selection of the hydraulic powered support, coal shearer and face conveyor was preliminarily determined. With the site practices, the ZF4800/16/30 two leg chock-shield powered support was determined as the main part of the above three machine matched equipment. A mining technique including coal cutting from the upward to downward, the conveyor and powered support moving from downward to upward and the top coal caving from the downward to upward was summarized.%为了确定急倾斜煤层走向长壁综放开采"三机"(液压支架、采煤机和刮板输送机)配套选型及安全可靠的回采工艺,针对王家山煤矿急倾斜煤层赋存条件及开采技术特点,采用三维数值模拟,分析了采场围岩与支架受力过程,顶板及顶煤破坏变形特征,结合工作面设备防倒防滑需要,初步确定"三机"选型.通过现场实践,确定了ZF4800/16/30型2柱支撑掩护式支架为主体的"三机"配套,总结出了由上向下割煤、由下向上推刮板输送机并移架、由下向上放顶煤的回采工艺.

  11. Developing selective mining capability for longwall shearers using thermal infrared-based seam tracking

    Institute of Scientific and Technical Information of China (English)

    Jonathon C. Ralston; Andrew D.Strange

    2013-01-01

    Longwall mining continues to remain the most efficient method for underground coal recovery.A key aspect in achieving safe and productive longwall mining is to ensure that the shearer is always correctly positioned within the coal seam.At present,this machine positioning task is the role of longwall personnel who must simultaneously monitor the longwall coal face and the shearer's cutting drum position to infer the geological trends of the coal seam.This is a labour intensive task which has negative impacts on the consistency and quality of coal production.As a solution to this problem,this paper presents a sensing method to automatically track geological coal seam features on the longwall face,known as marker bands,using thermal infrared imaging.These non-visible marker bands are geological features that link strongly to the horizontal trends present in layered coal seams.Tracking these line-like features allows the generation of a vertical datum that can be used to maintain the shearer in a position for optimal coal extraction.Details on the theory of thermal infrared imaging are given,as well as practical aspects associated with machine-based implementation underground.The feature detection and tracking tasks are given with real measurements to demonstrate the efficacy of the approach.The outcome is important as it represents a new selective mining capability to help address a long-standing limitation in longwall mining operations.

  12. Announcement concerning the promotion of research and development projects through the promotion scheme 'Environmental Research and Environmental Engineering' in the field of 'Rehabilitation and ecological design of the landscapes in brown coal mining areas of the new Laender'

    International Nuclear Information System (INIS)

    The BMFT intends to promote research projects serving the rehabilitation and ecological re-design of the landscapes bordering the Lausitz and in the region of Leipzig and Halle as they present after the demise of brown coal mining. The following types of projects will be considered for promotion: recultivation projects; projects on environmentally benign design concepts for the landscapes left by mining; on techniques for the water-economical rehabilitation and rehabilitation of old deposits in the brown coal mining areas. Short presentations for project proposals can be submitted until 30 April 1994. (orig./HP)

  13. COAL GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20110359 Feng Lijuan(Graduate School,Southwest Petroleum University,Chengdu 610500,China);Guo Dali Experimental Study on the Stress Sensitivity of Coal and Its Impact on the Filtration of the Fracturing Fluid(Coal Geology & Exploration,ISSN1001-1986,CN61-1155/P,38(2),2010,p.14-17,4 illus.,5 tables,9 refs.)Key words:coal seam,stressIn the paper,the relationship between the stress and permeability in the coal r

  14. COAL GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20132555 Bao Yuan(School of Resources and Geosciences,China University of Mining and Technology,Xuzhou 221008,China);Wei Chongtao Simulation of Geological Evolution History of the Upper Permian Coal Seam No.8in Shuigonghe Syncline,Zhina Coalfield,Guizhou Province(Coal Geology&Exploration,ISSN1001-1986,CN61-1155/P,40(6),2012,p.13-16,23,1illus.,1table,17refs.)

  15. System for detecting interfaces between mineral seams and the surrounding earth formations

    International Nuclear Information System (INIS)

    The present invention contemplates a system for detecting an interface between a mineral seam and the surrounding earth formation utilizing a radiation source and a radiation receiver mounted on a miner having a positionable cutter assembly. As the miner is moved into the coal seam, a first distance is continuously sensed between one surface formed in the mineral seam by the miner cutter assembly and the surrounding earth formation and the miner cutter assembly is positioned in response to the sensed first distance. As the miner is withdrawn from the coal seam, a second distance is continuously sensed between one surface formed in the mineral seam by the miner cutter assembly and the surrounding earth formation and the miner cutter assembly is positioned in response to the sensed second distance. A substantial portion of the space between the wall formed in the mineral seam by the miner cutter assembly and the radiation source and radiation receiver is substantially filled with a material having a density greater than the density of air to direct a substantial portion of the radiation through the mineral seam

  16. 松软特厚煤层区域穿层钻孔风动卸煤消突效果分析%Effect Analysis of Outburst Elimination in Soft and Superhigh Coal Seam by Dismounting Coal Capitalize on Wind-Force in Grossmeasures Boreholes

    Institute of Scientific and Technical Information of China (English)

    王远声; 冉小勇

    2015-01-01

    针对超化矿区域煤层厚度大,煤质松软,采用水力冲孔措施消突效果差的现状,通过分析采用风动卸煤措施与水力冲孔措施后钻孔卸煤量、瓦斯抽采浓度和抽采量的差异,结果表明:利用风动卸煤措施后单孔平均卸煤量和单位时间卸煤量为水力冲孔措施钻孔的2.55倍、3.63倍, 钻孔施工班时仅为水力冲孔的0.7倍;瓦斯有效抽采时间增加12%,单孔瓦斯抽采量大幅度提升,有效的降低煤层瓦斯含量达到了理想的卸煤增透消除煤层突出危险性的效果.%According to the inferior effect of the application of hydraulic flushing technology to soft and superhigh coal seam in Chaohua mine, this paper discussed the differences of the amount of coal dismountd capitalize on Wind-Force and hydraulic flushing,also the disparity of the concentration and the quantity of gas extraction. The study showed that the average amount of coal dismountd capitalize on Wind-Force in the single hole is 2.55 times as many as hydraulic flushing,while the amount of coal disburdened per unit time is 3.63 times and the time spend on drilling is 0.7 times. Under the action of the measures,the effective drainage time is increased 12%,whatever,the quantity of gas extraction aregreatly enhanced.The depressurization efficiency has been successfully reached when the gas content declined substantially..

  17. A Poromechanical Model for Coal Seams Injected with Carbon Dioxide: From an Isotherm of Adsorption to a Swelling of the Reservoir Un modéle poromécanique pour l’injection de dioxyde de carbone dans des veines de charbon : d’une isotherme d’adsorption à un gonflement du réservoir

    Directory of Open Access Journals (Sweden)

    Nikoosokhan S.

    2012-11-01

    Full Text Available Injecting carbon dioxide into deep unminable coal seams can enhance the amount of methane recovered from the seam. This process is known as CO2-Enhanced Coal Bed Methane production (CO2-ECBM. The seam is a porous medium whose porous system is made of cleats (small natural fractures and of coal pores (whose radius can be as small as a few angström. During the injection process, the molecules of CO2 get adsorbed in the coal pores. Such an adsorption makes the coal swell, which, in the confined conditions that prevail underground, induces a closure of the cleat system of the coal bed reservoir and a loss of injectivity. In this work, we develop a poromechanical model which, starting from the knowledge of an adsorption isotherm and combined with reservoir simulations, enables to estimate the variations of injectivity of the coal bed reservoir over time during the process of injection. The model for the coal bed reservoir is based on poromechanical equations that explicitly take into account the effect of adsorption on the mechanical behavior of a microporous medium. We consider the coal bed reservoir as a dual porosity (cleats and coal porosity medium, for which we derive a set of linear constitutive equations. The model requires as an input the adsorption isotherm on coal of the fluid considered. Reversely, the model provides a way to upscale an adsorption isotherm into a meaningful swelling of the coal bed reservoir at the macroscopic scale. The parameters of the model are calibrated on data on coal samples available in the literature. Reservoir simulations of an injection of carbon dioxide in a coal seam are performed with an in-house finite volume and element code. The variations of injection rate over time during the process of injection are obtained from the simulations. The effect of the compressibility of the coal matrix on those variations is discussed. L’injection de dioxyde de carbone dans des veines de charbon profondes peut augmenter

  18. 特厚易自燃煤层综放工作面临界瓦斯抽放量的确定%Determination of Critical Gas Drainage Volume in Fully Mechanized Caving Face in Extra-thick Inflammable Coal Seam

    Institute of Scientific and Technical Information of China (English)

    杜海刚; 冯姗; 褚廷湘; 余明高

    2015-01-01

    基于特厚煤层瓦斯抽采与煤自燃双重耦合影响,确定综放工作面的临界瓦斯抽放量. 根据束管监测系统现场实测及利用Fluent软件数值模拟,得出煤自燃防治条件下的综放工作面临界风量为1 100 m3/min,综合瓦斯抽采与煤自燃防治耦合影响下的临界瓦斯抽放量为180 m3/min.%Based on the double coupling influence of gas drainage and coal spontaneous combustion in the extra-thick coal seam, the critical gas drainage volume in the fully mechanized caving face was determined. According to the site measurement by the bundle tube monitoring system and the numerical simulation with Fluent software, it was obtained that the critical air quantity in the fully mechanized caving face was 1 100 m3/min under the control conditions of coal spontaneous combustion and the critical gas drainage volume in the fully mechanized caving face under the coupling influence of the comprehensive gas drainage and the prevention and control of coal spontaneous combustion was 180 m3/min.

  19. Vibration performance research of a new shearer cutting unit in shin coal seam%新型薄煤层采煤机截割部振动特性研究

    Institute of Scientific and Technical Information of China (English)

    赵丽娟; 宋朋; 谢波

    2014-01-01

    In order to study the vibration performance of a new type shearer cutting unit working in thin coal seam for improving its stability in the course of work, a virtual rigid-flex coupled prototype of the shearer cutting unit is established in the co-simulation environment based on Pro/E,MATLAB, ADAMS, ANSYS. The forced vibration simulation of the shearer cutting unit is done using the ADAMS/Vibration module to analyze the effect of main vibration sources to shearer cutting unit. Combined with the ADAMS simulation result, the dynamic contact analysis of the pair of gear which bears the maximum contact force of shearer cutting unit is done by the use of ANSYS/LS-DYNA, and the profile modification is done with consideration of the dynamic contact analysis result to im-prove the engagement performance of this pair gear. The results showed that the hearer cutting unit could be motivated easily and needs some necessary optimization that profile modification reduced the shocks and vibrations of the gear pairs of shearer cutting unit, and the Z-direction vibration ac-celeration of the gear pair reduced by 33.8% after modification. These results provide a quantitative basis for the performance improvements and structural optimization of the shearer cutting unit.%为了研究某新型薄煤层采煤机截割部的振动特性,以提高其在工作过程中的稳定性,应用 Matlab、Pro/E、ADAMS和ANSYS四款软件构造的协同仿真环境建立该采煤机截割部刚柔耦合模型,利用ADAMS/Vibration模块进行强迫振动仿真,分析和讨论了截割部的主要振源频率对其振动特性的影响,结合ADAMS动力学仿真结果,运用ANSYS/LS-DYNA对截割部受力最大的一级齿轮进行了动态接触分析,并根据分析结果对齿轮副进行齿廓修形,改善了轮齿啮合状态。结果表明:该采煤机截割部系统存在易被激发的振型,需对结构进行进一步的改进和优化;合理的齿廓修行可以降

  20. Face shield system for semi-steep seams

    Energy Technology Data Exchange (ETDEWEB)

    Betting, B.

    1981-01-01

    About 25% of the coal produced by the HBL coalfield comes from longwall rise faces and is won using double-drum shearers and powered supports for semi-steep workings (30 to 40 degrees). Face spills present a hazard to personnel. Describes tests with a shield system for rise faces with a worked thickness of 2.20 m (seam thickness 2.06 m). Explains how the system operates : a prop, set automatically from inside the support unit, is used to support a shield plate which is anchored between the roof and the floor, thereby supporting the coal face. This shield system effectively protects the solid, even when weakened. (In French)

  1. Methods of determining methane emission in coal mines of Great Britain and India

    Energy Technology Data Exchange (ETDEWEB)

    Sobala, J.

    1980-10-01

    Methane prediction methods used in Great Britain are discussed in the light of methane prediction methods used in Poland and other countries. The following methods are discussed: Stuffken method (Holland), Schulz method, Fluegge method, Winter method (FRG), Gunther method (France), Lidin method (USSR), Barbara Experimental Coal Mine method (Poland) and MRDE method (UK). Factors taken into account in the 8 methods are evaluated: gas content in adjacent rock and coal layers, thickness of adjacent coal seams, distance to adjacent coal seams, length of a working, intensity of gas drainage, angle of inclination of mined coal seam, thickness of mined seam, method of roof control of the mined seam, depth, advance rate, and gas emission from hauled coal. It is noted that methods of classifying coal seams in India taking into account methane hazard are similar to the system used in Poland up to 1970 (three classes of methane hazard). Methods of coal sampling used in India are described. (6 refs.)

  2. Effect of Water Invasion on Outburst Predictive Index of Low Rank Coals in Dalong Mine

    OpenAIRE

    Jiang, Jingyu; Cheng, Yuanping; Mou, Junhui; Jin, Kan; Cui, Jie

    2015-01-01

    To improve the coal permeability and outburst prevention, coal seam water injection and a series of outburst prevention measures were tested in outburst coal mines. These methods have become important technologies used for coal and gas outburst prevention and control by increasing the external moisture of coal or decreasing the stress of coal seam and changing the coal pore structure and gas desorption speed. In addition, techniques have had a significant impact on the gas extraction and outb...

  3. Gas Chromatography/Atmospheric Pressure Chemical Ionization-Fourier Transform Ion Cyclotron Resonance Mass Spectrometry of Pyrolysis Oil from German Brown Coal.

    Science.gov (United States)

    Zuber, Jan; Kroll, Marius M; Rathsack, Philipp; Otto, Matthias

    2016-01-01

    Pyrolysis oil from the slow pyrolysis of German brown coal from Schöningen, obtained at a temperature of 500°C, was separated and analyzed using hyphenation of gas chromatography with an atmospheric pressure chemical ionization source operated in negative ion mode and Fourier transform ion cyclotron resonance mass spectrometry (GC-APCI-FT-ICR-MS). Development of this ultrahigh-resolving analysis method is described, that is, optimization of specific GC and APCI parameters and performed data processing. The advantages of GC-APCI-FT-ICR-MS hyphenation, for example, soft ionization, ultrahigh-resolving detection, and most important isomer separation, were demonstrated for the sample liquid. For instance, it was possible to separate and identify nine different propylphenol, ethylmethylphenol, and trimethylphenol isomers. Furthermore, homologous series of different acids, for example, alkyl and alkylene carboxylic acids, were verified, as well as homologous series of alkyl phenols, alkyl dihydroxy benzenes, and alkoxy alkyl phenols. PMID:27066076

  4. Changes in char reactivity due to char-oxygen and char-steam reactions using Victorian brown coal in a fixed-bed reactor

    Institute of Scientific and Technical Information of China (English)

    Shu Zhang; Yonggang Luo; Chunzhu Li; Yonggang Wang

    2015-01-01

    This study was to examine the influence of reactions of char–O2 and char–steam on the char reactivity evolution. A newly-designed fixed-bed reactor was used to conduct gasification experiments using Victorian brown coal at 800 °C. The chars prepared from the gasification experiments were then collected and subjected to reactivity characterisation (ex-situ reactivity) using TGA (thermogravimetric analyser) in air. The results indicate that the char reactivity from TGA was generally high when the char experienced intensive gasification reactions in 0.3%O2 in the fixed-bed reactor. The addition of steam into the gasification not only enhanced the char conversion sig-nificantly but also reduced the char reactivity dramatical y. The curve shapes of the char reactivity with involve-ment of steam were very different from that with O2 gasification, implying the importance of gasifying agents to char properties.

