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Sample records for brown coal seam

  1. 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

  2. Mining vertical coal seams in France

    Energy Technology Data Exchange (ETDEWEB)

    Schneiderman, S.J.

    1981-05-01

    French coal miners in the Lorraine Basin coalfields of Charbonnages de France, work under extremely difficult mining conditions. The coal seams are located in two parallel anticlines dipping to the southwest. On the northwest flanks the coal dips at angles up to 40/sup 0/; on the southeast flanks the coal dips as steep as 90/sup 0/. In addition to the problems associated with steeply dipping coal seams, the coal is often more than 3 meters (10 feet) thick, thus contributing the additional problems that are associated with thick seams. A cut-and-fill mining method is used and production of up to 400 tons per day for a three-shift working face has been achieved. The cut-and-fill mining method employed at Puit Reumaux, rising horizontal rooms with hydraulic stowing, is used in areas of the mine where seam dips exceed 45/sup 0/ and where seam thickness is from 2 to 5 meters (6.5 to 16.5 feet). Hydraulic stowing has many advantages for the Merlebach mine: The coalis located under urbanized areas and is also covered by water-bearing strata with hydraulic sand stowing there is little subsidence, so disturbances to the surface and the aquiferous zones are minimized. Hydraulic sand stowing also helps prevent eating and combustion.

  3. Coal seam clue to Abbeystead disaster

    Energy Technology Data Exchange (ETDEWEB)

    1985-04-01

    The Health and Safety Executive Report on the Abbeystead valve house explosion is critically studied. The body of evidence is examined which suggests that the tunnel could have crossed the line of a coal seam. Coal outcrops, bell pit making suggest that a coal seam following the 99 m contour crosses the tunnel near the Rowton Portal, and hence provided a source of methane. Also the formation of stalactites in the tunnel is discussed. Whether or not these mainly mineral formations can grow under water is a matter of debate. If they cannot then significant voids must have been present.

  4. Economic assessment of utilizing protective properties of level coal seams

    Energy Technology Data Exchange (ETDEWEB)

    Bakhtin, A.F.; Batmanov, Yu.K.; Gainutdinov, I.A.

    1982-12-01

    Increasing mining depth negatively influences mining efficiency and safety. At depths to 600 m 10% of coal comes from seams prone to rock bursts. At depths exceeding 600 m proportion of coal from seams prone to rock bursts increases to 40%. Investigations carried out in Ukrainian coal mines show that coal losses (due to rock burst hazard) in level seams mined by a longwall system amount to 4.6 Mt per year. Cost of rock burst prevention and repairs after rock bursts amounts to 12 million rubles per year. About 68% of coal from level coal seams comes from long coal pillars mined by a longwall system. In level coal seams prone to rock bursts this proportion is 40% lower (proportion of longwall mining is reduced due to increased rock burst hazards). Only 10% of coal seams prone to rock bursts are mined using a system of stress relaxation by cutting another overlying or underlying coal seam (utilizing protective properties of a coal seam). A method for economic analysis of protective properties of coal seams in seam groups is described. Using the method the optimum order of mining coal seams in a seam group is determined. Examples of the method's use are analyzed. (3 refs.) (In Russian)

  5. Mining adjacent inclined coal seams of varying thickness

    Energy Technology Data Exchange (ETDEWEB)

    Batmanov, Yu.K.; Bakhtin, A.F.; Bulavka, E.I.

    1980-01-01

    In the Donbass coal basin a large number of thin coal seams located near other thicker coal seams are left. It is suggested that coal output from the Donbass could be increased by 100% and cost of mining could be lowered by 0.4-1.1 roubles per 1 ton of coal if thinner coal seams were also mined. Mining methods in the Donbass are analyzed from the point of view of reducing the cost of mining and increasing coal production. Recommendations on methods of mining thin inclined coal seams are given. (6 refs.) (In Russian)

  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. Research on New Method of Full-Seam Mining for Gently Inclined Thick Coal Seams

    Institute of Scientific and Technical Information of China (English)

    赵景礼; 郭志飙; 柳慧鹏; 赵立军

    2002-01-01

    The recovery ratio of top-coal caving mining plays a key role in the development of this mining method. For the proposes to raise the recovery ratio and considering heading advance and roadway maintenance, a new method of full - seam mining for gently inclined thick coal seams is put forward on the basis of a theoretic research and engineering practice.

  9. Assessment of reliability and efficiency of mining coal seams located above or below extracted coal seams with support coal pillars. [USSR

    Energy Technology Data Exchange (ETDEWEB)

    Batmanov, Yu.K.; Bakhtin, A.F.; Bulavka, E.I.

    1981-04-01

    Mining thin (under 1.1 m) coal seams located above or below extracted thicker coal seams in which coal support pillars were left is one of the ways of increasing coal output without major investment in Donbass coal mines. It is planned that by 1985 25 thin coal seams will be mined in the Donbass. Investigations show that mining thin coal seams with gradients up to 12 degrees by a system of raise faces without leaving coal pillars is economical using mining systems available at present. This mining scheme is economical also in the case of coal seams located in zones of geologic dislocations. Using integrated mining systems (coal cutter, powered supports and face conveyor) in this coal seams would reduce mining cost from 0.2 to 0.3 rubles/t. Using automated integrated mining systems is economical in working faces with coal output exceeding 900 t/d. (3 refs.) (In Russian)

  10. Prediction of Coal Seam Methane Enriched Areas Using Seismic Data

    Institute of Scientific and Technical Information of China (English)

    CHEN Tong-jun; CUI Ruo-fei; LIU En-ru; LANG Yu-quan

    2006-01-01

    All coal mine disasters are dynamic geological phenomenon and affected by many factors. However, locating the enriched areas of CSM (coal seam methane) may be the precondition for the successful prediction of such disasters. Traditional methods of investigating CSM enriched areas use limited data and only consider a few important factors. Their success rate is low and cannot meet practical needs. In this paper, an alternative method is proposed. The procedure is given as follows: 1) fracture attributes derived from azimuth variations of P-wave data in coal seams and wall rocks can be extracted; 2) AVO attributes, such as the intercept P and gradient G parameters can be extracted from different azimuths from 3D seismic data; 3) seismic cubes can be inverted and the relative attributes of impedance cubes can be extracted; 4) using a GIS platform, multi-source information can be obtained and analyzed; these include fracture attributes of coal seams and wall rocks, the thickness of coal seams, the distribution of faults and structures, the depth of coal seams, the inclination and exposure of coal seams and the coal rank. Through this processing procedure, methane enriched areas can be systematically detected.

  11. 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.

  12. 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.

  13. 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.

  14. Elasto-plastic analysis of collapse pressure for deep coal seam drilling based on Hoek-Brown criterion%基于Hoek-Brown准则的深部煤层钻井坍塌压力弹塑性分析

    Institute of Scientific and Technical Information of China (English)

    张立松; 闫相祯; 杨秀娟; 田中兰; 杨恒林

    2013-01-01

    Elasto-plastic characteristics of deep coal seam at Pingding region in Qinshui Basin was determined under the effect of high confining pressure using triaxial compression test. Taking Hoek-Brown criterion as the limit equilibrium condition, elasto-plastic calculation method of collapse pressure for deep coal seam was derived based on plastic zone radius, and influence factors which control wellbore collapse were obtained, including Geologic Strength Index ( GSI) , non-uniform stress coefficient and engineering allowable plastic zone radius. Taking CBM well PD-095 in Pingding region as an example, the elasto-plastic results of collapse pressure were compared with elastic results, and the relationship between collapse pressure and influence factors was analyzed. The results show that the elasto-plastic results of collapse pressure decrease 6. 52% ,4. 66% than the elastic results of Hoek-Brown criterion and Mohr-Coulomb criterion when the plastic zone radius is 1. 5 times of wellbore radius;the elasto-plastic results of collapse pressure decrease with the increment of plastic zone radius and the descendent of the stress non-uniform; minus power function relationship between the collapse pressure and the GSI value is presented.%利用三轴压缩实验确定了沁水盆地平定区块深部煤岩在高围压条件下的弹塑性特征.以Hoek-Brown准则为极限平衡条件,提出了基于工程允许塑性区半径的深部煤层井眼坍塌压力弹塑性计算方法,得到控制深部煤层井壁坍塌的主要参数:煤岩地质强度指标GSI值、非均匀地应力系数及工程允许塑性区半径.以平定区块PD-095井为例,分析了深部煤层坍塌压力弹塑性结果与弹性结果的差别,讨论了坍塌压力弹塑性结果随影响因素的变化规律.结果表明,当工程允许塑性区半径为井眼半径的1.5倍时,PD-095井坍塌压力弹塑性结果较Hoek-Brown准则、Mohr-Cou-lomb准则弹性结果分别降低6.52%,4.66%;随着

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. 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.

  1. 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...

  2. 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.

  3. Study on ascending mining roadway layout of close distance coal seams in deep mine

    Institute of Scientific and Technical Information of China (English)

    SHI Yong-kui; MO Ji

    2007-01-01

    To solve the problems appeared in mining process of No.2 seam, the ascending stress-releasing mining method was adopted. Studying on the reasonable layout of actual mining roadway in upper coal seams is the precondition of successful ascending mining.By using "device of leak measuring by blocking up double ends", it detected the height of overburden water flowing fractured zone originated from sub-coal seams mining. Thus it proved that the actual mining roadway of No.2 upper ascending seam was located in the smooth sagging zone. On the basis of analyzing the stress-releasing effect of sub-coal seams mining to upper coal seams by using RFPA software, it analyzed the stability of up-face coal seams and the reasonable location of starting cut in up-face coal seams. It also analyzed the reasonable gateway location in upper coal seams, which ensured the crossheading in upper coal seams out of the effect of sub-coal work face mining by using theory of underground pressure. Meanwhile, the reasonable pillars dimensions in upper coal seams by building the structure mechanics model of stope were researched. It can make the roadway driven along next goaf to be located in low stress zone, and be beneficial to keeping roads stable owing to less stress of surrounding rock. Finally, it tested the rationality of the layout method of roads in upper coal seams by engineering field measurement in 3221 working face.

  4. Process for the extraction of thick coal seams

    Energy Technology Data Exchange (ETDEWEB)

    Barsi, K.; Salamon, H.; Solymos, A.; Takacs, J.; Toth, I.

    1983-08-23

    There is disclosed a process for the extraction of thick coal seams by means of which coal seams not extractable in one bank or slice and/or located at peripheral areas may also be extracted under improved mine safety conditions and with high productivity. According to the invention the thick coal seam is if required, divided horizontally and/or vertically into extraction blocks which are bounded and separated by stowing pillars arranged according to the direction of advance of the extraction. The cavity of the pillars is advanced at a level higher than the level of the roof of the extraction space, after which the cavity of the pillar is back-filled. Then the block is extracted by means of block caving in a manner known per se. In a preferred embodiment of the invention incombustible material that agglomerates under the effect of the static pressure of the rock is used for stowing. The utilization of the process for extraction according to the invention results in a considerable increase of intensity. Whether the extraction is in one or more slices and whether using individual self-advancing supports, using track-bound or independent loading/conveyor equipment, an economic extraction of coal seams is achieved.

  5. PHYSICAL SIMULATION AND ANALYSIS OF METHANE TRANSPORT IN COAL SEAM

    Institute of Scientific and Technical Information of China (English)

    罗新荣; 俞启香

    1994-01-01

    This paper studies the effect of ground stress, pore gas pressure and adsorbed methane on methane transport in coal seam, and researches into the applicability of Darcy's law to methane transport. The additional expansion stress of coal induced by adsorbed methane is measured. The paper establishes the constitutive equation of methane transport, taking ground stress, pore gas pressure and Klinkcnburg's effects into considcration, The features of methane transport under the condition of given stress or strain have been analyzed.

  6. 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 ...

  7. 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...

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

    Directory of Open Access Journals (Sweden)

    Gökhan AYDIN

    2009-01-01

    Full Text Available 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 this study, the utilization technologies of methane are defined in detail and the examples being in practice are given.

  9. Thick seam coal mining - Collinsville. [Queensland

    Energy Technology Data Exchange (ETDEWEB)

    Richards, O.J.; O' Beirne, T.

    1982-01-01

    After model tests and mathematical modelling, field trials of a slicing system using a modified Wongawilli system of pillar extraction are being carried out. Continuous miners extract the coal. Extraction of up to 75% of the coal is possible in good geological conditions.

  10. 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.

  11. 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

  12. 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

  13. Coal and rock fissure evolution and distribution characteristics of multi-seam mining

    Institute of Scientific and Technical Information of China (English)

    Zhang Dongming; Qi Xiaohan; Yin Guangzhi; Zheng Binbin

    2013-01-01

    Henan Pingdingshan No.10 mine is prone to both coal and gas outbursts. The E9-10 coal seam is the main coal-producing seam but has poor quality ventilation, thus making it relatively difficult for gas extraction. The F15 coal seam, at its lower section, is not prone to coal and gas outbursts. The average seam separa-tion distance of 150 m is greater than the upper limit for underside protective seam mining. Based on borehole imaging technology for field exploration of coal and rock fracture characteristics and discrete element numerical simulation, we have studied the evolution laws and distribution characteristics of the coal and rock fissure field between these two coal seams. By analysis of the influential effect of group F coal mining on the E9-10 coal seam, we have shown that a number of small fissures also develop in the area some 150 m above the overlying strata. The width and number of the fissures also increase with the extent of mining activity. Most of the fissures develop at a low angle or even parallel to the strata. The results show that the mining of the F15 coal seam has the effect of improving the permeability of the E9-10 coal seam.

  14. Gas drainage technology of high gas and thick coal seam

    Institute of Scientific and Technical Information of China (English)

    HE Tian-cai; LI Hai-gui; ZHANG Hai-jun

    2009-01-01

    Gas drainage in Jincheng Mining Group Co., Ltd. was introduced briefly and the importance of gas drainage in gas control was analyzed. Combined with coal-bed gas oc-currence and gas emission, the double system of gas drainage was optimized and a pro-gressive gas drainage model was experimented on. For guaranteed drainage, excavation and mining and realization of safety production and reasonable exploitation of gas in coal seams, many drainage methods were adopted to solve the gas problem of the working face.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. The migration law of overlay rock and coal in deeply inclined coal seam with fully mechanized top coal caving.

    Science.gov (United States)

    Liu, Jian; Chen, Shan-Le; Wang, Hua-Jun; Li, Yu-Cheng; Geng, Xiaowei

    2015-07-01

    In a mine area, some environment geotechnics problems always occure, induced by mined-out region such as the subsidence and cracks at ground level, deformation and destruction of buildings, landslides destruction of water resources and the ecological environment. In order to research the migration of surrounding rock and coal in steeply inclined super high seams which used fully mechanized top coal caving, a working face of a certain mine was made as an example, analyzed the migration law of the overlay rock and coal under different caving ratio of fully mechanized top coal caving with numerical simulation analysis. The results suggest that the laws of overlay rock deformation caused by deeply inclined coal seam were different from horizontal coal seam. On the inclined direction, with an increase of dip angle and caving ratio, the vertical displacement of overlay rock and coal became greater, the asymmetric phenomenon of vertical displacement became obvious. On the trend direction, active region and transition region in goaf became smaller along with the increase of mining and caving ratio. On the contrary, the stable region area became greater. Therefore, there was an essential difference between the mechanism of surface movement deformation with deeply inclined coal seam and that with horizontal coal seam.

  20. 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.

  1. 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.

  2. 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.

  3. 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%.

  4. 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.

  5. 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...

  6. 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

  7. 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.

  8. Calculation of gas content in coal seam influenced by in-situ stress grads and ground temperature

    Institute of Scientific and Technical Information of China (English)

    王宏图; 李时雨; 吴再生; 杨晓峰; 秦大亮; 杜云贵

    2002-01-01

    On the basis of the analysis of coal-bed gas pressure in deep mine, and the coal-bed permeability (k) and the characteristic of adsorption parameter (b) changing with temperature, the author puts forward a new calculating method of gas content in coal seam influenced by in-situ stress grads and ground temperature. At the same time, the contrast of the measuring results of coal-bed gas pressure with the computing results of coal-bed gas pressure and gas content in coal seam in theory indicate that the computing method can well reflect the authenticity of gas content in coal seam,and will further perfect the computing method of gas content in coal seam in theory,and have important value in theory on analyzing gas content in coal seam and forecasting distribution law of gas content in coal seam in deep mine.

  9. 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.

  10. Gas seepage equation of deep mined coal seams and its application

    Institute of Scientific and Technical Information of China (English)

    HU Guo-zhong; WANG Hong-tu; TAN Hai-xiang; FAN Xiao-gang; YUAN Zhi-gang

    2008-01-01

    In order to obtain a gas seepage law of deep mined coal seams, according to the properties of eoalbed methane seepage in in-situ stress and geothermal temperature fields, the gas seepage equation of deep mined coal seams with the Klinkenberg effect was obtained by confirming the coalbed methane permeability in in-situ stress and geothermal temperature fields. Aimed at the condition in which the coal seams have or do not have an outcrop and outlet on the ground, the application of the gas seepage equation of deep mined coal seams in in-situ stress and geothermal temperature fields on the gas pressure calculation of deep mined coal seams was investigated. The comparison between calculated and measured results indicates that the calculation method of gas pressure, based on the gas seepage equation of deep mined coal seams in in-situ stress and geothermal temperature fields can accurately be identical with the measured values and theoretically perfect the calculation method of gas pressure of deep mined coal seams.

  11. 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.

  12. A method of working a coal seam which has coal and gas outbursts

    Energy Technology Data Exchange (ETDEWEB)

    Batmanov, Y.K.; Bakhtin, A.F.; Mochseev, M.A.; Petukhov, I.M.; Saratikyants, S.A.; Voronin, V.A.

    1983-01-01

    The purpose of this invention is to reduce expenditures on the working of an outburst-prone formation. This is achieved by using the method of working a coal seam which is prone to coal and gas outbursts; this method involves local safety excavation in the protection formation and opening air passage and ventilation workings; the ventilation working proceeds through the formation which is prone to gas and coal outbursts, while the local protection excavation in the protection formation is performed on both sides of the air passage working simultaneously with the ventilation working which is connected occasionally to the air passage working by blind shafts.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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...

  18. Stimulation of commercial coal seam methane production aimed at improving mining technology

    Science.gov (United States)

    Shubina, E. A.; Lukyanov, V. G.

    2016-09-01

    The relevance of the current research is due to the urgent need to revise the existing normative bases and procedures involved in intensive development of coal-methane deposits and commercial production of coal seam methane. The article presents the analysis of data on coal production volume and amount of methane emitted into the atmosphere in Kuzbass. There is a need to develop the exploration techniques that would allow implementing pre-mining gas drainage of coal seams and provide the companies with the guidance on coal seam methane drainage in very gassy coal mines. Commercial production of methane should become an integral part of economy and energy balance of the Russian Federation, which, in its turn, would enhance environmental protection due to reducing methane emissions, the largest source of greenhouse effect.

  19. New development of longwall mining equipment based on automation and intelligent technology for thin seam coal

    Institute of Scientific and Technical Information of China (English)

    Guo-fa WANG

    2013-01-01

    The paper introduced complete sets of automatic equipment and technology used in thin seam coal face,and proposed the comprehensive mechanization and automation of safe and high efficiency mining models based on the thin seam drum shearer.The key technology of short length and high power thin seam drum shearer,and new type roof support with big extension ratio and plate canopy were introduced.The new research achievement on automatic control system of complete sets of equipment for the thin seam coal,which composed of electronic-hydraulic system,compact thin seam roof supports,high effective shearer with intelligent control system,and characterized by automatical follow-up and remote control technology,was described in this paper..

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. Law of surface movement for multi-coal seam strip mining 

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-ya; ZHANG Hong-mei

    2014-01-01

    It is an important part of green mining to control the disasters of coal mining which have caused irreversible damages to buildings and ecological environment. Strip mining is one of the efficient measures to control surface subsidence and mining damage. However, the research on the laws of the surface subsidence are still deficient in multi-coal seam strip mining at present. Based on the Fast Lagrangian Analysis of Continua (short for FLAC3D) numerical simulation software, the laws of the surface subsidence and horizontal movement were systematically studied for different depths, different mining widths, different distances between seams, different mining thickness, different parameters between seams and the special relations of the upper pillar and the lower pillar in the vertical direction in multi-seam strip mining. The function relation between the maximum subsidence and the maximum horizontal movement with the depth, the mining width, the seam distance, mining thickness, different parameters between seams and the partial offset are summarized respectively. Finally the formula integrating the surface maximum subsidence value and the maximum horizontal movement was deduced. The results can be used for reference theory and measure in forecasting the surface displacement in multi-coal seam strip mining.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. Applicable conditions for a classification system of aquifer-protective mining in hallow coal seams

    Institute of Scientific and Technical Information of China (English)

    Liu Yude; Zhang Dongsheng; Fan Gangwei; Yan Shoufeng

    2011-01-01

    Based on the conclusions of domestic and foreign research,we have analyzed the collapse-fall characteristics of overlying strata and the mechanism of aquifer-protective mining in shallow coal seam working faces at the Shendong Mine.We have selected the height of the water-conducting fracture zone in overlying strata as a composite index and established the applicable conditions of aquifer-protective mining in shallow coal seams with a multi-factor synthetic-index classification method.From our calculations and analyses of variance,we used factors such as the overlying strata strength,mining disturbing factors and rock integrity as related factors of the composite index.We have classified the applicable conditions of aquifer-protective mining in shallow coal seams into seven types by comparing the result of the height of water-conducting fractured zones of long-wall and short-wall working faces with the thickness of the bedrock.the thickness of the weathered zone and the size of safety coal-rock pillars.As a result,we propose the preliminary classification system of aquifer-protective mining in shallow coal seams.It can provide a theoretical guidance for safe applications of aquifer-protective mining technology in shallow coal seams under similar conditions.

  10. 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.

  11. 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.

  12. 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.

  13. Polymer Drilling Fluid with Micron-Grade Cenosphere for Deep Coal Seam

    Directory of Open Access Journals (Sweden)

    Peng Xu

    2015-01-01

    Full Text Available Traditional shallow coal seam uses clean water, solid-free system, and foam system as drilling fluid, while they are not suitable for deep coal seam drilling due to mismatching density, insufficient bearing capacity, and poor reservoir protection effect. According to the existing problems of drilling fluid, micron-grade cenosphere with high bearing capacity and ultralow true density is selected as density regulator; it, together with polymer “XC + CMC” and some other auxiliary agents, is jointly used to build micron-grade polymer drilling fluid with cenosphere which is suitable for deep coal seam. Basic performance test shows that the drilling fluid has good rheological property, low filtration loss, good density adjustability, shear thinning, and thixotropy; besides, drilling fluid flow is in line with the power law rheological model. Compared with traditional drilling fluid, dispersion stability basically does not change within 26 h; settlement stability evaluated with two methods only shows a small amount of change; permeability recovery rate evaluated with Qinshui Basin deep coal seam core exceeds 80%. Polymer drilling fluid with cenosphere provides a new thought to solve the problem of drilling fluid density and pressure for deep coal seam drilling and also effectively improves the performance of reservoir protection ability.

  14. Principle and engineering application of pressure relief gas drainage in low permeability outburst coal seam

    Institute of Scientific and Technical Information of China (English)

    LIU lin; CHENG Yuan-ping; WANG Hai-feng; WANG Liang; MA Xian-qin

    2009-01-01

    With the increase in mining depth, the danger of coal and gas outbursts increases. In order to drain coal gas effectively and to eliminate the risk of coal and gas outbursts, we used a specific number of penetration boreholes for draining of pressure relief gas. Based on the principle of overlying strata movement, deformation and pressure relief, a good effect of gas drainage was obtained. The practice in the Panyi coal mine has shown that, after mining the Cllcoal seam as the protective layer, the relative expansion deformation value of the protected layer C13 reached 2.63%, The permeability coefficient increased 2880 times, the gas drainage rate of the C13 coal seam increased to more than 60%, the amount of gas was reduced from 13.0 to 5.2 m3/t and the gas pressure declined from 4.4 to 0.4 MPa, which caused the danger the outbursts in the coal seams to be eliminated. The result was that we achieved a safe and highly efficient mining operation of the C 13 coal seam.

  15. 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.

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

    Institute of Scientific and Technical Information of China (English)

    A.M. Suchowerska Iwanec; J.P. Carter; J.P. Hambleton

    2016-01-01

    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.

  17. 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.

  18. 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…

  19. 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

  20. Assessment of uncertainty and degasification efficiency in coal seam gas drainage through stochastic reservoir simulation

    Science.gov (United States)

    Özgen Karacan, C.

    2016-04-01

    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 bed reservoir simulation, as a reservoir management and forecasting tool, is one of the most effective ways to help with these two main objectives. However, as in all modeling and simulation studies, reservoir description and whether observed productions can be predicted are important considerations. Using geostatistical realizations as spatial maps of different coal reservoir properties is a more realistic approach than assuming uniform properties across the field. In fact, this approach can help with simultaneous history matching of multiple wellbores to enhance the confidence in spatial models of different coal properties that are pertinent to degasification. The problem that still remains, however, is the uncertainty in geostatistical, and thus reservoir, simulations originating from partial sampling of the seam that does not properly reflect the stochastic nature of coal property realizations. This study demonstrates the use of geostatistical realizations generated through sequential Gaussian simulation and co-simulation techniques and assesses the uncertainty in coal seam reservoir simulations with history matching errors. 100 individual realizations of 10 coal properties were generated using geostatistical techniques. These realizations were used to create 100 realization bundles (property datasets). Each of these bundles was then used in coal seam reservoir simulations for simultaneous history matching of degasification wells. History matching errors for each bundle were evaluated and the single set of realizations that would minimize the error for all wells was defined. Errors were compared with those of E-type and the average realization of the best matches. The study helped to determine the realization bundle that consisted of the spatial maps of coal properties, which resulted in minimum error. In

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Design and trial of a multi lift Wongawilli mining method for thick coal seams. [Australia

    Energy Technology Data Exchange (ETDEWEB)

    O' Beirne, T.J.

    1981-01-01

    The Australian Coal Industry Research Laboratories (ACIRL) designed a system of mining coal seams over 5 m thick with near complete extraction using a multi-slice Wongawilli operation. As conceived, the seam was divided into three slices with the top slice worked first and the bottom slice following some distance behind. During retreat of the bottom slice the middle section would be cut down with the raised head of the continuous miner. Field trials began at Collinsville, Australia, in 5.4 m thick seam in July 1978 and ceased in August 1981. Details of the original model are presented, and the performance under field conditions is assessed. The applications and limitations of the system are assessed. (16 refs.)

  6. Adsorption-induced coal swelling and stress: Implications for methane production and acid gas sequestration into coal seams

    Science.gov (United States)

    Cui, Xiaojun; Bustin, R. Marc; Chikatamarla, Laxmi

    2007-10-01

    Sequestration of CO2 and H2S into deep unminable coal seams is an attractive option to reduce their emission into atmosphere and at the same time displace preadsorbed CH4 which is a clean energy resource. High coal seam permeability is required for efficient and practical sequestration of CO2 and H2S and recovery of CH4. However, adsorption of CO2 and H2S into coals induces strong swelling of the coal matrix (volumetric strain) and thus reduces significantly coal permeability by narrowing and even closing fracture apertures. Our experimental data on three western Canadian coals show that the adsorption-induced volumetric strain is approximately linearly proportional to the volume of adsorbed gas, and for the same gas, different coals have very similar volumetric strain coefficient. Impacts of adsorption-induced swelling on stress and permeability around wellbores were analytically investigated using our developed stress and permeability models. Our model results indicate that adsorption-induced volumetric strain has significant controls on stress and permeability of producing and sequestrating coal seams and consequently the potential of acid gas sequestration. Coal seams may undergo >10 times enhancement of permeability around CH4-producing wellbores due to a reduction in effective stress as a result of coal shrinking caused by methane desorption accompanying a reduction in reservoir pressure. Injection of H2S and CO2 on the other hand results in strong sorption-induced swelling and a marked increase in effective stress which in turn leads to a reduction of coal seam permeability of up to several orders of magnitude. Injection of mixtures of N2 and CO2 such as found in flue gas results in weaker swelling, the amount of which varies with gas composition, and provides the greatest opportunity of sequestering CO2 and secondary recovery of CH4 for most coals. Because of the marked swelling of coal in the presence of H2S, even minor amounts of H2S result in a marked

  7. Determining areas in an inclined coal seam floor prone to water-inrush by micro-seismic monitoring

    Institute of Scientific and Technical Information of China (English)

    Sun Jian; Wang Lianguo; Wang Zhansheng; Hou Huaqiang; Shen Yifeng

    2011-01-01

    The failure depth of the coal seam floor is one important consideration that must be kept in mind when mining is carried out above a confined aquifer. Determining the floor failure depth is the essential precondition for predicting the water-resisting ability of the floor. We have used a high-precision microseismic monitoring technique to overcome the limited amount of data available from field measurements. The failure depth of a coal seam floor, especially an inclined coal seam floor, may be more accurately estimated by monitoring the continuous, dynamic failure of the floor. The monitoring results indicate the failure depth of the coal seam floor near the workface conveyance roadway (the lower crossheading) is deeper and that the failure range is wider here compared to the coal seam floor near the return airway (the upper crossheading). The results of micro-seismic monitoring show that the dangerous area for water-inrush from the coal seam floor may be identified. This provides an important field measurement that helps ensure safe and highly efficient mining of the inclined coal seam above the confined aquifer at the Taoyuan Coal Mine.

  8. Innovations in the field of brown coal beneficiation

    Energy Technology Data Exchange (ETDEWEB)

    Scholz, G.; Brandt, H.; Weidlich, G. (Gaskombinat Fritz Selbmann, Schwarze Pumpe (German Democratic Republic))

    1990-03-01

    Summarizes technological research achievements of the GDR brown coal industry over the past decade. In the field of brown coal combustion, improved swirl burners and swirl ignition burner types were put into operation in coal power plants. Furthermore, a fluidized bed coal predrying chamber at a low-grade fuel combusting power plant was tested, for increasing the calorific value of coal feed in by-pass operation, thus stabilizing steam generator combustion if coal quality reaches low limits. In the field of brown coal gasification, the GSP pulverized brown coal gasification process is commercially employed in a generator with 30 t/h coal throughput and 50,000 m{sup 3}/h gas production. Furthermore, a process for producing high quality brown coal coke for blast furnaces has been developed that requires brown coal dust and HSC-ROSE pitch (waste product of petroleum processing) as binder. Other achievements include production of activated carbon at low cost from the processing of brown coal coke and development of computer-based monitoring and operation control equipment for brown coal gasification. 12 refs.

  9. Installed capacity of coal seam gas power generation exceeds 480 MW under SGCC s coverage

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The journalist learned from the "National Gas Security Working Conference" held recently that the coal seam gas power generation has been rapidly developed in recent years.As of July 2009,within the SGCC's business area,the power generation units

  10. 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.

  11. 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.

  12. Comparison of outburst danger criteria of coal seams for acoustic spectral and instrumental forecast methods

    Science.gov (United States)

    Shadrin, A. V.; Bireva, Yu A.

    2016-10-01

    Outburst danger criteria for the two methods of current coal seam outburst forecast are considered: instrumental - by the initial outgassing rate and chippings outlet during test boreholes drilling, and geo-physical - by relation of high frequency and low frequency components of noise caused by cutting tool of operating equipment probing the face area taking into consideration the outburst criteria correction based on methane concentration at the face area and the coal strength. The conclusion is made on “adjustment” possibility of acoustic spectral forecast method criterion amended by control of methane concentration at the coal face and the coal strength taken from the instrumental method forecast results.

  13. 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

  14. 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.

  15. 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

  16. Element geochemistry and cleaning potential of the No. 11 coal seam from Antaibao mining district

    Institute of Scientific and Technical Information of China (English)

    WANG; Wenfeng; QIN; Yong; SONG; Dangyu; SANG; Shuxun; JIAN

    2005-01-01

    Based on the analyses of sulfur and 41 other elements in 8 channel samples of the No. 11 coal seam from Antaibao surface mine, Shanxi, China and 4 samples from the coal preparation plant of this mine, the distribution of the elements in the seam profile, their geochemical partitioning behavior during the coal cleaning and the genetic relationships between the both are studied. The conclusions are drawn as follows. The coal-forming environment was probably invaded by sea water during the post-stage of peatification, which results in the fact that the contents of As, Fe, S, etc. associated closely with sea water tend to increase toward the top of the seam, and that the kaolinite changes into illite and montmorillonite in the coal-sublayer near the roof. These elements studied are dominantly associated with kaolinite, pyrite, illite, montmorillonite, etc., of which the As, Pb, Mn, Cs, Co, Ni, etc. are mainly associated with sulfides, the Mo, V, Nb, Hf, REEs, Ta etc. mainly with kaolintie, the Mg, Al etc. mainly with epigenetic montmorillonite, and the Rb, Cr, Ba, Cu, K, Hg, etc. mainly with epigenetic illite. The physical coal cleaning is not only effective in the removal of ash and sulfur, but also in reducing the concentration of most major and trace elements. The elements Be, U, Sb, W, Br, Se, P, etc. are largely or partly organically bound showing a relatively low removability, while the removability of the other elements studied is more than 20%, of which the Mg, Mn, Hg, Fe, As, K, Al, Cs, and Cr associated mostly with the coarser or epigenetic minerals show a higher removability than that of ash. The distribution of the elements in the seam profile controls their partitioning behavior to a great degree during the coal cleaning processes.

  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. Study on the non-linear forecast method for water inrush from coal seam floor based on wavelet neural network

    Institute of Scientific and Technical Information of China (English)

    ZHOU Rong-yi; LIU Ai-qun; LI Shu-qing

    2007-01-01

    Directing at the non-linear dynamic characteristics of water inrush from coal seam floor and by the analysis of the shortages of current forecast methods for water inrush from coal seam floor,a new forecast method was raised based on wavelet neural network(WNN)that was a model combining wavelet function with artificiaI neural network.Firstly basic principle of WNN was described.then a forecast model for water inrush from coal seam floor based on WNN was established and analyzed,finally an example of forecasting the quantity of water inrush from coal floor was illustrated to verify the feasibility and superiority of this method.Conclusions show that the forecast result based on WNN is more precise and that using WNN model to forecast the quantity of water inrush from coal seam floor is feasible and practical.

  19. 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.

  20. 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.

  1. A New Accumulation Model of Coal Seams in France Extensional Basins

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper, based on the sedimentary features of the coal seams in the typical extensional (faulted) coal basins between two inland mountainous areas of the Central Massif (France) deals with the accumulation mechanism and the corresponding sedimentary-tectonic conditions of these thick coalbeds, and proposes a new coal accumulation model for the inland lacustrine-basin thick coalbeds. The presence of a great number of gravity-flow sediments such as detrital flow, diluted slurry flow or turbidity-current sediments in the coal seams, and that of the contemporaneous gravity slump and deformation structure in the coal seam itself bath indicate that thelacustrine environment in the accumulation of the thick coalbeds was characterized by the relatively deep flood and violent sedimentation. This model can not only interpret reasonably the accumulation mecha nism of the thick coalbeds developed in the fault basins in the Central Massif, France, but also show its features distinctively from those of the accumulation model of the traditional thick coalbeds.

  2. 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.

  3. Dynamic destabilization analysis based on AE experiment of deep-seated, steep-inclined and extra-thick coal seam

    Institute of Scientific and Technical Information of China (English)

    Fenhua Ren; Xingping Lai; Meifeng Cai

    2008-01-01

    No. 5 coal seam in Huating Coal Mine is a deep-seated, steep-inclined extra-thick coal seam where excavation disturbance is quite frequent. The maximum and minimum principal stresses differ widely. During mining, dynamical destabilization happens frequently and induce tragedies. Based on the comparison between the acoustic emission (AE) experiment on dynamical destabilization of coal rock and the related in situ testing results, this article provides comprehensive analysis on the regular quantificational AE patterns (energy rate, total events) of coal rock destabilization in complex-variable environment. The comparison parameters include dynamic tension energy rate, deformation resistance to compression, and shear stress.

  4. 论煤层的加积方式%On Accreation Pattern of Coal Seams

    Institute of Scientific and Technical Information of China (English)

    赵万福

    2012-01-01

    The origin of coal seams is the kernel of coal geology. Coal seam is a kind of sedimentary stratum, it adheres to the basic principles of the sedimentology, stratigraphy, petrology and study of ore deposits, but still has its particularity, and its origin differs from origin of coal. Classic kernel viewpoint of coal geology is coal seam evolving from peat bog; its essence is vertical accretion of coal-forming material. Through coal seam vertical and lateral accretions contrastive analyses and large area stable distributed thick coal seam low gamma-ray multi-crest phenomenon, sedimentary features of bedding and banded structure studies have considered that the coal-forming material is mechanically deposited, while coal seam likes most sedimentary strata is laterally accreted. As to thick coal seams, multi -stage lateral accretions bring on secondary vertical accretions; their formation process is not a simple, consecutive, linear vertical progressive process, but a rather complicated, inconsecutive, nonlinear lateral superimposed process. Coal-forming material is inconsecutive, multi -staged and multi -sourced, ubiquitous parting in thick coal seams is the evidence of inconsequence, moreover, thick coal seams are diachronous. Coal seam lateral accretion coexisting with deeper water or marine deposit, which is an organically consecutive en bloc, in harmony with Walther's law of facies, principle of paleoecology, in harmony with coal seam thickness, changeable configuration, many and varied underlying sedimentary systems, also in harmony with coalforming material super huge industrial enrichment, coal-bearing strata gray, grayish black in color and coal deposit high quality facts.%煤层成因是煤地质学的核心.煤层是一种沉积地层,它遵循沉积学、地层学、岩石学以及矿床学的基本规律,也有其特殊性,其成因并不同于煤的成因.传统煤地质学的核心观点是煤层由泥炭沼泽演化而成,其本质就是成煤物质的

  5. 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

  6. 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 stress

  7. The effect of the fracture distribution on CO2 injection into a coal seam

    Institute of Scientific and Technical Information of China (English)

    Yao Banghua; Wu Yu; Liu Jishan

    2012-01-01

    The effect of the fracture distribution on CO2 injection into coal seams was studied with a heterogeneous model having dual porosity to represent both the primary medium (the coal matrix) and the secondary medium (the fractures) under variable stress conditions.A numerical generation method and a digital image processing method were used to model the heterogeneous fracture distribution in the coal.The model solutions demonstrate that:(1) the fractures are the main channel for gas flow and their distribution has an important impact on the gas injection rate; (2) the fractures only affect the injection rate of CO2 into the coal but not the final storage amount; (3) when gas is injected into coal the fractures will first expand and then close due to the changing effective stresses and the adsorption induced swelling of coal grains.This fully coupled dual-porosity model with a heterogeneous fracture distribution provides a way to predict the CO2 injection into a coal seam.

  8. Design and trial of a multilift Wongawilli mining method for thick coal seams

    Energy Technology Data Exchange (ETDEWEB)

    O' Beirne, T.

    1980-01-01

    ACIRL designed a system of mining coal seams over 5.0 metres thick with near complete extraction using a multislice Wongawilli operation. As conceived, the seam was divided into three slices with the top slice worked first and the bottom slice following some distance behind. During retreat of the bottom slice the middle section would be cut down with the raised head of the continuous miner. Physical and mathematical model studies were performed to test the concept and in general showed that: development headings should be superimposed for maximum stability; the central portion between the top and lower lifts, known as the septum, benefits from reinforcement; top and lower workings could be worked simultaneously or as totally separate workings; when working both slices simultaneously an optimum separation distance existed (dependent on geotechnical environment); coal pillars remaining amongst the top slice goaf adversely affected the lower workings; and the septum could be successfully extracted whilst retreating the lower workings. A full scale trial of the method on a coal block 300 x 300 m was held at the Collinsville Coal Company mine, in the 5.3 m thick Bowen Seam between July 1978 and August 1981.

  9. Forward Modeling of the Relationship Between Reflection Coefficient and Incident Angle of the P Wave in a Coal Seam

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Although the Zoeppritz equation is suitable for a single interface in a thick deposit, it has some limitations for composite reflection waves from both the floor and the roof of coal seams. Based on the ray model, the relationship of the overall reflection coefficient of composite reflection P waves, from coal seam versus incidence angle (AVO), is discussed. The result shows that: 1) the overall reflection coefficient of composite reflection waves from coal seams is a negative value and is determined mainly by the lithology of roof and floor, which is different from the reflection coefficient of a single interface; 2) if the incidence angle ranges from 0° to 6°, the reflection coefficient of composite waves of a coal seam does not change with the incidence angle and 3) if the incidence angle ranges from 6-60° , the reflection coefficient increases monotonically.

  10. Radiation-thermal desulphurization of brown coal

    Energy Technology Data Exchange (ETDEWEB)

    Mustafaev, I.; Mahmudov, O.; Gulieva, N. [Azerbaijan Academy of Sciences, Baku (Azerbaijan). Sector of Radiation Research

    1999-07-01

    The paper presents results of an investigation of radiation-thermal hydrodesulphurization of brown coal in the presence of methane under accelerated electrons with a dose rate P = 350 Gy/s in the intervals of temperature T = 200-500{degree}C, absorbed dose up to 60 kGy. It has been established that at the more favourable conditions (T = 400-450{degree}C, D{gt} 60 kGy) about 80% of sulphur is removed from the coal and in the solid product sulphur decreased up to 1.0-1.1%. In these conditions the selectivity of desulphurization processes is s = 2.6-3.8 and energy consumption towards removal of sulphur is E = 0.5-0.6 kW.h/kg. The mechanism of selective activation by irradiation for the desulphurization process is discussed.

  11. Numerical simulation of influence of Langmuir adsorption constant on gas drainage radius of drilling in coal seam

    Institute of Scientific and Technical Information of China (English)

    Lin Haifei; Huang Meng; Li Shugang; Zhang Chao; Cheng Lianhua

    2016-01-01

    To determine reasonable distance of gas pre-drainage drillings in coal seams, a solid–gas coupling model that takes gas adsorption effect into account was constructed. In view of different adsorption constants, the paper conducted the numerical simulation of pre-drainage gas in drillings along coal seam, studied the relationship of adsorption constants and permeability, gas pressure, and effective drainage radius of coal seams, and applied the approach to the layout of pre-drainage gas drillings in coal seams. The results show that the permeability of coal seams is on the gradual increase with time, which is divided into three sections according to the increase rate:the drainage time 0–30 d is the sharp increase section;30–220 d is the gradual increase section;and the time above 200 d is the stable section. The permeability of coal seams is in negative linear and positive exponent relation with volume adsorption constant VL and pressure adsorption constant PL, respectively. The effective drainage radius is in negative linear relation with VL and in positive exponent relation with PL. Compared with the former design scheme, the engi-neering quantity of drilling could be reduced by 25%.

  12. 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...

  13. 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...

  14. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Takla, G.; Froml, K. [OKD, DPB, Paskov (Czech Republic)

    2005-07-01

    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)

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. The effect of mineral matrix and seam thickness on reflectance of vitrinite in high coals

    Energy Technology Data Exchange (ETDEWEB)

    Gentzis, T. (Alberta Research Council, Devon (Canada)); Goodarzi, F.; Snowdon, L.R.; Labonte, M. (Geological Survey of Canada, Calgary, Alberta (Canada)); Bustin, R.M. (Univ. of British Columbia, Vancouver (Canada))

    1991-06-01

    The variation of vitrinite reflectance with respect to mineral matrix (lithology), thickness of coal seams and coal lenses, as well as type of organic matter was studied from two cores in a 550-m sedimentary succession from the Upper Jurassic-Lower Cretaceous Kootenay Group. The data obtained indicate that reflectance in high- to low-volatile bituminous coals (% R{sub o}, max = 0.8 - 1.35) with depth of burial is affected by the percentage of organic matter in the samples. A positive correlation between the % R{sub o} and the percent of organic matter and a negative correlation with the percent of mineral matter were shown to exist. It was also observed that the thicker the coal interval, the higher the reflectance. Thick coal seams (greater than 1 m) with mineral content of less than 20% generally exhibited higher vitrinite reflectance than thin coaly lenses (15-30 cm thick) with mineral content of greater than 20%. Vitrinite dispersed in sandstone - and, to a lesser extent, siltstone and carbonaceous shale - had the lowest reflectance. Variations in vitrinite reflectance were attributed to chemical differences in the organic matter, possibly induced by degradation and diagenesis syn- or postdepositionally, the effect of geocatalysts present in the sediments, and possibly variations in thermal conductivity in the succession. Any differences in vitrinite reflectance of organic matter observed would be of great significance in the time-temperature history of a sediment needed to generate hydrocarbons.

  6. 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.

  7. Environmental protection in brown coal mining with the example of the Belchatow brown coal surface mine

    Energy Technology Data Exchange (ETDEWEB)

    Wasowicz, J.

    1986-01-01

    Discusses environmental policy of Poland with the example of the Belchatow brown coal surface mine, the largest in Poland. The following problems are evaluated: collecting detailed information on water conditions in the Belchatow mine and environmental pollution prior to mine construction, construction of a pipeline system for water supply prior to mine draining, effects of mine draining on formation of a large drawdown cone, effects of lowering the ground water table on vegetation, forests, agriculture in the area, water conditions, river flow, water pollution from the Belchatow mine, water treatment plants, dust emission from Belchatow cuts and spoil banks, land reclamation after surface mining (plant growth, grass, afforestation), standardized methods for land reclamation, economic aspects of environmental protection, organizational models of environmental protection in a large brown coal surface mine.

  8. 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.

  9. Research into comprehensive gas extraction technology of single coal seams with low permeability in the Jiaozuo coal mining area

    Institute of Scientific and Technical Information of China (English)

    Fu Jiangwei; Fu Xuehai; Hu Xiao; Chen Li; Ou Jianchun

    2011-01-01

    For a low permeability single coal seam prone to gas outbursts,pre-drainage of gas is difficult and inefficient,seriously restricting the safety and efficiency of production.Radical measures of increasing gas extraction efficiency are pressure relief and infrared antireflection.We have analyzed the effect of mining conditions and the regularity of mine pressure distribution in front of the working face of a major coal mine of the Jiaozuo Industrial (Group) Co.as our test area,studied the width of the depressurization zone in slice mining and analyzed gas efficiency and fast drainage in the advanced stress relaxation zone.On that basis,we further investigated and practiced the exploitation technology of shallow drilling,fan drilling and grid shape drilling at the working face.Practice and our results show that the stress relaxation zone is the ideal region for quick and efficient extraction of gas.By means of an integrated extraction technology,the amount of gas emitted into the zone was greatly reduced,while the risk of dangerous outbursts of coal and gas was lowered markedly.This exploration provides a new way to control for gas in working faces of coal mines with low permeability and risk of gas outbursts of single coal seams in the Jiaozuo mining area.

  10. 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.

  11. 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.

  12. 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.)

  13. Classification of conditions for short-wall continuous mechanical mining in shallowly buried coal seam with thin bedrock

    Institute of Scientific and Technical Information of China (English)

    LIU Yu-de; ZHANG Dong-sheng; MA Li-qiang; ZHAO Yong-feng; WANG Hong-sheng

    2008-01-01

    The room and pillar method is usually used to extract coal from shallowly buried seams with thin bedrock. This results in a very low production efficiency and in a low degree of extraction. In recent years short-wall continuous mechanical mining has been extensively used in many situations except shallowly buried coal seams with thin bedrock. The principles governing movement of the overlying strata above the 2.35 m, which was done using fuzzy clustering results. A series of reasonable,relative parameters in each category have been calculated and analyzed. One proposed way to perform short-wall continuous mechanical mining in shallowly buried coal seams is given. This is significant for coal mines with similar geological conditions.

  14. 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.

  15. Research on propagation law of AE wave in coal seam

    Institute of Scientific and Technical Information of China (English)

    WEN Guang-cai; YANG Hui-ming; ZOU Yin-hui; DONG Guo-wei

    2007-01-01

    Based on mechanism of AE creation, put forward sphere cavity model, and deduced wave Equation of AE wave radiated by the AE source in detail, and analyzed the propagation attenuation law of AE stress wave in coal (rock) strata. Displacement function of AE wave indicates that displacement field can be divided into two parts. Firstly, displacement of particle is approaching to the source intensity function in zone near the AE source. Secondly, in zone far away from the AE source, displacement of particle is approaching to the derivative of source intensity function. AE wave changes gradually in the spreading process, and notable change of the wave form happens when wave propagates far away from the AE source.

  16. Forecast of Geological Gas Hazards for "Three-Soft" Coal Seams in Gliding Structural Areas

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Gas outbursts from "three-soft" coal seams (soft roof, soft floor and soft coal) constitute a very serious problem in the Ludian gliding structure area in western Henan.By means of theories and methods of gas geology, structural geology, coal petrology and rock tests, we have discussed the effect of control of several physical properties of soft roof on gas preservation and proposed a new method of forecasting gas geological hazards under open structural conditions.The result shows that the areas with type Ⅲ or Ⅳ soft roofs are the most dangerous areas where gas outburst most likely can take place.Therefore, countermeasures should be taken in these areas to prevent gas outbursts.

  17. Evaluation of data gathered from unmineable coal seams. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1982-06-01

    As part of the US Department of Energy's (DOE) programs directed at gas recovery from unconventional sources INTERCOMP Resource Development and Engineering, Inc. (INTERCOMP) is under contract to the Morgantown Energy Technology Center (METC) to provide for the reduction of uncertainties in critical parameters related to the methane recovery from unmineable coals in the United States. To accomplish this objective INTERCOMP has assisted in test site selection, planning, and monitoring when requested and evaluated the results of test in terms of methane production potential and economics for selected well sites, geologic settings, and geographical areas. This is a continuation of two earlier contracts in which an optimized test program was specified and in which the results of that program were partially implemented and evaluated. In this report INTERCOMP's effort in assisting the Bureau of Mines to understand the nature of a communication problem between the vertical dewatering hole and the three horizontal degasification legs in the Emerald Mines Horizontal Drilling project is described. Recommendations made by INTERCOMP on how to determine the amount of communication and the answers to several other questions asked are given in the section Assistance in Test Planning. The use of INTERCOMP's numerical simulation model was necessary in this effort. The section entitled Resource Assessment gives the evaluation of each specific well site tested for methane production that furnished to INTERCOMP by METC.

  18. 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.

  19. 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.

  20. Auxiliary transportation mode in a fully-mechanized face in a nearly horizontal thin coal seam

    Institute of Scientific and Technical Information of China (English)

    Wang Chen; Tu Shihao; Zhang Lei; Yang Qianlong; Tu Hongsheng

    2015-01-01

    On fully-mechanized faces in nearly horizontal thin coal seams (NHTCS), the selection of the auxiliary transportation mode is difficult. Generally, auxiliary transportation mainly includes trackless or rail transportation. Combined with a familiar NHTCS fully-mechanized face, a multi-attribute decision-making model was set up for the decision. The index weight was objectively determined with the fuzzy number and entropy method. The priority order of auxiliary transportation modes was obtained from the Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE). The results show that: the net flow of the mode can be expressed by the function of the surrounding rock deformation of the roadway, the dimension of equipment and the thickness of the coal seam;Based on the cost type index, there is a positive correlation between the net flow with the height and width of the trackless aux-iliary transportation equipment, respectively. The trackless auxiliary transportation equipment selection principle should be‘height first then width”. Combined with the field application of the trackless auxil-iary transportation in Liangshuijing coal mine, the proper method to achieve the safe and high-efficient exploitation of a NHTCS fully-mechanized face is trackless tyred vehicle auxiliary transportation.

  1. Study on stress distribution and failure criterion of the roof for the severely inclined coal seam under long wall working

    Institute of Scientific and Technical Information of China (English)

    MENG Xiang-rui; GAO Zhao-ning; WANG Xiang-qian

    2012-01-01

    By turning to the theory of elastic thin plates,a mechanical model of the main roof breaking for severely inclined seam under long wall working was esbalished,in which formulaes were deduced for the calculation of the stress distribution.When the main roof stress distribution was characterized,the failure form of the roof in the long wall coal seam under work was given with the failure criterion deduced.The deduced failure criterion was then applied to the No.3232(3) face of the Lizuizi Coal Mine; the first pressure for the working face was accurately predicted.Results of the field application show that the main roof of the severely inclined coal seam under long wall working breaks in the O-X pattern,which is basically in accordance with the reality.

  2. Sequence stratigraphy, organic petrology and chemistry applied to the upper and lower coal seams in the Candiota Coalfield, Parana Basin, RS, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, J.S. de; Kalkreuth, W. [Instituto de Geociencias, UFRGS, Porto Alegre (Brazil)

    2010-12-01

    The Permian age coal seams in the Candiota Coalfield represent the largest coal deposit of the country. Currently two seams are mined, called ''Camada Candiota Superior'' and ''Camada Candiota Inferior''. The other coal seams of the coalfield, seams S1-S9 (upper seams) and I1-I5 (lower seams) have as yet not been exploited. The objective of this paper is to perform a detailed sequence stratigraphic, petrologic and chemical study of the upper and lower coal seams, thereby generating data for assisting in the development and better use of the coal-bearing interval. The methodology includes application of the concepts of sequence stratigraphy, which includes the lithological interpretation of the core to establish the depositional environments and genetic correlation between facies associations to define parasequences and bounding surfaces; coal petrology (analysis of the reflectance of vitrinite, determination of the petrographic composition of the coals by maceral analyses), and chemical analyses such as sulphur determination, proximate analyses (ash, moisture, volatile matter, and fixed carbon), and elemental analyses. Three main depositional systems were so far identified: alluvial fan, fluvial system, lagoonal estuary system. This study shows that coal development was controlled by accommodation/accumulation rates, with coal seams with greater thickness and lateral continuity being formed within the transgressive systems tract (lagoonal depositional system) of parasequence 2 (PS2), indicating that the accumulation rates of the peat and distribution of the coal seams were controlled by stratigraphic setting. Vitrinite reflectances for the upper and lower coal seams are indicative of subbituminous rank (Rrandom = 0.36-0.47%), with evidence that anomalously low reflectance values are related to high mineral-matter contents. Maceral composition is highly variable, with some coal seams being extremely rich in inertinite (up to

  3. 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.

  4. Production of gas from coal seams in the Upper Silesian Coal Basin in Poland in the post-injection period of an ECBM pilot site

    NARCIS (Netherlands)

    Bergen, F. van; Krzystolik, P.; Wageningen, N. van; Pagnier, H.; Jura, B.; Skiba, J.; Winthaegen, P.; Kobiela, Z.

    2009-01-01

    A pilot site for CO2 storage in coal seams was set-up in the Upper Silesian Coal Basin in Poland in the scope of the RECOPOL project, funded by the European Commission. About 760 tons CO2 were injected into the reservoir from August 2004 to June 2005. Breakthrough of the injected CO2 was established

  5. 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

  6. Origin of Minerals and Elements in the Late Permian Coal Seams of the Shiping Mine, Sichuan, Southwestern China

    Directory of Open Access Journals (Sweden)

    Yangbing Luo

    2016-07-01

    Full Text Available Volcanic layers in coal seams in southwestern China coalfields have received much attention given their significance in coal geology studies and their potential economic value. In this study, the mineralogical and geochemical compositions of C19 and C25 coal seams were examined, and the following findings were obtained. (1 Clay minerals in sample C19-r are argillized, and sedimentary layering is not observed. The acicular idiomorphic crystals of apatite and the phenocrysts of Ti-augite coexisting with magnetite in roof sample C19-r are common minerals in basaltic rock. The rare earth elements (REE distribution pattern of C19-r, which is characterized by positive Eu anomalies and M-REE enrichment, is the same as that of high-Ti basalt. The concentrations of Ti, V, Co, Cr, Ni, Cu, Zn, Nb, Ta, Zr, and Hf in C19-r are closer to those of high-Ti basalt. In conclusion, roof sample C19-r consists of tuffaceous clay, probably with a high-Ti mafic magma source. (2 The geochemical characteristics of the C25 coals are same as those reported for coal affected by alkali volcanic ash, enrichment in Nb, Ta, Zr, Hf, and REE, causing the C25 minable coal seams to have higher potential value. Such a vertical study of coals and host rocks could provide more information for coal-forming depositional environment analysis, for identification of volcanic eruption time and magma intrusion, and for facilitating stratigraphic subdivision and correlation.