  5. Review of the study ''Development of the energy markets - energy reference forecast'' from the perspective of brown coal

    International Nuclear Information System (INIS)

    In June 2014 the Federal Ministry for Economic Affairs and Energy (BMWi) published an expertise prepared by the EWI, GWS and Prognos institutes entitled ''Development of the energy markets - energy reference forecast''. This study presents probable developments in the energy economy up to the year 2030 (reference forecast) on the assumption of a yet more stringent energy and climate protection policy as well as continuing impediments to its implementation. Complementing the forecast is an outlook up to the year 2050 (scenario of trends). But what do the findings of this expertise say about the future utilization of Germany's greatest domestic energy resource, namely brown coal? This question is addressed in the following article.

  6. Gas Chromatography/Atmospheric Pressure Chemical Ionization-Fourier Transform Ion Cyclotron Resonance Mass Spectrometry of Pyrolysis Oil from German Brown Coal

    Directory of Open Access Journals (Sweden)

    Jan Zuber

    2016-01-01

    Full Text Available Pyrolysis oil from the slow pyrolysis of German brown coal from Schöningen, obtained at a temperature of 500°C, was separated and analyzed using hyphenation of gas chromatography with an atmospheric pressure chemical ionization source operated in negative ion mode and Fourier transform ion cyclotron resonance mass spectrometry (GC-APCI-FT-ICR-MS. Development of this ultrahigh-resolving analysis method is described, that is, optimization of specific GC and APCI parameters and performed data processing. The advantages of GC-APCI-FT-ICR-MS hyphenation, for example, soft ionization, ultrahigh-resolving detection, and most important isomer separation, were demonstrated for the sample liquid. For instance, it was possible to separate and identify nine different propylphenol, ethylmethylphenol, and trimethylphenol isomers. Furthermore, homologous series of different acids, for example, alkyl and alkylene carboxylic acids, were verified, as well as homologous series of alkyl phenols, alkyl dihydroxy benzenes, and alkoxy alkyl phenols.

  7. Organic geochemistry and coal petrology of Tertiary brown coal in the Zhoujing mine, Baise Basin, South China -4. Biomarker sources inferred from stable isotope compositions of individual compounds

    Energy Technology Data Exchange (ETDEWEB)

    Schoell, M.; Simoneit, B.R.T.; Wang, T.-G. (Chevron Petroleum Technology Co., La Habra, CA (United States))

    Carbon isotopic compositions of extractable compounds derived from higher land plants are with [+-]2[per thousand] of the bulk coal ([delta][sup 13]C -27.0[per thousand]) from Baise Basin. This data suggests that either similar species contributed these compounds or that the plants from which this coal was formed imposed similar biosynthetic fractionations. The terpenoid hydrocarbons form two isotopically distinct groups: the diterpenoids ([delta][sup 13]C 2.50 [+-] 1.4[per thousand]) and the sesquiterpenoids ([delta][sup 13]C 25.9 [+-] 1.5[per thousand]) are on average 1-2[per thousand] enriched in [sup 13]C compared to the bulk coal, whereas the oleanane-ursane-lupane derivatives ([delta][sup 13]C 29.0 [+-] 0.8[per thousand]) are on average 1-2[per thousand] depleted in [sup 13]C compared to the bulk coal. The n-alkanes, ranging from C[sub 15] to C[sub 35], have a mean [delta][sup 13]C value of -32.4 [+-] 0.6[per thousand], whereby averages for the C[sub 17]-C[sub 22] and C[sub 23]-C[sub 33] n-alkanes do not significantly differ from the overall average. Hopane derivatives in this coal extract are depleted in [sup 13]C compared to the bulk coal by 8-34[per thousand] suggesting that bacterial cycling of methane played a role during formation of this coal. 19 refs., 4 figs., 1 tab.

  8. Estimation of potentially toxic elements contamination in anthropogenic soils on a brown coal mining dumpsite by reflectance spectroscopy: a case study.

    Science.gov (United States)

    Gholizadeh, Asa; Borůvka, Luboš; Vašát, Radim; Saberioon, Mohammadmehdi; Klement, Aleš; Kratina, Josef; Tejnecký, Václav; Drábek, Ondřej

    2015-01-01

    In order to monitor Potentially Toxic Elements (PTEs) in anthropogenic soils on brown coal mining dumpsites, a large number of samples and cumbersome, time-consuming laboratory measurements are required. Due to its rapidity, convenience and accuracy, reflectance spectroscopy within the Visible-Near Infrared (Vis-NIR) region has been used to predict soil constituents. This study evaluated the suitability of Vis-NIR (350-2500 nm) reflectance spectroscopy for predicting PTEs concentration, using samples collected on large brown coal mining dumpsites in the Czech Republic. Partial Least Square Regression (PLSR) and Support Vector Machine Regression (SVMR) with cross-validation were used to relate PTEs data to the reflectance spectral data by applying different preprocessing strategies. According to the criteria of minimal Root Mean Square Error of Prediction of Cross Validation (RMSEPcv) and maximal coefficient of determination (R2cv) and Residual Prediction Deviation (RPD), the SVMR models with the first derivative pretreatment provided the most accurate prediction for As (R2cv) = 0.89, RMSEPcv = 1.89, RPD = 2.63). Less accurate, but acceptable prediction for screening purposes for Cd and Cu (0.66 ˂ R2cv) ˂ 0.81, RMSEPcv = 0.0.8 and 4.08 respectively, 2.0 ˂ RPD ˂ 2.5) were obtained. The PLSR model for predicting Mn (R2cv) = 0.44, RMSEPcv = 116.43, RPD = 1.45) presented an inadequate model. Overall, SVMR models for the Vis-NIR spectra could be used indirectly for an accurate assessment of PTEs' concentrations. PMID:25692671

  9. Production of synthetic liquid fuel from run-of-mine oil shales, brown coals and waste of petrochemical and chemical industry

    International Nuclear Information System (INIS)

    Modern and perspective technologies have been developed for processing run-of-mine oil shales into liquid products foreseen for producing motor fuels and chemical feedstock. Baltic run-of-mine oil shales, high-sulfur oil shales of the Volga basin, brown coals of Kansk-Atchinsk basin, as well as heavy crude oils and oil-bearing sands, solid waste of petrochemical and chemical industry may be processed. The proposed high-efficiency technology enables to produce high yields of naphtha (gasoline fraction) and diesel fuel fraction, feedstock for catalytic and hydro cracking processes, electrode coke, different adhesive materials, refractories, anodic mass, phenols, individual hydrocarbons, Ni- and V- concentrates. The process proposed is carried out using oil shales. Their organic matter has unique hydrogen donor properties which enable them to activate the thermal conversion of brown coals, high-boiling waste of petrochemical industry etc. This complex technology is based on the thermochemical conversion process of oil shales in the hydro carbonic solvent at 333-440 deg C, under the pressure of 3-5 MPa, and volumetric rate 3-6 h-1. A paste-forming substance boiling between 200-340 deg C is used as the medium. The process runs with a deficiency (up to 30 %) of regenerated paste-forming substance and therefore respective measures have been worked out to intensify the process. It enabled to close the process with respect to regenerated paste-forming substance and to design new routes for thermochemical processing of oil shales. These procedures have the following essential advantages: 1.There is no need for previous separation of asphaltenes and metals (Ni, V) from heavy petrochemical feedstock as they precipitate on the mineral part of oil shales and are discharged together with liquid products of the process. 2. Thermal cracking is carried out without molecular hydrogen and thermal hydro cracking without catalysts. 3. Raw material is considerably desulfurized.(author)

  10. Analysis and Research of Factors Affecting Coal Mining with Plough

    Institute of Scientific and Technical Information of China (English)

    刘过兵; 陈胜利

    2002-01-01

    Coal mining with ploughs is an ideal coal mining technology for thin a nd thinner coal seams. The existence conditions of coal seams are different for each other, which affects coal mining with ploughs to different degrees, and the application results are also different. The authors analyze the affecting factors by means of mathematical methods. The research is useful to the wide appli cation of ploughs.

  11. Coal

    International Nuclear Information System (INIS)

    Coal world production represents 3.5 billions of tons, plus 900 millions of tons of lignite. 50% of coal is used for power generation, 16% by steel making industry, 5% by cement plants, and 29% for space heating and by other industries like carbo-chemistry. Coal reserves are enormous, about 1000 billions of tons (i.e. 250 years of consumption with the present day rate) but their exploitation will be in competition with less costly and less polluting energy sources. This documents treats of all aspects of coal: origin, composition, calorific value, classification, resources, reserves, production, international trade, sectoral consumption, cost, retail price, safety aspects of coal mining, environmental impacts (solid and gaseous effluents), different technologies of coal-fired power plants and their relative efficiency, alternative solutions for the recovery of coal energy (fuel cells, liquefaction). (J.S.)

  12. Unique Project of Single-Cutting Head Longwall Shearer Used for Thin Coal Seams Exploitation / Projekt Jednoorganowego Kombajnu ŚCIANOWEGO O Specjalnej Konstrukcji Przeznaczonego do Eksploatacji POKŁADÓW Cienkich

    Science.gov (United States)

    Bołoz, Łukasz

    2013-12-01

    Problem of thin hard coal seams exploitation, including chosen data related with their resources in Poland, has been discussed in the introduction of the present study. On the basis of actually operated machines the assumptions, which should be satisfied by the longwall shearer used for exploitation of thin hard coal seams, have been made. A project of such longwall shearer combined with band conveyor and mechanized longwall support, including description of the machine operation technology and analysis of possible day output achievement, have been presented. Polska dysponuje stosunkowo dużymi zasobami surowców energetycznych, a ciągle rosnące zapotrzebowanie na energię skłania do ich racjonalnego wykorzystywania. Jedną z możliwości takiego racjonalnego gospodarowania zasobami naturalnymi jest eksploatacja węgla kamiennego z pokładów cienkich. W związku z wybieraniem coraz cieńszych pokładów węgla, zalegających bardzo głęboko, w trudnych warunkach górniczo-geologicznych napotyka się na duże problemy związane z uzyskaniem wymaganej wydajności wydobycia przy użyciu stosowanych aktualnie metod. Przyjmuje się, ze pokłady cienkie to takie o miąższości od 1.0 m do 1.5 m i właśnie ta niewielka wysokość wyrobiska ścianowego powoduje szereg ograniczeń związanych z efektywną eksploatacją węgla. Na podstawie dostępnych danych określono, że ilości węgla kamiennego w cienkich pokładach wynosi około 600 mln Mg. Znaczna część pokładów cienkich w ostatnich latach została przeklasyfikowana na nieprzemysłowe, co pozwala stwierdzić, że rzeczywista ilość węgla w pokładach cienkich jest znacznie większa. Na podstawie analizy wad i zalet jak i danych technicznych produkowanych obecnie maszyn, określono wytyczne i założenia do nowego rozwiązania maszyny urabiającej przeznaczonej do wydobywania węgla w ścianach niskich. Kombajn do eksploatacji cienkich pokładów powinien spełniać następujące wymagania (Bołoz, 2012

  13. On the constitutionality of subsidizing regimes for energy sources. Part 2. First the ``coal penny``, then the ``wind penny``, and now perhaps the ``brown coal penny`` to support brown coal mining in eastern Germany?; Zur Verfassungsmaessigkeit energiewirtschaftlicher Subventionsregime. T. 2. Vom ``Kohlepfennig`` ueber den ``Windpfennig`` zum ``ostdeutschen Braunkohlepfennig``?

    Energy Technology Data Exchange (ETDEWEB)

    Blanke, H.J.; Peilert, A.

    1999-10-01

    While the first part of this review discusses the so-called ``coal penny`` tax and the act for enhanced use of renewable energy sources for electricity generation (StrEG) as one of the subsidizing and financing models of the German legislator, this second part deals with the `protection of interest clause` laid down in the recent German legislation for reform of the energy industry law in compliance with European open energy market directives. This clause is intended to protect to a certain extent the brown coal mining industry and the electric power industry in the eastern federal states of Germany from the harsh winds of competition in the liberalized German and European energy market. Those states have been making tremendous efforts after the German re-unification to catch up with modern standards in the energy sector, and the Government wishes to prevent the considerable investments made in those states from becoming ``stranded investments``. The analysis examines economic, political, and legal aspects of the legislative intent and the subsidizing schemes of the German government with regard to the question of whether such shift of financial burden from the public to the private sector is in compliance with constitutional law. (orig./CB) [Deutsch] Nachdem im Teil 1 der sog. ``Kohlepfennig`` und die Verguetungsregelung des Stromeinspeisungsgesetzes zur Foerderung erneuerbarer Energien als Formen der Subventionierung diskutiert wurden, befasst sich der 2. Teil der Abhandlung mit der Verfassungsmaessigkeit der Schutzklausel zugunsten der ostdeutschen Braunkohle. Diese Schutzklausel ist erstmals im Gesetz zur Neuregelung des Energiewirtschaftsrechts enthalten und soll der Stromwirtschaft in den neuen Bundeslaendern einen gewissen Schutz gegen Verdraengungswettbewerb im liberalisierten Energiemarkt gewaehren, u.a. auch um die erst vor kurzem getaetigten hohen Investitionen in neue Stromerzeugungs- und Verteilungsanlagen in den oestlichen Bundeslaendern davor zu

  14. Soil algae in brown coal and lignite post-mining areas in central Europe (Czech Republic and Germany)

    Czech Academy of Sciences Publication Activity Database

    Lukešová, Alena

    2001-01-01

    Roč. 9, č. 4 (2001), s. 341-350. ISSN 1061-2971 R&D Projects: GA MŠk ME 076 Institutional research plan: CEZ:AV0Z6066911 Keywords : algae * cyanobacteria * coal mining Subject RIV: EH - Ecology, Behaviour Impact factor: 1.011, year: 2001

  15. A moving baseline for evaluation of advanced coal extraction systems

    Science.gov (United States)

    Bickerton, C. R.; Westerfield, M. D.

    1981-01-01

    Results from the initial effort to establish baseline economic performance comparators for a program whose intent is to define, develop, and demonstrate advanced systems suitable for coal resource extraction beyond the year 2000 are reported. Systems used were selected from contemporary coal mining technology and from conservation conjectures of year 2000 technology. The analysis was also based on a seam thickness of 6 ft. Therefore, the results are specific to the study systems and the selected seam extended to other seam thicknesses.

  16. Non-mine technology of hydrocarbon resources production at complex development of gas and coal deposits

    International Nuclear Information System (INIS)

    Non-mine technology of coal gas seams exploitation is new geological technological method of complex exploitation of coal gas deposits. The method allows sequentially to extract hydrocarbon resources in technological aggregative-mobile condensed states. According to natural methane content in seams the technology includes: methane extraction from sorption volume where it is bounded up with coal; gas output intensification of coal is due to structural changes of substance at the cost of physico-chemical treatment of seam; increase of seam permeability by the methods of active physical and physico-chemical actions on coal seam (hydro-uncovering, pneumatic hydro action etc.). Pilot testing shows efficiency of well mastering with help of depth pumps. In this case works of action of pumping out of operating liquid and gas extraction from coal seam are integrated

  17. Distributed Seams for Gigapixel Panoramas.

    Science.gov (United States)

    Philip, Sujin; Summa, Brian; Tierny, Julien; Bremer, Peer-Timo; Pascucci, Valerio

    2015-03-01

    Gigapixel panoramas are an increasingly popular digital image application. They are often created as a mosaic of many smaller images. The mosaic acquisition can take many hours causing the individual images to differ in exposure and lighting conditions. A blending operation is often necessary to give the appearance of a seamless image. The blending quality depends on the magnitude of discontinuity along the image boundaries. Often, new boundaries, or seams, are first computed that minimize this transition. Current techniques based on multi-labeling Graph Cuts are too slow and memory intensive for gigapixel sized panoramas. In this paper, we present a parallel, out-of-core seam computing technique that is fast, has small memory footprint, and is capable of running efficiently on different types of parallel systems. Its maximum memory usage is configurable, in the form of a cache, which can improve performance by reducing redundant disk I/O and computations. It shows near-perfect scaling on symmetric multiprocessing systems and good scaling on clusters and distributed shared memory systems. Our technique improves the time required to compute seams for gigapixel imagery from many hours (or even days) to just a few minutes, while still producing boundaries with energy that is on-par with Graph Cuts. PMID:26357067

  18. Naturally occurring radioactive material (NORM) in brown coal and copper shale mining areas and its consequences for landscape mitigation

    International Nuclear Information System (INIS)

    Extensive uranium mining and processing was widely spread in the former socialist european countries, especially former G.D.R., Romania, Hungary and Bulgaria. The exploration and the use of other radioactive contaminated mining products, e.g. hard coal for uranium winning in eastern Germany and highly radium contaminated coal in Upper Silesia (Poland) for energetic purposes was also a common practice. Besides uranium and coal mining activities naturally occurring radioactivity was also observed in copper shale mining. All these mining activities led to the accumulation of vast amounts of radioactive wastes and to the contamination of large areas. Very often these wastes not only contain elevated concentrations of radionuclides like uranium, thorium and the relevant daughter nuclides but also other toxic chemical elements (Schneider et. al. 2001a). Now these polluted areas are a permanent source of ground and surface water contamination in the mining districts. Due to establishment of the new Radiation Protection Law in Germany in 2001, the management of radioactive wastes from non uranium mining activities is increasingly gaining attention. For reasons of environmental security and to avoid the uncontrolled spread of radioactive pollution, a permanent cost effective monitoring and control of pollution levels is necessary as long as the wastes are deposited in interim disposal sites. To avoid the current situation of these normally low radioactive contaminated wastes to become the final deposition state, new waste management concepts are needed

  19. Effects of increased chlorine freights at the cocombustion of secondary fuels at the site of the brown coal fired power station Jaenschwalde; Auswirkungen von erhoehten Chlorfrachten bei der Mitverbrennung von Sekundaerbrennstoffen am Standort des Braunkohlenkraftwerks Jaenschwalde

    Energy Technology Data Exchange (ETDEWEB)

    Mielke, F. [Vattenfall Europe Waste Management GmbH, Hamburg (Germany); Sparmann, A. [Vattenfall Europe Generation AG und Co. KG, Peitz (Germany). Kraftwerk Jaenschwalde, Blockbetrieb RCA; Kappa, S. [Vattenfall Europe Generation AG und Co. KG, Luebbenau (Germany)

    2007-07-01

    Vattenfall Europe Waste to Energy GmbH (Hamburg, Federal Republic of Germany) also is active in the range of the energetic utilization of wastes. The co-combustion of refuse-derived fuels in brown coal power stations is a new area of operation. The authors of the contribution under consideration report on the effects of increased chlorine freights in the co-combustion of secondary fuels at the location of the brown coal power station Jaenschwalde (Federal Republic of Germany). In particular, problems arose with the parameter chlorine. It frequently does not succeed at this point of time, to attain the claimed value of < 1.0 wt-% TS. The adherence to the demanded and contractually agreed qualities with secondary fuels requires a permanent input monitoring. A crucial quality improvement could be obtained. Like that, interfering materials, insufficient grain size and the given bulk density hardly are to be criticized. Only partial successes were obtained with the parameter chlorine.

  20. Observation of variability in radon concentration in the gases of eruptive seams

    International Nuclear Information System (INIS)

    The methods and the results of preliminary measurements of radon concentration in the gases emitted in coal seams threatened with gases and rocks eruptions have been presented. The changes of concentrations are given in the function of excavation progress. The nature of radon concentration changes points to relationship between radon concentration and the probability of the occurrence of eruption. 4 refs., 2 figs. (author)

  1. Hydrochemical and geochemical processes in superficial dump sediments in Zwenkau open brown coal mine; Hydro- und geochemische Prozesse in oberflaechennahen Kippensedimenten des Braunkohlentagebaus Zwenkau

    Energy Technology Data Exchange (ETDEWEB)

    Wiegand, U.

    2002-07-01

    The present study was performed as part of a project titled ''Ground and air-based spectrometric studies for the differentiation of reactively altered brown coal open mining areas in Central Germany'' (Project 02 WB 9667/5) which was funded by the Federal Ministry for Education and Research. It was carried out as a cooperation between GeoForschungszentrum Potsdam (GFZ, Potsdam GeoResearch Centre), Deutsches Zentrum for Lust- und Raumfahrt (DLR, German Aerospace Centre), Gesellschaft fuer Angewandte Fernerkundung (GAF, Society for Applied Remote Sensing) and Umweltforschungszentrum Leipzig/Halle GmbH (UFZ, Leipzig/Halle Environmental Research Centre). The idea of the project was to calibrate aerial data obtained by means of spectrometric remote sensing methods using conventional petrographic, mineralogical and geochemical analysis. This would provide the mining industry with a powerful method with low time and staff requirement for reliably classifying the vast dump areas produced by open pit mining, accurately assigning findings to location data and thus identifying suitable uses for different sites. The focus of the present study was on characterising hydrochemical and geochemical alterations in dump sediments of the Zwenkau brown coal open mining area south of Leipzig in Central Germany. The collection of these data plays a decisive role in plans for cultivating and assessing the potential hazard to the open mining landscape. [German] Die vorliegende Arbeit wurde im Rahmen des BMBF-gefoerderten Projektes 'Luft- und bodengestuetzte spektrometrische Untersuchungen zur Differenzierung reaktiv veraenderter Braunkohlentagebaugebiete in Mitteldeutschland' (Vorhaben 02 WB 9667/5) als Kooperation zwischen dem GeoForschungsZentrum Potsdam (GFZ), dem Deutschen Zentrum fuer Luft- und Raumfahrt (DLR), der Gesellschaft fuer Angewandte Fernerkundung (GAF) und dem Umweltforschungszentrum Leipzig/Halle GmbH (UFZ) angefertigt. Idee des Projektes war

  2. 78 FR 41946 - Notice of Competitive Coal Lease Sale Maysdorf II North, WY

    Science.gov (United States)

    2013-07-12

    ... in order to mine the last of the LBA coal. Reasonable costs to move features such as utilities and... mineable seam. The average total coal thickness is approximately 69 feet and the range of overburden... coal. This estimate of mineable reserves includes the main seam mentioned above but does not...

  3. A Computer Aided Design and Simulation System for Upward Cross-seam Boreholes

    OpenAIRE

    Hou Shao-Jie; Zhang Yu-Wei; Cheng Yuan-Ping

    2013-01-01

    In order to prevent gas hazards, thousands of upward cross-seam boreholes for gas pre-drainage are widely used in underground coal mines. Their construction quality directly determines whether coal gas accidents happen and touches miners’ lives closely. However, the quality is difficult to be guaranteed, because of the hostile underground environment, complicated spatial calculation, sightless strata reserves and little digitalized supporting. Based on the ...

  4. Prediction, prevention and fight automatic control in mining an outburst prone coal seam; Control Automatico de las Medidas de Prediccion, Prevencion y Lucha, para la Explotacion Mecanizada de una Capa Susceptible de desprendimientos Instantaneos

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    Outburst are instantaneous catastrophic failure of the coal mine structure, characterised by emissions of large quantities of finely divided coal dust and gas from a coal face. In Spain, outbursts have represented a serious problem in the zone of Aller (Asturias), particularly in San Antonio mine. The main objective of the research work was to determine whether outburst precursory micro seismic activity could be discerned by monitoring the coal mining district of San Antonio. Micro seismic activity on the underground seismometer contains distinct style of events: natural events, stress events and outburst events. The correlation between the rate of extraction and the number of micro seismic activity has been analysed. A real time software was developed which would discriminate mining activity from background seismic noise. the algorithm used for event detection in based on comparing the short term average (STA) with the long term average (LTA) of the signal energy. (Author)

  5. Measurements for monitoring ground motion resulting from mining operations in the Rhenish brown coal district; Messungen zur Ueberwachung von bergbaubedingten Bodenbewegungen im rheinischen Braunkohlenbergbau

    Energy Technology Data Exchange (ETDEWEB)

    Duddek, H.; Schaefer, W. [Rheinbraun AG, Koeln (Germany)

    1996-12-31

    Coal mining in the Rhenish brown coal district resulted in loose rock slopes with a total height of more than 350 m. Mining operations caused ground motion in open-cast mines, in the slopes and in the region ahead of the face. Internal dumping caused motions of the floors, the overburden tip and te slopes of the open-cast mines. The deformations were measured by different methods, and the evaluations are presented here. As examples, permanent monitoring of a slope using the GEOROBOT measuring system and continuous subsidence measurements in an overburdan dump by means of hydrostatic measuring systems are presented. GEOROBOT ensures quasi-continuous measurements of slope motion with an error of 5-7 mm. Hydrostatic measuring systems on the basis of pressure sensors were developed for measurements of single overburden dump strata and the overburden dump basis during dumping. (orig.) [Deutsch] In den rheinischen Braunkohlentagebauen entstehen Lockergesteinsboeschungen mit Gesamthoehen von mehr als 350 m. Die Gewinnungstaetigkeiten verursachen Entlastungsbewegungen im Tagebau, in den Boeschungen und im Tagebauvorfeld. Die Innenverkippung fuehrt erneut zu Bodenbewegungen im Liegenden, im Kippenkoerper und im Bereich der Tagebauraender. Die auftretenden Deformationen werden mit verschiedenen Messverfahren erfasst, ausgewertet und dargestellt. Beispielhaft werden die permanente Ueberwachung einer Boeschung mittels des automatischen Messsystems GEOROBOT und kontinuierliche Setzungsmessungen in einer Tagebaukippe mit hydrostatischen Messsystemen vorgestellt. Mit GEOROBOT werden quasi kontinuierlich Boeschungsbewegungsmessungen mit einer Genauigkeit von {+-}5 bis 7 mm durchgefuehrt. Auf der Basis von Drucksensoren wurden hydrostatische Messsysteme konzipiert, mit denen Setzungen einzelner Kippscheiben und der Kippenbasis waehrend des Kippenaufbaues ermittelt werden. (orig.)

  6. Development a New Classification for Assessing the Coal Mine Mechanization / Opracowanie nowej klasyfikacji dla oceny mechanizacji w kopalniach węgla

    Science.gov (United States)

    Mehdi, Hosseini Seyed; Reza, Mikaeil; Mohammad, Ataei; Khalokakaei, Reza

    2013-03-01

    The coal mine mechanization is important to achieve optimum quality and maximum efficiency of coal production. Mechanization is an objective that can result in significant cost reductions and higher levels of profitability for underground mines. The potential of coal mine mechanization depends on some important factors Such as seam inclination and thickness, geological disturbances, seam floor conditions and roof conditions. These factors should be considered in coal mine mechanization analysis. In this study, the new classification was developed with the respect to the mentioned factors. Using this system the coal seam mechanization index (CSMi) of several types of coal seams was evaluated and classified into five categories; very good, good, medium, low and very low. As a case study, the mechanization of the Takht coal seams in Golestan area of Iran was investigated using this new classification system. The results show a low potential for mechanization in most of the Takht coal seams

  7. Underground Coal Thermal Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P. [Univ. of Utah, Salt Lake City, UT (United States); Deo, M. [Univ. of Utah, Salt Lake City, UT (United States); Eddings, E. [Univ. of Utah, Salt Lake City, UT (United States); Sarofim, A. [Univ. of Utah, Salt Lake City, UT (United States); Gueishen, K. [Univ. of Utah, Salt Lake City, UT (United States); Hradisky, M. [Univ. of Utah, Salt Lake City, UT (United States); Kelly, K. [Univ. of Utah, Salt Lake City, UT (United States); Mandalaparty, P. [Univ. of Utah, Salt Lake City, UT (United States); Zhang, H. [Univ. of Utah, Salt Lake City, UT (United States)

    2012-01-11

    The long-term objective of this work is to develop a transformational energy production technology by insitu thermal treatment of a coal seam for the production of substitute natural gas (SNG) while leaving much of the coal's carbon in the ground. This process converts coal to a high-efficiency, low-GHG emitting gas fuel. It holds the potential of providing environmentally acceptable access to previously unusable coal resources. This topical report discusses the development of experimental capabilities, the collection of available data, and the development of simulation tools to obtain process thermo-chemical and geo-thermal parameters in preparation for the eventual demonstration in a coal seam. It also includes experimental and modeling studies of CO2 sequestration.

  8. Presence of commercial coal in the Taimyr coal basin

    Energy Technology Data Exchange (ETDEWEB)

    Androsov, B.N.