  7. Geological controls on the sulphur content of coal seams in the Northumberland Coalfield, Northeast England

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Brian R. [Department of Earth Sciences, Science Laboratories, University of Durham, South Road, Durham DH1 3LE (United Kingdom); Richardson, David [H.J. Banks and Co. Ltd, Bishop Auckland DL13 4HG (United Kingdom)

    2004-12-03

    The sulphur content of coal is an important consideration when developing reserves for exploitation, driven by emission limits from power stations becoming more stringent. Variations in the sulphur content of Westphalian A and B coals from the predominantly freshwater Northumberland Coalfield, Northeast England, were studied according to their regional, stratigraphic and in-seam location. The observed variation in sulphur content spatially increases towards the source area away from more marine influenced areas, with increased sulphur content through time linked to changes in the general depositional environment as conditions became more marine-influenced. A model of basinal surface water and groundwater flow driven by post-depositional source area tectonism is thought to have played only a minor role in contributing secondary sulphur to the coal. However, the isotopic composition of coal pyrite shows a similar range in composition to that of pyrite and other sulphides from the North Pennine Orefield along the southern margin of the coalfield, suggesting an additional potential source of secondary sulphur, as sulphur-rich fluids were expelled northwards through the coal measures during early Permian Variscan transpression from the south. The Westphalian A and B are interpreted as third-order depositional sequences, defined by third-order maximum flooding surfaces. Each sequence is made up of several coal-bearing fourth-order parasequences, which tend to be more brackish to marine in character, on either side of the third-order maximum flooding surfaces when base level was relatively high. The lowest sulphur coals are confined to the lower to middle, relative low stand part of the Westphalian A third-order base level curve and the lowest part of the Westphalian B third-order base level curve. This difference is attributed to a more rapid rise of base level in the Westphalian B. The stratigraphic and spatial distribution of coal sulphur has been used as a guide to

  8. 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)

  9. 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.

  10. Current status and technical challenges of CO2 storage in coal seams and enhanced coalbed methane recovery:an overview

    Institute of Scientific and Technical Information of China (English)

    Xiaochun Li; Zhi-ming Fang

    2014-01-01

    In the past two decades, research on CO2 storage in coal seams and simultaneously enhanced coalbed methane recovery (ECBM) has attracted a lot of attention due to its win–win effect between greenhouse gas (CO2) emission reduction and coalbed methane recovery enhancement. This paper presents an overview on the current status of research on CO2-ECBM in the past two decades, which involves CO2 storage capacity evaluations, laboratory investigations, mod-elings and pilot tests. The current status shows that we have made great progress in the ECBM technology study, especially in the understanding of the ECBM mechanisms. However, there still have many technical challenges, such as the definition of unmineable coal seams for CO2 storage capacity evaluation and storage site characterization, methods for CO2 injec-tivity enhancement, etc. The low injectivity of coal seams and injectivity loss with CO2 injection are the major technique challenges of ECBM. We also search several ways to promote the advancement of ECBM technology in the present stage, such as integrating ECBM with hydraulic fracturing, using a gas mixture instead of pure CO2 for injection into coal seams and the application of ECBM to underground coal mines.

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. Huge thick conglomerate movement induced by full thick longwall mining huge thick coal seam

    Institute of Scientific and Technical Information of China (English)

    Ma Liqiang; Qiu Xiaoxiang; Dong Tao; Zhang Jixiong; Huang Yanli

    2012-01-01

    A discrete elemental method was used to study the thickness of conglomerate layer in a full thick seam mining activities under the influence of the law,pointing out the thickness of the conglomerate at different seam mining,and during the destruction and instability of existing state of laws.At 21141 thick seam mining,the face toward the direction of separation between the thick layer of conglomerate rock and the next bit after reaching its maximum capacity due to pull from the bottom of the plastic zone,formed a stratified and hierarchical down collapse.The shape of caving area is a "triangular block",the length of the plastic zone and face advancement from the linear fit between the height of the plastic zone and the advancing face is a quadratic function of distance,while the top layer of thick gravel layer is the overall bending subsidence trend.Tilting the direction of the face,a thick gob of collapsed conglomerate layer is formed in the coal gob entity on both sides of the thick conglomerate at the top of the overall fracture morphology performance,thus forming a mutual extrusion of articulated block structure.The instability,separation and balance of the thick conglomerate layer in the hinged block stope stress leads to abnormal occurrence of rock burst induced by face as the major factor in the accident.This research reveals the form of stress distribution in the destroyed layer of the thick conglomerate rock,analyzes the stope law of coupling for the pressure burst behavior law for the mining work face,and the choice of preventive measures to provide a theoretical basis and implementation.

  16. 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

  17. 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.

  18. Selection of development and working methods of coal seams in complicated mining and geological conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kaufman, L.L.; Bakhtin, A.F.; Zel' vyanskii, M.Sh. (Donetskaya Proektnaya Kontora (USSR))

    1991-07-01

    Presents the design and technological patterns developed at the Donetsk Design Office for planning mining work in difficult mining conditions. The recommended patterns of working are based on the following principles. The most progressive panel development of mine-take and horizon layout methods are used. The main workings are driven as rock drifts with support pillars or they are driven in stress relaxed zones. Seams are worked with pillars or in a combined way. The pillarless technology is based on conducting workings with coal cutting along the excavated space or on repeated utilization of workings. Reduction in stone hoisting to the surface is achieved by execution of drifts that follow the longwalls. Variants of pillar systems with panel development of mine-take and horizon layout development are shown and described.

  19. Nonlinear coupling analysis of coal seam floor during mining based on FLAC3D

    Institute of Scientific and Technical Information of China (English)

    YAO Duo-xi; XU Ji-ying; LU Hai-feng

    2011-01-01

    Based on the hydro-geological conditions of 1028 mining face in Suntuan Coal Mine, mining seepage strain mechanism of seam floor was simulated by a nonlinear coupling method, which applied fluid-solid coupling analysis module of FLAC3D. The results indicate that the permeability coefficient of adjoining rock changes a lot due to mining. The maximum value reaches 1 379.9 times to the original value, where it is at immediate roof of the mined-out area. According to the analysis on the seepage field, mining does not destroy water resistance of the floor aquiclude. The mining fissure does not conduct lime-stone aquifer, and it is less likely to form damage. The plastic zone does not exactly correspond to the seepage area, and the scope of the altered seepage area is much larger than the plastic zone.

  20. 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

  1. ECONOMIC EFFICIENCY IN USAGE OF BELARUSIAN BROWN COAL DEPOSITS

    Directory of Open Access Journals (Sweden)

    V. V. Kravchenko

    2011-01-01

    Full Text Available Methodology for economic evaluation of the effective use of the Belarusian brown coal deposits has been developed on the basis of systematic analysis of scientific, statistical and economic data. The obtained methodology allows to perform multi-variant optimization calculations under various uncertainty level without reduction to the same energy effect that is especially important while developing economic forecasts and programs for the long term perspective. Using this methodology evaluation of various directions pertaining to usage of the Belarusian brown coal has been done and recommendations on their possible application have been given in the paper.

  2. 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...

  3. 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)

  4. 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.

  5. 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.

  6. Primary energy resource brown coal - difficulties, problems, solutions

    Energy Technology Data Exchange (ETDEWEB)

    Altmann, W.; Effenberger, H.; Retschke, W.; Weidlich, H.-G. (Technische Universitaet, Dresden (German Democratic Republic))

    1989-06-01

    Outlines general aspects of burning low calorific brown coal in power plants of the GDR, which produce 83% of the country's electric energy supply. Combustion of declining coal qualities led to lower plant efficiency, higher fuel consumption, emissions, equipment wear and other negative effects. Technological variants for adapting steam generators, coal pulverizers and burner systems to low and fluctuating fuel quality are discussed. Variants include optimization of burner design, slag and ash removal from combustion chamber surfaces; measures to reduce steam generator wear as well as increase equipment service life are noted. 7 refs.

  7. 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.

  8. 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.

  9. 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 also 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.

  10. 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.

  11. 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.)

  12. 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.

  13. Top coal flows in an excavation disturbed zone of high section top coal caving of an extremely steep and thick seam

    Institute of Scientific and Technical Information of China (English)

    Miao Shengjuna; Lai Xingping; Cui Feng

    2011-01-01

    Compared with gentle dip long-wall caving, the length of a working face in fully-mechanized top-coal caving for extremely steep and thick seams is short, while its horizontal section is high with increasing production. But the caving ratio is low, which might result in some disasters, such as roof falls, induced by local and large area collapse of the top coal in a working face and dangers induced by gas accumulation. After the development of cracks and weakening of the coal body, the tall, broken section of the top coal (a granular medium) of an extremely steep seam (over 60°) shows clear characteristics of nonlinear movement, We have thoroughly analyzed the geological environment and mining conditions of an excavation disturbed zone. Based on the results from a physical experiment of large-scale 3D modeling and coupling simulation of top coal-water-gas, we conclude that the weakened top coal can be regarded as a non-continuous medium. We used a particle flow code program to compare and analyze migration processes and the movements of a 30 m high section top coal over time before and after weakening of an extremely steep seam in the Weihuliang coal mine. The results of our simulation,experiment and monitoring show that pre-injection of water and pre-splitting blasting improve caving ability and symmetrical caving, relieve space for large area dynamic collapse of top coal, prolong migration time of noxious gases and release them from the mined out area and so achieve safety in mining.

  14. 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.

  15. 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.

  16. 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.)

  17. 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.

  18. Application of pressure relief and permeability increased by slotting a coal seam with a rotary type cutter working across rock layers

    Institute of Scientific and Technical Information of China (English)

    Shen Chunming; Lin Baiquan; Meng Fanwei; Zhang Qizhi; Zhai Cheng

    2012-01-01

    Pressure relief to increase permeability significantly improves gas extraction efficiency from coal seams.In this paper we report results from simulations using FLAC3D code to analyze changes in coal displacement and stress after special drill slots were formed.We investigated the mechanism of pressure relief and permeability increase in a high-gas and low-permeability coal seam through the modeling of gas flow.This allows the development of the technology.Slotting across rock layers in the coal seam with a rotary type cutter was then applied in the field.The results show that pressure relief and permeability increases from slotting the coal seam can increase the transport and the fracture of the coal.This expands the range of pressure relief from the drilling and increases the exposed area of the seam.The total quantity of gas extracted from slotted bore holes was three times that seen with ordinary drilling.The concentration of gas extracted from the slotted drills was from two to three times that seen using ordinary drills.The gas flow was stable at 80%.Improved permeability and more efficient gas extraction are the result of the slotting.The roadway development rate is increased by 30-50% after gas drainage.This technology diminishes the lag between longwall production and roadway development and effectively prevents coal and gas outburst,which offers the prospect of broad application.

  19. Analysis of the Harmfulness of Water-Inrush from Coal Seam Floor Based on Seepage Instability Theory

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A theory of seepage instability was used to estimate the harmfulness of water-inrush from a coal seam floor in a particular coal mine of the Mining Group, Xuzhou.Based on the stratum column chart in this coal mine, the distribution of stress in mining floors when the long-wall mining was respectively pushed along to 100 m and to 150 m was simulated by using the numerical software (RFPA2D).The permeability parameters of the coal seam floor are described given the relationship between permeability parameters.Strain and the water-inrush-indices were calculated.The water-inrush-index was 67.2% when the working face was pushed to 100 m, showing that water-inrush is possible and it was 1630% when the working face was pushed to 150 m, showing that water-inrush is quite probable.The results show that as long-wall mining is pushed along, the failure zone is enlarged, the strain increased, and fissures developed correspondingly, resulting in the formation of water-inrush channels.Accompanied by the failure of the strata, the permeability increased exponentially.In contrast, the non-Darcy flow β factor and the acceleration coefficient decreased exponentially, while the increase in the water-inrush-index was nearly exponential and the harmfulness of water-inrush in the coal mine increased accordingly.

  20. 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.

  1. 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}).

  2. Method of mining heavy coal seams in two or more benches

    Energy Technology Data Exchange (ETDEWEB)

    Barsi, K.; Dorombozi, L.; Forisek, I.; Kuburczik, G.; Stuber, G.

    1982-07-20

    In mining a heavy coal seam that must be excavated in several benches, the excavation of the uppermost bench is accompanied by the introduction of a cementitious slurry into the resulting stope for consolidating the waste rock present therein, preparatorily to the excavation of the next-lower bench, and proceeding in like manner with the second bench if a third one is to follow. The cementitious slurry comprises burnt or slaked lime, and/or Portland cement, suspended in water in a quantity of about 10 to 60% by weight and preferably together with a small percentage of chlorides of one or more alkali or alkaline-earth metals, to which ceramic aggregates at large specific surface such as mineral ashes, slag, sand or dolomite powder may be added in a quantity of up to about 30% of the weight of the water. The slurry, on being admitted to the stope in an amount of at least 10% of the volume thereof, causes the waste rock to swell and form a solid layer of up to approximately a meter in thickness which allows the next-lower bench to be excavated after only about a month's delay.

  3. 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

  4. 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.

  5. Mechanical model of water inrush from coal seam floor based on triaxial seepage experiments

    Institute of Scientific and Technical Information of China (English)

    Yihui Pang; Guofa Wang; Ziwei Ding

    2014-01-01

    In order to study the mechanism of confined water inrush from coal seam floor, the main influences on permeability in the process of triaxial seepage experiments were analyzed with methods such as laboratory experiments, theoretical analysis and mechanical model calculation. The crack extension rule and the ultimate destruction form of the rock specimens were obtained. The mechanism of water inrush was explained reasonably from mechanical point of view. The practical criterion of water inrush was put forward. The results show that the rock permeability ‘‘mutation’’ phe-nomenon reflects the differences of stress state and cracks extension rate when the rock internal crack begins to extend in large-scale. The rock ultimate destruction form is related to the rock lithology and the angle between crack and principal stress. The necessary condition of floor water inrush is that the mining pressure leads to the extension and transfixion of the crack. The sufficient condition of floor water inrush is that the confined water’s expansionary stress in normal direction and shear stress in tangential direction must be larger than the internal stress in the crack. With the two conditions satisfied at the same time, the floor water inrush accident will occur.

  6. 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.

  7. Research on downward crack closing of clay aquiclude in shallow coal seam safety mining

    Institute of Scientific and Technical Information of China (English)

    HUANG Qing-xiang; ZHANG Wen-zhong

    2011-01-01

    The water resisting property ofaquiclude is the key factor of water conservation and safety mining,and the mining induced cracks in aquiclude is major factor of water resisting property.The aquiclude is composed by loess layer and red clay layer in Yushuwan Coal Mine,and the water reaction property of clay and loess of aquiclude was tested by soil mechanics method.The permeability coefficient of the loess is 0.856 m/d and the clay is 0.434 rn/d.The dilatability coefficient of the loess is 16.1% and the clay is 14.6%.Through physical solid-liquid simulation with whole stress-stain similarity,the distribution of "downward crack zone" and "upward crack zone" was found to be the major factor of aquiclude stability.The downward crack closing length is about 30% of the downward crack length.The expanding of clay and loess with water are principal factors of downward crack closing.At last,the mechanical model of downward crack closing was constructed,and the criterion of crack closing was put forward at all.This work will provides the theoretical base for aquiclude stability research and safety mining in shallow seam.

  8. 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.

  9. 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

  10. 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.

  11. 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.)

  12. Mechanism and Application of Coal Seam Water Injection Ability%煤层注水可注性机理及应用

    Institute of Scientific and Technical Information of China (English)

    刘先新

    2016-01-01

    针对煤层注水可注性问题,对煤层注水的可注性机理及鉴定指标进行了论述。通过应用实例,重点介绍了煤样的选取方法以及各鉴定指标的检测过程,为煤层注水可注性工作提供了理论依据和应用经验。%In view of the coal seam water injection problem, discussed the coal seam water injection ability mechanism and appraisal index. Through the example of application, mainly introduced the method of choosing coal sample and the testing process of the appraisal index, provided theoretical basis and application experience for coal seam water injection.

  13. Three-dimensional strata movement around coal face of steeply dipping seam group

    Institute of Scientific and Technical Information of China (English)

    WU Yong-ping; XIE Pan-shi; REN Shi-guang; LI Rui-bin

    2008-01-01

    Steeply dipping seam group, which has complex occurrence conditions, belongs to the steeply dipping seam. The research on the strata movement around the coalface not only improves safe production technology in practice, but also develops the mining theory. By using physical simulation experiments, numerical simulation and site test,the deformation, failure and movement of surrounding rock in Iongwall working face wereanalyzed. According to the analysis, characteristics of the seam group were formed whichis different from the single seam. Asymmetry mechanics, sequential changes and imbalance of strata movement along the tendency working face were summarized. Furthermore,the features of upper and lower seams were different. The mining of the lower seam induced more complex strata movement along the strike. Multi-section mining disturbedsurrounding rocks in larger areas than the single section mining did, which had an impacton and dynamic loading function to the support when mining the lower seam, and produced a great influence on the stability of support-rock system.

  14. 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.

  15. 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.

  16. 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

  17. 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.

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

    Directory of Open Access Journals (Sweden)

    David Lloyd

    2013-01-01

    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 on 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 affected 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 interconnectivity 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.

  19. Pore pressure propagation in a permeable thin-layer coal seam based on a dual porosity model: A case of risk prediction of water inrush in coalmines

    Science.gov (United States)

    Zhu, B.; Gao, F.; Yang, J. W.; Zhou, G. Q.

    2016-08-01

    Thin-layer coal seams, a type of filling coal rock body, are considered aquifer systems made up of dual porosity medium with immediate floor. A numerical simulation for the pore pressure propagation along a thin-layer coal seam was carried out for the case of the Zhaogezhuang coalmine in China. By valuing the permeability (Kf ) of the thin-layer coal seam, pore pressure variation with time was simulated and compared to the analytical solutions of a dual porosity model (DPM). The main conclusions were drawn as follow: (1) Seepage in the thin-layer coal seam was predominant in the whole process, and the distance of seepage was lengthened and the pore pressure decreased with increased Kf , (2) A series of simulated hydraulic graphs demonstrated that the pore pressure characteristics of peak-occurring and time-lag effects agreed with the analytical solutions of DPM; (3) By adjusting the parameters of DPM, two results of analytical solutions and numerical solutions fit well, particularly in the thin-layer coal seam, (4) The power law relationship between the peak-values and lag time of pore pressure were derived statistically under consideration of the Kf parameter in the range of 10-8 to 10-10 m2/pa-s orders, and it was reasonable that the Kf of the thin-layer coal seam was in the range of 10-8 m2/pa-s orders. The results were significantly helpful in decision-making for mining water prevention and prediction in practice.

  20. Numerical analysis of the destruction of water-resisting strata in a coal seam floor in mining above aquifers

    Institute of Scientific and Technical Information of China (English)

    Jiang Zhihai

    2011-01-01

    With the increase in mining depth many mining areas in China have entered a period necessitating mining above aquifers.Production safety in coal mines in northern China is under serious threat from Ordovician karst water on coal seam floors.In order to analyze the destruction of water-resisting strata in floors of coal seams being mined and to achieve safe mining above deep aquifers,we established a numerical model of water-resisting strata,considering the structural characteristics and mechanical properties of a floor layered with hard and soft rock.We simulated the distribution characteristics of deformation,failure and seepage using the analytical module of fluid-structure interaction of FLAC.We also obtained the corresponding stress distribution,deformation and flow vectors.Our results indicate that:(1) the advance of the working face causes water-resisting strata in goaf floors to form a deep double-clamped beam,subject to homogeneous loading at the bottom; (2) the two sides of the rock beam are subject to shear failure; (3) both sides of the rock seam at the bottom of the water-resisting strata are subject to tension and the greater the working face advance,the more serious the failure; (4) the original balance of the stress and seepage fields are broken and redistributed due to mining activities,especially the interaction of the abutment pressure in both sides of the goaf; the lateral pressure on the goaf floor and the water pressure on the floor of the aquifer promote floor heave and shear failure on both sides of the floor,forming a water-inrush passage.Our study results can provide references for the mechanism of water-inrush on mine floors.

  1. 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.

  2. Brown coal mining and environment in the Rhineland

    Energy Technology Data Exchange (ETDEWEB)

    Schultze, H.J.

    1985-02-01

    Between the cities of Cologne and Aix-la-Chapelle, a brown coal deposit containing approx. 55 x 10/sup 9/ tonnes is extracted by means of open cast mining methods. The deposit is covered by aquiferous loose rock, which is to be drained before actual mining can start. The entire region is densely populated. In planning and mining, particular importance should be attached to the impact on the environment. Before coal mining starts, the surface has to be cleared. This means transfer of villages, relocation of streets, rivers and the like. As provided for by statute, the local authorities and the population to be transferred are consulted and asked for their ideas about mine planning and its subsequent implementation. With regard to the technical side, it is necessary to minimize dust and noise pollution. Refilling of the exhausted mines followed by proper reclamation schemes, in particular recultivation of agricultural land, is to make up for the land lost to mining.

  3. 急倾斜薄煤层采煤方法发展趋势%On development tendency for coal mining methods of inclined thin seams

    Institute of Scientific and Technical Information of China (English)

    迟学海; 孟鑫

    2016-01-01

    The PaPer introduces the develoPment features of the coal mining methods in the inclined thin seams based on the blasting mining tech-nology,exPlores the develoPment of the hydroPower coal mining and mechanized coal mining,and forecasts the develoPment of the coal mining methods of the inclined thin seams,so as to enhance the oPtimization of the coal mining craft.%介绍了基于炮采工艺的急倾斜薄煤层采煤方法的发展特点,并探讨了水力采煤与机械化采煤的发展现状,预测了急倾斜薄煤层采煤方法的发展趋势,有利于促进采煤工艺的不断优化改进。

  4. 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.

  5. Environmental protection at the Belchatow brown coal mine

    Energy Technology Data Exchange (ETDEWEB)

    Wasowicz, J.; Ozog, J.

    1987-01-01

    Discusses environmental effects of brown coal surface mining in Belchatow. Mine construction started in 1975. In 1985 coal output had increased to 18.0 Mt/a, coal calorific value was 1,860 kcal/kg. A system of 345 wells was used for mine draining. Drawdown cone radius ranged from 34.0 to 13.4 km, drawdown area was 445.5 km/sup 2/. Sedimentation tanks with a total capacity of 290,337 m/sup 3/ were used for waste water treatment. In the initial phase of mine development air pollution was relatively low. Air pollution will increase after a coal-fired power plant is constructed. Damage caused by surface mining in the mine area is associated with drawdown and earth tremors (caused by overburden removal and its disposal in new areas). Two land reclamation trends in Belchatow are comparatively evaluated: reforestation and agriculture. The average land reclamaton cost was 4.2 million zlotys/ha. Organizations which coordinate environmental control and land reclamation in Belchatow are listed.

  6. 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.

  7. 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.

  8. A probe into "mining technique in the condition of floor failure" for coal seam above longwall goafs

    Institute of Scientific and Technical Information of China (English)

    FENG Guo-rui; WANG Xian-xia; KANG Li-xun

    2008-01-01

    Targeting at the coal seam with useful value discarded above goafs, attempted to explore the feasibility of "mining technique in the condition of floor failure" from theoretical point of view, and predicted. It indicated that mining technique in the condition of floor failureused above Longwall Goafs in Baijiazhuang Mining is totally feasible. At law, the deformation of the floor in the mining technique by means of probability-integral method. And it is discov-ered that deformed basin can emerge in the footwall of No.6 coal seam and its maximum subsidence was possibly 1 633 mm or so and its maximum positive curvature is 61.74/10-3.At last, it therefore suggests appropriate ground pressure control measures as strengthening observation of ground pressure and adopting false slope for exploitation and strengthening support for reasonable push and slide based on the adverse ground pressure behaviors possibly occurring in the mining technique. This serves to gather data and lay sturdy founda-tion for further probe into the mining technique, and offers theoretical and technical grounds for concrete implementation of the mining technique.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. Brown Coal Dewatering Using Poly (Acrylamide-Co-Potassium Acrylic Based Super Absorbent Polymers

    Directory of Open Access Journals (Sweden)

    Sheila Devasahayam

    2015-09-01

    Full Text Available With the rising cost of energy and fuel oils, clean coal technologies will continue to play an important role during the transition to a clean energy future. Victorian brown coals have high oxygen and moisture contents and hence low calorific value. This paper presents an alternative non evaporative drying technology for high moisture brown coals based on osmotic dewatering. This involves contacting and mixing brown coal with anionic super absorbent polymers (SAP which are highly crossed linked synthetic co-polymers based on a cross-linked copolymer of acryl amide and potassium acrylate. The paper focuses on evaluating the water absorption potential of SAP in contact with 61% moisture Loy Yang brown coal, under varying SAP dosages for different contact times and conditions. The amount of water present in Loy Yang coal was reduced by approximately 57% during four hours of SAP contact. The extent of SAP brown coal drying is directly proportional to the SAP/coal weight ratio. It is observed that moisture content of fine brown coal can readily be reduced from about 59% to 38% in four hours at a 20% SAP/coal ratio.

  14. 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.

  15. 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...

  16. 含构造煤煤层的AVA响应特性分析%Analysis on AVA corresponding of coal seams contain tectonic coals

    Institute of Scientific and Technical Information of China (English)

    程龙

    2015-01-01

    The outburst of gas and CBM mining are seriously inlfuenced by the distribution and thickness of tectonic coals in coal seams. The paper obtained the seismic recordings with the incidence angle from 0 to 35 °by forward modeling the different distribution and thickness of tectonic coals in coal seams, and the AVA corresponding of both cases were analyzed. The Gaussian White noise with different SnR was added to the seismic recordings, for discussing the characteristics of AVA corresponding inlfuenced by the SNR of recordings. And we realized that the AVA corresponding was serious affected when the SnR was less than 2. Though the above analysis, we believe this study can guide the exploration of tectonic coals.%煤层中构造煤的分布位置和厚度对瓦斯突出和煤层气开采影响较大。本文通过建立构造煤在煤层中的不同分布位置和厚度模型,褶积得到入射角为0-35°的地震记录,并分析两种情况下的煤层AVA响应特性。考虑到资料信噪比对煤层AVA响应的影响,在褶积记录中加入不同信噪比的高斯白噪声进行分析,认为当资料信噪比低于2时,含构造煤煤层的AVA响应特性受影响较大。通过以上分析,本研究可用于指导地震勘探中的构造煤解释。

  17. 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。

  18. Effect of mineral matrix and seam thickness on reflectance of vitrinite in high to low volatile bituminous coals - an enigma

    Energy Technology Data Exchange (ETDEWEB)

    Goodarzi, F.; Gentzis, T.; Snowdon, L.R.; Bustin, R.M.; Feinstein, S.; Labonte, M. (Geological Survey of Canada, Calgary, AB (Canada). Inst. of Sedimentary and Petroleum Geology)

    1993-04-01

    The variation of vitrinite reflectance with respect to mineral matrix (lithology), the thickness of coal seams and coal lenses and the type of organic matter was studied from two cores in a 550 m sedimentary succession from the Upper Jurassic to Lower Cretaceous Kootenay Group. The data obtained indicate that reflectance in high to low volatile bituminous coals (%R[sub o], max0.8-1.35) with depth of burial is affected by the percentage of organic matter in the samples. A positive correlation between the vitrinite reflectance and the percentage of organic matter and a negative correlation with the percentage of mineral matter exist and the thicker the coal interval, the higher the vitrinite reflectance. Variations in vitrinite reflectance may be attributed to chemical differences in the organic matter, possibly induced by degradation and diagenesis syn- or post-depositionally, and to the effect of some clay minerals present in the sediments, which may act as catalysts. Differences in the thermal conductivity of the strata have demonstrably not accounted for the observed variations in reflectance with lithology. The differences in the vitrinite reflectance of organic matter between lithotypes is substantial and is thus an important consideration in resolving the time-temperature history and generation of hydrocarbons from a sedimentary succession.