    1980-05-01

    This article presents the results of a geologic expedition to the Far North of the USSR, where coal resources in the Taimyr Peninsula have been discovered. The surface of the basin is 80,000 square kilometers. Maps provide general information on the geological structure of the basin, location of coal deposits, and the richest seams. Geological structure of the basin, strata in which coal deposits are located, and properties of the coal are described (petrographic components, caking and coking properties, calorific value, ash content etc.). The so-called coefficient of coal content which ranges from 3% or below up to 11% is given for individual regions of the basin. The number of coal seams, their thickness and geological disturbances are described. Taimyr coals represent a full range of various ranks from gas coals to anthracite. The Taimyr coals have lower calorific value and lower nitrogen content than coals from the Donetsk basin. The majority of Taimyr coals have low ash and sulfur content. The best outlook for discovering rich seams of coking and fat coal are in the Taimyr-Ozerskii region of the basin particularly in Chernoyarskoe, Ugol'noe, Ozernoe, and Zayach'e. (13 refs.) (In Russian)

  9. 特厚煤层综放开采冲击地压防治技术与实践%Technology and Practices on Mine Pressure Bumping Prevention and Control of Fully Mechanized Top Coal Caving Mining in Ultra Thick Seam

    Institute of Scientific and Technical Information of China (English)

    周澎

    2011-01-01

    According to the serious mine pressure bumping, gateway repair difficulty and other production problems of No. 250102 fully mechanized top coal caving mining face in Huating Mine, a series technical research and the prevention and control practices was conducted. The analysis showed that the deep mining depth, seam with pressure bumping tendency, hard and thick sandstone roof and irrational width of the gateway coal pillars would be main influence factors to cause the pressure bumping in the coal mining face. The comprehensive index was applied to judge the pressure bumping danger index as 0. 89 of the fully mechanized top coal caving mining face and the mining face would have a strong pressure bumping danger. Based on the early prediction, the micro seismic method was applied to monitor and measure the bumping danger zone. As for the bumping danger zone, the pressure releasing blasting in the gateway side wall, deep borehole blasting in the roof, dynamic water injection (8 ~ 13 MPa) and static water injection as well as other pressure releasing and danger control measures were comprehensively applied to reduce the mine pressure bumping behavior strength and to effectively reduce the pressure bumping occurred in the fully mechanized top coal caving mining face.%基于华亭煤矿250102综放工作面冲击地压显现强烈、巷道返修难度大,开展了一系列技术研究和防治实践.分析表明,大采深、煤层具有冲击倾向性、坚硬厚层砂岩顶板、护巷煤柱留宽不合理是导致该工作面发生冲击地压的主要因素,并采用综合指数法判定该综放面冲击危险指数0.89,具有强冲击地压危险性.在早期预测的基础上,采用微震法对冲击危险区域进行监测.对具备冲击危险的区域,综合采用巷帮煤体卸压爆破、顶板深孔爆破、动压注水(8~13 MPa)与静压注水等卸压解危措施,削弱了冲击地压显现强度,有效降低了综放工作面冲击地压的发生.

  10. Fiscal 1998 overseas geological structure survey. Japan-China joint coal survey Mei-Xian project; 1998 nendo kaigai chishitsu kozo nado chosa hokokusho. Nippon Chugoku sekitan kyodo tansa Mei-Xian project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Japan-China joint coal survey was made through seismic prospecting by Japanese group and drilling prospecting by Chinese group. Mei-Xian mine property includes coal seams of the Jurassic period, and is covered with the quaternary period stratum without any coal seam. The base of the quaternary period stratum exists at depth of 50-400m, while the coal seams at depth of 300-700m. Among 11 existing seams, the 1st and 5th seams are main objects for prospecting. The 5th seam of 0.2-8.96m (2.95m in average) thick is the most expected important one, distributing all over the mine property. The 5th seam also has branch seams spreading over 2.5km from east to west and 1.2km from south to north in the center part of the mine property. The 1st seam of 0-8.62m (2.90m in average) thick is most thick in the south part of the mine property. The theoretical amount of coal deposits in the whole coal seam is estimated to be nearly 290,000,000t by Chinese group (nearly 50% of it in the 5th seam). That is also estimated to be nearly 346,000,000t by Japanese group (155,000,000t in the 5th seam). Both 1st and 5th seams are composed of sub-bituminous coal. (NEDO)

  11. Influence of Geological Structure on Coal and Gas Outburst Occurrences in Turkish Underground Coal Mines

    Science.gov (United States)

    Esen, Olgun; Özer, Samet Can; Fişne, Abdullah

    2015-04-01

    Coal and gas outbursts are sudden and violent releases of gas and in company with coal that result from a complex function of geology, stress regime with gas pressure and gas content of the coal seam. The phenomena is referred to as instantaneous outbursts and have occurred in virtually all the major coal producing countries and have been the cause of major disasters in the world mining industry. All structures from faults to joints and cleats may supply gas or lead to it draining away. Most geological structures influence the way in which gas can drain within coal seams. From among all the geological factors two groups can be distinguished: parameters characterising directly the occurrence and geometry of the coal seams; parameters characterising the tectonic disturbances of the coal seams and neighbouring rocks. Also dykes may act as gas barriers. When the production of the coal seam is advanced in mine working areas, these barriers are failed mostly in the weak and mylonitized zones. Geology also plays a very important role in the outburst process. Coal seams of complex geological structure including faults, folds, and fractured rocks are liable to outbursts if coal seams and neighbouring rocks have high gas content level. The purpose of the study is to enlighten the coal industry in Turkey to improving mine safety in underground coal production and decrease of coal and gas outburst events due to increasing depth of mining process. In Turkey; the years between 1969 and 2013, the number of 90 coal and gas outbursts took place in Zonguldak Hard Coal Basin in both Kozlu and Karadon Collieries. In this study the liability to coal and gas outburst of the coal seams are investigated by measuring the strength of coal and the rock pressure. The correlation between these measurements and the event locations shows that the geological structures resulted in 52 events out of 90 events; 19 events close to the fault zones, 25 events thorough the fault zones and 8 events in

  12. Geology and coal bed methane resource potential of the Gondwana Barapukuria Coal Basin, Dinajpur, Bangladesh

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Md. Rafiqul; Hayashi, Daigoro [Department of Physics and Earth Sciences Faculty of Science, University of the Ryukyus, Okinawa, 903-0213 (Japan)

    2008-08-05

    With an area of 5.16 km{sup 2}, the Barapukuria coal deposit is one of the five largest Gondwana coal basins in Bangladesh, and is located in the north west of the country close to the towns of Dinajpur and Saidpur. The existence of the basin was initially indicated by a negative gravity anomaly in oil and gas exploration. Exploration for the deposit was commenced by the Geological Survey of Bangladesh (GSB), with seven surface boreholes that confirmed the existence of a significant coal deposit. The deposit occurs as an asymmetrical synclinal structure with an axis striking approximately N-S. The deposit is limited to the east by a large normal fault which has displaced Archaean metamorphics against the Gondwana sediments. The coal-bearing sediments are comprised of Gondwana Permian-age sandstones, siltstones, subordinate carbonaceous shales, and six correlated coal seams. The Gondwana sediments are unconformably overlain by Tertiary and Quaternary deposits, against which the coal seams are successively subcropped to the west. Within the structural limits of the basin, approximately 377 Mt coal in-situ has been quantified in the six coal seams that range in depth from 118 to 518 m below surface. Due to the synclinal nature of the deposit, the upper coal seams, designated I to V, occur over diminishing areal extent with decreasing depth. The principal seam of interest is the lowermost Seam VI, with a variable thickness across the deposit from 22 m in the northern part of the deposit to more than 42 m in the southern and eastern areas. Development of the Barapukuria Mine, the country's first coal mine, commenced in 1996 with the construction of two vertical shafts. Coal production from Seam VI began in 2005 and continues at the present time. Seam VI coal is high volatile B bituminous rank. About 34 Mt of coal has been estimated as recoverable resources, utilising descensional multi-slice longwall mining. The mine design and development have been severely

  13. Analysis on the cavability and recovery of top coal in fully mechanized caving face with thick seam%厚煤层综放工作面顶煤冒放性及回收率分析

    Institute of Scientific and Technical Information of China (English)

    郝雷; 武光辉; 袁西亚; 许永刚; 余智秘

    2015-01-01

    The lower recovery ratio of top-coal in fully mechanized caving face is a main problem , and improving the recov-ery ratio of top-coal has great significance to the high production and high efficiency of fully mechanized caving mining . Based on actual practice of №401102 fully mechanized caving face in Hujiahe Mine , the crushing mechanism and cavability of top-coal was researched , and the influence of different way of moving supports to the recovery ratio of top -coal is analyzed too.%顶煤回收率偏低一直是困扰综放开采的一个核心问题,提高综放工作面顶煤回收率对实现综放开采高产高效具有重大意义。本文结合胡家河煤矿401102综放工作面的实际情况,对顶煤破碎机理和冒放性进行了研究,并分析了不同移架方式对顶煤回收率的影响。

  14. 煤层底板破坏深度灰色-神经网络预测模型的建立与应用%Establishment and Application of Grey -Neural Network Model for Forecasting Failure Depth of Coal Seam Floor

    Institute of Scientific and Technical Information of China (English)

    许继影; 戴洪宝; 胡儒

    2015-01-01

    The failure depth of coal seam floor is one of the important parameters in the course of water burst-ing,so more accurately predict the parameters can reduce the water bursting accidents.This paper applied grey correlation analysis to quantitatively analyze the influence factors and got the correlation degree sort of each factor by sorting of correlation degree.Choosing four dominant factors as the input layers,grey -neural forecasting network has been built.Applying neural network algorithm,this model was trained by a total of 15 typical measured data collected from working face all over China,and 5 examples from coal mines of Huaibei&Huainan coalfield were used to test the practicability and the accuracy of model.The results indicate that high consistency between predic-ted value and measured values.Finally,applying the model in 1011 working face of Yuandian coal mine,the pre-dicted value is 14.23m.So this method can satisfy the precision requirement and can be used to predict failure depth of coal seam floor.%煤层底板破坏深度是煤矿底板突水研究中的重要参数之一,较为准确预测该参数可减少突水事故的发生。本文首先对煤层底板破坏深度的影响因素,按照关联度的大小排序进行了灰色关联定量分析,筛选出4个主控因子作为神经网络的输入元,同时应用优化 BP 算法,选用国内15个典型实测数据进行网络训练学习,建立灰色-神经网络预测模型,并以两淮矿区5个煤矿工作面的实例数据进行模型精准度检验,检验结果显示实测数据与预测结果有很好的一致性。最后将该模型应用袁店煤矿1011工作面,预测其煤层底板破坏深度值为14.23m。因此,该方法精度较高,适用于煤层底板破坏深度的预测。

  15. 大倾角特厚煤层分层开采瓦斯综合治理技术研究及实践%Research and practice on the comprehensive gas control technology of slice mining in steep dipping extra-thick coal seam

    Institute of Scientific and Technical Information of China (English)

    姜华

    2014-01-01

    根据大倾角特厚煤层分层开采的实际特点,结合某矿B5001工作面的瓦斯涌出规律,进行了包含采前预抽、边采边抽、高位钻孔抽放、采空区插管抽放等方式在内的瓦斯综合治理技术的研究与实践,确定了合理的抽放参数,取得了良好的瓦斯治理效果。%Based on the practical characteristics of slice mining in steep dipping extra-thick coal seam, combing with the gas emission law of B5001 working face, the comprehensive gas control technology , including drainage before the mining, drainage while mining, high drilling drainage, mined-out area buried tube drainage, are researched and practiced. The reasonable drainage parameters are determined. Good controlling effect is obtained.

  16. WATER RESERVOIRS UNDER CONSTRUCTION AS A RESULT OF THE ACTIVITIES OF “KONIN” AND “ADAMÓW” BROWN COAL MINES

    Directory of Open Access Journals (Sweden)

    Mirosława Gilewska

    2015-11-01

    Full Text Available Post-exploitation opencast pits constitute a final stage of mining activities and turning them into public utility facilities is taking place now by their water reclamation. They constitute basins without outflows with the depth of 15 to 69 m and areas ranging from 2.5 to 692 ha. The bottoms of these basins are situated in pyrite-containing Miocene formations. Products of Fe2S weathering comprise sulphuric acid and iron compounds – sulphate II and sulphate III. This study presents the basic parameters of the reservoirs constructed in the final opencast pits of the “Konin” and “Adamów” brown coal mine,s as well as the properties of the formations making up the bottoms of two water reservoirs under construction: Lubstów and Władysławów. It is evident from the performed investigations that these formations are characterised by very acid reaction and very high exchangeable acidity. The total sulphur content ranges from 446 to 962 mg·kg-1 of the ground and that of sulphate sulphur – from 71 to 187 mg·kg-1 of the ground. The chemism of these grounds will exert influence on the quality of water accumulating in the opencast pits during the initial period of their spontaneous flooding. Together with the increase of the capacity of these reservoirs, the contact of waters with boulder clays of the Warta River glaciation abounding in calcium compounds will increase and concentrations of calcium ions in the waters of the reservoirs will also grow.

  17. 沿空掘巷防治煤层自然发火技术探讨%Discussion on Prevention and Control Coal Seam Spontaneous Combustion Technology in Gob-side Entry Driving

    Institute of Scientific and Technical Information of China (English)

    李亚斌; 于强

    2015-01-01

    Mine Fire is one of the major natural disasters in coal mine,according to heat source the fire is divid-ed into external and internal fire.The flame of external fire is on the surface of things in general,it is easy to extin-guish if discovery and remedy in time.But internal fire is covert,it often occurs in goaf or coal pillar where difficult to enter.Hidden danger of spontaneous combustion exists when Gob-side entry driving with a narrow pillar if treat-ment is not timely,because of surrounding coal pressure relief,air leakage passage formation and tender sealing lead to air leakage.Limin coal mine analyzes the cause of coal combustion,adopts comprehensive fire prevention and con-trol technology such as pressure balancing ventilation,yellow slurry injection,whitewashing sealing and injecting rockshow,it achieves good control effect.%矿井火灾是煤矿的重大自然灾害之一,根据引火热源不同分为外因火灾和内因火灾。外因火灾的火焰一般在燃烧物的表面,如果能及时发现和补救,是容易熄灭的,而内因火灾比较隐蔽,经常发生在人们难以进入的采空区或煤柱内。矿井采用留窄煤柱沿空掘巷时由于周边煤体卸压,形成漏风通道,封闭不严易导致漏风,存在自燃隐患,如不及时治理会引起矿井火灾。利民煤矿通过分析发火原因,采取均压通风、注黄泥浆、喷浆封闭及注罗克休等综合防灭火技术,取得了良好的防治效果。

  18. Introduction to the coal mining industry in China

    International Nuclear Information System (INIS)

    Some basic data on the coal mining industry in China, such as energy production and construction, coal consumption, production by classification, coal reserves, coal produced by seams angle, by thickness, by mechanization, by methods, etc., are introduced in this paper. 3 refs., 9 figs., 9 tabs

  19. Coal-Face Fracture With A Two-Phase Liquid

    Science.gov (United States)

    Collins, E. R., Jr.

    1985-01-01

    In new method for mining coal without explosive, two-phase liquid such as CO2 and water, injected at high pressure into deeper ends of holes drilled in coal face. Liquid permeates coal seam through existing microfractures; as liquid seeps back toward face, pressure eventually drops below critical value at which dissolved gas flashvaporizes, breaking up coal.

  20. Preventing Coal and Gas Outburst Using Methane Hydration

    Institute of Scientific and Technical Information of China (English)

    吴强; 何学秋

    2003-01-01

    According to the characteristics of the methane hydrate condensing and accumulating methane, authors put forward a new technique thought way to prevent the accident of coal and gas outburst by urging the methane in the coal seams to form hydrate. The paper analyzes the feasibility of forming the methane hydrate in the coal seam from the several sides, such as, temperature,pressure, and gas components, and the primary trial results indicate the problems should be settled before the industrialization appliance realized.

  1. Dynamics of CO2 in coal as a reservoir

    OpenAIRE

    Mazumder, S.

    2007-01-01

    The mechanisms, by which the coal seams sorb, retain and store gases needs, to be understood. The results presented in this thesis give an insight into the dynamics of CO2 and other flue gas components in coal that are related to operation feasibility of ECBM projects. The main issues relate to the permeability behavior and the flue gas/ CO2 sorption. The cleat network in coal seams provides the principal source of permeability for fluid flow. Understanding and predicting the cleat attributes...

  2. Production of Hydrogen from Underground Coal Gasification

    Science.gov (United States)

    Upadhye, Ravindra S.

    2008-10-07

    A system of obtaining hydrogen from a coal seam by providing a production well that extends into the coal seam; positioning a conduit in the production well leaving an annulus between the conduit and the coal gasification production well, the conduit having a wall; closing the annulus at the lower end to seal it from the coal gasification cavity and the syngas; providing at least a portion of the wall with a bifunctional membrane that serves the dual purpose of providing a catalyzing reaction and selectively allowing hydrogen to pass through the wall and into the annulus; and producing the hydrogen through the annulus.

  3. Coal-bed methane water effects on dill and essential oils

    Science.gov (United States)

    Pumping water from coal seams decreases the pressure in the seam and in turn releases trapped methane; this is the most common and economic way of methane extraction. The water that is pumped out is known as coal-bed methane water (CBMW), which is high in sodium and other salts. In past 25 years, th...

  4. CO{sub 2} Sequestration Potential of Charqueadas Coal Field in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Romanov, V [NETL

    2012-10-23

    The I2B coal seam in the Charqueadas coal field has been evaluated as a target for enhanced coal bed methane production and CO{sub 2} sequestration. The samples were low rank coals (high volatile bituminous and sub-bituminous) obtained from the I2B seam as �3� cores. Such properties as sorption capacity, internal structure of the samples, porosity and permeability were of primary interest in this characterization study.

  5. Determination of coal mine mechanization using fuzzy logic

    Institute of Scientific and Technical Information of China (English)

    Ataei M; Khalokakaei R; Hossieni M

    2009-01-01

    Two of the most important tasks in coal mines are to improve efficiency and to increase production besides keeping safety constantly in mind. In order to obtain these goals, mine mechanization is required. Mine mechanization needs high levels of investment and should therefore be studied carefully before final decisions about mechanization are made. When analysizing the potential for mechanization the following, rather imprecise, factors should be considered: seam inclination and thickness, geologi-cal disturbances, seam floor conditions, roof conditions, water at the working face and the extension of seams. In our study we have used fuzzy logic, membership functions and created fuzzy rule - based methods and to considered the ultimate objective: mechanization of mining. As a case study, the mechanization of the Takht coal seams in Iran was investigated. The results show a high potential for mechanization in most of the Takht coal seams.

  6. Vertical quality variation and correlation of coal beds of the Sabaletas Member of the Amaga Formation

    International Nuclear Information System (INIS)

    In the Amaga Formation in order to determine the vertical variation in quality of coal seams and associated shales and to establish correlation between them, lithotype associations (plies) were sampled in eight coal seams of the Sabaletas Member. The following investigations were carried out: proximate, ultimate and rockeval pyrolysis analysis, petrographic analysis of polished sections, palynofacies and sporomorph analysis in slides prepared using a Schulze modified method for subbituminous coals and associated shales. Shales were studied with x ray diffraction. Coals are subbituminous (VM > 40% y Ro 70) and liptinite >15% and poor in inertinite <5%. Results are showing important differences in studied coals seams, which demonstrate that no correlation can be established between seams 1, 2 and 3 from the Nechi and El Bloque Mines, and between seams 3 from the El Arenal and El Ponton mines.

  7. Geochemical characteristics of different maceral groups in the Huangxian Coal,China

    Institute of Scientific and Technical Information of China (English)

    CAI Zhen-yu; WANG Jin-xi; JIN Yu-jie; ZHANG Hong-jian; JIN Kan-kun

    2004-01-01

    In order to research how lignite is utilized, two coal samples of seams 2 and 4were taken from the Huangxian Basin, China. The samples were separated into vitrinite,sporinite, and resinite. Geo-chemical and pyrolysis methods were used to analyse three maceral groups and two seam samples. The results indicate that the resinite and sporinite groups have higher extract yields, S1, S2, HI values, and pyrolysis compounds.These differences may shed light on the usage of the Huangxian lignite. Seam 2 produces more gas and oil than seam 4 does because seam 2 contains more resinite and sporinite macerals.

  8. Influence of palaeotopography on the distribution of coal in the Western Coalfield, Sydney basin, Australia: comparison with South African coals

    Science.gov (United States)

    Hutton, A. C.; Feldtmann, R.

    1996-07-01

    The Western Coalfield of New South Wales, centred on the town of Lithgow, is one of several areas of the Sydney Basin (Australia) that produces Permian coals for export and for domestic: use. The lowermost seam of the Illawarra Coal Measures, the Lithgow seam, was deposited in an alluvial fan to proximal braidplain complex. The style of clastic sedimentation and coal seam development was strongly influenced by the palaeotopography, especially basement highs which represent erosional remnants of the pre-Permian erosional cycle. The influence of the palaeotopography is seen in the distribution of the basal conglomerate, the thickness of the basal Shoalhaven Group (which is thinnest on and near the basement highs), the location of the alluvial fan facies of the Illawarra Coal Measures (which are adjacent to the highs and received a large proportion of the clastic detritus from these highs) and the development of the coal seams (which are distal to the basement highs). Of great significance is the location of economic sections of the Lithgow seam with respect to palaeotopographic highs. Adjacent to the highs the Lithgow seam is either too thin or contains too many claystone bands to allow mining. Between the highs: and further to the east and north of the highs, where the precursor peats formed on the floodplain and interfan areas, the seam is of significantly better quality and has been mined.

  9. 浅埋煤层高强度开采覆岩(土)破坏演化及溃沙控制技术%Failure characteristics of overburden rock (soil) and sand control technology in high strength mining of shallow coal seam

    Institute of Scientific and Technical Information of China (English)

    张玉军; 李凤明

    2016-01-01

    -bedrock weathering zone-bedrock" with different clay layers and bedrock thicknesses.Therefore,the failure characteristics of overburden rock (soil) and height of development were obtained,the sand inrush disaster factors and prediction criterion were analyzed,and the technical means of prevention and control of water inrush of sand were accordingly proposed.The results show that the overlying rock (soil) damage development height and characteristics were varied because of the control effects of different bedrocks and soil thicknesses under the condition of "sandy-soil-rock type of overlying strata" in the shallow buried coal seam.Water and sand,channel,power source,and space were the main factors causing the disaster of water inrush of sand in unconsolidated aquifer.The prediction criterion of sand inrush has been proposed.The sand inrush disaster of shallow coal seam was controlled through preventing roof cut,pumping aquifer head pressure,locally grouting and fixing sand and reasonably retaining the coal rock pillar.

  10. Formation and retention of methane in coal

    Energy Technology Data Exchange (ETDEWEB)

    Hucka, V.J.; Bodily, D.M.; Huang, H.

    1992-05-15

    The formation and retention of methane in coalbeds was studied for ten Utah coal samples, one Colorado coal sample and eight coal samples from the Argonne Premium Coal Sample Bank.Methane gas content of the Utah and Colorado coals varied from zero to 9 cm{sup 3}/g. The Utah coals were all high volatile bituminous coals. The Colorado coal was a gassy medium volatile bituminous coal. The Argonne coals cover a range or rank from lignite to low volatile bituminous coal and were used to determine the effect of rank in laboratory studies. The methane content of six selected Utah coal seams and the Colorado coal seam was measured in situ using a special sample collection device and a bubble desorbometer. Coal samples were collected at each measurement site for laboratory analysis. The cleat and joint system was evaluated for the coal and surrounding rocks and geological conditions were noted. Permeability measurements were performed on selected samples and all samples were analyzed for proximate and ultimate analysis, petrographic analysis, {sup 13}C NMR dipolar-dephasing spectroscopy, and density analysis. The observed methane adsorption behavior was correlated with the chemical structure and physical properties of the coals.

  11. Algorithm For Simplified Robotic Tracking Of Weld Seams

    Science.gov (United States)

    Gutow, David A.; Paternoster, Vincent Y.

    1992-01-01

    Algorithm computes small cross-seam corrections to programmed path of welding robot. Intended for use with add-on vision system loosely coupled to robot, transmitting small amount of information about weld seam ahead of torch. Position of welding torch in reference frame of moving window estimated on basis of data on weld seam and speed of torch. Does not need data on position of torch, and does not transform data on seam to another reference frame.

  12. Distribution of sulphur in the Tertiary coals of Meghalaya, India

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, D.; Mazumdar, K.; Basumallick, S.

    1983-08-01

    The distribution pattern of the different forms of sulphur in the coal seams of Meghalaya has been worked out. In general, the total sulphur content is found to increase from the base to the top of a seam. There is also a general trend of upward increase of sulphur content in the seam-wise sequence, i.e. the upper seam is found to contain more sulphur than the seam lying below. Pyritic sulphur shows an upward increasing tendency both intraseam- and interseam-wise. Variation in organic sulphur shows an apparent parallelism with that of total sulphur. A gradual decrease in total sulphur content is also seen in the coals of Meghalaya from east to west within the basin of deposition. This regional lateral variation in sulphur content was due to the more marine nature of the peat-forming swamps of the Khasi and Jaintia Hills (eastern Meghalaya) as compared to that of the Garo Hills (western Meghalaya)

  13. Model test of the overburden deformation and failure law in close distance multi-seam mining

    Institute of Scientific and Technical Information of China (English)

    YANG Wei-feng; SUI Wang-hua; XIA Xiao-hong

    2008-01-01

    Based on characteristic of the associated mining of multi-coal seam and the engineering geological characteristics of overburden, the mining impact pattern of multiseam mining and the dynamic fracture mechanism of overburden were characterized by applying the engineering geological mechanical model test. The related strata movement arameters and influence area of multi-seam mining were obtained, the strike boundary angle is 61°, the full extraction coefficient is 0.93, the greatest subsidence angle is 81°, the horizontal movement factor is 0.38, the deviation of inflection point/mining deep is 0.11.The development height of caving zone and water flowing fractured zone of multi-seam mining were calculated, is 32 m and 81.5 m separatly. The assess of influence degree of coal layer safety mining is that, there exists the possibility of water and sand inflow when mining, some messures for mine water prevention and control should be used, and the mining thickness should be local strictly limit.

  14. Scope and results of selective brown coal winning with hydraulic power shovels, as illustrated by the example of Dimnjace opencast mine. Moeglichkeiten und Ergebnisse selektiver Braunkohlegewinnung mit hydraulischen Loeffelbaggern, dargestellt am Beispiel des Tagebaues 'Dimnjace'

    Energy Technology Data Exchange (ETDEWEB)

    Popovic, N. (Fakultaet des Bergbaus und der Geologie, Tuzla (Bosnia and Herzegovina)); Marincic, Z. (Kohlenbergwerk ' Gracanica' , Gornji Vakuf (Bosnia and Herzegovina)); Komljenovic, D. (Fakultaet des Bergbaus und der Geologie, Tuzla (Bosnia and Herzegovina))

    1994-09-01

    The present paper discusses the selective winning of brown coal, using hydraulic excavators that are equipped with the TRY-POWER system. Taking the Dimnjace opencast mine as an example, the author examines the scope of selective winning up to a thickness of 0.2 m. In this connection the relationship between the duration of the excavator work cycle and the thickness of the layers to be removed is determined. By correlation the relationships thus determined are expressed by generally valid formulae, and methods of applying these formulae to general cases are indicated. By using the method of selective winning in the Dimnjace opencast mine a considerable saving in costs has been achieved. (orig.)

  15. Analysis on the Initial Cracking Parameters of Cross-Measure Hydraulic Fracture in Underground Coal Mines

    Directory of Open Access Journals (Sweden)

    Yiyu Lu

    2015-07-01

    Full Text Available Initial cracking pressure and locations are important parameters in conducting cross-measure hydraulic fracturing to enhance coal seam permeability in underground coalmines, which are significantly influenced by in-situ stress and occurrence of coal seam. In this study, stress state around cross-measure fracturing boreholes was analyzed using in-situ stress coordinate transformation, then a mathematical model was developed to evaluate initial cracking parameters of borehole assuming the maximum tensile stress criterion. Subsequently, the influences of in-situ stress and occurrence of coal seams on initial cracking pressure and locations in underground coalmines were analyzed using the proposed model. Finally, the proposed model was verified with field test data. The results suggest that the initial cracking pressure increases with the depth cover and coal seam dip angle. However, it decreases with the increase in azimuth of major principle stress. The results also indicate that the initial cracking locations concentrated in the second and fourth quadrant in polar coordinate, and shifted direction to the strike of coal seam as coal seam dip angle and azimuth of maximum principle stress increase. Field investigation revealed consistent rule with the developed model that the initial cracking pressure increases with the coal seam dip angle. Therefore, the proposed mathematical model provides theoretical insight to analyze the initial cracking parameters during cross-measure hydraulic fracturing for underground coalmines.

  16. Application of fractal theory to top-coal caving

    International Nuclear Information System (INIS)

    The experiences of underground coal mining in China show that coal in a thick hard coal seam with a hard roof, the so-called 'double hard coal seam', is difficult to be excavated by top-coal caving technique. In order to solve the problem, a top-coal weakening technique is proposed in this paper. In the present study, fractal geometry provides a new description of the fracture mechanism for blasting. By means of theoretical analysis of the relationship between the fractal dimension of blasting fragments and the dynamite specific energy, a mechanical model for describing the size distribution of top-coal and the dissipation of blasting energy is proposed. The theoretical results are in agreement with laboratory and in situ test results. Moreover, it is shown that the fractal dimension of coal fragments can be used as an index for optimizing the blasting parameters for a top-coal weakening technique

  17. Depositional setting, petrology and chemistry of Permian coals from the Paraná Basin: 2. South Santa Catarina Coalfield, Brazil

    Science.gov (United States)

    Kalkreuth, W.; Holz, M.; Mexias, A.; Balbinot, M.; Levandowski, J.; Willett, J.; Finkelman, R.; Burger, H.