  19. 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

  20. 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

  1. Collembola and Oribatei of brown coal dumps in Siberia

    Energy Technology Data Exchange (ETDEWEB)

    Stebaeva, S.K.; Andrievsky, V.S. [Russian Academy of Sciences, Novobirsk (Russian Federation)

    1997-09-01

    Nature and rates of forming Collembola and Oribatei groups in catena of technogenic ecosystems on brown coal dumps in Siberia were studied. With increasing age of dumps, the taxonomic diversity and abundance of microarthropod groups increase, the dominance structure is transformed. Colonization of technogenic landscapes by Collembola proceeds faster than that by Oribatei, especially at initial and middle stages of forming the groups resulting in the sharp increase of species abundance and diversity. At the late successional stage the rates of colonizing dumps by Collembola and Oribatei become identical due to increasing the rate of forming the Oribatei group. The dominance structure in microarthropod groups is transformed during succession and becomes similar to the structure, characteristic of the groups from undisturbed meadow ecosystems. In Oribatei this is displayed more distinctly, but in both groups the indicator species for technogenic ecosystems are distinguished.

  2. 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.

  3. 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。

  4. Early Eocene carbon isotope excursions: Evidence from the terrestrial coal seam in the Fushun Basin, Northeast China

    Science.gov (United States)

    Chen, Zuoling; Ding, Zhongli; Tang, Zihua; Wang, Xu; Yang, Shiling

    2014-05-01

    A series of transient global warming events between 56 and 50 Ma are characterized by a pronounced negative carbon isotope excursion (CIE). However, the documents of these hyperthermals, such as Eocene Thermal Maximum 2 and H2 events, have come chiefly from marine sediments, and their expression in terrestrial organic carbon is still poorly constrained. Here we yield a high-resolution carbon isotope record of terrestrial organic material from the Fushun Basin, which displays four prominent CIEs with magnitudes larger than 2.5‰. Based on age constraint and comparisons with deep-sea records, our data provide the first evidence of the four hyperthermals in coal seams and suggest a global significance of these events. Moreover, the difference of CIE magnitudes between marine and terrestrial records shows a significant linear correlation with the marine carbonate CIE, implying that these events are likely attributable to recurring injections of 13C-depleted carbon from submarine methane hydrates and/or permafrost.

  5. 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.

  6. 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.

  7. Enhanced recovery of unconventional gas. Volume II. The program. [Tight gas basins; Devonian shale; coal seams; geopressured aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Kuuskraa, V.A.; Brashear, J.P.; Doscher, T.M.; Elkins, L.E.

    1978-10-01

    This study was conducted to assist public decision-makers in selecting among many choices to obtain new gas supplies by addressing 2 questions: 1) how severe is the need for additional future supplies of natural gas, and what is the economic potential of providing part of future supply through enhanced recovery from unconventional natural gas resources. The study also serves to assist the DOE in designing a cost-effective R and D program to stimulate industry to recover this unconventional gas and to produce it sooner. Tight gas basins, Devonian shale, methane from coal seams, and methane from geopressured aquifers are considered. It is concluded that unconventional sources, already providing about 1 Tcf per year, could provide from 3 to 4 Tcf in 1985 and from 6 to 8 Tcf in 1990 (at $1.75 and $3.00 per Mcf, respectively). However, even with these additions to supply, gas supply is projected to remain below 1977 usage levels. (DLC)

  8. 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...

  9. 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.

  10. Underground Coal Mine Methane Displacement by Injecting Low-pressure Gas into the Meta-anthracite Seam: Laboratory and Field Tests

    Directory of Open Access Journals (Sweden)

    Yu Hong

    2014-09-01

    Full Text Available Because of the strong adsorption capacity of meta-anthracite, the gas content of a meta-anthracite seam can be as high as 10 m3/t, with a gas pressure lower than 0.74 MPa; this results in low efficiency of gas extraction in underground mines. To enhance low-pressure methane extraction efficiency in meta-anthracite seams, a new approach – methane displacement by gas injection – has been developed, investigated in the laboratory, and then applied in the field in the Fuyanshan coal mine. Laboratory results show that when the gas content of the coal seam is high, methane displacement by nitrogen injection is difficult. The volume of methane displaced is directly related to the pressure difference between the coal seam gas pressure and the injection gas pressure. If the total gas pressure is greater than 0.5 MPa after nitrogen injection, then the methane displacement efficiency will be greatly enhanced. It is also confirmed that the displacement efficiency can be improved by injecting inert gas to change the partial pressure of the methane. Field test data show quite good methane displacement efficiency.

  11. Practice of Gas Drainage of Relaxed Adjacent Seam from Thin Coal Seam and Use of Gas for Power Generation%极薄煤层卸压瓦斯抽采与发电利用实践

    Institute of Scientific and Technical Information of China (English)

    刘益文

    2011-01-01

    Gas emission from the comer of coal working face always exceeded the specified limitation in min- ing extremely thin coal seam in Shengli coal mine, Sichuan. After building of a fixed gas drainage system on the surface, cross-measure roof (or floor) boreholes were used to extract pressure - relief gas in the adjacent coal seams above (or below) the gob area of the working face, and obtained satisfactory safety and economic benefits, through achieving zero electricity fee for production and living, which is of important significance to mines with similar conditions.%四川胜利煤矿开采极薄煤层,采煤工作面隅角瓦斯经常超限,矿井建立了地面抽采瓦斯系统后,采用顶(底)板穿层钻孔抽采工作面采空区上(下)邻近层卸压瓦斯,有效地治理了瓦斯灾害。瓦斯抽采系统运行稳定后,将瓦斯进行发电利用,实现了矿井生产和生活零电费,取得了很好的安全与经济效益,对相似条件下的煤矿具有重要借鉴意义。

  12. 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.

  13. 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.

  14. 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.

  15. Co-pyrolysis of a Ukrainian low-grade coal (brown) with plastics

    Energy Technology Data Exchange (ETDEWEB)

    V.N. Shevkoplyas [National Academy of Sciences of Ukraine, Donetsk (Ukraine)

    2003-07-01

    An effective pathway of the wastes plastics utilization can be its co-pyrolysis with a low-grade (brown) coal. The Dneprovsky deposit brown coal (Ukraine) and waste plastics as a polyethyleneterephthalate in this investigation were taken. The brown coal-plastics mixed used: 19:1; 9:1 and 4:1 ratio that was as 5, 10 and 20 % plastics additive to the brown coal. The co-pyrolysis mix prepared in the temperature region 450-800{sup o}C in a fixed bed reactor has been carried out. The process time was 0, 60 and 120 min., heating rate - 25{sup o}C/min. The influence plastics additive on the co-pyrolysis yield has been estimated. The influence of the co-pyrolysis isothermal time on the yield and properties of the tars produced has been studied. The mass balances of co-pyrolysis brown coal with plastics have been calculated. It was concluded that the co-pyrolysis brown coal with plastics is a way to utilize organic pollutants. 3 refs., 1 fig., 6 tabs.

  16. 松软低透煤层群开采保护层工作面瓦斯综合治理技术%Comprehensive Gas Control Technology for Mining Protective Seam Face in Soft Coal Seams with Low Permeability

    Institute of Scientific and Technical Information of China (English)

    胡明; 张玉明; 雷洪波; 姚峰

    2014-01-01

    In order to solve the problem of gas emission during the extraction of the protective seam in Yuyang Coal Mine, comprehensive gas control measures such as “U+ tailing way drainage” ventilation, gas pre-drainage from the seam being mined by large-diameter deep holes, gas drainage by crossing hole in the floor and so on were taken. The result showed that the gas concentration in return air of the working face was controlled below 0. 7% during coal mining and the month coal output of the face raised by 50%. This thus solved the gas overrun problem in the protective seam working face, improved the drawing rate of the face and realized safe production of the mine.%为了解决渝阳煤矿突出矿井煤层群开采保护层工作面时瓦斯涌出的问题,采取了“U+尾排”通风、大直径深孔预抽本煤层瓦斯、底板穿层钻孔抽采瓦斯等综合治理措施,治理效果表明:回采期间工作面回风流中瓦斯体积分数控制在0.7%以下,工作面月产量提高了50%。解决了保护层工作面的瓦斯超限问题,同时提高了工作面的回采速度,实现了安全生产。

  17. 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.)

  18. 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。

  19. Study on fasART neuro-fuzzy networks for distinguishing the difficulty degree of top coal caving in steep seam

    Institute of Scientific and Technical Information of China (English)

    FENG Tao; ZHAO Fu-jun; LIN Jian

    2005-01-01

    Distinguishing the difficulty degree of top coal caving was a precondition of the popularization and application of the roadway sub-level caving in steep seam. Because of complexity and uncertainty of the coal seam, the expression of influence factors was difficulty with exact data. According to the fuzzy and uncertainty of influence factors, triangular fuzzy membership functions were adopted to carry out the factors ambiguity, of which the factors not only have the consistency of semantic meaning, but also dissolve sufficiently expert knowledge. Based on the properties and structures of fasART fuzzy neural networks of fuzzy logic system and practical needs, a simplified fasART model was put forward, stability and reliability of the network were improved, the deficiency of learning sampies and uncertainty of the factors were better treated. The method is of effective and practical value was identified by experiments.

  20. 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。

  1. Effects of pretreatment in steam on the pyrolysis behavior of Loy Yang brown coal

    Energy Technology Data Exchange (ETDEWEB)

    Cai Zeng; George Favas; Hongwei Wu; Alan L. Chaffee; Jun-ichiro Hayashi; Chun-Zhu Li [Monash University, Vic. (Australia). CRC for Clean Power from Lignite, Department of Chemical Engineering

    2006-02-01

    Dewatering/drying of Victorian brown coal will be an integral part of future brown coal utilization processes aimed at the reduction of greenhouse gas emissions. This study aims to investigate the effects of the thermal pretreatment of brown coal in the presence of steam/water on its subsequent pyrolysis behavior. A Victorian (Loy Yang) brown coal was thermally pretreated in pressurized steam and inert atmospheres. The pyrolysis behavior of these pretreated coal samples was investigated in a wire-mesh reactor. While the pretreatment in steam at temperatures higher than 250{sup o}C increased the char yield of the steam-treated coal, it did not affect the overall pyrolysis char yield at 1000{sup o} C s{sup -1} if the weight loss during the pretreatment in steam was also considered. However, the tar yield decreased significantly after the pretreatment in the presence of steam. The UV-fluorescence spectroscopy of tars revealed that the release of large aromatic systems from the steam-treated coal was only affected by the pretreatment in steam if the treatment temperature was very high (e.g. 350{sup o}C). The loss of NaCl and the use of high pressure during the pretreatment of brown coal in steam were not the main reasons for the changes in the observed tar yield. The hydrolysis of O-containing structures such as ethers, esters, and carboxylates during the pretreatment in the presence of steam plays an important role in the fates of these O-containing structures during pretreatment and subsequent pyrolysis, leading to changes in the pyrolysis behavior of the brown coal. 36 refs., 8 figs.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. Co-pyrolysis of hydrothermally upgraded brown coal and wax prepared from waste plastics

    Energy Technology Data Exchange (ETDEWEB)

    Kouichi Miura; Susan A. Roces; Monthicha Pattatapanusak; Hiroyuki Nakagawa; Ryuichi Ashida; Masato Morimoto [Kyoto University, Kyoto (Japan). Department of Chemical Engineering

    2007-07-01

    We have recently presented a hydrothermal extraction method that not only removes water from brown coal but also upgrades the coal and extracts low molecular mass compounds simultaneously. The upgraded coal contained much less oxygen than the raw coal. However, it still needs to be further upgraded to be utilized as a substitute for bituminous coal. In this study co-pyrolysis of the upgraded coals and waxes formed from waste plastics was investigated for this purpose. Waxes were prepared through pyrolysis of polyethylene, polypropylene, and polyethylene terephtalate. Upgraded coals were then impregnated with the waxes in an autoclave at 200{sup o}C under pressure. The mixtures of coal and wax were rapidly heated up to 1040{sup o}C at about 3000{sup o}C/s using a Curie point pyrolyzer in an inert atmosphere. The char yield was greatly enhanced by a factor of 1.1 to 1.3 compared to the char yield obtained when the upgraded coals and waxes were pyrolyzed independently. Even under a slower heating rate (0.17{sup o}C/s) the char yields increased by a factor of 1.2 for the all mixtures of the upgraded coal and waxes. Since no such effect was found when the raw brown coal was impregnated with waxes, it was suggested that the modification of the structure of brown coal by the hydrothermal extraction could enhance interactions between the coal and the wax when co-pyrolyzed. Effect of wax mixing ratio on co-pyrolysis behavior was also examined. The char yield dramatically increased when the ratio exceeded about 0.3 g/g for the pyrolysis of both under slow and rapid heating rates. This trend coincided with that of the swelling ratio of the upgraded coal impregnated with wax, indicating that some physical change by wax-impregnation affected the co-pyrolysis behavior. 5 refs., 14 figs., 3 tabs.

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. Underground pressure characteristics analysis in back-gully mining of shallow coal seam under a bedrock gully slope

    Institute of Scientific and Technical Information of China (English)

    Wang Xufeng; Zhang Dongsheng; Fan Gangwei; Zhang Chengguo

    2011-01-01

    We studied underground pressure and its mechanism during back-gully mining in a shallow coal seam under a bedrock gully slope, by means of physical simulation, numerical modeling and field monitoring.The results show that the intensity of underground pressure is related to its relative position at the coalface. The underground pressure is intensive and the support resistance reaches a maximum when the coalface is at the bottom of the gully, whereas the underground pressure is moderate and decreases gradually when the coalface passes the gully. The mechanism of these changes is analyzed when the slope rotated in a reversed direction to the slope dip during back-gully mining and form an unstable, multilateral block hinged structure, due to slipping. The subsidence of multilateral blocks is considerable when the block fragmentation is small, resulting in enormous changes in the underground pressure. With an increase in the mass of the block body, the block displacement will be reduced in conjunction with an increased clamp effect by both the unbroken rocks and broken rocks in the goaf, resulting in a decrease of the underground pressure.

  12. On design for gas drainage of coal seam at 15th Seam at Shangshe Coal Company of Yangquan%阳泉上社煤炭公司15号煤层本煤层瓦斯抽放设计

    Institute of Scientific and Technical Information of China (English)

    武风元

    2012-01-01

    The paer introduces the gas drainage design at the coal seam of 15103 fully mechanized coal face of Shangshe Coal Mine in Yan- gquan, illustrates the design for the advanced deficient pumping holing and the drilling connection craft, sums up the safety operation points for the drainage of the coal seam, and proves by the practice that it has better gas drainage effect of the coal seam, so as to provide some precious experience for similar projects in future.%对阳泉上社煤矿15103综采工作面本煤层瓦斯抽放孔设计进行了介绍,分别阐述了预抽钻孔设计,钻孔连接工艺等内容,并总结出本煤层抽放的安全操作要点,经实践取得了良好的煤层瓦斯抽放效果,为今后类似工程提供了宝贵经验。

  13. Origin and distribution of tonsteins in late permian coal seams of Southwestern China

    Science.gov (United States)

    Zhou, Yinzhu; Ren, Y.-L.; Bohor, B.F.

    1982-01-01

    We have surveyed the areal and stratigraphic distribution of tonsteins in Late Permian coalfields of southwestern China over an area of several hundred thousand square kilometers. We studied the relationship between tonstein distribution and sedimentary environment. Based on mineralogical and petrographic data, we have concluded that these tonsteins originated as air-fall volcanic ashes. Following accumulation in the peat swamps, in situ alteration of the vitric and lithic components took place under acidic conditions, leading to the formation of kaolinite. Based on petrologic, mineralogic, and chemical analytical data, we have determined that the application of mineralogic and geochemical criteria for tonsteins may be useful in correlating coal beds, predicting coal qualities and reconstructing related sedimentary paleoenvironmental conditions. ?? 1982.

  14. Numerical simulation of shearer drum loads on complex coal seam%复杂煤层采煤机滚筒载荷的数值模拟

    Institute of Scientific and Technical Information of China (English)

    麻晓红; 于信伟; 芦玉梅; 唐庆菊

    2012-01-01

    Directed at overcoming severe wear and break of shearer picks operating in a more compli- cated coal seams, and lower service life of drum, this paper describes the development of mechanical model of the shearer drum designed for a more complex coal seam by investigating the contact postures be- tween picks and coal and mechanical model of single pick. The paper features a simulation algorithm of shearer drum loads tailored to complex coal seams to facilitate engineering analysis and application by properly simplifying cutting state of picks and coal and determining the force state occurring between them by way of discrete stochastic process. The algorithm allows the simulation of three directional loads and torque of shearer drum on some rotating period, thus contributing to digital design of shearer drum.%为解决复杂煤层下工作的采煤机截齿磨损严重、缺失以及滚筒寿命低等问题,通过分析截齿与煤岩的接触位姿以及单齿的力学模型,建立了复杂煤层条件下采煤机滚筒的力学模型。为便于工程分析与应用,适当简化了截齿与煤岩的截割状态,以离散随机过程判断每一时刻截割过程中的受力状态,给出了复杂煤层下采煤机滚筒载荷的模拟算法。该模拟算法可实现任意旋转周期内滚筒三向载荷和负载扭矩的模拟,为采煤机滚筒的数字化设计提供条件。

  15. 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...

  16. Working adjacent seams separated by thin interbeddings

    Energy Technology Data Exchange (ETDEWEB)

    Batmanov, Yu.K.; Bakhtin, A.F.; Bulavka, E.I. (Donetskii Nauchno-Issledovatel' skii Ugol' nyi Institut (Ukraine))

    1992-10-01

    Discusses problems related to working pairs of seams separated by thin interbeddings in Ukrainian black coal mines. Working pairs of seams in descending or ascending order is considered. Exemplary cases of working closely lying seams in five mines are studied. It was found that excavation of under- or overworked seams causes deterioration of the immediate roof and caving of draw roof. It is concluded that very close lying seams should not be worked in ascending order; pillarless working of the upper seam is indispensable in the case of working in descending order. Caving of unstable roofs can be prevented by roof bolting and consolidation by fluid injection. 4 refs.

  17. 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.

  18. 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.

  19. A Field Study on Simulation of CO2 Injection and ECBM Production and Prediction of CO2 Storage Capacity in Unmineable Coal Seam

    Directory of Open Access Journals (Sweden)

    Qin He

    2013-01-01

    Full Text Available CO2 sequestration into a coal seam project was studied and a numerical model was developed in this paper to simulate the primary and secondary coal bed methane production (CBM/ECBM and carbon dioxide (CO2 injection. The key geological and reservoir parameters, which are germane to driving enhanced coal bed methane (ECBM and CO2 sequestration processes, including cleat permeability, cleat porosity, CH4 adsorption time, CO2 adsorption time, CH4 Langmuir isotherm, CO2 Langmuir isotherm, and Palmer and Mansoori parameters, have been analyzed within a reasonable range. The model simulation results showed good matches for both CBM/ECBM production and CO2 injection compared with the field data. The history-matched model was used to estimate the total CO2 sequestration capacity in the field. The model forecast showed that the total CO2 injection capacity in the coal seam could be 22,817 tons, which is in agreement with the initial estimations based on the Langmuir isotherm experiment. Total CO2 injected in the first three years was 2,600 tons, which according to the model has increased methane recovery (due to ECBM by 6,700 scf/d.

  20. Research on the fully mechanized mechanization technology of the very thin coal seam with hard gangue%含硬夹矸极薄煤层综采机械化技术研究

    Institute of Scientific and Technical Information of China (English)

    葛家新; 位建峰; 王为东

    2015-01-01

    By the shearer renovation, Beisu Coal Mine improve the thin seam (especially containing iron sulfide concretions and hard inclusion of thin coal seam) comprehensive mechanized mining technology level, eliminate the safety hidden danger of blasting working face, greatly reduce the mining coal worker's labor intensity, and improve the working environment, which ifnd a new path for realizing thin seam coal mine safety, high efifcient mining.%北宿煤矿通过对采煤机的改造,提高了薄煤层(特别是含有硫化铁结核和硬夹矸薄煤层)综合机械化工艺适用条件,大大降低采煤工人的劳动强度,改善作业环境,为薄煤层矿井实现安全、高效开采探出一条新路子。

  1. The CO2 Geological Sealing Conditions and Potential Evaluation in Coal Seams in Jiangsu Province%江苏省CO2煤层地质封存条件与潜力评价

    Institute of Scientific and Technical Information of China (English)

    姚素平; 汤中一; 谭丽华; 裴文明

    2012-01-01

    The geological conditions of CO2 sequestration in coal seams in Jiangsu Province contain the distribution of Carboniferous-Permian coal measures,coal resources and coal seam reservoir conditions. According to the comprehensive research about the geological conditions of CO2 sequestration in coal seams, the preliminary assessments of the storage potential are made for the coal fields in southern Jiangsu, Xuzhou and Fengpei, respectively. The results show that the coal seams in these coal fields have considerable potential and disposal prospect for CO2 sequestration. The estimate of CO2 storage resources in coal seams in Jiangsu Province is over three hundred million tons of CO2. Among these coal seams .southern Jiangsu coal area could sequester 81 million tons of CO2,Xuzhou coal area of nearly 150 million tons of CO2 and Fengpei coal area of 87 million tons of CO2. The prospect of typical coal-seam CO2 sequestration can be divided into three categories : suitable storage area( Class A), less suitable storage area ( B), and poor storage area ( Class C).%根据江苏省石炭—二叠纪煤系的分布、煤炭资源量和煤层的储集条件等煤封存CO2地质条件的综合研究,分别对苏南煤田、徐州煤田、丰沛煤田煤层封存CO2的潜力进行了初步评估,认为该区CO2煤层封存具有一定的潜力和前景.评估结果表明江苏省煤层可存储CO2总量超过3×108t,其中苏南含煤区可存储CO2容量为8.1×107 t,徐州煤矿区可存储容量近1.5×108t,丰沛煤矿区为8.7× 107t.并对各典型含煤区块CO2煤封存前景进行分类:适合存储区(A类)、较适合存储区(B类)和较差存储区(C类).

  2. 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 uranium was present as uranyl-carbonate complexes. Since NORM are often enriched in target geological formations containing unconventional gas, establishing radon and uranium concentrations in overlying aquifers comprises an important component of baseline groundwater investigations.

  3. 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.

  4. 缓倾斜严重突出煤层快速揭煤优化研究%Research on Optimization of Fast Exposing Gently-inclined Serious Outburst Coal Seam by a Crosscut

    Institute of Scientific and Technical Information of China (English)

    王建; 张荻; 李正刚

    2015-01-01

    为了提高缓倾斜严重突出煤层的揭煤效率,采用缩短揭煤巷道距离、水力压裂增透结合底板穿层钻孔预抽的方法,优化揭煤步骤. 现场应用表明,该方法可以减少2次区域验证次数,减少施工9~24个钻孔,揭煤时间平均缩短5. 0~15. 4 d,费用减少50%,实现了安全快速石门揭煤.%In order to improve the efficiency of exposing the gently-inclined serious outburst coal seam by a crosscut, the steps of exposing the outburst coal seam by a crosscut were optimized by adopting the measures of shortening the distance of the roadway exposing the outburst coal seam, gas permeability enhancement by hydraulic fracturing and gas pre-drainage by floor crossing holes. The site application showed that this method can reduce two regional verifications, reduce the drilling construction of 9~24 holes, the average time for exposing the outburst coal seam was shortened by 5. 0~15. 4 d and the costs were reduced by 50%, as a result, the fast exposing outburst coal seam by a crosscut was realized.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. Co-pyrolysis of polymethyl methacrylate with brown coal and effect on monomer production

    Energy Technology Data Exchange (ETDEWEB)

    A. Orinak; L. Halas; I. Amar; J.T. Andersson; M. Adamova [University of P.J. Safarik, Kosice (Slovakia). Faculty of Sciences, Institute of Chemistry

    2006-01-01

    Pyrolysis capillary gas chromatography has been applied to the study of the co-pyrolysis of polymethyl methacrylate (PMMA) with Slovakian brown coal with the aim of finding pyrolysis conditions yielding a maximum amount of methyl methacrylate (MMA). Effects of pyrolysis temperature and PMMA-coal weight ratios were investigated. Capillary gas chromatography coupled with mass spectrometric detector (cGC-MS) was used for MMA identification. The highest yield of MMA in the pyrolysate was obtained at 750{sup o}C. The optimal PMMA-coal weight ratio for maximum MMA production lies in the interval 0.5 mg PMMA and 0.6-0.8 mg brown coal with an MMA yield of 64%. Coal addition to the sample affects species recombination in gaseous phase, augments MMA production at higher temperatures and eliminates degradation products of PMMA and coal pyrolysis. Different conversion diagrams are characteristic for thermal degradation of single PMMA and in the mixture with coal. Detailed mechanism of synergetic effects arisen during co-pyrolysis are not yet known. It was also found that lower pyrolysis temperatures are more suitable to study degradation mechanism and kinetics while higher temperatures are more applicable for identification purposes. MMA decomposes completely at 900{sup o}C. 24 refs., 5 figs., 2 tabs.

  10. Numerical Simulation of Coal and Gas Outburst Process in Uncovering Frozen Coal Seam in Cross - Cut%石门揭露冻结煤层瓦斯突出过程的数值模拟

    Institute of Scientific and Technical Information of China (English)

    谢雄刚; 冯涛; 余照阳

    2012-01-01

    针对新提出的石门揭煤注液冻结防突方法,根据煤与瓦斯突出与煤层力学性能、煤层冻结温度之间的关系,结合人工冻结工程实践,采用岩石破裂过程分析RFPA2D系统,确定模型尺寸和边界条件,建立了石门揭露冻结煤层过程气固耦合数学模型。设定冻结温度下煤层的单轴抗压强度、弹性模量及瓦斯压力等相关参数,数值模拟了不同冻结温度下龙家山煤矿-400m水平2#石门揭露6#煤层过程。数值模拟表明:当6#煤层温度降为-10--20℃时,该石门揭煤工作面突出危险性将大为降低。综合冻结时间、能源消耗和防突效果,选定-10℃作为该石门揭露冻结煤层控制温度,可以提高突出矿井石门揭煤工程的经济效益。%Aiming at a new- presented outburst prevention method by injecting liquid and freezing in uncovering coal seam in cross - cut, according to the relationship among the coal and gas outburst, the mechanical properties and coal seam freezing temperature, and combining with artificial freezing engineering practice, with the reek failure process analysis software - RFDA2D, the paper determines the model sizes and boundary conditions and establishes gas and solid coupling mathematics model of uncovering frozen coal seam in cross - cut. Setting the interrelated parameters of gas pressure, uniaxial compressive strength and elastic modulus of coal seam under freezing temperature, the paper simulates the process of uncovering 6# freezing coal seam in 2# cross - cut of - 400 levels in Longjias- hart mine under the different freezing temperature. The simulation shows that when the temperature of 6# frozen coal seam drops to - 15 - -20℃, the gas outburst risk of the working face in 2# rock cross -cut will be greatly reduced. Integrating freezing time, energy consumption and outburst prevention effect, -10℃ is selected as the frozen seam control temperature of the working face, which can

  11. Variability of production in the Tito brown coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Vukovic, S. (Institut za Rudarska Istrazivanja, Tuzla (Yugoslavia))

    1987-05-01

    Examines daily production fluctuations in the Banovici coal basin from 1978-1985, where 2,800-4,100 workers produced 2-2.3x10{sup 6} t/a from underground and surface mines. The underground mine used mechanized longwall mining, surface mines employed shovel excavators, draglines, dumpers and belt conveyors. Statistical data showed large variations (+/- 2.5%, from 4,630 to 7,792 t/day) in daily coal production; evaluation showed close correlations for surface and underground mines. Highest production was achieved on Saturdays and Sundays, lowest on Mondays, Wednesdays and Fridays. It is suggested that these variations may be due to maintenance work in the coal preparation plant, which was usually carried out on Mondays and Fridays. A stereogram of coal and overburden output for both types of mine and detailed statistical computations are included. 7 refs.