    2010-01-01

    In Brazil economically important coal deposits occur in the southern part of the Paran?? Basin, where coal seams occur in the Permian Rio Bonito Formation, with major coal development in the states of Rio Grande de Sul and Santa Catarina. The current paper presents results on sequence stratigraphic interpretation of the coal-bearing strata, and petrological and geochemical coal seam characterization from the South Santa Catarina Coalfield, Paran?? Basin.In terms of sequence stratigraphic interpretation the precursor mires of the Santa Catarina coal seams formed in an estuarine-barrier shoreface depositional environment, with major peat accumulation in a high stand systems tract (Pre-Bonito and Bonito seams), a lowstand systems tract (Ponta Alta seam, seam A, seam B) and a transgressive systems tract (Irapu??, Barro Branco and Treviso seams).Seam thicknesses range from 1.70 to 2.39. m, but high proportions of impure coal (coaly shale and shaley coal), carbonaceous shale and partings reduce the net coal thickness significantly. Coal lithoypes are variable, with banded coal predominant in the Barro Branco seam, and banded dull and dull coal predominantly in Bonito and Irapu?? seams, respectively. Results from petrographic analyses indicate a vitrinite reflectance range from 0.76 to 1.63 %Rrandom (HVB A to LVB coal). Maceral group distribution varies significantly, with the Barro Branco seam having the highest vitrinite content (mean 67.5 vol%), whereas the Irapu?? seam has the highest inertinite content (33.8. vol%). Liptinite mean values range from 7.8. vol% (Barro Branco seam) to 22.5. vol% (Irapu?? seam).Results from proximate analyses indicate for the three seams high ash yields (50.2 - 64.2wt.%). Considering the International Classification of in-Seam Coals, all samples are in fact classified as carbonaceous rocks (>50wt.% ash). Sulfur contents range from 3.4 to 7.7 wt.%, of which the major part occurs as pyritic sulfur. Results of X-ray diffraction indicate the

  18. Microbial reactions in coal and coal relevant structures. Part project: fungal and enzymatic depolarisation of brown coal for the production of low-molecular compounds. Interim report; Mikrobielle Umsetzung an Kohle und kohlenrelevanten Strukturen. Teilvorhaben: Pilzliche und enzymatische Depolymerisation von Braunkohle zur Gewinnung niedermolekularer Verbindungen. Zwischenbericht (Berichtszeitraum 01.01.1998 - 31.12.1998)

    Energy Technology Data Exchange (ETDEWEB)

    Ziegenhagen, D.; Bublitz, F.; Sorge, S.; Ullrich, R.; Hofrichter, M.; Fritsche, W.

    1999-04-29

    The present research project involved a study of the depolymerisation of brown coal constituents. The purpose of the depolymerisation experiments, which were carried out with fungi as well as their (acellular) enzymes, was to obtain products with a potential market value. Research focussed on one of the key enzymes of lignocellulose degradation, namely manganese (II) peroxidase (MnP). The effects of this enzyme on the depolymerisation of brown coal was studied in detail in acellular systems. The insights gained in this way then served as a basis for optimising the fungal and enzymatic depolymerisation processes for maximum yields of low-molecular products. The experiments carried out during the period under review were oriented to finding new types of lignolytically active organisms, isolating lignolytic enzymes and immobilising them on natural support materials, and further examining the action spectrum of MnP. Different model substrates were used in order to gain information on what bond types are MnP-cleavable and on possible reaction products. Substrates were either fixed to silica gel as support material or used without support material. The idea of using substrates fixed to support materials was motivated by the need to distinguish between intracellular and extracellular reactions involving the fungal mycelium. [Deutsch] Im Rahmen des Forschungsvorhabens wird die Depolymerisation von Braunkohle-Bestandteilen untersucht. Ziel der sowohl mit Pilzorganismen als auch mit deren Enzymen (zellfrei) durchgefuehrten Depolymerisationsversuche ist die Gewinnung von Produkten mit potentiellem Werkstoffcharakter. Im Mittelpunkt der Forschung steht eines der Schluesselenzyme des Ligninozellulose-Abbaus: Die Mangan(II)-Peroxidase (MnP). Die Wirkung dieses Enzyms bei der Depolymerisation von Braunkohle (Bk) in zellfreien Systemen wird weitergehend untersucht. Auf Grundlage der gewonnenen Erkenntnisse werden die pilzlichen und enzymatischen Depolymerisationsprozesse so

  19. Provenance of coals recovered from the wreck of HMAV Bounty

    Energy Technology Data Exchange (ETDEWEB)

    Erskine, N.; Smith, A.H.V.; Crosdale, P.J. [Australian National Maritime Museum, Sydney, NSW (Australia)

    2008-03-15

    Coal samples from HMAV Bounty were analysed using standard techniques to shed light on their provenance. Petrographic analysis indicated they were Carboniferous, with high vitrinite and liptinite content and a mean random reflectance of vitrinite of 0.99%. Palynological analysis indicated the samples were derived from the Middle Coal Measures, Westphalian B. Combining coal rank (vitrinite reflectance), age, knowledge of seam distributions and coalfield history indicates the most like source to be the Durham Coalfield, possibly the Hutton or Low Main Seams. These coals were mined along the valley of the Wear in the latter part of the 18th century.

  20. Study on welded seam recognition using circular laser vision sensor

    Institute of Scientific and Technical Information of China (English)

    Peiquan Xu; Xinhua Tang; Ri Na; Shun Yao

    2007-01-01

    A novel visual robotic arc welding system based on circular laser vision sensor is developed. After image de-noising, image segmentation, and image thinning, the relation of depth value of workpiece and off-axis angle γ, three-dimensional (3D) calculation, and seam tracking experiments are carried out. Finally, the error for seam tracking system is analyzed. The results show that 1) 3D information can be obtained using the proposed visual robotic arc welding system and the real-time seam tracking is realized; 2) the seam tracking error is small enough for gas tungsten arc welding (GTAW) process, and this system can be used for seam location and seam tracking or seam finder.

  1. Investigation on the stress field characteristic of top coal at FMTC faces under the influence of caving thickness

    Institute of Scientific and Technical Information of China (English)

    XIE Guang-xiang; CHANG Ju-cai; YANG Ke

    2007-01-01

    In the background of the technology condition and the geological condition of the 1151(3) fully mechanized top-coal caving face (FMTC face), and by means of taking nonlinear 3D numerical simulation, the stress redistribution rules of top coal with different thick coal seam were obtained by investigation on the numerical simulation of the redistributions of the stress with different coal seam's thickness. The research showes that there exists a certain difference on the stress distributions of the top coal at face, the maximum principal stress is located near to the tailentry's corner. The vertical stress's peak of the top coal decreases and the distance ahead of face position increases as the once mining thickness of the coal seam increases. At the same coal seam, the vertical stresses' peak of top coal gradually decreases from the top to the bottom, the peak's position is basically the same and its changes are gradually obvious with the thickness of coal seam increasing. The vertical stress of top coal places in a low stress state at a certain range ahead of face and over the face, which reveals the essence that the support loads are generally low under the condition of FMTC. The study supplies the theoretical foundation for the support design and selection, the theory of top coal's fragmentation, the movement rules of top coal and improving the recovery of top coal.

  2. Numerical analysis of coal-gas flow and pressure relief on the mining method of extreme short-range protective strata

    Institute of Scientific and Technical Information of China (English)

    LEI Wen-jie

    2008-01-01

    The coal-gas existing condition was ameliorated in the coal seams prone to coal-gas outburst adopting the mining method of protective strata. The gas volume and the gas pressure were reduced synchronously in the protected coal seam, and the coal seam of high permeability prone to the coal-gas outburst was changed into that of low perme-ability with no proneness to the coal-gas outburst. The D15 coal seam was treated as the protective strata, and the D16-17 coal seam was treated as the protected strata in the Fifth coal mine in the Pingdingshan Coal Mining Group. The distance between the two coal seams was 5 m averagely, clarified into the extreme short-range protective strata. The numerical analysis was based on the theory of the porous media flow with the finite ele-ment method. The gas flow process and the change mechanism of the coal-gas pressure were analyzed in the process of mining the protective strata.

  3. CO2 sequestration in deep 'unmineable' coal seams

    International Nuclear Information System (INIS)

    A project to enhance coalbed methane recovery and production at an economic rate by injection of carbon dioxide in Alberta, and to reduce greenhouse gas emissions by subsurface injection of carbon dioxide into coalbeds is discussed. The process is based on ARC's single well carbon dioxide injection micro-pilot at Fenn Big Valley, in central Alberta. It is supported by domestic and international participants; it aims to accurately measure the injection and production behaviour for a single well; estimate reservoir properties and sorption behaviour; calibrate numerical models based on history matching of field data; and forecast expanded pilot or full-field development production. The paper describes the processes involved in primary and carbon dioxide-enhanced coalbed methane recovery mechanisms, the mechanism for nitrogen-enhanced coalbed methane recovery, and discusses the benefits to be derived from using this process, i.e. increased total gas reserves, methane as fuel for power plants, the environmental benefits accruing from using coalbed methane and the disposal of carbon dioxide in geologic sinks. Success in the project will mean reduction in carbon dioxide, the principal culprit in global warming and long-term climate instability

  4. STUDY ON GATEWAY BOLTING EXCAVATED IN INCLINED COAL SEAM

    Institute of Scientific and Technical Information of China (English)

    陶连金; 王泳嘉; 张倬元

    1997-01-01

    A typical gateway is analyzed using fully-deformable discrete element method. The fractured zone around the gateway is measured in field. Based on the measurement results and theoretical analysis, a comprehensive support scheme adopting bolt and steel belt is proposed. Discrete element method is used to assess the bolting scheme, and displacement monitoring in field is also carried out. Having been put into practice, it is proved that the scheme is both successful and rational. According to theoretical analysis and monitoring in field, some importan tkeynotes that should be noticed in gateway bolting practice are presented as well.

  5. Application of fuzzy logic for determining of coal mine mechanization

    Institute of Scientific and Technical Information of China (English)

    HOSSEINI SAA; ATAEI M; HOSSEINI S M; AKHYANI M

    2012-01-01

    The fundamental task of mining engineers is to produce more coal at a given level of labour input and material costs,for optimum quality and maximum efficiency.To achieve these goals,it is necessary to automate and mechanize mining operations.Mechanization is an objective that can result in significant cost reduction and higher levels of profitability for underground mines.To analyze the potential of mechanization,some important factors such as seam inclination and thickness,geological disturbances,seam floor conditions and roof conditions should be considered.In this study we have used fuzzy logic,membership functions and created fuzzy rule-based methods and considered the ultimate objective:mechanization of mining.As a case study,the mechanization of the Tazare coal seams in Shahroud area of Iran was investigated.The results show a low potential for mechanization in most of the Tazare coal seams.

  6. Petrological, organic geochemical and geochemical characteristics of coal from the Soko mine, Serbia

    Energy Technology Data Exchange (ETDEWEB)

    Zivotic, Dragana; Simic, Vladimir [Faculty of Mining and Geology, University of Belgrade, Djusina 7, 11000 Belgrade (RS); Wehner, Herman; Scheeder, Georg; Vidal, Angelika [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Stilleweg 2, 30655 Hannover (Germany); Cvetkovic, Olga; Sajnovic, Aleksandra [Center of Chemistry, IChTM, Studentski trg 16, 11000 Belgrade (RS); Jovancicevic, Branimir [Center of Chemistry, IChTM, Studentski trg 16, 11000 Belgrade (RS); Faculty of Chemistry, University of Belgrade, Studentski trg 16, 11000 Belgrade (RS); Grzetic, Ivan [Faculty of Chemistry, University of Belgrade, Studentski trg 16, 11000 Belgrade (RS); Ercegovac, Marko [Serbian Academy of Sciences and Arts, Knez Mihailova 35,11000 Belgrade (RS)

    2008-02-01

    A petrological, organic geochemical and geochemical study was performed on coal samples from the Soko Mine, Soko Banja basin, Serbia. Ten coal and two carbonaceous clay samples were collected from fresh, working faces in the underground brown coal mine from different parts of the main coal seam. The Lower Miocene, low-rank coal of the Soko Mine is a typical humic coal with huminite concentrations of up to 76.2 vol.%, liptinite less than 14 vol.% and inertinite less than 11 vol.%. Ulminite is the most abundant maceral with variable amounts of densinite and clay minerals. Sporinite and resinite are the most common macerals of the liptinite group. Inertodetrinite is the most abundant maceral of the inertinite group. The mineral-bituminous groundmass identified in some coal samples, and carbonaceous marly clay, indicate sub-aquatic origin and strong bacterial decomposition. The mean random huminite reflectance (ulminite B) for the main coal seam is 0.40 {+-} 0.05% Rr, which is typical for an immature to early mature stage of organic matter. The extract yields from the coal of the Soko Banja basin ranges from 9413 to 14,096 ppm, in which alkanes constituted 1.0-20.1%, aromatics 1.3-14.7%, asphaltenes 28.1-76.2% and resins 20.2-43.5%. The saturated hydrocarbon fractions included n-C{sub 15} to n-C{sub 32}, with an odd carbon number that predominate in almost all the samples. The contents of n-C{sub 27} and n-C{sub 29} alkanes are extremely high in some samples, as a contribution of epicuticular waxes from higher plants. Acyclic isoprenoid hydrocarbons are minor constituents in the aliphatic fraction, and the pristane/phytane (Pr/Ph) ratio varies between 0.56 and 3.13, which implies anaerobic to oxic conditions during sedimentation. The most abundant diterpanes were abietane, dehydroabietane and 16{alpha}(H)-phyllocladane. In samples from the upper part of the coal seam, diterpanes are the dominant constituents of the alkane fraction. Polycyclic alkanes of the triterpane

  7. Forecast and Prevention of Coal and Gas Outbursts in the Case of Application of a New Mining Method - Drilling of a Coal Pillar

    OpenAIRE

    Vlastimil Hudeček; Milan Stoniš

    2010-01-01

    Coal and gas outbursts are one of risk factors accompanying the mining of coal in low seams in the Ostrava-Karviná Coalfield.At the use of the method of longwall mining, all coal reserves have not been mined out owing to tectonic faults. For mining outthe residual reserves, the application of a new mining method - drilling of a coal pillar was proposed.The method of mining of a coal seam utilizing long large diameter boreholes is verified in the Paskov Mine (company OKD, JSC –Czech Republic) ...

  8. Coal in the Mura Formation (Pontian between Lendava (Slovenia and Mursko Središće (Croatia, and in the wider area of NE Slovenia

    Directory of Open Access Journals (Sweden)

    Miloš Markič

    2011-06-01

    Full Text Available Geological setting, occurrences, extent, quality and reserves of coal seams in the Mura Formation of the Mura-Zala Basin in NE Slovenia are presented in the paper. The Mura-Zala Basin consists of antiforms and sinforms bounded by normal and reverse faults. It is filled in its deepest parts by more than 4000 m of clastic sediments from the late lower Miocene upwards. It represents one of the western basins of the Pannonian Basin System. The coal-bearing Mura Formation is of the Pontian age. It is more than 1000 m thick and consists of marls, silts and sands, and of numerous (10–30 beds of brown coal which are relatively thin. The coal-bearing depositional systemis clearly paralic. Original peat-lands developed in freshwater environments while bulk sedimentation in-between(according to paleontological investigations of the Ostracoda microfauna took place under influence of brackishwaters. Well ascertained coal beds are only those in a restricted area (ca. 60 km2 between Lendava (Slovenia andMursko Središće (Croatia, where the coal beds dip almost from the surface (under 10–20 m of Quaternary gravel downwards to depths of not more than 400 m. The whole coal-bearing bed-set in the Lendava area is about 130 m thick but contains only three coal seams which are generally 1.0–2.2 m thick. At the “as received basis” (25–30 %moisture content, 15–20 % ash yield, the net calorific value of the Lendava coal reaches ca. 14.5 MJ/kg, and the average sulphur content is ca. 1.6 %. The Mursko Sredi{}e coal is of a similar quality.Tectonic structure of coal beds is simple and uniform. In the Ormož-Selnica Antiform (which continues to the Budafa – Lovászi Antiform in Hungary, strata inclination follows gentle flanks of this antiform and similar is true for other sinforms and antiforms throughout the Mura-Zala Basin. Several very small collieries were in operationin the area of the Ormož-Selnica Antiform between the 1850s and 1970s. The only a

  9. A Case Study of Damage Energy Analysis and an Early Warning by Microseismic Monitoring for Large Area Roof Caving in Shallow Depth Seams

    Directory of Open Access Journals (Sweden)

    Like Wei

    2015-01-01

    Full Text Available Shallow depth coal seams are widely spread in Shendong mining area, which is located in the Northwestern region of China. When working face is advanced out of concentrated coal pillar in upper room and pillar goaf, strong strata behaviors often cause support crushing accidents, and potentially induce large area residual pillars instability and even wind blast disaster. In order to predict the precise time when the accident happens, guaranteeing life-safety of miner, microseismic monitoring system was for the first time applied in shallow coal seam. Based on damage mechanics correlation theory, the damage energy model is established to describe relationship between damage level and cumulative energy of microseismic events. According to microseismic monitoring data of two support crushing accidents, the damage energy model is verified and an effective early warning method of these accidents is proposed. The field application showed that the early warning method had avoided miners suffering from all support crushing accidents in Shigetai coal mine.