  12. 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

  13. 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.

  14. 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.

  15. Study of the Physical Parameters of High Coal Seam%高瓦斯煤层的物性参数研究

    Institute of Scientific and Technical Information of China (English)

    赵文利

    2016-01-01

    煤与瓦斯突出是一种复杂的多因子瓦斯动力灾害,主要与煤体的瓦斯吸附解吸特征及突出危险性结构组成、力学特性、瓦斯赋存等一系列因素有关。为了研究煤体瓦斯的吸附解吸特性及突出危险性,通过对某煤矿4个采样点取样,并进行了工业性分析、煤岩学分析与孔隙结构分析,测定了煤样的瓦斯特征参数,为研究煤层瓦斯赋存状况、确定煤与瓦斯突出危险性敏感指标提供借鉴。%Coal and gas outburst is a complicated multi-factor gas dynamic disaster,it mainly relat-ed to the coal ore-body factors of gas adsorption,desorption characteristics,outburst dangerous,structural composition,mechanical properties and gas occurrence.In order to analyze the gas adsorption and desorp-tion characteristics and outburst dangerous of coal ore-body,the samples are obtained from the four sam-pling points of a coal mine,the samples are conducted industrial analysis,coal petrology analysis and pore structure analysis,the gas characteristics parameters of coal samples are obtained to provide refer-ence for studying the gas occurrence conditions of coal seam and determining the sensitive indicators of the coal and gas outburst dangerous.

  16. 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.

  17. 滴道盛和煤矿立井18~#煤层瓦斯地质规律分析%Laws Analysis of Gas Geology in Vertical Shaft of Didaoshenghe Coal Mine No.18 Coal Seam

    Institute of Scientific and Technical Information of China (English)

    苏广福

    2012-01-01

    在现场收集大量瓦斯与地质资料的基础上,结合大量的实测数据,采用瓦斯与地质理论相结合的方法,定性定量分析了滴道盛和煤矿立井18#煤层的瓦斯地质规律。分析了地质构造、煤层顶底板岩性、岩浆岩侵入、煤层底板标高对瓦斯赋存的影响,并对矿井瓦斯涌出量进行了预测。%On the basis of on-site collecting a lot of gas and geological data,with a large number of measured data,Using a method of combining gas and geological theory,gas geology laws in vertical shaft of Didaoshenhe coal mine No.18 coal seam are analyzed qualitatively and quantitatively.The influencing of geological structure,roof and floor lithologic,magmatic intrusion and coal seam floor elevation on gas occurrence is analyzed,and the gas emmission of coal mine is predicted.

  18. 模糊集合在煤变质程度与煤层气预测中的应用%The Application of Fuzzy Sets in Forecasting Coal Metamorphic Degree and Coal Seam Gas

    Institute of Scientific and Technical Information of China (English)

    李东; 张学梅; 程实; 王震

    2015-01-01

    煤的变质(煤化)程度在很大程度上决定了煤层最终的生烃能力和煤层气吸附能力的强弱. 煤的变质(煤化)程度可以用最大反射率Rmax来判定. 用计算所得强度指数(SI)和组分平衡指数(CBI)作为自变量,最大反射率(R)max为因变量,得到的回归方程就是煤的变质程度与最大反射率(R)max的非线性函数关系. 因此,最大反射率(R)max与煤的生气量或煤的吸附煤层气能力是非线性的函数关系.%The metamorphic degree of coal is a predominated factor which determines both the methane production capacity from seams and the methane adsorption capacity of seams. The metamorphic degree of coal can be evaluated through the maximum reflectivity (R)max. Using the strength index (SI) and composition balance index (CBI) as the independent variables, and the maximum reflectivity (R)max as dependent variable, a regression equation is obtained, which shows a nonlinear relationship. Therefore, the maximum reflectivity (R)max should have non-linear relationship with the methane production capacity from seams and the methane adsorption capacity of seams.

  19. Effects of fractal surface on rheological behavior and combustion kinetics of modified brown coal water slurries

    Institute of Scientific and Technical Information of China (English)

    Zhifang Gao; Shuquan Zhu; Mingdong Zheng; Zhaojin Wu; Huihong Lu; Weiming Liu

    2015-01-01

    The paper reports the effects of surface fractal structures on the rheological behavior and combustion kinetics of raw brown coal and three modified coal water slurries (CWSs). The results show that the fractal structures and physicochemical properties of samples are dependent on various modification processes. The apparent viscosities of the coal water slurries increase with increasing surface fractal dimensions (D), especially with decreasing shear rates. Fur-thermore, it has been proved that the ignition temperatures and apparent activation energies of modified CWSs are lower than that of raw coal water slurry. Compared with the traditional qualitative analysis of the effect of pore structures on CWSs properties, D can more efficiently indicate the quantificational effect of pore structures on the rheological behavior and combustion kinetics of CWSs.

  20. 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。

  1. 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.

  2. 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

  3. 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).

  4. The competitive strength of German brown coal; Deutsche Braunkohle im Wettbewerb

    Energy Technology Data Exchange (ETDEWEB)

    Henning, D.

    1997-01-01

    On the occasion of a celebration on 4 December 1996, Dr.-Ing. Dieter Henning, Chairman of the Board of Rheinbraun-AG, outlined the changes in the energy-political boundary conditions in Germany and Europe, strategies for maintaining the competitive strength of brown coal, and the importance of this feld of industry, and especially of the Garzweiler II oopen-cast mine, for the structural development of the Rhenish brown coal district. (orig.) [Deutsch] Die gemeinsame Barbara-Feier am 4. Dezember 1996 in der Erfthalle Kerpen-Tuernich war dem Vorstandsvorsitzenden der Rheinbraun AG, Bergwerksdirektor Dr.-Ing. Dieter Henning Anlass genug, von den Fuehrungskraeften des Rheinischen Braunkohlenbergbaus und den Bergingenieuren vom Bezirksverein Rheinische Braunkohle, die Veraenderungen der energiewirtschaftlichen Rahmenbedingungen in Deutschland und Europa, die Sicherung der Wettbewerbsfaehigkeit der Braunkohle und die Bedeutung dieses Industriezweiges und vor allem von Garzweiler II fuer die strukturelle Entwicklung des rheinischen Reviers, darzulegen. (orig.)

  5. 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.

  6. 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

  7. 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).

  8. Mechanochemical activation of iron ore-based catalysts for the hydrogenation of brown coal

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, P.N.; Kuznetsova, L.I.; Chumakov, V.G.; Moiseeva, G.A. [Rossijskaya Akademiya Nauk, Krasnoyarsk (Russian Federation). Inst. of Chemistry and Chemical Technology

    2000-10-01

    Genesis of pyrrhotite catalysts from different iron ore concentrates and pure iron oxides was investigated using the method of mechanochemical treatment in a planetary mill. The dispersion and fine crystalline structure of oxide and pyrrhotite particles were studied as the function of mechanical load, sulfiding temperature and mode of preparation. Methods for the preparation of high performance iron ore-based catalysts for brown coal hydrogenation have been developed. (orig.)

  9. 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)

  10. 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。

  11. 近距离煤层群下行开采切眼错距确定分析%Analysis on determination of alternate distance for open-off cut in downward mining of close distance coal seam group

    Institute of Scientific and Technical Information of China (English)

    陈善乐; 王坤; 汪华君; 崔铁军

    2015-01-01

    在近距离煤层群的开采中,工作面巷道位置选择直接影响其支护方式、顶底板管理等生产工作。为了得到下位煤层工作面切眼的合理位置,利用基于三维显式有限差分法的计算工具Flac3D,以矿井近距离煤层9、101、102为工程实例,分析了在近距离煤层群回采时期,下邻近层综采工作面切眼位置与上邻近层预留保护煤柱错距。结果表明,上邻近层回采后,在其因支承压力和拉张作用下的下沉盆地中岩层内,主要发生塑性变形;上覆岩层破坏范围为26m,底板破坏范围为5.6m,采空区左右两侧破坏范围3~5m;下位煤层10603工作面切眼与上位煤层9煤保护煤柱错距应大于5m。%The position of working face roadway directly influences its support way, roof and floor management, and other production work in mining of close distance coal seam group.In order to get the reasonable position of open-off cut in working face of the lower coal seam, the computing tools -Flac3D based on three dimensional explicit fi-nite difference method was applied.Taking the close distance coal seams 9th , 101 th, 102 th as engineering exam-ples, the alternate distance of open-off cut in the fully mechanized working face of lower adjacent coal seam to guard coal pillar in upper adjacent coal seam during the stoping period of close distance coal seam group was ana-lyzed.The results showed that after the stoping of upper adjacent coal seam, the plastic deformation is mainly dis-tributed in rock strata of subsidence basin under the effect of abutment pressure and tensile.The damage range of o-verlying strata is 26 m, the damage range of floor is 5.6m, and that in both sides of goaf is 3-5 m.The alternate distance of open-off cut in the 10603 working face of lower coal seam to guard coal pillar in 9th of upper coal seam should be greater than 5m.

  12. 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.

  13. 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.

  14. 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.

  15. 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。

  16. 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)

  17. 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

  18. 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)

  19. 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%.

  20. 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%

  1. 硬质体构造对煤层瓦斯流动的力学控制效应%Mechanical control effect of hard tectonic structure on coal seam gas flow

    Institute of Scientific and Technical Information of China (English)

    张春华; 张卫亮; 王继仁

    2014-01-01

    为研究煤层内硬质体构造对瓦斯流动的力学控制效应,运用数值模拟分析和现场验证相结合的研究方法,对正常煤层和含硬质体煤层掘进工作面的应力异常分布特性、煤层渗透性变化和瓦斯流动规律进行了对比分析。研究结果表明:掘进工作面前方硬质体构造附近的集中应力就像一道“闭合闸门”,明显降低了附近煤体的渗透性,阻碍了较远处煤体内的瓦斯向掘进工作面的正常渗流流动,这是高瓦斯矿井采掘过程中瓦斯异常涌出的诱因之一。为避免高瓦斯煤层掘进工作面瓦斯异常涌出威胁,所采取的各种卸压增透措施必须打开或卸除这个“闭合闸门”,为前方煤层瓦斯的安全释放提供畅通通道。%To analyze the controlling effect of hard tectonic structure to gas flow at the coal seam heading face,two physical mechanical models are established,normal coal seam driving and hard body embedding coal seam driving.Then according to the above two numerical models,it numerically analyzes the stress distribution characteristics,the coal seam permeability change and the gas flow rule at the coal seam heading face by using rock fracture finite element software RFPA2D-GAS with solid-gas coupling analysis module,and carries on comprehensive comparative analysis.Finally,combining with two ordinary cases from product field,it verifies the conclusion from the numerical simulation that the concentrated stress influences the coal seam permeability and controls the gas flow.The results show that:the concentrated stress at the coal heading face with hard tectonic structure is like a “closed gate”,as it makes the coal seam permeability obviously lower and blocks the normal migration of gas in the vicinity to the freedom space.In order to eliminate the gas abnormal emission threat at the high gassy coal seam heading face,stress and gas relief measures must be taken to rip the “closed gate

  2. Demineralization of Gondwana coal with Pseudomonas mendocina strain B6-1: a case study of coal from Gopinathpur top and bottom seams of Mugma mine, Dhanbad, Jharkhand (India)

    Institute of Scientific and Technical Information of China (English)

    Prakash K.Singh; Asha Lata Singh; Mahendra P.Singh; A.S.Naik; Dharmshila Singh; Spardha Rai; Aniruddha Kumar

    2016-01-01

    In the present investigation an attempt has been made to demineralize the Gondwana coal of Gopinathpur top and bottom seams of Mugma mine,Raniganj coalfield,Dhanbad with the help of Pseudomonas mendocina strain B6-1.The change in the amount of ash yield and decrease in the concentration of selected minor elements like Na,K,Mn and Ca and environmentally sensitive selected trace elements such as Cd,Pb,Se,Ni,Mn,and Zn have been studied as a function of time of bacterial treatment as well as with variation in the bacterial biomass.After 28 days of bacterial treatment there was variable amount of decrease observed in ash yield as well as in the concentration of minor and trace elements.The removal of the elements was further enhanced with the increase in the bacterial biomass from 10 to 25 mg/mL.Due to over exploitation of superior grade coals in the country,the remaining coal resources,available for current use,are inferior in grade and contain high level of impurities and there is ample scope of bio-beneficiation of these coals using bacterial biomass.

  3. 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)

  4. Sulfur emission from Victorian brown coal under pyrolysis, oxy-fuel combustion and gasification conditions.

    Science.gov (United States)

    Chen, Luguang; Bhattacharya, Sankar

    2013-02-01

    Sulfur emission from a Victorian brown coal was quantitatively determined through controlled experiments in a continuously fed drop-tube furnace under three different atmospheres: pyrolysis, oxy-fuel combustion, and carbon dioxide gasification conditions. The species measured were H(2)S, SO(2), COS, CS(2), and more importantly SO(3). The temperature (873-1273 K) and gas environment effects on the sulfur species emission were investigated. The effect of residence time on the emission of those species was also assessed under oxy-fuel condition. The emission of the sulfur species depended on the reaction environment. H(2)S, SO(2), and CS(2) are the major species during pyrolysis, oxy-fuel, and gasification. Up to 10% of coal sulfur was found to be converted to SO(3) under oxy-fuel combustion, whereas SO(3) was undetectable during pyrolysis and gasification. The trend of the experimental results was qualitatively matched by thermodynamic predictions. The residence time had little effect on the release of those species. The release of sulfur oxides, in particular both SO(2) and SO(3), is considerably high during oxy-fuel combustion even though the sulfur content in Morwell coal is only 0.80%. Therefore, for Morwell coal utilization during oxy-fuel combustion, additional sulfur removal, or polishing systems will be required in order to avoid corrosion in the boiler and in the CO(2) separation units of the CO(2) capture systems.

  5. 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.

  6. 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...

  7. The issues of the self-fill aquifer in the north Bohemian brown coal basin

    Energy Technology Data Exchange (ETDEWEB)

    Halir, J.; Zizka, L. [Brown Coal Research Inst., Most (Czech Republic)

    2010-07-01

    The brown coal basin in the Czech Republic is located in the northwestern region of the country. Mining activities in the region have led to the flooding of various underground areas. This paper described the dewatering activities conducted as a safety procedure in a mine located in the brown coal basin. Pumping stations were established in various parts of the basin to collect inflows. Average annual pumping for the stations is approximately 990,000 m{sup 3} of mine water. The deepest pumping station in the basin is 90 meters under sea level. The activities are being conducted to ensure that a self-fill system is established to create a large self-filling water horizon after mining activities have stopped. Depressions in the mine will be successively flooded to create reservoirs of self-filling water. A computerized model of the water fluctuation rates in the mine is being prepare to accurately characterize the filling process. 6 refs., 2 figs.

  8. Gas -bearing Property and Main Geological Controls of Coal Seam in Shaqu Minefield Liliu Mining Area%离柳矿区沙曲井田煤层含气性及主控因素分析

    Institute of Scientific and Technical Information of China (English)

    常会珍

    2015-01-01

    Through the research of coal seam gas bearing characteristics in Shaqu coalfield,analysis of the main control factors of gas distribution,the results show that the different types of geologicalstructure,hydrogeological con-ditions,roof and floor lithology influence on coalbed gas enrichment are different;coal seam gas content and buried depth of coal seam,the bedrock thickness,vitrinite content have a positive correlation,Overall,hydrogeology is favor-able to coalbed methane enrichment.%通过研究沙曲井田煤层含气性特征,分析了影响含气性分布的主控因素,结果表明,不同地质构造类型、水文地质条件、顶底板岩性对煤层气富集的影响均不同;煤层含气量与煤层埋深、上覆基岩厚度、镜质组含量呈正相关关系。总体上看,水文地质有利于煤层气的富集。

  9. 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)

  10. 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

  11. 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.

  12. 东滩煤矿煤层底板岩层阻水能力试验研究%Experiment of reduction infiltration ability of rock formation under the coal seam floor at Dongtan Coal Mine

    Institute of Scientific and Technical Information of China (English)

    张维建; 张新武; 张冬

    2015-01-01

    底板岩层压水试验能够获得可靠的底板岩层阻水能力实测数据, 为深部煤层开采底板岩层阻水能力提供量化依据,对东滩煤矿深部煤层底板岩层进行压水测试,获得了大量的实测数据并依此计算出岩层的渗透系数. 试验结果表明测试底板岩层段在原始状态下的渗透性很低,阻水能力较强.研究结果可为矿区深部工作面的安全开采提供重要的参考依据.%The reliable reduction infiltration characteristics of rock mass could be obtained by the water injection experiment under the coal seem floor. The data of water injection experimnt were obtained and permeability coefficient of floor formation were deduced through water in-jection experiment at Dongtan Coal Mine. Result shows that the test rock formations are all low-permeability, which mean they have high re-duction infiltration ability. The results make a important reference for safety-mining of deep coal seam working face.

  13. 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.

  14. The mechanism and field test of permeability improvement by hydraulic flushing in three-soft and single coal seam%“三软”单一煤层水力冲孔卸压增透机理及现场试验

    Institute of Scientific and Technical Information of China (English)

    冯文军; 苏现波; 王建伟; 秦俊宾; 李贤忠

    2015-01-01

    Hydraulic flushing is the most effective way for high-efficient extraction in three-soft coal seam. In this paper, the mechanism was studied by laboratory experiment, theoretical analysis and field test for pressure relief and permeability improvement in three-soft coal seam after hydraulic flushing. The coupling experiment of stress and strain-coal structure-permeability revealed the evolution of permeability along with the change of the structure and stress, and found that permeability of soft coal was improved on a large scale after pressure relief. Based on Hoek-Brown criterion theory, the numerical simulation results show that the relief range increased significantly af-ter hydraulic flushing in coal. The hydraulic flushing tests using self-developed machine for gas drainage borehole in 21141 floor drainage tunnel of Daping Mine shows, the machine made hydraulic flushing more secure and effi-cient, and made it possible to repair the old drainage borehole . The field tests fully tested the reliability of the equipment and the accuracy of the above theoretical analysis, and improved the extraction efficiency significantly.%水力冲孔是实现“三软”煤层瓦斯高效抽采的有效途径之一。通过应力应变–煤体结构–渗透率的耦合实验,揭示了“三软”煤层渗透率随煤体结构和应力变化的演化规律,发现软煤在卸压后渗透率得到大规模提升。以Hoek-Brown准则为理论依据,通过数值模拟,发现水力冲孔出煤后的卸压增透范围显著增加。采用自主研发的“瓦斯抽采孔水力作业机”,在郑煤集团大平煤矿21141底板抽放巷进行了水力冲孔试验,使得水力冲孔更加安全、高效,并使得老孔的修复成为现实。现场试验充分检验了装备的可靠性和理论分析的准确性,显著提高了煤层瓦斯的抽采效率。

  15. INFLUENCE OF SATURATION PERIOD ON BURSTING LIABILITY INDICES FOR COAL SEAM #2 IN QIANQIU COAL MINE%饱水时间对千秋煤矿2#煤层冲击倾向性指标的影响

    Institute of Scientific and Technical Information of China (English)

    苏承东; 翟新献; 魏向志; 李宝富

    2014-01-01

    为分析饱水时间对煤体的力学性质与冲击倾向性指标的影响,对千秋煤矿2#煤层自然和饱水7~28 d处理后煤样,在RMT-150B岩石力学试验系统进行冲击倾向性指标测定。结果表明:在自然与饱水状态下,煤样的抗压强度与弹性模量、峰前积蓄能量和冲击能量指数均成正相关。饱水煤样的抗压强度、弹性模量、冲击能量指数以及峰前积蓄能量均有不同程度降低。饱水7~10 d后煤的力学性质和冲击倾向性指标变化显著,而后有所减缓。在自然含水状态下,2#煤层属于中等冲击类(II类),饱水7~28 d后2#煤层的冲击倾向性指标有较大降低,由中等冲击类变为弱冲击类(弱II类);建议千秋煤矿采煤工作面注水超前时间7~10 d,超前距离约30 m为宜。%To analyze the influence of saturation period on the mechanical properties and bursting liability indices of coal mass,the bursting liability indices were tested on the specimens of coal seam #2 in Qianqiu coal mine with natural water content and saturation for 7-28 d,respectively. The results show that,under natural and saturation states,the elastic modulus,impact energy index and pre-peak accumulated energy of the coal specimens are all positively correlated with the compression strength. Water saturation of the coal specimens can decrease their compression strength,elastic modulus,impact energy index and pre-peak accumulated energy in different degrees. The saturation period of 7-10 d for the coal specimens has a significant effect on their mechanical properties and bursting liability indices;after then,the influence degree would decrease. Under natural state,the bursting liability of coal seam #2 belongs to moderate impact type(type II). After the saturation period of 7-28 d,the bursting liability index decreases obviously,and becomes weak impact type(weak type II). Therefore,it is suggested that the water should be injected about 7-10 d

  16. 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。

  17. 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。

  18. Land management in surface mining with the example of the Belchatow brown coal mine

    Energy Technology Data Exchange (ETDEWEB)

    Wasowicz, J.; Skalska, T.

    1986-01-01

    The Belchatow brown coal surface mine will cover 5720 ha of land - 2563 ha of arable land, 831 ha of pasture land, 1598 ha of forests and 678 ha of other land types (e.g. waste, roads, etc.). Regulations on land management and environmental protection in Poland are analyzed. Their effects on land management in the Belchatow mine are evaluated. Types of soils, their agricultural use, types of private and state farms in the mine area are discussed. Problems associated with expropriation, expropriation cost and effects of mine construction on agriculture in the Belchatow area are also analyzed. Selected problems associated with balance of manpower in the area and effects of growing employment in the mine on lack of manpower in agriculture are evaluated. Program for land reclamation, its cost, planned investment, organizational models of land reclamation and types of land utilization after reclamation are described. 1 refs.

  19. Transformation of chlorine in NaCl-loaded Victorian brown coal during the gasification in steam

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shu; Mohammad Asadullah; Rosalie Hocking; LIN Jian-ying; LI Chun-zhu

    2012-01-01

    This study is to examine the changes in Cl volatilizations and chemical forms in NaCl-loaded Victorian brown coal during gasification in steam at 800 ℃ using Cl K-edge X-ray absorption near-edge structure (XANES) spectroscopy.The char samples were prepared in a novel one-stage fluidised-bed/fixed-bed quartz reactor at a fast heating rate.The samples were then collected and sealed in an argon-filled bag in order to minimise possible oxidation of char and Cl by air prior to analysis by XANES.Char-steam reactions were found to significantly affect the transformation of Cl,including the possible formation of chlorine-containing organic structures.On the other hand,volatile-char interactions during the gasificauon appeared to enhance the Cl retention and prevent the formation of organic chlorine compounds in chars.

  20. 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。

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 煤矿井下煤层密闭取心装置%Study on Coal Seam Airtight Coring Facility in Coalmines

    Institute of Scientific and Technical Information of China (English)

    张丁亮

    2015-01-01

    The underground sampling facilities now available for CBM content test in coalmines have a defect of coal core exposing, thus caused incorrect measuring of lost gas, and impact CBM content measuring accuracy;while the airtight (pressure-tight) coring fa-cilities used in oil and gas fields should be matched with wire-line coring tools on surface, thus expensive and unfit for underground coal seams. The USC-1 coalmine underground airtight coal coring facility is a swivel barrel corer, including coring bit, outer barrel and drill rod sub connected in turn;within outer barrel, an inner barrel hanging, on upper end of inner barrel connected a ball-seat swivel and hanging assemblage, on lower end connected an inner barrel airtight ball valve;a hydraulic closing setup installed between inner and outer barrels;the upper end of hydraulic closing setup connected with ball-seat swivel, while the lower end connected with closing ball valve semi-slip ring. Taking the Hujiahe coalmine of the Shaanxi Binchang Mining Group as the application site, main mineable coal No.4 as the coring test target, using a borehole in the site carried out common coring barrel and airtight coring facility gas content determination respectively, the result has shown that the later can make the coal core under airtight status during the coring, thus can reduce sample gas loss, thus can effectively improve coalmine underground CBM content measuring accuracy.%现有煤矿井下煤层气含量测试取样装置在提心过程中煤心暴露,致使损失气测算不准,影响煤层气含量测定精度,而油气田上使用的密闭(保压)取心装置需在地面配合绳索取心工具使用,且费用高昂,不适合井下煤层.USC-Ⅰ型煤矿井下煤层密闭取心装置为一个双筒单动式取心器,包括依次连接的取心钻头、外筒和钻杆接头;外筒内悬挂有内筒,内筒上端连接有球座分水接头和悬挂总成,内筒下端连接有内筒密闭球阀;内筒和外筒之

  6. 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

  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. The Controlling Factors of Coal Seam Gas Enrichment in Jiaozuo Coalfield%焦作煤田煤层气富集的控制因素

    Institute of Scientific and Technical Information of China (English)

    高灶其; 刘文波; 闫广厚; 徐红伟

    2015-01-01

    Jiaozuo coalfield was rich in coalbed methane resources .Due to restriction conditions such as formation, migration, storage and cap rock of coalbed methane , each mining field and block also had big differences in enrichment and mineralization .Based on survey and assessment of coalbed methane resource potential in Jiaozuo coalfield , the influencing factors of coalbed methane enrichment and distribution in this region were deeply studied , especially the bedrock buried depth , fault structure , hydrogeological conditions , combination relations of coal seam roof and floor lithologic as well as degree of coalification .Furthermore based on the comprehensive analysis of a-bove aspects , the enrichment regularity of the coalbed methane resources in Jiaozuo coalfield and geological conditions in favor of preservation of coalbed methane were put forward .%焦作煤田蕴藏着丰富的煤层气资源,因受煤层气的生成、运移、储藏、盖层等条件的制约,各井田、区块富集成藏也存在较大差异。深入研究了该地区影响煤田煤层气富集和分布的因素,即煤层埋深特别是基岩埋深、断裂构造、水文地质条件、煤层顶底板岩性的组合关系以及煤化程度,并提出了焦作煤田煤层气资源富集规律,以及有利于煤层气保存的地质条件,为焦作煤田煤层气的勘查与开发提供了理论依据。

  9. 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。

  10. 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.

  11. 瓦斯抽放煤层增透深孔聚能爆破钻孔参数%Drilling parameters of deep-hole cumulative blasting to improve coal seam permeability in gas drainage

    Institute of Scientific and Technical Information of China (English)

    郭德勇; 吕鹏飞; 单智勇; 谢安

    2013-01-01

    以焦作煤业集团九里山矿煤层深孔聚能爆破试验为基础,利用数值模拟分析了爆破煤体应力变化规律,发现聚能爆破效应导致应力峰值增大,扩大了煤体裂隙区范围.同时对聚能爆破钻孔参数进行优化,确定了合理的炮孔直径、爆破孔间距、爆破孔与邻近抽放孔及煤层顶底板间距.现场试验结果表明:优化的钻孔参数不仅使聚能爆破增透效果显著而且保证了爆破过程的安全.%Based on coal seam deep-hole cumulative blasting experiments in Jiulishan Coal Mine of Jiaozuo Coal Group, the law of stress change in a blasting coal body was analyzed by numerical simulation. It is found that cumulative blasting effect leads to the increase of peak stress and enlarges the crack zone range of the coal body. Drilling parameters for cumulative blasting, such as blast hole diameter, blast hole spacing, distance between the blast hole and the adjacent gas drainage hole, and distance from the blast hole to the coal seam roof and floor, were determined by optimization. Field experimental results show that after using these optimized drilling parameters the cumulative blasting not only gets remarkable permeability increasing effect but also ensures blasting safety.