  10. Study on‘‘fracturing-sealing’’ integration technology based on high-energy gas fracturing in single seam with high gas and low air permeability

    Institute of Scientific and Technical Information of China (English)

    Zhang Chao; Lin Baiquan; Zhou Yan; Zhai Cheng; Zhu Chuanjie

    2013-01-01

    To improve the gas extraction efficiency of single seam with high gas and low air permeability, we devel-oped the‘fracturing-sealing’ integration technology, and carried out the engineering experiment in the 3305 Tunliu mine. In the experiment, coal seams can achieve the aim of antireflection effect through the following process:First, project main cracks with the high energy pulse jet. Second, break the coal body by delaying the propellant blasting. Next, destroy the dense structure of the hard coal body, and form loose slit rings around the holes. Finally, seal the boreholes with the‘strong-weak-strong’ pressurized sealing technology. The results are as follows:The average concentration of gas extraction increases from 8.3%to 39.5%. The average discharge of gas extraction increases from 0.02 to 0.10 m3/min. The tunneling speeds up from 49.5 to 130 m/month. And the permeability of coal seams improves nearly tenfold. Under the same conditions, the technology is much more efficient in depressurization and antireflection than common methods. In other words, it will provide a more effective way for the gas extraction of single seam with high gas and low air permeability.

  11. Coal fire interferometry

    International Nuclear Information System (INIS)

    This BCRS project demonstrates the use of SAR interferometry for measuring and monitoring land subsidence caused by underground coal fires and underground mining in a remote area of north west China. China is the largest producer and consumer of coal in the world. Throughout the N.W., N. and N.E. of China, the coal-seams are very susceptible to spontaneous combustion, causing underground coal fires. As the thick coal seams are burned out, the overburden collapses, causing land subsidence, and producing new cracks and fissures, which allow more air to penetrate and continue the fire to spread. SAR interferometry, especially differential interferometry has been shown to be able to measure small differences in surface height caused by such land subsidence. This report describes the problems, the test area, the procedures and techniques used and the results obtained. It concludes with a description of some of the problems encountered during the project plus provides some general conclusions and recommendations. 127 refs

  12. Underground coal gasification. Gasificacion subterranea del carbon

    Energy Technology Data Exchange (ETDEWEB)

    Del Amor, G.; Obis, A. (ITGE, Madrid (Spain))

    1990-07-01

    In spite of the low price of both oil and gas, underground coal gasification is still an attractive option because of the possibility for exploiting coal which it would be uneconomic to mine by conventional methods. New technology has recently made gasification into a reality and methods have been developed to gasify both deep and superficial inclined seams. Recent tests in nearly level seams in the USA have been successful so that the process has become competitive in spite of current oil prices. 3 figs.

  13. Modeling and finite element analysis of the nonstationary action on a multi-layer poroelastic seam with nonlinear geomechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Nasedkina, A.A.; Nasedkin, A.V.; Iovane, G. [Southern Federal University, Rostov Na Donu (Russian Federation)

    2009-07-15

    The paper discusses modeling of a multi-layer coal seam under hydrodynamic action based on the coupled equations of poroelasticity and filtration with the nonlinear relationship of permeability and porous pressure. The calculations by the finite element method use correspondence between the poroelasticity and thermoelasticity equations. The influence of input data on the size of a degassing hole area is analyzed for the couple problem and pure filtration problem.

  14. A Case Study of Damage Energy Analysis and an Early Warning by Microseismic Monitoring for Large Area Roof Caving in Shallow Depth Seams

    OpenAIRE

    Like Wei; Qingxin Qi; Hongyan Li; Bin Zhang; Yongren Wang; Linghai Kong

    2015-01-01

    Shallow depth coal seams are widely spread in Shendong mining area, which is located in the Northwestern region of China. When working face is advanced out of concentrated coal pillar in upper room and pillar goaf, strong strata behaviors often cause support crushing accidents, and potentially induce large area residual pillars instability and even wind blast disaster. In order to predict the precise time when the accident happens, guaranteeing life-safety of miner, microseismic monitoring sy...

  15. Detailed coal exploration in Sungaililin area, South Sumatra, Indonesia (Summary)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    For the purpose of evaluating coal resource in the Sungaililin area located about 100km northwest of Palembang city, South Sumatra, Indonesia, survey was conducted on geology, test boring, chemical analysis, infrastructure, etc. The range of geological survey was about 10km{sup 2}. Test boring was carried out for 51 holes (total length: 3,676.50m). Using 102 coal samples, analysis of coal seams was conducted, and measurement was made of the combustion calorie, sulfur content, water content, gravity, ash, ash melting temperature, etc. Survey was also made on roads for coal transportation, places for barge loading, transshipping ports, etc. The results of the survey/study were as follows. Coal seams suitable for drilling are B seam and C seam, which are continuing and 5-9m thick. As to the quality of coal, they are lower bituminous coal or lignite and are high in water content, low in ash and low in sulfur content. The minable coal reserves are more than 76,000,000 tons, and coal of 3,000 tons/year is minable by the conventional method. They are suitable for the supply to thermal power plants in Indonesia and to neighboring countries. (NEDO)

  16. Underground coal gasification and the ways of their admission

    OpenAIRE

    Beáta Jágerová; Ján Pinka; Mariana Mihočová

    2006-01-01

    Underground Coal Gasification (UCG) is the conversion of coal in the seam into a combustible gas. UCG is conceptually very simple but controlling the reaction and producing a consistent gas quality under a variety of geological and coal conditions is difficult to achieve. The basic concept has two boreholes, one for the injection of oxidants and the other for the removal of the product gas.UCG requires boreholes to access the coal, and three methods have been developed to connect them, namely...

  17. Carbon Dioxide Sorption Capacities of Coal Gasification Residues

    OpenAIRE

    Thomas Kempka; T. Fernandez-Steeger; Li, D.; Schulten, M.; Schlüter, R; B. M. Krooss

    2011-01-01

    Underground coal gasification is currently being considered as an economically and environmentally sustainable option for development and utilization of coal deposits not mineable by conventional methods. This emerging technology in combination with carbon capture and sorptive CO2 storage on the residual coke as well as free-gas CO2 storage in the cavities generated in the coal seams after gasification could provide a relevant contribution to the development of Clean Coal Technologies. Three ...

  18. APPLICATION OF EXPERT SYSTEM BASED ON NEURAL NETWORK IN MINING THE GENTLE INCLINED THICK SEAM

    Institute of Scientific and Technical Information of China (English)

    朱川曲; 施式亮

    1997-01-01

    This paper presents a new method for the correct selection of mining methods and prediction of main technological and economic indexes of the face in the gentle inclined thick seams with the application of the artificial neural network theory and the expert system. The theory analysis and calculating results indicate that the method is reliable, practical and precise. This method has strongly capabilities of self-study and non-linear dynamic data process. It is expected to be widely applied in the policy decision and prediction of mining technology in coal mine.

  19. Controllable theory and applications for the wall bolting reinforcement in the roadway of seam

    Institute of Scientific and Technical Information of China (English)

    TAN Yun-liang; ZHANG Li-jun; XIAO Ya-xun

    2007-01-01

    By using the Radar penetrating technology and numerical simulations, the fractured zone could be easily determined. Both wall fractured zone and mining action of coal seam roadway were considered, and the bolt reinforcing criteria for wall including low limit condition and up limit condition were put up, which supply a basis for the bolt reinforcement design. For a particular engineering, there existed a bolt reinforcing controllable range which can be determined by the method put up in this paper. For the out of controllable range of bolt reinforcement in engineering, it is necessary to seek for other kind reinforcing technology, because the bolt reinforcing technology is not omnipotent.

  20. Cryogenic Testing of Different Seam Concepts for Multilayer Insulation Systems

    Science.gov (United States)

    Johnson, Wesley L.; Fesmire, J. E.

    2009-01-01

    Recent testing in a cylindrical, comparative cryostat at the Cryogenics Test Laboratory has focused on various seam concepts for multilayer insulation systems. Three main types of seams were investigated: straight overlap, fold-over, and roll wrapped. Each blanket was comprised of 40 layer pairs of reflector and spacer materials. The total thickness was approximately 12.5-mm, giving an average layer density of 32 layers per centimeter. The blankets were tested at high vacuum, soft vacuum, and no vacuum using liquid nitrogen to maintain the cold boundary temperature at 77 K. Test results show that all three seam concepts are all close in thermal performance; however the fold-over method provides the lowest heat flux. For the first series of tests, seams were located 120 degrees around the circumference of the cryostat from the previous seam. This technique appears to have lessened the degradation of the blanket due to the seams. In a follow-on test, a 20 layer blanket was tested in a roll wrapped configuration and then cut down the side of the cylinder, taped together, and re-tested. This test result shows the thermal performance impact of having the seams all in one location versus having the seams clocked around the vessel. This experimental investigation indicates that the method of joining the seams in multilayer insulation systems is not as critical as the quality of the installation process.

  1. STUDIES ON THE LAW OF ROOF-COAL MOVEMENT BY USING THE ROOF-COAL CAVING METHOD

    Institute of Scientific and Technical Information of China (English)

    张海戈; 徐秉业; 沈新普; 王志勤

    1996-01-01

    In this paper, the law of roof-coal movement has been investigated through the fieldmeasurement, theoretical analysis and numerical calculation. Several results, which are of im-portant values for caving process, design of the supports, controlling end-face stability, raisingrecovery rate, realizing working face high output and other related aspects in practice, havebeen obtained. These results mainly include the following: roof-coal breaking curve of soft-coalseam, roof-coal movement curve of soft-coal and medium-hard coal seam, and roof-coal move-ment equation. The roof-coal caveability has been analyzed.

  2. Deformation mechanism and control of lower seam roadway of contiguous seams%极近距离煤层下位巷道变形机理及控制

    Institute of Scientific and Technical Information of China (English)

    于洋; 神文龙; 高杰

    2016-01-01

    为了解决极近距离煤层下位巷道围岩维护的难题,以山西蒲县北峪煤矿工程地质条件为背景,通过数值计算研究了极近距离上位煤层采空区下底板岩层的应力分布规律及下位煤层巷道变形破坏特征,确定了下位巷道顶板控制原则,并对不同顶板控制方式进行了现场测试;在此基础上,提出了基于水力膨胀锚杆全长锚固和顶板超前插管法的三维联合控顶技术,并依据力学计算和现场测试结果确定了关键参数。工业性试验表明,研究开发的控制技术对极近距离煤层下位巷道围岩的控制作用显著,巷道整体维护状况良好,给类似条件下的巷道围岩控制提供了有益的参考。%In order to solve the support problem of roadway locating in the lower seam of contiguous coal seams, this paper, taking Beiyu coalmine in Pu County, Shanxi Province as a case, has studied the stress field in the floor of gob belonging to upper seam and characteristics of deformation and instability for roadway locating in lower seam by means of numerical simulation. Principles of ground control for roadway roof in lower seam have been determined and different roof control methods have been tested in field. According to this research, three-dimensional combined roof control techniques based on hy-draulic expansion bolt and advancing insertion of tube on roof have been put forward with corres-ponding key parameters being determined through theoretical analysis and field test. Field test has sug-gested that control techniques raised in this paper are effective for the ground control of roadway in lower seam of contiguous coal seams and the general condition of roadway is good, which has provided great reference value for ground control of roadway in similar conditions.

  3. 极近距离煤层下位巷道变形机理及控制%Deformation mechanism and control of lower seam roadway of contiguous seams

    Institute of Scientific and Technical Information of China (English)

    于洋; 神文龙; 高杰

    2016-01-01

    In order to solve the support problem of roadway locating in the lower seam of contiguous coal seams, this paper, taking Beiyu coalmine in Pu County, Shanxi Province as a case, has studied the stress field in the floor of gob belonging to upper seam and characteristics of deformation and instability for roadway locating in lower seam by means of numerical simulation. Principles of ground control for roadway roof in lower seam have been determined and different roof control methods have been tested in field. According to this research, three-dimensional combined roof control techniques based on hy-draulic expansion bolt and advancing insertion of tube on roof have been put forward with corres-ponding key parameters being determined through theoretical analysis and field test. Field test has sug-gested that control techniques raised in this paper are effective for the ground control of roadway in lower seam of contiguous coal seams and the general condition of roadway is good, which has provided great reference value for ground control of roadway in similar conditions.%为了解决极近距离煤层下位巷道围岩维护的难题,以山西蒲县北峪煤矿工程地质条件为背景,通过数值计算研究了极近距离上位煤层采空区下底板岩层的应力分布规律及下位煤层巷道变形破坏特征,确定了下位巷道顶板控制原则,并对不同顶板控制方式进行了现场测试;在此基础上,提出了基于水力膨胀锚杆全长锚固和顶板超前插管法的三维联合控顶技术,并依据力学计算和现场测试结果确定了关键参数。工业性试验表明,研究开发的控制技术对极近距离煤层下位巷道围岩的控制作用显著,巷道整体维护状况良好,给类似条件下的巷道围岩控制提供了有益的参考。

  4. Coal mining applications of CdTe gamma ray sensors

    Energy Technology Data Exchange (ETDEWEB)

    Entine, G.; Tiernan, T.; Waer, P.; Hazlett, T. (Radiation Monitoring Devices, Inc., Watertown, MA (USA))

    1990-01-01

    Cadmium telluride (CdTe) solid-state radiation detectors have been used in the development of instrumentation that improves the efficiency of coal-mining operations by helping to locate coal seams and preventing the mining of high-sulfur coal near the edges of the seam. CdTe detectors were selected for these applications because while they are small and durable, they offer good stopping power, deliver adequate spectral response and operate at low voltage. These CdTe-based instruments have passed the mine-safety standards and are now in operation in the mine. (author).

  5. Coal mining applications of CdTe gamma ray sensors

    International Nuclear Information System (INIS)

    Cadmium telluride (CdTe) solid-state radiation detectors have been used in the development of instrumentation that improves the efficiency of coal-mining operations by helping to locate coal seams and preventing the mining of high-sulfur coal near the edges of the seam. CdTe detectors were selected for these applications because while they are small and durable, they offer good stopping power, deliver adequate spectral response and operate at low voltage. These CdTe-based instruments have passed the mine-safety standards and are now in operation in the mine. (author)

  6. Effect of Water Invasion on Outburst Predictive Index of Low Rank Coals in Dalong Mine.

    Directory of Open Access Journals (Sweden)

    Jingyu Jiang

    Full Text Available To improve the coal permeability and outburst prevention, coal seam water injection and a series of outburst prevention measures were tested in outburst coal mines. These methods have become important technologies used for coal and gas outburst prevention and control by increasing the external moisture of coal or decreasing the stress of coal seam and changing the coal pore structure and gas desorption speed. In addition, techniques have had a significant impact on the gas extraction and outburst prevention indicators of coal seams. Globally, low rank coals reservoirs account for nearly half of hidden coal reserves and the most obvious feature of low rank coal is the high natural moisture content. Moisture will restrain the gas desorption and will affect the gas extraction and accuracy of the outburst prediction of coals. To study the influence of injected water on methane desorption dynamic characteristics and the outburst predictive index of coal, coal samples were collected from the Dalong Mine. The methane adsorption/desorption test was conducted on coal samples under conditions of different injected water contents. Selective analysis assessed the variations of the gas desorption quantities and the outburst prediction index (coal cutting desorption index. Adsorption tests indicated that the Langmuir volume of the Dalong coal sample is ~40.26 m3/t, indicating a strong gas adsorption ability. With the increase of injected water content, the gas desorption amount of the coal samples decreased under the same pressure and temperature. Higher moisture content lowered the accumulation desorption quantity after 120 minutes. The gas desorption volumes and moisture content conformed to a logarithmic relationship. After moisture correction, we obtained the long-flame coal outburst prediction (cutting desorption index critical value. This value can provide a theoretical basis for outburst prediction and prevention of low rank coal mines and similar

  7. Effect of Water Invasion on Outburst Predictive Index of Low Rank Coals in Dalong Mine.

    Science.gov (United States)

    Jiang, Jingyu; Cheng, Yuanping; Mou, Junhui; Jin, Kan; Cui, Jie

    2015-01-01

    To improve the coal permeability and outburst prevention, coal seam water injection and a series of outburst prevention measures were tested in outburst coal mines. These methods have become important technologies used for coal and gas outburst prevention and control by increasing the external moisture of coal or decreasing the stress of coal seam and changing the coal pore structure and gas desorption speed. In addition, techniques have had a significant impact on the gas extraction and outburst prevention indicators of coal seams. Globally, low rank coals reservoirs account for nearly half of hidden coal reserves and the most obvious feature of low rank coal is the high natural moisture content. Moisture will restrain the gas desorption and will affect the gas extraction and accuracy of the outburst prediction of coals. To study the influence of injected water on methane desorption dynamic characteristics and the outburst predictive index of coal, coal samples were collected from the Dalong Mine. The methane adsorption/desorption test was conducted on coal samples under conditions of different injected water contents. Selective analysis assessed the variations of the gas desorption quantities and the outburst prediction index (coal cutting desorption index). Adsorption tests indicated that the Langmuir volume of the Dalong coal sample is ~40.26 m3/t, indicating a strong gas adsorption ability. With the increase of injected water content, the gas desorption amount of the coal samples decreased under the same pressure and temperature. Higher moisture content lowered the accumulation desorption quantity after 120 minutes. The gas desorption volumes and moisture content conformed to a logarithmic relationship. After moisture correction, we obtained the long-flame coal outburst prediction (cutting desorption) index critical value. This value can provide a theoretical basis for outburst prediction and prevention of low rank coal mines and similar occurrence conditions

  8. A quality problem in seam welds in aluminum extrusion

    Directory of Open Access Journals (Sweden)

    M.S. Keskin

    2007-07-01

    Full Text Available Purpose: Seam welds occur during the hollow profile extrusion; the billet’s material is divided into separate metal streams by the bridges of the die which support a mandrel, and then these metal streams are welded in welding chamber behind the bridges. When the desired conditions have not been provided, the required quality in seam welds may not occur. One of the possible reasons for this situation is a poor metal feed. In this study, an insufficient pressure problem occurring in seam welds on an aluminum extrusion profile section is investigated.Design/methodology/approach: The study was realized on a hollow extrusion profile type which has seam weld zones. The experimental profile was produced by a real extrusion press which has a capacity of 1460 tones.Findings: The poor metal feed occurring on specimen is shown by microstructural pictures. Microstructure of the main region has a homogenous appearance. In the microstructure, containing seam weld region, only a slight change was observed in seam weld region. However, there was no significant change in near of seam weld regions. This points out that there has been no metallurgical problem. Therefore, the problem is an insufficient pressure problem and this caused poor metal feeding. In the other hand, micro hardness tests are realized on seam weld region, main region and defective region’s surround of specimen’s section. After the micro hardness tests important differences are shown among these regions’ strength. Hardness values of seam weld region were lower than the main material’s hardness values, but higher than the defective region’s.Practical implications: In application, seam welds occur on hollow profiles produced by aluminum extrusion.Originality/value: As a result, this study shows a quality problem in seam welds in aluminum extrusion.

  9. Coal properties and mine operational factors that impact gas drainage

    Energy Technology Data Exchange (ETDEWEB)

    Black, D.J.; Aziz, N.I. [Wollongong Univ., Wollongong, NSW (Australia)

    2010-07-01

    Areas of increased gas content, which are difficult to drain, are encountered in many underground coal mines in Australia. Several factors have the potential to influence the overall efficiency and effectiveness of gas drainage from the mined coal seam. This paper reported on a study that was conducted at an operating coal mine in the Bulli seam of Australia's Illawarra coal measures. Gas composition in the mining domain ranged from almost pure methane in the east to almost pure carbon dioxide in the west. Gas production data from many inseam gas drainage boreholes was evaluated relative to a variety of coal properties and mine operational factors to determine their impact on gas production performance. The study showed that although the design of the boreholes and the drainage time had some impact on gas production, the coal properties were found to have the greatest impact. In particular, coal rank, ash content, gas content, seam thickness and gas composition all had an influence on gas production. The total gas in place and degree of saturation had the most significant impact on coal seam gas production performance. Several recommendations were made to optimize gas drainage productivity. 3 refs., 12 figs.

  10. Formation and retention of methane in coal. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hucka, V.J.; Bodily, D.M.; Huang, H.

    1992-05-15

    The formation and retention of methane in coalbeds was studied for ten Utah coal samples, one Colorado coal sample and eight coal samples from the Argonne Premium Coal Sample Bank.Methane gas content of the Utah and Colorado coals varied from zero to 9 cm{sup 3}/g. The Utah coals were all high volatile bituminous coals. The Colorado coal was a gassy medium volatile bituminous coal. The Argonne coals cover a range or rank from lignite to low volatile bituminous coal and were used to determine the effect of rank in laboratory studies. The methane content of six selected Utah coal seams and the Colorado coal seam was measured in situ using a special sample collection device and a bubble desorbometer. Coal samples were collected at each measurement site for laboratory analysis. The cleat and joint system was evaluated for the coal and surrounding rocks and geological conditions were noted. Permeability measurements were performed on selected samples and all samples were analyzed for proximate and ultimate analysis, petrographic analysis, {sup 13}C NMR dipolar-dephasing spectroscopy, and density analysis. The observed methane adsorption behavior was correlated with the chemical structure and physical properties of the coals.

  11. The application of the radon-measuring method in the coal mine geology

    International Nuclear Information System (INIS)

    Radon-Measuring method is a new type technique of nuclear geophysical. By using this technique, hidden fracture, hidden depressed column, empty hollow of old coal pit and growth region of contain water fracture or crevice in bottom of coal seam can be detected in coal mine. The test results have proved that this technique is quick, flexible and economical

  12. Overall requirements for an advanced underground coal extraction system. [environment effects, miner health and safety, production cost, and coal conservation

    Science.gov (United States)

    Goldsmith, M.; Lavin, M. L.

    1980-01-01

    Underground mining systems suitable for coal seams expoitable in the year 2000 are examined with particular relevance to the resources of Central Appalachia. Requirements for such systems may be summarized as follows: (1) production cost; (2)miner safety; (3) miner health; (4) environmental impact; and (5) coal conservation. No significant trade offs between production cost and other performance indices were found.

  13. Nuclear borehole logging techniques for coal quality

    International Nuclear Information System (INIS)

    The progress achieved by nuclear logging in the coal industry has been significant. The 'in-situ' information about coal seams provided by borehole logging can significantly reduce exploration and development costs. Nuclear borehole logging is used routinely in the exploration for coal and is getting more acceptance in the mining stage for quality control. Nuclear borehole logging is used to delineate the coal strata and to determine their thickness, depth, ash content, calorific value and Fe and Si content of ash. Two techniques have been developed in the last 7 years for coal logging in boreholes: (i) The spectrometric gamma-gamma for the determination of ash content in coal; and (ii) the prompt neutron-gamma method for the determination of ash, calorific value, Si and Fe in coal. In this paper both gamma-gamma and neutron-gamma techniques were developed for delineating the coal seams and predicting the ash content in coal. The neutron-gamma technique is superior because it can also determine the Si and Fe content of coal and it can sample a larger volume of coal. The neutron-gamma technique is less affected by the rugosity and condition of the borehole. (author). 6 refs, 5 figs, 2 tabs

  14. Forecast fire damp emission in thin, steep coal bed; Prevision de Desprendimiento de Grisu en Capas Estrechas e Inclindas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    A model to forecast fire damp emission in thin, steep coal bed, mining in advance and backfill works, has been developed and validated. The model estimates the amount of methane released towards the works, including fire damp proceeding from the actually mined seam, as well as methane coming from adjacent seams layers, depending on easy-to find parameters. Methane coming from the mined seam is determined as a function of the methane concentration in the seam and methane from adjacent seams is assessed by the degassification degree. This parameter depends also on the distance to the mined seam. The influence volume of a thin, steep mined coal bed has been determined, in order to study which seams and layers release methane towards the works. The works to develop the methane emission model were done in a coal face on Maria seam, in San Antonio mine, belonging to HUNOSA. The validation works were carried out in 24 left south seam, in the belonging to Minas de Figaredo, S. A. (Author)

  15. SEAM PUCKERING EVALUATION METHOD FOR SEWING PROCESS

    Directory of Open Access Journals (Sweden)

    BRAD Raluca

    2014-07-01

    Full Text Available The paper presents an automated method for the assessment and classification of puckering defects detected during the preproduction control stage of the sewing machine or product inspection. In this respect, we have presented the possible causes and remedies of the wrinkle nonconformities. Subjective factors related to the control environment and operators during the seams evaluation can be reduced using an automated system whose operation is based on image processing. Our implementation involves spectral image analysis using Fourier transform and an unsupervised neural network, the Kohonen Map, employed to classify material specimens, the input images, into five discrete degrees of quality, from grade 5 (best to grade 1 (the worst. The puckering features presented in the learning and test images have been pre-classified using the seam puckering quality standard. The network training stage will consist in presenting five input vectors (derived from the down-sampled arrays, representing the puckering grades. The puckering classification consists in providing an input vector derived from the image supposed to be classified. A scalar product between the input values vectors and the weighted training images is computed. The result will be assigned to one of the five classes of which the input image belongs. Using the Kohonen network the puckering defects were correctly classified in proportion of 71.42%.

  16. Filter properties of seam material from paved urban soils

    Directory of Open Access Journals (Sweden)

    T. Nehls

    2007-08-01

    Full Text Available We studied pavement seam material. This is the soil substrate in joints of pervious pavements in urban areas. It is mostly 1 cm thick and develops from the original seam filling by depositions of all kinds of urban residues, including anthropogenic organic substances. It was investigated, how this unique form of organic matter influences the filter properties of seam material and how the seam material influences heavy metal transport through the pavement. The seam material is characterised by a darker munsell colour, higher organic carbon content, higher surface areas, higher cation exchange capacities, but a lower fraction of high adsorption energy sites compared to the original seam filling. The deposited anthropogenic organic matter itself could be characterised as particulate and non-polar. Compared to natural soils, it has a small surface area and a low surface charge density resulting in a small cation exchange capacity of only 75 cmol(+ kg−1C. The seam material shows stronger sorption of Pb and Cd compared to the original construction sand. The retardation capacity of seam material towards Pb is similar, towards Cd it is much smaller compared to natural soils. The simulated long term displacement scenarios for a street in Berlin do not indicate an acute contamination risk for Pb. For Cd the infiltration from ponds can lead to a displacement of Cd during only one decade.

  17. An explanation of large-scale coal and gas outbursts in underground coal mines: the effect of low-permeability zones on abnormally abundant gas

    OpenAIRE

    F. H. An; Cheng, Y. P.

    2014-01-01

    Large-scale coal and gas outbursts pose a risk of fatal disasters in underground mines. Large-scale outbursts (outburst of coal and rock greater than 500 t) in recent years in China indicate that there is abundant gas in areas of outbursts containing large amounts of potential energy. The adequate sealing properties of the roof and floor of a coal seam are required for local abundant gas around the site of an outburst, but an annular low-permeability zone in a coal seam, whi...

  18. An explanation of large-scale coal and gas outbursts in underground coal mines: the effect of low-permeability zones on abnormally abundant gas

    OpenAIRE

    F. H. An; Cheng, Y. P.

    2013-01-01

    Large-scale coal and gas outbursts post a risk of fatal disasters in underground mines. Large-scale outbursts (outburst of coal and rock greater than 500 t) in recent years in China indicate that there is abundant gas in areas of outbursts containing large amounts of potential energy. The adequate sealing properties of the roof and floor of a coal seam are required for local abundant gas around the site of an outburst, but an annular low-permeability zone in a coal seam, whi...

  19. The influence of particle size on the steam gasification kinetics of coal / Gert Hendrik Coetzee

    OpenAIRE

    Coetzee, Gert Hendrik

    2011-01-01

    Steam gasification has been extensively researched in order to optimise and efficiently utilise coal. Reactivity on powdered coal has received considerable attention, however, due to equipment limitation large coal particle research has not progressed to the same extent. The lack of knowledge regarding the steam gasification reactivity of large coal particles is the main motivation of this study. A South African Highveld seam 4 coal was used in this investigation. Conventional ...

  20. 信息动态%Dual poroelastic response of coal to C02 sequestration

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Geological sequestration of CO2 in coal seams shows great potential to reduce greenhouse gas emissions and has been studied worldwide in recent years. The typical dual-porosity property and organic component of coal together with the liquid state and steady property of C02, as well as methane production make coal seams a promising target.However, the C02 sequestration in coal seams involved a serial of mechanical problems such as coal deformation, the adsorption, seepage and diffusion of gas, which restricted the implement of this technology. Studied the multi-physics system which coupled the coal deformation, gas adsorption, seepage and diffusion equations on the basis of poroelastic medium, theory analysis and numerical simulation, and the following conclusions are obtained.