  12. 浅埋煤层开采的矿井水来源判别%Source Discrimination of Mine Water from Shallow Buried Coal Seams Mining

    Institute of Scientific and Technical Information of China (English)

    申涛; 马雄德; 戴国锋

    2011-01-01

    以陕北侏罗纪煤田凉水井煤矿为例,研究了浅埋煤层开采涌水量规律,根据煤矿井下水样的氢氧同位素构成,计算了矿井水的来源.该区矿井水接受风化基岩裂隙承压水和萨拉乌苏组潜水的补给,矿井水8D为-70‰,裂隙水8D为-80‰,萨拉乌苏组潜水8D为-67.46‰,由此可以计算出矿井水的补给来源主要是萨拉乌苏组地下水,萨拉乌苏组潜水补给占79.74%,基岩裂隙水补给占20.26%,据此提出该区保水采煤重点是保护萨拉乌苏组地下水含水结构的稳定性.%Taking the liangshuijing coalmine in the northern Shaanxi Jurassic coalfield as an example, studied the regular pattern of water inflow during shallow buried coal seams mining. Based on hydrogen and oxygen isotopic composition of water samples from coalmine underground, discriminated mine water source. The mine water in the area accepts recharges from weathered bedrock fissure confined water and Xar Us Formation phreatic water. The 8D of mine water is -70%0, fissure water -80%o and phreatic water -67.46%0, thus the main recharging source of mine water is from the Xar Us Formation groundwater can be calculated, the percent sharing of phreatic water is 79.74%, bedrock fissure water 20.26%. In view of the above, the emphasis on water conservation coal mining is to protect stability of Xar Us Formation water-bearing structure.

  13. Brief Discussion on Methods of Increase Production of Coal Seam Gas%煤层气增产方法浅析

    Institute of Scientific and Technical Information of China (English)

    侯飞强

    2014-01-01

    煤层气是一种清洁能源,煤层气产业是我国在“十二五”期间重点鼓励发展的产业之一。随着我国煤矿瓦斯抽采工作的进一步深化和煤层气资源地面开发的逐步商业化,煤层气资源的开发模式也以逐步完善。根据煤层气的存储状态及煤层所处的构造位置,煤层气可划分为自生自储吸附型、自生自储游离型和内生外储型3种成藏模式,不同成藏模式的富集高产机制不同[1]。而煤层气的成藏模式的不同使得不同的矿井需要因地适宜地使用不同的开采方式。主要介绍了煤层气开发过程中的制约问题及一些增大产量的方法。%Coalbed methane is a kind of clean energy. Coalbed methane industry is one of the industries are encouraged de-velopment during the“twelfth five-year”. Along with further deepening of our country coal mine gas extraction work and gradually commercialized of development of Coalbed methane resources in the ground, CBM resources development mode is to gradually improved. According to the Coalbed methane storage state and position in the construction of the coal seam, CBM can be divided into adsorption model, self-reservoir sequestration and endogeny externally storaged. High yielding mech-anism of different enrichment is different. And, differences of reservoiring patterns make different mines need to use different mining way. This paper mainly was introduced constraints and some of the ways to increase production in the process of coalbed methane development.

  14. A Discussion on Gamma-gamma Logging Traces Coal Seam Thickness Interpreting Accuracy Improvement%提高伽马伽马曲线煤层定厚解释精度方法探讨

    Institute of Scientific and Technical Information of China (English)

    罗忠文

    2014-01-01

    In coal shortage areas, there have larger coal resources hosting differentia, the coal thickness lower limit can be incorporated into resource estimation is rather low, in some areas even downgrade to 0.30m. At present, coal seam thickness interpretation commonly uses apparent resistivity and gamma-gamma traces. Coal roof and floor interpreting points on apparent resistivity traces is according to the“root knee points”, thus smaller human errors;while on gamma-gamma traces are 2D functions of coal seam density and coal roof, floor density, thus larger changes. Based on symmetry principle in gamma-gamma logging, using average density method to determine coal seam thickness has been put forward. Those is using coal seam gamma-gamma traces amplitude multiplies by coal roof, floor coun-try rock gamma-gamma traces amplitudes respectively, and then extract to get gamma-gamma amplitude to interpret thickness deter-mining roof and floor points. The method can not only improve gamma-gamma traces coal thickness interpretation accuracy, but also simplify complex issues, thus stronger operability and applicability in practices.%在贫煤地区,煤炭资源赋存差异较大,纳入资源量计算的煤层厚度也较低,个别地区甚至降到0.30m。目前煤层定厚解释常用视电阻率曲线和伽马伽马曲线。煤层顶底板在视电阻率曲线的解释点是“根部拐点”,因此人为误差较小;而伽马伽马曲线的解释点是煤层密度和煤层顶底板密度的二维函数,变化较大。根据伽马伽马测井曲线的对称性原理,提出利用平均密度法确定煤层定厚点,即用煤层伽马伽马曲线幅值分别与顶、底板围岩的伽马伽马曲线幅值相乘后再开方的方法获得煤层定厚顶、底板解释点的伽马伽马幅值。该方法既提高了伽马伽马曲线煤层定厚解释精度,又将复杂问题简单化,在实际工作中具有较强的可操作性和使用性。

  15. Geothermal, Geochemical and Geomagnetic Mapping Of the Burning Coal Seam in Fire- Zone 18 of the Coal Mining Area Wuda, Inner Mongolia, PR China.

    Science.gov (United States)

    Kessels, W.; Han, J.; Halisch, M.; Lindner, H.; Rueter, H.; Wuttke, M. W.

    2008-12-01

    Spontaneous combustion of coal has become a world wide problem caused by and affecting technical operations in coal mining areas. The localization of the burning centre is a prerequisite for any planning of fire fighting operations. In the German - Chinese coal fire project sponsored by the German Ministry of Science and Technologies (Grant No. 0330490K) the so called fire zone 18 of the coal mining area of Wuda (InnerMongolia, PR China) serves as a test area for geophysical measurements. For the geothermal and geochemical mapping 25 up to 1m deep boreholes with a diameter of approx. 30 mm are distributed over the particular fire-zone with an extension of 320 × 180 m2. To avoid the highly dynamic gas flow processes in fire induced fractures caused by weather conditions, all boreholes were situated in the undisturbed rock compartments. In these boreholes, plastic tubes of 12 mm diameter provide access to the borehole ground filled with highly permeable gravel. The boreholes are otherwise sealed to the atmosphere by clay. The geothermal observations consist of measurements of temperature profiles in the boreholes and thermal conductivity measurement on rock samples in the lab. For depths greater then 0.2 m diurnal variations in the temperature gradient were neglected. The derived heat flow with maximum values of 80 W/m2 is more then three orders of magnitude higher than the natural undisturbed heat flow. The high heat flow suggests that the dominant heat transport is gas convection through the system of porous rock and fractures. Any temperature anomaly caused by the burning coal in a depth of more than 18 m would need years to reach the surface by a heat transport restricted to conduction. The geochemical soil gas probing is performed by gas extraction from the boreholes. Measured are the concentrations of O2, CO, CO2, H2S and CH4. The O2 deficit in the soil air and the concentrations of the other combustion products compared to the concentrations in the free

  16. 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.

  17. 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.

  18. 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.

  19. 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。

  20. 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.

  1. 基于突变理论的煤层不连续性检测技术%Technology for detection of coal seam discontinuity based on catastrophe theory

    Institute of Scientific and Technical Information of China (English)

    于鹏飞; 董守华; 杨小慧; 薛海飞; 程彦

    2011-01-01

    通过突变理论的尖点突变模型及分析,将地震信号转化为尖点突变的标准形式.在时间域、频域计算突跳势、突跳时间等突跳参数,分析突跳参数异常,较好的反映了煤层的不连续性;比较相干、突跳理论两种技术在反映煤层不连续性上的效果,分析了各种技术的优缺点.尝试将相干属性和突跳参数属性进行融合,得到新的属性切片,很好的反映了煤层断层和裂隙富集区的分布情况.研究表明,利用突变参数进行断层的检测是可行的,突变理论将为煤层不连续性检测提供一种新的方法.%The cusp model of catastrophe theory and its expression are mentioned in this paper. The seismic record is transformed into the normal form of cusp catastrophe. Catastrophic potential, catastrophic time and so on are calculated in time domain and in frequency domain. Analysis of catastrophic anomalies can better reflect the discontinuity of coal seam. Comparing the effect of the theories of coherence and catastrophe in reflecting coal seam discontinuity, advantages and disadvantages of these two techniques were analyzed. Finally attempting to attribute catastrophe parameters with coherence and getting the new sections can reflect the distribution of zones rich in faults and fractures in coal seams. The study indicates that using catastrophe parameters to detect faults is feasible and catastrophe theory provides a new method for coal seam discontinuity detection.

  2. Discussion on GFC-018 Coal Seam Drilling in 1022 Working Face,Jianxin Colliery%浅谈建新矿1022工作面过GFC-018煤层气钻孔

    Institute of Scientific and Technical Information of China (English)

    刘华明; 邹海泉

    2015-01-01

    The paper introduces the action of reasonable drilling on GFC-018 coal seam ,in 1022 working face , Jianxin Colliery ,which ensures the safety of working face while drilling .%介绍了丰城矿务局建新煤矿1022工作面过G FC-018煤层气钻孔时,合理留设钻孔保护煤柱的作法,确保了工作面过钻孔时的安全。

  3. Methods and costs of thin-seam mining. Final report, 25 September 1977-24 January 1979. [Thin seam in association with a thick seam

    Energy Technology Data Exchange (ETDEWEB)

    Finch, T.E.; Fidler, E.L.

    1981-02-01

    This report defines the state of the art (circa 1978) in removing thin coal seams associated with vastly thicker seams found in the surface coal mines of the western United States. New techniques are evaluated and an innovative method and machine is proposed. Western states resource recovery regulations are addressed and representative mining operations are examined. Thin seam recovery is investigated through its effect on (1) overburden removal, (2) conventional seam extraction methods, and (3) innovative techniques. Equations and graphs are used to accommodate the variable stratigraphic positions in the mining sequence on which thin seams occur. Industrial concern and agency regulations provided the impetus for this study of total resource recovery. The results are a compendium of thin seam removal methods and costs. The work explains how the mining industry recovers thin coal seams in western surface mines where extremely thick seams naturally hold the most attention. It explains what new developments imply and where to look for new improvements and their probable adaptability.

  4. Growth strategy of heterotrophic bacterial population along successional sequence on spoil of brown coal colliery substrate

    Energy Technology Data Exchange (ETDEWEB)

    Kristufek, V.; Elhottova, D.; Chronakova, A.; Dostalkova, I.; Picek, T.; Kalcik, J. [Academy of Science in Czech Republic, Ceske Budejovice (Czech Republic). Inst. of Soil Biology

    2005-07-01

    The bacterial population of brown coal colliery spoil (Sokolov coal mining district, Czech Republic) was characterized by measuring viable bacterial biomass, the culturable to total cell ratio (C:T), colony-forming curve (CFC) analysis and species and/or biotype diversity. Bacterial representatives that differed in colony-forming growth (fast and/or slow growers) were used for growth-strategy investigation of heterotrophic bacteria. Spoil substrates from the surface (0-50 mm) and the mineral (100-150 mm) layers were sampled on 4 sites undergoing spontaneous succession corresponding to 1, 11, 21 and 43 years after deposition (initial, early, mid and late stages). The bacterial biomass of the surface layer increased during the initial and early stages with a maximum at mid stage and stabilized in the late stage while mineral layer biomass increased throughout the succession. The maxima of C:T ratios were at the early stage, minima at the late stage. Depending on the succession stage the C:T ratio was 1.5-2 times higher in the mineral than the surface layer of soil. An increase in the fraction of nonculturable bacteria was associated with the late succession stage. CFC analysis of the surface layer during a 3-d incubation revealed that the early-succession substrate contained more (75%) rapidly colonizing bacteria than successively older substrates. The culturable bacterial community of the mineral layer maintained a high genera and species richness of fast growers along the succession line in contrast to the surface layer community, where there was a maximum in the abundance of fast growers in the early stage. A markedly lower abundance of slow growers was observed in the mineral in contrast to the surface layer.

  5. Material and structural characterization of alkali activated low-calcium brown coal fly ash.

    Science.gov (United States)

    Skvára, Frantisek; Kopecký, Lubomír; Smilauer, Vít; Bittnar, Zdenek

    2009-09-15

    The waste low-calcium Czech brown coal fly ash represents a considerable environmental burden due to the quantities produced and the potentially high content of leachable heavy metals. The heterogeneous microstucture of the geopolymer M(n) [-(Si-O)(z)-Al-O](n).wH(2)O, that forms during the alkaline activation, was examined by means of microcalorimetry, XRD, TGA, DSC, MIP, FTIR, NMR MAS ((29)Si, (27)Al, (23)Na), ESEM, EDS, and EBSD. The leaching of heavy metals and the evolution of compressive strength were also monitored. The analysis of raw fly ash identified a number of different morphologies, unequal distribution of elements, Fe-rich rim, high internal porosity, and minor crystalline phases of mullite and quartz. Microcalorimetry revealed exothermic reactions with dependence on the activator alkalinity. The activation energy of the geopolymerization process was determined as 86.2kJ/mol. The X-ray diffraction analysis revealed no additional crystalline phases associated with geopolymer formation. Over several weeks, the (29)Si NMR spectrum testified a high degree of polymerization and Al penetration into the SiO(4) tetrahedra. The (23)Na NMR MAS spectrum hypothesized that sodium is bound in the form of Na(H(2)O)(n) rather than Na(+), thus causing efflorescence in a moisture-gradient environment. As and Cr(6+) are weakly bonded in the geopolymer matrix, while excellent immobilization of Zn(2+), Cu(2+), Cd(2+), and Cr(3+) are reported.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. Study on safe thickness of overlying thin bedrock in fully-mechanized top-coal caving face with thick coal seam

    Institute of Scientific and Technical Information of China (English)

    FANG Xin-qiu; HUANG Han-fu; HE Jie

    2007-01-01

    To prevent support crush, the overlying strata safe thickness and its influential elements were studied by the adoption of theoretical analysis, numerical simulation and in-situ measurement. According to the production and geological condition of first face in Sima coal mine, the results indicate that the clay contains large permissible bearing ability and has better arching force. After mining destruction, stable structure is formed in bedrock to ensure face safety. The clay thickness & bedrock thickness are the key influential elements to stable structure. The minimal bedrock thickness is about 40 m to ensure safe mining under loose surface soil condition. When surface soil contains mainly thick clay, it forms steady structure with the composition of thin bedrock, so that it can reduce minimal thickness of bedrock and to ensure safe mining. When clay thickness is 40 m, minimal bedrock thickness is 20 m. When clay thickness is 30 m, minimal bedrock thickness is 30 m. Bearing pressure peak ranges from 5 to 15 m in the front face under thin bedrock condition. The bearing pressure distribution range is 15 m. Main roof break distance is small, and initial weighting of main roof is not distinctive, while first periodic weighting of main roof is quite distinctive.

  12. Characteristics of fracture development and gas extraction of a lower protected seam

    Institute of Scientific and Technical Information of China (English)

    王海锋

    2009-01-01

    To ensure the mining safety of working face in the protective seam and meanwhile extract pressure-relief gas of the lower protected seam and eliminate its outburst risk,the present study researched into fracture development of floor coal-rock mass of the protective seam and migration rule of pressure-relief gas from a protected seam so as to obtain an effective pressure- relief gas extraction method.The results show that after the upper protective seam was mined,mining-induced fracturing floor coal-rock mas...

  13. 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

  14. Design of drilling parameter measuring system of drill rig in soft coal seam%松软煤层坑道钻机钻进参数测量系统设计

    Institute of Scientific and Technical Information of China (English)

    翁寅生; 殷新胜; 赵良

    2014-01-01

    In order to meet the requirements of operation of tunnel drilling rig in the soft coal seam, a drilling parameter measuring system was designed. The hardware and software were designed separately. Hardware with the automotive programmable logic controller(PLC) as control core and with controller area net(CAN) bus as communication network was focused in the design especially for the requirements of usage in coal mine. Driver software was designed with CoDeSys development tool and PC software interface was developed based on LabVIEW. Practical application results show that the measurement system can accurately obtain drilling parameters required for operation of tunnel drilling rig in the soft coal seam, and has advantages such as strong real-time performance, accuracy and high reliability, friendly man-machine interaction, etc.%针对松软煤层坑道钻机施工需要,设计了一种钻进参数测量系统。系统的硬件以车用可编程逻辑控制器(PLC)为控制核心,以控制器局域网(CAN)总线为通信网络,针对煤矿使用要求重点对电路进行设计。采集器底层软件设计利用CoDeSys开发工具,上位机软件界面则基于LabVIEW。实际应用结果表明:该测量系统能准确获取松软煤层坑道钻机施工所需的钻进参数,具有实时性强、准确性和可靠性高,人机交互友好等优点。

  15. 特厚煤层大采高综放工作面覆岩上层活动规律的相似模拟研究%Analog Simulation Study on Deformation and Failure Laws of Overlying Strata of Full -mechanized Top- coal Caving Face with Large Mining Height in Extra Thick Coal Seam

    Institute of Scientific and Technical Information of China (English)

    陈义东; 李英明

    2011-01-01

    In order to know well the movement pattern of overlying strata and the distribution of abutment pressure in the fullmechanized top - coal caving face with large mining height of the 4# coal seam of which thickness is form 14 m to 20 m, in Liuhuanggou coal mine of Xinjiang Hami Coal Industry (Group)Co.Ltd, physical simulation experiment and studies were carried out.The results showed that a stable arch structure can form in overlying strata of full - mechanized top - coal caving face with large mining height of extra thick coal seam, under the stable arch structure the fractured rock beam becomes a multispan beam structure.The deformation and unstability of the structure in overlying strata of full - mechanized top - coal caving face with large mining height dominate the abutment pressure distribution and strata pressure behavior of coal mining face.%新疆哈密煤业集团硫磺沟矿4号煤层厚度为14~20m,为掌握该特厚煤层综放工作面上覆岩层活动规律以及支承压力分布特点,采用物理相似模拟方法进行了研究,研究结果表明,特厚大采高综放工作面的上位岩层可以形成稳定拱结构,而在稳定拱大结构之下,断裂岩梁形成多跨梁的结构.大采高综放采场上覆岩层的这种结构的变形和失稳将决定采场的支承压力分布和工作面的矿压显现.

  16. 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

  17. 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。

  18. 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

  19. Late Cretaceous-Paleogene Palynostratigraphy from the Arkhara-Boguchan Brown Coal Mine of Zeya-Bureya Depression, Russia

    Institute of Scientific and Technical Information of China (English)

    Tatyana V. Kezina

    2003-01-01

    A well-preserved Late Cretaceous-Paleogene palynological flora from the middle member of the Tsagajan Formation and the upper member of the Tsagajan Formation including the Kivda Beds is reported for the first time from the Arkhara-Boguchan brown coal mine, southeastern part of the Zeya-Bureya Basin. Four palynocomplexes were established for the Cretaceous-Tertiary transition. The climate and phytocoenoses were also analyzed,based on the detailed palynological data. The results are coincident with those of mega-flora studied by Akhmetiev et al. (2002).

  20. 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)

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. “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.

  7. Metallization of oxide-ore-containing wastes with the use of brown coal semicoke from Berezovsky deposit of the Kansk- Achinsk Basin

    Science.gov (United States)

    Anikin, A. E.; Galevsky, G. V.; Nozdrin, E. V.; Rudneva, V. V.; Galevsky, S. G.

    2016-09-01

    The research of the metallization process of the roll scale and sludge after gas treatment in the BOF production with the use of brown coal semicoke mined in Berezovsky field of the Kansk-Achinsk Basin was carried out. A flow diagram of “cold” briquetting using a water-soluble binder was offered. The reduction of iron from its oxide Fe2O3 with brown coal semicoke in the laboratory electric-tube furnace in the argon atmosphere was studied. The mathematical models of dependence of the metallization degree on variable factors were developed. The optimal values of technological factors and essential characteristics of the obtained metallized products were revealed.

  8. 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

  9. Influence of coal mining on the deformation-failure and permeability of seam floor%煤炭开采对煤层底板变形破坏及渗透性的影响

    Institute of Scientific and Technical Information of China (English)

    孟召平; 王保玉; 徐良伟; 吴志远; 白刚; 路波涛

    2012-01-01

    Except the geological factors, the deformation and failure of seam floor are also controlled by mining factors. The influence of coal mining on stress-strain and permeability of seam floor in working face and its failure regularities were studied through theoretical analysis and the experiment. The research result shows that the permeability of the rock with different lithology is a function of strain in the process of complete stress-strain. In the micro-fracture closure and elastic deformation stage, the primary pores and cracks of rocks are easily compacted, it is obviously that rock permeability decreases with the increase of stress, when the stress intensity increases to the limit, the rock sample is destroyed and cracks through the sample are formed,, the rock permeability rapidly increases to the maximum. There are some differences between rocks with different lithology. With advancement of working face, the seam floor rocks are divided into four areas horizontally, they are initial stress area, advanced stress compression area, direct damaged area of mining stress and stress recovery area of floor rock mass. Permeability of seam floor rock shows regular variation with the deformation and failure of seam floor rock during coal mining.%煤层底板变形破坏除受地质因素控制外,还受开采因素影响.通过试验和理论分析,系统研究了煤炭开采对回采工作面底板应力、应变和破坏及渗透性的影响.研究结果表明,不同岩性岩石的渗透性在全应力-应变过程中为应变的函数,在微裂隙闭合和弹性变形阶段,岩石的原生孔隙和裂隙容易被压密,岩石的渗透率随应力的增加由大变小明显,当应力增大至极限强度时岩石试件破坏形成贯穿裂隙,岩石的渗透率迅速增大至最大,不同岩性岩石存在一定差异性;随着回采工作面推进,煤层底板岩层在横向上划分为原岩应力区、超前压力压缩区、采动矿压直接破坏区和

  10. 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.

  11. Impact of Calcium on Pyrolysis and Gasification Characteristics of Brown Coal%钙元素对褐煤热解和气化特性的影响

    Institute of Scientific and Technical Information of China (English)

    王磊; 余江龙; 尹丰魁; 王冬梅

    2012-01-01

    综述了钙元素对褐煤热解和气化特性的影响,讨论了钙元素对热解产物中挥发分、焦油产率和气体产物分布的影响,以及对褐煤半焦气化的催化作用.结果表明,与酸洗煤相比,热解过程中,钙元素降低焦油产率,提高半焦产率;气化过程中,钙元素的植入提高褐煤半焦的反应活性,缩短了反应时间.高温时钙元素主要以氧化态的形式存在,低温时则不断与半焦基体键合而参与交联反应,少部分挥发.%This paper provides an overview on the impact of calcium on the pyrolysis and gasification characteristics of brown coal. The impact of calcium on the total volatile matter yield, the tar yield and the distribution of gaseous products during pyrolysis as well as its influences on the catalysis of the gasification of brown coal and chars are discussed. It is shown that the tar yield of the Ca-enriched coal is lower than that of the acid-washed coal and the char yield is higher than that of the acid-washed coal in the pyrolysis process. The reactivity of brown coal is increased and the reaction time is shortened in the gasification process because of the calcium implantation into the brown coal. Calcium oxide is the main form existing in the coal at high temperatures, but it is strongly bonded to the char structure and attends cross linking reactions and a small proportion of volatilizes.

  12. 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

  13. 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.

  14. Application of directional fracturing increased permeability technology in No. II -1 Coal Seam%定向压裂增透技术在二煤层中的应用

    Institute of Scientific and Technical Information of China (English)

    张晓伟; 余加正; 刘俊龙

    2011-01-01

    Coal mine gas disaster has been an important factor that restricted coal enterprises secure and efficient production within a long time. With underground mining depth increases, the gas gauge phenomena have occurred, and it brings the hidden danger to mine safety production. To coal seam that permeability coefficient is lower and gas drainage is difficult, it is very difficult to achieve the balance of digging, pumping and mining in the aspect of management. Therefore, directional hydraulic fracturing increased permeability technology was recommend to Wangxingzhuang coal mine, and the field experiment was conducted suc- cessfully ; the test result shows that the quantity of gas drainage increases substantially after hydraulic fracture and the effect of hydraulic fracturing increased permeability is very good.%长期以来煤矿瓦斯灾害一直是制约煤矿安全、高效生产的重要因素。随着矿井开采深度的增加,瓦斯超限现象时有发生,给矿井生产带来了安全隐患。对于透气性系数低,抽放困难的煤层,管理上很难实现“掘、抽、采”的平衡。为此,王行庄煤矿引进了定向水力压裂增透技术,并成功的进行了现场试验;试验结果显示,水力压裂后,瓦斯抽放量大幅度上升,水力压裂增透效果良好。

  15. Experimental research on low permeability coal seams group of first layer hollow out coal mining without pillars for release of eliminate the highlight and gas control%低透气性突出煤层群首采层掏心无煤柱开采卸压消突与瓦斯治理试验研究

    Institute of Scientific and Technical Information of China (English)

    姚尚文; 卢平; 张纯如; 李庆明

    2015-01-01

    针对深井高瓦斯低透气性突出煤层群消突和首采层开采卸压瓦斯治理难题,以谢桥煤矿11426工作面开采为例,设计首采中间层无煤柱开采、实现上下突出煤层均消突的技术方案,研究了Y型通风工作面采空区瓦斯及风压分布规律,结合煤层群开采巷道布置条件,提出并实施留巷侧井下暗立眼回风阶段留巷Y型通风技术,强化留巷墙体封闭和留巷采空侧回风立眼封闭等卸压瓦斯抽采技术,实现了深井煤层群首采层工作面的安全高效回采和邻近突出煤层的全面消突。11426工作面回采期间,绝对瓦斯涌出量最大47.67 m3/min,工作面瓦斯抽采率高达65%以上,研究成果为今后类似深井煤层群开采的卸压瓦斯抽采和治理提供技术指导。%As for the problem of deep gas low permeability outburst coal seam group of release of eliminate the highlight and pressure relief and the gas control of first layer mining, based on Xeqiao mine 11426 working face mining as an example,the design of first layer without coal pillar mining,realize technical proposal on up and down coal seams of eliminate the highlight,research laws of goaf gas and wind pressure distribution on Y type ventilation working face,combinate condition on multi-seam mining of roadway layout,innovation present and implementation technology of the side for downhole dark set eyes return air phase for Y type ventilation,strengthen technology of the walls closed and the goaf side return for eye closed on pressure relief gas extraction, realized the working face of deep coal seam group of first floor safe and efficient mining and adjacent coal seams outburst elimination. During the 11426 mining face,the absolute gas emission maximum 47.67 m3/min,the working face gas extraction rate as high as 65%above,provide technical guidance on research of pressure relief gas extraction and government from similar deep well multi-seam mining for the

  16. 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)

  17. 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.

  18. Impermeability and Mining Impacts of Key Aquifuges for Shallowly Buried Coal Seams%浅埋煤层关键隔水层隔水性能及采动影响变化

    Institute of Scientific and Technical Information of China (English)

    蒋泽泉; 王建文; 王宏科

    2011-01-01

    The mining of shallowly buried coal seams has brought a series of ecological environmental problems; water conservation coal mining is the key issue in coal resource scientific mining in the northern Shaanxi and even whole Northwest China. Taking the Shennan mining area as an example, the paper studied impermeabilities of loess and red loam aquifuges and mining impacts on them.Coal seams in water conservation mining are covered with clay and sands; the overlying clay is the crucial aquifuge. Laboratory and field tests have demonstrated that: after the overlying clay is disturbed, water inflow will soar to rise rapidly and form fissure flow, that is went against to water conservation coal mining. When loess is subjected to the ground surface tension fissure developed shearing will be in broken state, permeability coefficient variation will appear as some orders of magnitude after mining; while the red loam is stand in the integral settlement zone, subjected to additional stress and is indicative of greater plastic deformation, permeability is reduced after mining, thus in favor of water conservation coal mining. To realize water conservation coal mining and keep clay bed undisturbed integrally, gob area stowing is advised to control surface subsidence and soil mass confining pressure. When surface subsidence is reduced, loess bed can keep undisturbed, and confining stress is existed, clay bed stability can also be kept.%陕北浅埋煤层开采引起了一系列的生态环境问题,保水采煤成为陕北乃至整个西北地区煤炭资源科学开采的关键.以神南矿区为例,研究了黄土、红土隔水层的隔水性及采煤对其隔水性的影响.神南矿区砂土基型煤层的保水开采的关键隔水层为上覆粘土层,室内、外试验显示:粘土层失稳后流量猛增形成裂隙流,不利于保水采煤;黄土受地面张裂隙发育的剪切作用处于破碎状态,采动后渗透系数表现为数个数量级的变化;红土处于

  19. 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。

  20. 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。

  1. 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

  2. Ash removal plants in large power stations designed for higher ash contents in brown coal and the utilization of waste products

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, G.; Nicko, K.H.; Weidlich, H.G.

    1984-12-01

    More than 80% of the electric power generated in the GDR is produced on the basis of raw brown coal. Mean ash concentrations of 18 to 20% in raw brown coal and calorific values of 7000 kJ/kg are quite common. This means a higher amount of combustion residues, e.g. slag, fly ash and fly dust. In consequence, ash removal technologies for coal-fired power plants are getting increasingly important. Most of the present systems are combinations of suction and pressure-pneumatic systems. The most widely used system consists of a conveying trough, a pressure vessel conveyor, and a dry ash bunker. This combination is economically efficient, easy to operate, and requires little maintenance.

  3. Experimental Studying of the Shortest Natural Spontaneous Combustion Period of 3-1 Coal Seam of Menkeqing Coal Mine%门克庆煤矿3-1煤层最短自然发火期实验研究

    Institute of Scientific and Technical Information of China (English)

    孙喜贵; 徐长富; 姚海飞; 张群; 吴海军

    2016-01-01

    最短自然发火期是衡量煤自然发火危险性的重要指标之一。为了科学地测试煤层最短自然发火期,以门克庆3-1煤层为研究对象,利用煤的绝热氧化反应装置,测试了煤样升温过程中各种气体的生成量,确定了3-1煤的交叉点温度,并根据生成的CO与CO2键能值计算氧化升温过程中的放热量,再根据差示扫描量热实验测定了不同温度时煤的比热容,进而分段计算达到交叉点温度所需要的时间。结果表明:门克庆煤矿3-1煤自燃倾向性等级属于I类,最短自然发火期43d,为煤矿制定有效防灭火措施提供了依据。%The shortest natural spontaneous combustion was an important indicator of natural spontaneous combustion risk evalua-tion. In order to test the shortest natural spontaneous combustion scientific, it taking 3-1 coal seam of Menkeqing coal seam as studying object, and isolated heat oxidation reaction device was utilized, the production of all kinds gases were test during temperature rise pe-riod, and the intersection temperature of 3-1 coal seam was confirmed, and the heat release during oxidation temperature rise period was calculated by chemical bond energy value of CO and CO2 that generated, and the specific heat capacity of coal in different temper-ature was test on the basis of DSC, and then the lasting time that reached intersection point temperature was calculated partition. The results showed that the natural spontaneous combustion tendency was belong I classification, the shortest natural spontaneous combus-tion period was 43d, it references for valid fire precaution formulated of coal mine.

  4. 浅埋煤层穿越河道采煤的实践与研究%Practices and Study on Coal Mining in Shallow Depth Seam Passing Through River Bed

    Institute of Scientific and Technical Information of China (English)

    王建文; 王宏科; 陈菲

    2012-01-01

    为防止煤层回采过程中地表水通过导水裂缝带流入井内,威胁矿井安全,基于神府矿区柠条塔煤矿N1201工作面新民沟区域富水区水文地质条件,运用经验公式计算出该工作面回采后,工作面上方地表河流段会形成塌陷区,塌陷后的导水裂缝带高约60 m,使工作面与地表相贯通,通过SF6气体试验得以证实。为此采用在井下设置排水仓、地表安设排水管道、河道裂缝处开挖充填等综合技术防止地表水向井下下渗,结果表明,回采过程中工作面涌水量仅较原来增加了4.7m3/h,实现了穿越河道浅埋煤层安全开采。%In order to prevent the surface water rushed into the mine through the water flow fissure zone during the seam mining operation to threaten the mine safety,based on the hydrological investigation conducted on the watery zone of Xinmingou Area for No.1201 coal mining face in Ningtiaota Mine of Shenfu Mining Area,the calculation with the experience formula showed that after the mining of the coal mining face,the river section of the surface ground above the coal mining face would be formed as a subsidence area.After the subsidence occurred,the height of the water flow cracking zone would be about 60 m and the water flow from the surface ground to the coal mining face would be connected.The SF6 gas experiment showed that the water drainage sump set in the underground mine,the water drainage pipeline set on the surface ground,the excavation and backfill of the river course and other comprehensive technology could be applied to prevent the surface ground water running into the underground mine.The results showed that during the mining process,the water inrush value in the coal mining face was 4.7 m3/h higher than the previous coal mining face.Thus a safety mining in the shallow depth seam was conducted passing through the river bed.

  5. 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.

  6. 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.

  7. 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。

  8. 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.

  9. 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.

  10. 厚煤层一次采全高支架围岩作用研究%Once Mining Full Height Support Surrounding Rock Function on Thick Coal Seam

    Institute of Scientific and Technical Information of China (English)

    王志强; 连永权; 倪亮; 史晓东

    2014-01-01

    Effect of support and surrounding rock is one of the key factors of high once mining full height mining technology efficiency of mine. The 8101 large mining height working face as the engineering background,analysis,numerical calculation and simulation and oth-er means of integrating the theory,it studied the interaction mechanism of support and surrounding rock in Wangzhuang Coal Mine. The thick seam mining all high support and surrounding rock interaction,the method to calculate the working resistance can meet the re-quired support safe and efficient production of coal wall;analyzes the characteristics and spalling mechanism,large mining height work-ing face coal wall spalling failure forms of the crack is presented,it made the reinforcement technology of coal wall grouting correspond-ing. Related research results in the field practice,this method the broken roof,control of the coal wall damage,ensure the safety in work-ing face rapid development,and achieved very good results.%支架围岩作用是影响煤矿大采高一次采全高技术效率的关键因素之一。文章以王庄煤矿8101大采高开采工作面为工程背景,综合运用理论分析、数值计算和相似模拟等手段,系统研究了支架-围岩的相互作用机理。得到了厚煤层一次采全高支架与围岩作用关系,确定了能够满足安全高效生产的所需的支架的工作阻力的计算方法;分析了煤壁片帮特征及片帮机理,大采高工作面煤壁破坏方式以拉裂式片帮为主,提出了对应的煤壁注浆加固技术。相关研究成果在指导现场实践过程中,托住了破碎直接顶,控制住了煤壁破坏,保证了工作面安全快速推进,取得了很好的效果。

  11. 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.

  12. Stability tables for opencast mining of coal and sedimentary deposits in inclined seams. Abacos de estabilidad para mineria de carbon y sedimentaria a cielo abierto con capas inclinadas

    Energy Technology Data Exchange (ETDEWEB)

    Ayala, F.J.; Granda, J.R.; Sarti, A.

    1985-01-01

    The six chapters of the book cover the following aspects of strata control in surface mining: design of opencast coal sites; parameters for the geomechanical design of opencast sites; methods for calculating slope stability; calculating the stability of spoil tips with a fractured cement base; calculation of stripping ratios; and stability tables.

  13. MECHANISN ON PROGRESSIVE INTRUSION OF PRESSURE WATER UNDER COAL SEAMS INTO PROTECTINE AQUICLUDE AND ITS APPLICATION IN PREDICTION OF WATER INRUSH

    Institute of Scientific and Technical Information of China (English)

    王经明; 葛家德; 吴玉华; 邓西清; 贺兆礼

    1996-01-01

    This article proposes a water inrush mechanism of progressive intrusion of pressurewater up into the coal floor aquiclude according to injection tests and observations. A numericalmodel and a criterion of water inrush are established based on the mechanism. The theory is suc-cessfully used in predictions of water inrush.

  14. 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.

  15. 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

  16. 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.

  17. ON BOLTING SUPPORT OF ROADWAY IN EXTREMELY SOFT SEAM OF COAL MINE WITH COMPLEX ROOF%复合顶板极软煤层巷道锚杆支护技术研究

    Institute of Scientific and Technical Information of China (English)

    柏建彪; 侯朝炯; 杜木民; 马东彩

    2001-01-01

    The bolting support principle is introduced to support roadwaysin extremely soft seam of coal mine with complex roof. The maintenance of surround rocks is controlled by reinforcing complex roof and two side walls. With an engineering example, a new kind of successful supporting technology is introduced. The roof is reinforced using full-column resin bonded high-strength bolts and pre-stressed anchor ware, and two side walls are strengthened using high water-coagulative material grouting.%复合顶板极软煤层巷道是围岩变形剧烈且顶板易冒落极难维护的巷道。分析该类巷道围岩破坏特点,提出运用注浆及锚杆支护控制巷道围岩稳定、加强顶板支护强度、充分利用围岩自身承载能力的支护原理,研究了合理的注浆、锚杆支护技术,包括高水速凝材料注浆加固两帮、顶板采用树脂全长锚固高强度锚杆和小孔径预应力锚索加强支护及两帮树脂加长锚固锚杆支护,并介绍一个工程实例。

  18. 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.

  19. “三软”煤层水力冲孔卸压增透技术研究%Study on pressure releasing and permeability improving technology with hydraulic flushing in “three soft”coal seam

    Institute of Scientific and Technical Information of China (English)

    何志龙; 孙谦; 宋大钊; 高勤琼

    2015-01-01

    针对糯东煤矿“三软”高瓦斯低透气性煤层易流变、难抽采的问题,提出了底板巷道穿层水力冲孔卸压增透技术,并在糯东煤矿11702掘进工作面进行了现场试验。结果表明:冲孔后比冲孔前抽采瓦斯浓度上升3.4倍,瓦斯抽采流量增加4.4倍,炮掘工作面回风流中的瓦斯(体积分数)由冲孔前0.8%的超限预警状态变成冲孔后的0.4%的安全范围,水力冲孔技术应用效果显著,在糯东煤矿取得了良好的卸压增透效果。%To solve the problem of easy rheology and hard drainage in"three soft"coal seam with high gas concentration and low permeability in Nuodong coal mine,the pressure releasing and permeability improving technology with hydraulic flushing in floor gateway was proposed,and corresponding field test at the No.11702 heading face of Nuodong coal mine was carried out.The re-sults show that the drained gas concentration after hydraulic flushing is 3.4 times as that without hydraulic flushing and the gas flow rate is increased by 4.4 times;and the gas concentration at the blasting working face changes from 0.8% (overrun warning state,before hydraulic flushing)to 0.4% (safety state,after hydraulic flushing).The application of hydraulic flushing technolo-gy is more effective and remarkable in releasing pressure and improving permeability in Nuodong coal mine.

  20. A Discussion on Coal Seam Methane Carbon Isotope Distribution Features and Gas Genetic Classification in China%我国煤层甲烷碳同位素分布特征与瓦斯成因类型划分探讨

    Institute of Scientific and Technical Information of China (English)

    孙四清; 李贵红; 安鸿涛

    2012-01-01

    Based on 170 plus sets of coal seam methane carbon isotope measured results, analyzed 513Ci value distribution features of Chinese coal seam gas, discussed its genetic classification. The studied results have demonstrated that: the distribution range of SaCi value is within - 73.3%e-27.3%e, the value increasing along with the degree of coal metamorphism. After the anthracite stage, the value variations tend to be stable, fluctuating about -35%o or so. According to varying relations between coal seam methane carbon isotope and coal ranks, taking maximum reflectance of vitrinite as indicator, classified Chinese coal seam gas genesis into 3 major types: secondary biogenetic, mixing origin and thermogenetic gases, and pointed out gas genetic types of part coal mining areas in China.%以170余组煤层甲烷碳同位素测定结果为依据,分析了我国煤层瓦斯的δ13C1值分布特征,探讨了瓦斯成因类型划分,研究结果显示:δ13C1值分布范围为-73.3‰~-27.3‰,δ13C1值随煤的变质程度的增加总体增大,无烟煤阶段以后,δ13C1的变化趋于平稳,在-35‰上下波动;根据煤层甲烷碳同位素与煤级之间的变化关系,以煤的最大镜质体反射率作为指标,将我国煤层瓦斯成因分为次生生物成因气、混合成因气和热成因气三大类,并指出了我国部分煤矿区的瓦斯成因类型.

  1. Regional Outburst Prevention Test by Coal Seam Infusion Humidification and Permeation Fluid Mechanics Numerical Solution of Parameter Optimization%煤层注水增湿区域防突试验与参数优化的渗流力学数值解

    Institute of Scientific and Technical Information of China (English)

    李志强; 唐旭; 王兆丰

    2012-01-01

    为增强煤体黏结力和塑性并抑制瓦斯放散强度,以达到稳定煤体区域防突的目的。以重庆天府三矿K4煤层为目标区,进行了低温液氮孔隙结构分析实验、煤体润湿性实验和湿润边角测定实验。分析了煤层注水可行性。实验表明:煤体孔隙多数为平板状开放孔,润湿边角〈90°,吸水性强。具注水可行性。在重庆天府矿业公司850m深井底板岩巷进行了煤体扩孔卸压后的高压注水试验,测定了卸压后煤体透水性系数。建立了煤层注水的径向渗流力学方程,以实测数据为基础,优化计算了合理的注水压力、时间、注水半径等动态时空参数。%To strengthen the coal bonding force and plasticity, inhibit the gas irradiation intensity and achieve the purposes of stabilizing the coal body and regional outburst prevention, taking K4 coal seam of Tianfu No. 3 coal mine in Chongqing as target area, cryogenic liquid nitrogen pore structure analysis experiments, coal wettability experiments and moist comers measurement experiment were carried out, and the feasibility of coal seam infusion was analyzed. The experiments showed that the majority of coal pores were plate - shaped open holes with strong water absorption, wetting corners were less than 90~and had the feasibility of water infusion. The high - pressure infusion test was carried out in the floor rock of deep shaft of Chongqing Tianfu mining company with depth of 850 m after the relief of the coal body reaming, and coal permeability coefficient was measured after relief. Based on measured data, the radial flow mechanics equation of coal seam infusion was established, and the dynamic spatial and temporal parameters of water infusion pressure, time, and infusion radius were optimized and calculated.

  2. 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...

  3. 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。

  4. 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.

  5. 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

  6. COAL GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20091159 Gao Yan(No.3 Prospecting Team of Anhui Bureau of Coal Geology,Suzhou 234000,China) Effect of Depositional Environment of Coal-Bearing Stratum on Major Coal Seams in Suntan Coalmine,Anhui Province(Geology of Anhui,ISSN 1005- 6157,CN34-1111/P,18(2),2008,p.114 -117,5 illus.,1 ref.,with English abstract)

  7. Utilizing aquiferous layers in advanced treatment of coal bearing strata

    Energy Technology Data Exchange (ETDEWEB)

    Perezhilov, A.E.; Lukash, A.S.; Kochetov, V.G.

    1984-01-01

    This article analyzes effects of aquiferous layers close to a coal seam on efficiency of water injection into a seam endangered by methane or rock bursts. Two procedures of water injection into a coal seam situated at depths of 850 m are compared: injection from ground surface directly to the seam, injection into an overlying limestone aquiferous layer and into an underlying sandstone aquiferous layer and in the last stage injection into the coal seam situated between 2 aquiferous layers. The overlying layer 2 m thick is situated 15 m from the seam; the underlying layer 4.0 m thick is separated from the seam by a rock layer 3.2 m thick. The results of comparisons are given in a table and in a diagram. Investigations show that aquiferous layers close to a coal seam actively influence water injection. When water is injected into a rock aquiferous layer first and at later stage into an adjacent coal seam the rock layer plays the role of an accumulating medium. When water injection from the ground surface is discontinued water accumulated in the aquiferous strata flows into a coal seam (filtration flow and capillary flow). Distribution of moisture in a coal seam is more regular. Use of aquiferous rock layers as accumulating strata during water injection into coal seams increases injection efficiency.

  8. 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

  9. 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

  10. Groundwater flowing the forefield of the CSA mine (North Bohemian Brown Coal Basin in the Czech Republic)

    Energy Technology Data Exchange (ETDEWEB)

    Zizka, L.; Halir, J. [Brown Coal Research Inst., Most (Czech Republic)

    2010-07-01

    The North Bohemian Brown Coal Basin is home to one of the largest active open cast mines in the Czech Republic. Groundwater flow in the quaternary sediments is causing stability problems in the upper overburden at the mine. A 3-D geological model was used to simulate groundwater flow in the area. The lithological characteristics and hydrogeological conditions of the mine were also considered in order to identify areas that may pose risks during the extraction of mineral resources. The simulation focused on the characterization of the quaternary and crystalline aquifer collectors located in the region of the mine. The study showed that groundwater flow is influenced by the configuration of the quaternary floor, as well as by the deposition and character of the basin sediments and crystalline rocks. The donation area corresponds with the mountain slopes. Groundwater flow is influenced by disruptions in the crystalline roof with quaternary sediments. The quaternary aquifer will be dewatered in order to ensure the future safety of the mine. 3 refs., 2 figs.

  11. Biotype assessment and evaluation as a method to quantify the external costs related to surface brown coal mining

    Energy Technology Data Exchange (ETDEWEB)

    Kabrna, M. [Vyzkumny ustav pro hnede uhli a.s., Prague (Czech Republic); Czech Univ. of Life Sciences, Faculty of Environmental Science, Prague (Czech Republic); Peleska, O. [Vyzkumny ustav pro hnede uhli a.s., Prague (Czech Republic)

    2009-07-01

    Externalities express the uncompensated effects of human individuals on each other and on nature. Externalities include costs and benefits which impact human individuals and environment and are not included in the costs and benefits of their creators and are often defined as the differences between social costs or revenues from economic activity and private costs or revenues. Surface brown coal mining can be characterized by a large range of adverse environmental effects. In order to compensate for the environmental damage caused by mining activities in the Czech Republic, various environmental fees paid by mining companies were introduced to the Czech legislation. The Hessian method of quantifying impacts on the environment is an expert methods that is appropriate for the evaluating environmental damage caused by large-scale impacts on landscape. This paper described the methodology of the Hessian method and its application to a selected opencast mine in north-western Bohemia called the Vrsany-Sverma mine. The paper also discussed current environmental charges in the Czech Republic. It was concluded that the calculated amount of environmental damage caused by surface mining balances the amount of environmental fees currently paid by mining companies. 4 refs., 1 tab.

  12. 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。

  13. 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.

  14. Calculation method for water inflow from exploited mine in shallowly-buried coal seam%浅埋煤层开采矿井涌水量计算方法研究

    Institute of Scientific and Technical Information of China (English)

    刘洋

    2012-01-01

    At present, prediction of mine inflow mostly focuses on aspects of calculated methods and applied conditions, but rarely considering mine inflow to be effected by excavating process and mined domino offect. Withal, the paper bases on water-bursting mechanism of roof and characteristic of mine inflow of exploited mine in shallowly-buried coal seam, taking mine inflow divide into the diversification water and the immobility water two parts, and according to respective characteristics, putting forward matching calculation methods. Meanwhile, the paper analyzed the condition that inflow of exploited working faces interfere with each other, contraposed different hydraulic boundary conditions, and construed the condition that the calculation formula of working face inflow are applied. In practice, the method has well defined consecution, specific classify, better practicability.%矿井涌水量预计主要侧重于计算方法和适用条件方面的研究,很少考虑采掘过程及采后影响效应对矿井涌水量影响,基于浅埋煤层顶板出水机理及矿井涌水特征,将矿井涌水量分为固定和变化水量两部分,并依据各自的特点,提出与之配套的水量计算方法.同时,在分析首采面、次采面等各工作面间涌水相互干扰的情况下,针对不同水力边界条件,对工作面水量计算公式的适用条件进行分析.在实践中,该矿井涌水量计算方法条理清晰、分类明确、实用性强.

  15. 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.

  16. 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

  17. Support of the business management of opencast brown coal mining with an enhanced variability of deposits based on mine surveyoral data management; Unterstuetzung der Betriebsfuehrung von Braunkohlentagebauen mit hoher Lagerstaettenvariabilitaet auf Grundlage des markscheiderischen Datenmanagements

    Energy Technology Data Exchange (ETDEWEB)

    Knipfer, Anja [Mitteldeutsche Braunkohlengesellschaft mbH, Zeitz (Germany). GIS/Risswerkfuehrung

    2012-04-15

    A variable manifestation of the deposit is a particular challenge for the operational management for the continuous supply of coal in a specified range. Mitteldeutsche Braunkohlengesellschaft mbH (Zeitz, Federal Republic of Germany) supports the planning and production process by a GNSS controlled dredging. The storage of all operating conditions at the database level is the basis for the different evaluations. The verification of the data separaed by waste and coal enables a statement to the recoverability of the seams under consideration of a impact mapping and production data. This is an aid for the continuous improvement of the extraction planning and management.

  18. SEEPAGE FIELD-STRAIN FIELD COUPLING ANALYSIS FOR ROCK MASSES OF COAL SEAM FLOOR DURING MINING ABOVE A CONFINED AQUIFER%煤层底板岩体采动渗流场-应变场耦合分析

    Institute of Scientific and Technical Information of China (English)

    姚多喜; 鲁海峰

    2012-01-01

    根据五沟煤矿1018 工作面地质及水文地质条件,应用三维快速拉格朗日(FLAC3D)流固耦合分析模块,采用变渗透系数方法,对该工作面底板岩体采动渗流应变机制进行数值模拟研究.分析结果表明:采动影响下,围岩渗透系数发生较大的变化,处在采空区正上方的泥岩段最大达到原始渗透系数的1293倍;根据渗流场分析,工作面采动并没有破坏底板隔水层的阻水性能,采动裂隙没有导通灰岩含水层,灰岩水涌入回采工作面形成水害可能性较小;工作面正下方岩体单元安全度小于1的区域最大深度为30 m.综合渗流场以及隔水底板单元安全度分析结果,10煤底板下灰岩水溃入工作面形成水害可能性较小.%Based on the geological and hydrogeological conditions of the face 1018 in Wugou coal mine, the fluid-solid coupling module in FLAC3D with changeable permeability coefficient is adopted to simulate the whole process of damage and failure of rock masses at floor of the coal seam No. 10. The results indicate that the permeability coefficient of surrounding rocks changes a lot due to mining. The maximum permeability coefficient reaches 1 293 times of the original one, which happens at the immediate roof of mined-out area. According to the analysis of seepage field, mining does not destroy water resistance of floor aquifer. Mining fissures do not connect limestone aquifers, and water in the limestone is less likely to flow into stopes to cause damage. The maximum depth of rock masses with element safety degree less than one is about 30 m. According to the change of permeability coefficient of and the analytical results of element safety degree of rock masses, safe mining of the face 1018 can be ensured.

  19. Dynamic prediction of ground deformation and drainage design for shallow thick coal seam mining%浅埋厚煤层开采地表变形动态预测与排水设计

    Institute of Scientific and Technical Information of China (English)

    张顺峰; 胡瑞林; 武雄

    2012-01-01

    以山西平朔井东矿浅埋厚煤层4201,4301,4302,4303及4401工作面开采为例,运用FLAC3D数值模拟软件对各工作面依次开采后的地表沉降量、沉陷影响半径及导水断裂带发育高度进行了动态预测,得出各工作面最大沉降量为6.4 ~10.3 m,沉陷影响半径为80.5 ~106.6 m,垮落带与导水断裂带最大发育高度为140.5 m.在此基础上,结合矿区地形地貌特征,进行了地表动态填挖与截水排水设计,有效预防了地表径流汇聚于沉陷洼地,再经由断裂带进入矿井造成的矿坑突水灾害,并为后期矿山环境修复治理提供依据.%Took the shallow thick coal seam 4201,4301,4302,4303 and 4401 workfaces of Jingdong mine area in Pingshuo for example, predicted the range of ground subsidence, settlement and the height of water flowing fracture zone dynamically after workface mining with the FLAC3D numerical modeling software. The calculation results are that the maximum settlement is 6. 4-10. 3 m,the average radium of ground subsidence is 80. 5-106. 6 m and the maximum height of the two zones is 140. 5 m. On the basis of the results above and combined with geomorphic characteristics of the mine area,come out the surface dynamical fill-cut and drainage design. It can effectively prevent water bursting disaster caused by the surface runoff which influxes to the subsidence area and then flows to roadway through fractured zone. It also can provide data for ecological environment restoration of the coal mine.

  20. 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.

  1. Comprehensive measurement of characteristics of deformation and failure of extra-thick coal seam floor induced by fully mechanized top-coal mining%特厚煤层综放采动底板变形破坏规律的综合实测

    Institute of Scientific and Technical Information of China (English)

    朱术云; 曹丁涛; 岳尊彩; 姜振泉; 赵连涛; 于旭磊

    2012-01-01

    为了探究兖州煤田兴隆庄煤矿特厚煤层综放开采对底板岩层的变形破坏规律,应用钻孔应变感应法和超声成像技术对该矿某综放工作面进行了综合实测,获得了底板下不同深度应变增量随工作面推进的变化曲线和工作面推进过程中不同深度钻孔超声成像图片资料。通过5个应变传感器监测数据和大量钻孔超声成像图片的关联对比分析,基本确定了该工作面采动底板扰动深度和矿压作用下支撑压力的影响范围。研究结果表明:①该工作面底板采动扰动深度约为19 m,具有较明显分带性,即可分为采动扰动破坏带和采动扰动变形带,带厚分别约为16 m和3 m;②采动扰动破坏带属于整体塑性变形,其强度条件已基本丧失,但采动扰动变形带仍以弹性变形为主,具有良好的承载条件和较强的抗渗强度;③采动矿压超前和滞后显现明显,其对底板影响程度具有由浅及深而减小的特征。该综合实测方法的成功应用不但为综放开采巷道支护、老空水防治等提供重要信息,而且对深部即将开采的下组煤能否安全带压采掘研究也将具有重要参考价值。%In order to study the characteristics of deformation and failure of fully mechanized top-coal seam floor under mining in Xinglongzhuang Coal Mine in Yanzhou Coal Field, comprehensive measurements are performed by means of the strain testing system and ultrasonic imaging technology in the fully mechanized top-coal working face, and the variation curves of strain increment and the ultrasonic imaging pictures at different depths are obtained in the monitoring boreholes with extending of the working face. Through the comprehensive comparison of monitoring data of five strain transducers and many hole wall pictures, the disturbance depth and underground pressure influence range are approximately ascertained. The results show that: (1) the disturbance depth of the coal seam

  2. 煤矿3煤层底板水害预测研究%Study on the Prediction of Floor Flood for the 3 Coal Seam of a Coal Mine

    Institute of Scientific and Technical Information of China (English)

    张有为; 肖标丁

    2016-01-01

    China is one of the countries that have serious flood disaster. In the process of safe production of many coal mines, the water inrush of coal floor is a common problem. Coal mine A faces with the coal mining safety problem of floor water inrush. In this paper, combining with the geological environment of coal mine A, the main flood and water inrush examples are described in detail. The water inrush coefficient method is used to predict the risk of water inrush in a coal mine. The research results have important theoretical and practical significance for preventing and controlling the water inrush and realizing the safe production of the coal mine.%我国是受水害较严重的国家之一,很多煤矿在安全生产过程中,煤层底板突水是比较常见的问题,煤矿A就面临着底板突水的采煤安全问题。本文结合煤矿A地质环境,详细介绍了矿井主要水害及突水实例,再运用突水系数法对某煤矿进行突水危险性预测。研究结果对防治煤层底板突水和实现煤矿安全生产具有重要的理论意义和实际意义。

  3. “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.

  4. 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

  5. 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.

  6. Ground subsidence zone and surrounding rock failure mechanism due to steep multiple coal seam mining: a case study at Muchenyjian Datai Mine%急倾斜多煤层开采地表沉陷分区与围岩破坏机理——以木城涧煤矿大台井为例

    Institute of Scientific and Technical Information of China (English)

    阎跃观; 戴华阳; 王忠武; 景胜强; 陈宏忠

    2013-01-01

    A similar material simulation was conducted to study the special characteristics of the ground displacement and the surrounding rock deformation caused by mining activities of steep inclined multiple coal seams,based on the conditions at Muchengjian Datai Mine.The pattern of ground displacement and the collapse mechanism of surrounding rock were identified.The magnitude and other features of the simulated ground displacement in different areas were presented and compared with field measurement data.The results show that the ground subsidence basin can be divided into four zones:outcrop collapse zone,main subsidence zone,gradual subsidence zone and mild subsidence zone.The ground partition pattern,especially caused by shallow coal seams exploration,can control the propagation of ground subsidence in the whole subsidence basin.The overburden strata will fall or crack as the main characteristics when they are affected by shallow coal seam exploration.Nevertheless,it will steeply sink or crack through separation layers to ground surface as the main features when they are affected by deep coal seam extraction.%为了研究急倾斜多煤层开采条件下地表及围岩移动变形特点,以木城涧煤矿大台井急倾斜多煤层开采为研究对象,进行了相似材料模拟研究.揭示了地表移动变形规律和围岩垮落、破坏机理,得出了不同区域移动变形的大小及主要特点,并与实地观测数据进行了对比分析.结果表明:该条件下开采,地表沉陷盆地可分为露头塌陷区、整体沉陷区、渐变沉陷区和轻微沉陷区,浅部开采形成的地表分区格局对整个采动影响区的地表移动变形起到了控制作用,浅部开采覆岩破坏以陷落和张裂为主要特征,深部开采以离层带裂隙顺层通达地表和台阶错落下沉为主要特征.

  7. 伊犁盆地ZK0161井褐煤中铀及其它元素的地球化学研究%Geochemistry study of its uranium and other element of brown coal of ZK0161 well in Yili Basin

    Institute of Scientific and Technical Information of China (English)

    杨建业; 狄永强; 张卫国; 刘善德

    2011-01-01

    用数理统计的方法,对伊犁盆地洪海沟ZKO161井的中下侏罗统11、12号煤层中的铀等59种常量、微量元素的地球化学行为进行了初步探讨.认为元素在灰分的分布和元素在内在水分及固定碳中的分布大体呈互为相反数关系,而和元素-挥发分相关系数则呈同步性变化.ZK0161井煤中u以后生铀为主,分别以可溶态和有机吸附态或结合态形式出现在12号煤和11号煤顶部的煤中内在水和煤有机质中.%The research of geochemistry of 59 kinds constant elements and trace elements in brown coal of ZK0161 well, which located at Honghaigou area in Yili Basin of Xinjiang Uyghur Autonomous Region, China, was completed by means of mathematical statistics methods. The results show that the correlation coefficients of ash-elements is each or-ther's opposite number with one of inherent moisture, and has synchronous changes with one of volatile-elements. Uranium in coal of ZK0161 well is mainly epigenetic one and may be respectively in the form of soluble existed in the internal water and organic absorbed or organic phase existed in organic matter on the top of No. 11,12 coal seams.

  8. 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.)

  9. 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.

  10. Circular overlying zone at longwall panel for efficient methane capture of mutiple coal seams with low permeability%低透气性煤层群煤与瓦斯共采中的高位环形裂隙体

    Institute of Scientific and Technical Information of China (English)

    袁亮; 郭华; 沈宝堂; 屈庆栋; 薛俊华

    2011-01-01

    以顾桥煤矿1115(1)工作面为试验点,运用国际先进的岩层应力、位移、孔隙流压等实时监测手段,围岩变形与水、气耦合的COSFLOW数值模拟技术以及研究采动区流场特征的CFD模拟技术,系统研究并基本掌握了11号煤层深部煤层开采过程中的围岩应力场、裂隙场以及瓦斯流动场之间的动态变化规律.研究表明,采动支承压力影响范围可达300 m,覆岩运动和采动裂隙发育范围在工作面后方170 m以内,170 m以后采动裂隙基本压实,采动裂隙发育高度以及孔隙流压明显降低的高度可达145 m.在此基础上判别了1115(1)工作面上覆煤层群瓦斯高效抽采范围,并初步建立了低透气性煤层群瓦斯高效抽采的高位环形裂隙体及其判别方法,为煤与瓦斯共采理论发展以及工程实践提供了一套新的科学研究方法和工程设计手段.%Presented key results from a recent comprehensive research programme based on integrated field monitoring of mining induced overburden displacement,stress and pore pressure changes at the longwall panel 1115 (1) of the Guqiao Coal Mine,and coupled modelling of strata and fluid behaviours using COSFLOW software,and gas flow simulations at the longwall panel with CFD software. Studied and got the complex dynamics of the interaction between mining induced strata stress changes,fractures,gas flow patterns. The results show that effective range of abutment pressure by mining can reach near 300 m, the range of overburden strata movement and mining-induced fractures area is within 170 m after working face, and beyond the range the fractures are generally compacted, development height for mining-induced fractures of overburden rock and the height of crack zone with flowing pressure dropping remarkablely both can reach 145 m. Based on these, methane drainage scope with high efficiency in overlying coal seam group of working face 1115 (1)were obtained, and a new concept that a

  11. Development of scientific and technological bases for application of brown coal semi coke in the technology of non- milled silicon carbide

    Science.gov (United States)

    Anikin, A. E.; Galevsky, G. V.; Rudneva, V. V.; Nozdrin, E. V.; Galevsky, S. G.

    2016-09-01

    Thermodynamics is investigated, and the optimum temperature and time modes of carbonization of a briquetted silica fume batch- brown coal semi coke are defined. The complete carbonization of the batch in the conditions of heat treatment is achieved at a temperature of 1923 - 1973 K within 15 - 20 minutes. The conditions and indicators of the chemical enrichment of carbonization products are established. After enrichment, the carbide content is more than 90%. Silicon carbide micro-powder is obtained with a specific surface area 8000 - 9000 m2/kg.

  12. 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

  13. 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.

  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. 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...

  16. 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.

  17. 水力压裂冲孔在松软低透气性高瓦斯煤层抽采中的应用%Application Of Hydraulic Fracturing Punching In Extraction In Soft Coal Seam With Low Permeability And High Gas

    Institute of Scientific and Technical Information of China (English)

    王彪; 王联; 卓泽强; 沈洪; 尹建荣

    2016-01-01

    In order to solve the problem of borehole collapse hole and long time extraction in soft coal seam(K1)with low permeability and high gas of The third coal mine of SANHUI,Processing technology of hydraulic fracturing, punching to solve in -60mN4 Shimen,which exposing K1 coal,the results showed that under the same geological condition, compared with -60mN6 Shimen,which also exposing K1 coal, without hydraulic fracturing punching,-60mN4 Shimen reduced to borehole 79 smoke coal, drainage standard time reduced by 954 days.%为解决三汇三矿松软低透气性高瓦斯煤层(K1)抽采钻孔垮孔严重,瓦斯预抽困难,抽采达标时间长的问题,采取水力压裂冲孔技术对该矿-60mN4石门揭穿K1煤层时进行了处理,结果表明:在相同的地质条件下,和未采取措施的-60mN6石门揭穿K1煤层相比,减少石门揭煤抽采钻孔79个,抽采达标时间减少105天.

  18. 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)

  19. 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.

  20. 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

  1. Watermanagement - related and ecological demands on brown-coal mining. A statement of position; Wasserwirtschaftlich-oekologische Forderungen fuer den Braunkohlenabbau. Positionspapier

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-01-01

    This statement of position aims to identify influences exerted before, during and after brown-coal open-pit mining activities and to assess them in general terms from a water-management and ecological viewpoint. The form chosen is that of individual, concise postulates. Each of these is followed by an explanation. To illustrate the great variety of potentially arising problems, the major German brown-coal mining districts Lausitz, eastern Germany, and Lower Rhine are dealt with. A particular characteristic of the eastern German and Lausitz mining districts is that as the demand structure abruptly collapsed early in the 90s, closures became necessary on a large scale without preparatory measures having been taken. (orig.) [Deutsch] Mit dem vorliegenden Positionspapier wurde der Versuch unternommen, die Beeinflussungen vor, waehrend und nach dem Abbau von Braunkohle im Tagebaubetrieb inhaltlich zu erfassen und aus wasserwirtschaftlich-oekologischer Sicht verallgemeinernd zu bewerten. Dabei ist die From einzelner kurzgefasster Forderungen gewaehlt worden. Jede dieser Forderungen ist durch eine Erlaeuterung untersetzt. Um die Vielfalt der auftretenden Probleme zu verdeutlichen, werden beispielhaft in einem Anhang die grossen deutschen Braunkohlenreviere in der Lausitz, in Mitteldeutschland und am Niederrhein vorgestellt. Fuer das Mitteldeutsche und das Lausitzer Revier ist besonders anzumerken, dass mit dem schlagartigen Zusammenbruch der Bedarfsstruktur am Anfang der 90er Jahre in grossem Umfang Stillegungen ohne entsprechende Vorarbeiten notwendig wurden. (orig.)

  2. Section Coal Pillar Width of Gob Side Entry Driving that Face to Working Face with Extra Thickness Coal Seam%特厚煤层迎回采面沿空掘巷区段煤柱宽度研究

    Institute of Scientific and Technical Information of China (English)

    裴晓建; 徐金海; 刘涛

    2016-01-01

    以新疆俄矿5104回风巷在5102工作面未回采完毕提前掘进的情况下,出现回风巷迎回采工作面掘巷的问题为例,基于弹性核理论计算了区段煤柱宽度合理范围,运用数值模拟软件FLAC3D 采用循环开挖的方式对迎采动掘巷条件下不同宽度煤柱的应力分布和位移进行了对比分析。结果表明:8~20m宽煤柱内应力呈现双驼峰状,4m和6m宽煤柱应力呈现单驼峰状;回风巷顶底板及两帮变形速率在煤柱宽度4~8m区间最大,在8~20m范围趋于平缓。综合考虑煤柱的黏弹塑性流变的时间效应,确定合理煤柱宽度为12m。在此基础上,提出高阻让压、加强底角、重点补强围岩控制技术,现场试验表明:该方案有效地控制了围岩的变形,保证了回采与掘进的正常进行。%It taking the problem of return airway driving along direction face to working face, under 5104 return air roadway driving before 5102 working face unfinished mining of E coal mine in Xinjiang district, the rational scope of coal pillar width was calculated by elastic core theory, detailed model was built by software FLAC3D , the stress distribution and displacement of different pillar width were compared under driving along face to working face with cycle excavation. The results showed that the stress shape of pillar width (8~20m) was double humps shape, but the stress shape was like single hump when pillar width were 4m and 6m, respectively. The de-formation speed of roof to floor and two sides of return air entry were the largest , when coal pillar width belong scope 4m to 8m, but the speed ratio was smooth when coal pillar width belong scope 8m to 20m. On the basis of time effect of viscoelasto-plastic rheological of pillar , then the reasonable coal pillar width was confirmed as 12m, so the surrounding rock supporting way was put forward, which include high resistance and yield, strengthen bottom corner, reinforcement emphasis and so on, the

  3. 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

  4. 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..

  5. 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

  6. 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.

  7. The impermeability of limestone aquifuge in bottom coal seam floor and its application in Xinji Second Coal Mine%新集二矿下组煤底板石灰岩层隔水性及应用研究

    Institute of Scientific and Technical Information of China (English)

    白海波; 戎虎仁; 杨城; 韦晓琪; 王延蒙; 陈耀杰

    2015-01-01

    Limestone layer is often regarded as the main cause of coal mine water damage and water inrush events, which actually happened more than once in old mining area in Huainan. A conception has been put forward that reconstruction or direct utility of relative impermeability of floor limestone layer can solve the problem of high water pressure and thin aquiclude and ensure safety during mining under pressure. Xinji Second coal mine has been selected as the research field which is located in the southern edge of the midwest coalfields and comprehensive methods have been used to research including the index test of rock composition, chemical action of compositions of groundwater, and rock mechanic, micro-pore structure, the laboratory experiment about permeability and the field test about hydrogeolog-ic drilling, geophysical prospecting. The research results show that:1) Xinji Second Coal Mine is cut by faults all around, with the top covered by quaternary system and metamorphic nappe. The in-situ stress changes from tensile in the shallow part to compressive at a depth under 500 m. The crack of deep rock layer is not easy to open up. 2) The hydrochemical type is Cl-Na. Salinity is greater than 1.5 g/L and rock voids is filled by the precipitation. 3) The permeability and water rich property of limestone floor is poor, so it can be regarded as aquiclude. It is confirmed that inrush boreholes mostly close to the large faults and water yield is small and disappear quickly through boreholes in the coal mine. Safe mining of the first coal mining face and safety tunneling of the second working face testify the result that the floor limestone layer is aquiclude and the water-resisting key strata after reconstruct is correct.%石灰岩层往往成为煤矿开采防水害的主要对象,且淮南老矿区也发生了多次底板灰岩层突水,为解决新区水压高、传统隔水层薄的问题,提出改造或直接利用底板石灰岩层相对隔水性实现带压安

  8. 基于压水试验的深部煤层底板岩层阻渗性能研究∗%Study on permeability barrier performance of deep coal seam floor based on packer permeability test

    Institute of Scientific and Technical Information of China (English)

    孙晓倩; 张冬; 张新武; 王言剑

    2014-01-01

    In situ field packer permeability test,being a reliable method to obtain the param-eters of permeability barrier performance of strata,was used to explore this performance of deep coal seam floor. A large amount of measured data were obtained after the test on two layers of floor strata. The test results showed that these two layers of floor strata could not seep in initial state due to stronger barrier performance until the fracture and connection led to seepage. Co MPared with the first and repeated packer permeability tests on these two layers of floor strata, the variation of water pressure in measured pore was associated with that in water injection hole, but the seepage pressure in the first time was higher than that in second time,showing that the permeability barrier performance of strata turned weaker after first packer permeability test and was easy to form seepage. Using permeability coefficient and permeability barrier strength as in-dexes,the permeability barrier performance of floor strata has been quantitatively evaluated,and the results showed that the tested strata was characterized with high barrier performance and weak permeability.%原位现场压水试验是获取岩层阻渗性能参数的可靠方法,为探究某煤矿深部煤层底板阻渗能力,采用现场压水试验方法对底板两段岩层进行了测试并获取了大量的实测数据。结果分析表明:该底板两测试段岩层在原始状态均不导渗,阻渗性较强,直至压裂导通才形成导渗条件;对两段岩层均进行了初次和重复两个压水过程,对比两次试验可知,测渗孔水压力与注水孔水压力的关联变化趋势大致相同,但初次压水的起始导渗水压明显高于重复压水,表明在初次压水后岩层的阻渗能力降低,更易形成导渗;采用渗透系数和阻渗强度作为指标,对底板岩层的阻渗性能进行了量化评价,结果表明测试岩层表现出明显的高阻弱渗的特点。

  9. 在线/离线式煤层瓦斯压力监测分析系统应用研究%Application of On-line/off-line Coal-seam Methane Pressure Monitoring and Analysis System

    Institute of Scientific and Technical Information of China (English)

    柴士彬; 常未斌; 孙赫; 张浪; 汪东

    2015-01-01

    Current methane pressure monitoring systems commonly exist following problems including fixed sampling frequency , high power dissipation , unitary function and low intelligentization degree , which resulted into difficult popularization and application in un-derground mine.In order to improve function diversification , intelligentization and reduce power dissipation , applying on-line and off-line modes, this system realized on-time monitoring and analysis of methane pressure in coal-seam and overcame defect of existing sys-tem which can only record but cannot on-line analyze.Low power dissipation operation was realized in this system with data collection frequency control module and it overcame the problem of existing systems which cannot well reflect methane pressure variation because of averagely setting collecting points .Intelligentization analysis function was realized with alarm module .There are respectively 2 pat-terns of measuring methane pressure and 4 patterns of setting methane drainage diameter in this system , which made the system ’ s functions diversification and could meet different working requirements .%针对现有煤层瓦斯压力监测系统存在采样频率固定、功耗高、功能单一、智能化程度低等问题而导致的无法在煤矿井下推广应用的现状,以提高监测系统的功能多样化、智能化和低功耗为目的,采用在线和离线2种模式,实现了煤层瓦斯压力的实时监测和分析,克服了已有系统只能记录无法实现在线分析的问题;通过数据采集频率控制模块实现了系统的低功耗运行,克服了已有监测系统采集点平均,不能很好地反映煤层瓦斯压力的变化规律的问题;通过报警模块实现了系统的智能化分析功能;设定了2种测定煤层瓦斯压力和4种考察煤层瓦斯抽放半径的工作模式,使监测系统功能多样化,可以满足不同的工作要求,提高了系统的适用性。

  10. 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

  11. 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.

  12. 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.)

  13. Adsorption of pure carbon dioxide and methane on dry coal from Sulcis coal Province (SW Sardinia, Italy).

    OpenAIRE

    Ottiger, S.; 0; Pini, R.; Storti, G.; 0; Mazzotti, M.; Bencini, R.; Quattrocchi, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Sardu, G.; Deriu, G.

    2006-01-01

    When coal seams are formed by compaction of plants, gases including methane are generated and accumulated into the coal cleats or adsorbed into the coal micropores. Such coalbed methane is normally recovered by means of reservoir-pressure depletion, i.e. by pumping out water and degassing the reservoir. A more attractive process with higher yields is the so-called Enhanced Coal Bed Methane recovery (ECBM), whereby carbon dioxide is pumped into the coal seam to displace methane thanks to highe...

  14. Micro-CT experimental of the thermal cracking of brown coal%褐煤热破裂的显微CT实验

    Institute of Scientific and Technical Information of China (English)

    孟巧荣; 赵阳升; 胡耀青; 冯增朝; 徐素国

    2011-01-01

    Using μCT225kVFCB high precision micro-CT system and a small moveable argon furnace, thermal cracking of brown coal from Pingzhuang mining in Inner Mongolia municipality was studied under different temperature.The results show that for brown coal,the big cracks( >800 μm) occupy leading position at about 100 ℃ ,the medium cracks ( 100 ~ 400 μm) are more important than others at about 200 ℃, the micro-cracks ( < 100 μm)become dominant above 300 ℃ ;threshold temperature of thermal cracking is 300 ℃, more or less;when temperature is lower than 300 ℃, the formation and evolution of crack and pore result mostly from thermal cracking, above 300 ℃, micro-cracks and pores produce mainly because coal pyrolysis produce and release oil gas, and turn coal skeleton into char gradually with temperature.%采用μCT25kVFCB型高精度显微CT试验系统并配以微型气氛炉,研究了内蒙古平庄褐煤热破裂随温度的变化关系.研究结果表明,褐煤在l00℃左右时,大裂隙(>800μm)占主导地位;200℃左右时,中等裂隙(100~400μm)占主导地位;300℃之后微裂隙(<100μm)占主导地位;热破裂的阈值为300℃左右;在300℃之前孔隙裂隙的产生发展主要是因为热破裂,300℃之后,微裂隙和孔隙的产生主要是因为煤体发生热解化学反应,油气逸出,固体骨架逐渐转变为半焦体.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Feasibility Study of Multi-layer Drainage for Nos.3 and 9 Coal Seams in Shouyang Block, Qinshui Basin%沁水盆地寿阳区块3号和9号煤层合层排采的可行性研究

    Institute of Scientific and Technical Information of China (English)

    王振云; 唐书恒; 孙鹏杰; 郑贵强

    2013-01-01

    The CBM coal reservoirs in the Shouyang block have characteristics of multiple layers, small single layer thickness, low pro-ductivity and hard to exploit. To reduce the cost, improve CBM resource recovery, the multi-layer drainage for the main target Nos. 3 and 9 coal seams is the preferred scheme. Based on the key control factors of vertical well multi-layer drainage systematic analysis, consid-ered that the coal and roof/floor rock mechanical property, reservoir pressure gradient, critical desorption pressure, permeability, coal reservoir fluid supply capacity are the key control factors. According to the CBM well exploration and exploitation data in the area and key control factors analyzed feasibility of multi-layer drainage for Nos.3 and 9 coal seams in the block, and pointed out the most advanta-geous range.%寿阳区块煤储层具有层数多、单层厚度小、产能低、开采难度大的特征,为降低成本、提高煤层气资源采收率,对该区主要目标层3号和9号煤层进行合层开采是制定开发方案时的首选。在系统分析煤层气直井合层排采的关键控制因素基础上,认为煤岩及顶底板岩石力学性质、储层压力梯度、临界解吸压力、渗透率、煤储层供液能力是合层排采的主控因素,根据区内煤层气井勘探开发资料及主控因素分析了区块合层排采的可行性,指出了适合3号和9号煤层合层排采的有利区域。

  1. 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)

  2. CO2 GASIFICATION REACTIVITY OF BROWN COAL CHAR%一种褐煤热解煤焦的CO2气化反应特性

    Institute of Scientific and Technical Information of China (English)

    范冬梅; 张海霞; 朱治平; 吕清刚

    2012-01-01

    Based on the step utilization of brown coal pyrolysis, partial gasification, and residual carbon combustion, a brown coal from Shigouyi Coal Mine in Ningxia was chosen as research object to produce the rapid and slow coal chars at temperature of 700 ℃-950 ℃ in a hori- zontal tube furnace. The effect of pyrolysis conditions on carbon microcrystal structure and BET surface area of chars was investigated. The carbon dioxide gasification reactivity was analyzed by thermogravimetric-mass spectrometric technology, and different evolution indexes were used to characterize the reactivity of chars. It is found that the gasification rate of Shigouyi chars increases by more than 50% with the temperature increasing by 50 ℃. When the pyrolysis temperature rises, the carbon microcrystal structure of coal chars becomes more orderly and the BET surface area decreases. However, the gasification reactivity is mainly controlled by gasification temperature. The gasification reactivity of rapid pyrolyzed coal char is better than that of slow pyrolyzed coal char, and the difference between them become greater as gasification temperature rises. Average specific reaction rates of both rapid and slow pyrolyzed chars have a linear relationship with reaction index.%针对褐煤的热解-部分气化-残炭燃烧梯级利用工艺,以宁夏石沟驿褐煤为原料,采用水平管式炉在700℃~950℃温度范围内分别制备快速和慢速热解煤焦,考察了煤焦微晶结构和比表面积随制焦条件的变化.利用热重-质谱联用技术研究煤焦CO2气化反应特性,并采用不同评价指标对煤焦气化活性进行了表征.结果表明:气化温度每升高50℃,煤焦CO2气化反应速率增加50%以上;热解温度升高,虽然煤焦微晶结构的有序化程度加深,比表面积减小,但煤焦CO2气化反应活性主要受气化温度影响;快速热解煤焦的CO2气化反应活性高于慢速热解煤焦,二者的差异随着气化温度升

  3. 单一低透突出煤层底抽巷煤气共采技术及实践%Application and Practice of Coal-gas Co-extraction Technology by Floor Drainage Roadway in Single Low-permeability Outburst Seam

    Institute of Scientific and Technical Information of China (English)

    冀超辉

    2015-01-01

    To counter to the serious gas troubles and low mining efficiency present in a single low-permeability outburst coal seam, based on the analysis of the distribution of stress and permeability in the working face, a coal-gas co-extraction technology by floor drainage roadway in a single low-permeability outburst seam was proposed, that is: gas extraction by hydraulic flushing in hole in the original pressure area before mining, gas extraction in the stress reduced area during mining and the gas extraction from gob after mining. The application in Ligou Mine showed that three gas extraction methods can be coordinated and complemented each other, the outburst hazard in the working face was not only eliminated, but also the gas extraction volume increased, as a result, the safe and efficient mining of the single low-permeability outburst seam was realized.%针对单一低透突出煤层存在瓦斯灾害严重、开采效率低等问题,在分析回采工作面应力分布和渗透率分布的基础上,提出了单一低透突出煤层底抽巷煤气共采模式,即采前未卸压区水力冲孔抽采、采中影响区的应力降低区瓦斯抽采和采后的采空区瓦斯抽采模式。李沟煤矿的工程应用结果表明:3种抽采方法互相协调、互为补充,不但消除了工作面突出危险性,而且大大地增加了瓦斯抽采量,实现了单一低透突出煤层煤与瓦斯的安全高效开采。

  4. 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

  5. Conversion of the compensation measures for the utilization of a FFH area of the brown coal open mining Cottbus North; Umsetzung der Kompensationsmassnahmen fuer die Inanspruchnahme eines FFH-Gebietes durch den Braunkohletagebau Cottbus-Nord

    Energy Technology Data Exchange (ETDEWEB)

    Gerstgraser, Christoph [gerstgraser - Ingenieurbuero fuer Renaturierung, Cottbus (Germany); Arnold, Ingolf; Dingethal, Heidemarie [Vattenfall Europe Mining AG, Cottbus (Germany)

    2008-08-15

    Since the year 1981, the open mining Cottbus-North (Brandenburg, Federal Republic of Germany) produces brown coal. Presently, 5 million tons of brown coal are produced. This brown coal is used in the power generation at the coal-fired power station Jaenschwalde. Within this area of mining there is the pond's group Lakoma. This pond's group consisted of 22 ponds with a total area of 69 ha. These ponds served for breeding of fishes and accommodated protected animal species. In December 2003, the pond's group Lakoma was suggested as a FFH area by the country Brandenburg. With the planning approval procedure for waters, a FFH area was completely eliminated in the approach of an open mining. A licensing procedure came to the result that a removal of these ponds was permissible with consideration of the public interest, if a reconciliation for the plants and animals is carried out. These compensation measures were realized within short time. Thus the open mining Cottbus-North could be continued according to plan.

  6. 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.

  7. 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...

  8. 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

  9. "3-Section" Technology of Full-Dimension Mining in Flat Thick-Seam

    Institute of Scientific and Technical Information of China (English)

    赵景礼

    2004-01-01

    To raise coal recovery ratio and solve the key problem of full-dimension mining, a new "3-section" technology of full-dimension mining is put forward in flat thick-seam according to the theory and mining practice. This technology is proved to be rational and feasible in rodway layout system of stagger arrangement.

  10. 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.

  11. 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.)

  12. 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)

  13. 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)

  14. 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)

  15. Improved schemes and methods of working closely lying flat seams. [USSR - Ukrainian SSR

    Energy Technology Data Exchange (ETDEWEB)

    Batmanov, Yu.K.; Bakhtin, A.F.; Bulavka, E.I. (DonUGI (USSR))

    1990-08-01

    Presents requirements that must be met in order to improve working of closely lying coal seams in the Ukraine. These requirements are: the working order should ensure effective utilization of protective seams for rock burst prevention, gas should be reduced by natural degassing during under- and overworking, and rock pressure should be controlled. A mixed order of seam working is recommended that combines the advantages of ascending and descending working order. Two working schemes that suit the requirements are presented: descending working order in a pillar system with countercurrent ventilation, and ascending working with combined system and concurrent ventilation. Three more improved schemes with air-flow freshening intended for deep highly methane bearing coal seams are considered to meet the requirements still better. Cost effectiveness of the working schemes is compared and an economic effect of 0.8-1.2 rubles/t is claimed. A method of seam grouping into winning and basic workings is recommended that allows the volume and maintenance cost of basic workings to be reduced by 30-40%. Application criteria of the working schemes are discussed. 7 refs.

  16. Ash removal equipment of large power plants designed for increased brown coal ash content and for economic use of waste products

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, G.; Nicko, K.H.; Weidlich, H.G.

    1984-12-01

    The design and performance of the pneumatic deashing system of a brown coal fired steam generator with 660 t/h steam capacity are explained. Experiments were carried out aimed at improving the performance of the pneumatic conveyor with its discontinuously working pressure vessel. A modified technology of operating the pneumatic system quasi-continuously was investigated, with which a 100% higher ash throughput, elimination of pipe clogging and a 40% reduction in air requirement were achieved. Equipment for loading ash from bunkers into closed container cars was further studied. Substantial steel wear was noted at the mixing screw of the ash moistening trough. A new ash moistening and mixing drum (4 m long, 1.8 m diameter, 20 kW drive) has been developed, capable of moistening 600 m/sup 3//h of ash with only 15% of the electrical energy and 30% of the maintenance expenditures of mixing screw equipment. The manufacturer, OBV Budapest, will produce 3 sizes of the new ash mixing drum for reconstruction of ash loading facilities at various power plants. 7 references.

  17. 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