关 键 词：

张小楼 煤矿 0.9 Mta 设计 CAD

资源描述：

张小楼煤矿0.9Mta新井设计含5张CAD图.zip,张小楼,煤矿,0.9,Mta,设计,CAD

内容简介：

英文原文Gas content based outburst control technology in AustraliaSheng XueCSIRO Exploration & Mining, PO Box 883, Kenmore, Queensland 4069 AustraliaTel.: +61 7 3327 4443; Fax: +61 7 3327 4666; Email: sheng.xuecsiro.auAbstractThe violent and unexpected nature of the phenomena enhances the mining risk and danger to mine workers. A number of techniques are used to predict and prevent the occurrence of the outbursts and to protect mine workers from the consequence of outburst incidents. This paper outlines the gas content based outburst control technology, one of the successful outburst control technologies, applied in Australian coal mines. Some aspects of the current technology, which are perceived as either inadequate, inappropriate or impractical, are also highlighted in this paper together with the research strategies to address the concerns.Keywords: Coal Mining; Outburst; Outburst prediction and control; Gas content1 IntroductionAn outburst of coal and gas is the sudden release of a large quantity of gas in conjunction with the ejection of coal and associated rock, into the working face or mine workings. Outbursts are hazardous through the mechanical effects of particle ejection and by asphyxiation and possible explosion from the gas produced. Outbursts occur as a result of mutual interaction of a number of factors such as rock pressure, gas present in coal, and physical and mechanical properties of coal. Gas content is an important factor in outburst proneness. Unless gas content reaches a critical level, outbursts of gas and coal will not manifest themselves at all. Though gas content, as a basic coal seam parameter, has been used to develop many gas-related indices for outburst prediction in Australia, this has not been used in practice elsewhere. This may be due to different coal seam conditions outside Australia and the lack of the development of a rapid method to measure gas content.Outbursts were a common occurrence in gassy Australian mines, up until the industry adopted outburst threshold gas content limits following a fatality at West Cliff Colliery in 1994. Since that time, only a handful of outbursts have been occurred with no fatalities. The Australian coal industry has achieved these results mainly through intensive gas pre-drainage practices as well as the use of shot firing or remote mining in coal that is difficult to drain. The current threshold gas contents have been successful in preventing outbursts in Australia. However, there are a number of aspects of the current gas content based control technologies of managing outburst risk that are perceived as either inadequate, inappropriate or impractical/costly in some seam conditions. Technology roadmaps are developed to address the issues.2 Outburst Control Protocols2.1 Development history in AustraliaOutbursts of gas and coal have occurred in both the major coal producing basins of Australia, namely the southern part of the Sydney basin (Illawarra coal field) and the central and northern part of the Bowen basin. Both pure methane and pure carbon dioxide outbursts have occurred in Australian coal mines. Over 700 outbursts have occurred in Australian mines over the last 100 years. The first outburst occurred in 1895 in Metropolitan Colliery in the Bulli seam. Since then 465 outbursts have occurred in the Bulli seam. The latest fatality from an outburst occurred in Australia in 1994. It is, therefore, not surprising that the outburst control technologies in Australia were developed to manage outburst risks in the Bulli seam. The occurrence of outbursts in the Bulli seam was thoroughly studied by a number of researchers in the early 1980s (Hargraves, 1985; Lama, 1982). The studies revealed that the outbursts in the Bulli seam were characterised by the following: Depth of workings is 350 600 m, dip of the seam varies from 20 to 50, gas content varies with seam depth (from 3-6 m3/t at 350m depth to 15-20 m3/t at 600m depth), seam gas composition varies from pure methane to carbon dioxide, strength of coal ranges from 8 21 MPa, ratio of two horizontal stresses varies from 1.6 to 2.4, intermediate principal stress is 1 1.6 times the vertical stress; Outbursts often occurred in development headings; As long as minimum distance (about 2.5m) from the structures (faults, dyke, strike slip, sheared zones etc) is maintained, an outburst will not occur; when the barrier width of solid coal and the rib line of a heading was reduced to under 2.5m, an outburst precipitated; No signs of any failure due to induced stress in coal in areas of outbursts; and Majority of outbursts have occurred on structures.Based upon these studies, a mechanism of outbursts in the Bulli seam was postulated. Figure 1 shows the generalised concept. The phenomenon of outburst occurrence in the Bulli seam was placed in the third quadrant (high gas, low stress/strength ratio). As the face approaches the structures and the minimum distance (thickness of barrier) is breached, the higher gas pressure displaces the material from the face and high flow rate provides the energy that resulted in the initiation of an outburst.Figure 1. Effect of stress and gas on stability of excavations (after Lama, 1995)The strength of the Bulli seam is placed somewhere in the middle of the band of coal strength around the world. The stress levels occurring in the seam are medium and since there is no indication of the role of stress, it was concluded that mining induced stress does not play an important role in the outbursts in the Bulli seam. Ejection of coal in outbursts in the Bulli seam is all gas controlled. It was thus concluded that virtually all outbursts in the Bulli seam are gas controlled and associated with structures, mostly shear zones, dykes and faults and the safe zone varies from 1 m to 2.5 m.Certain indices based upon measurement of gas emission rate were developed to predict outburst conditions in the Bulli seam in Australia (Hargraves, 1963; Hargraves et al, 1964; Lunarzewski, 1995). However several problems existed with the determination of the indices. These include effect of moisture, variability of coal ply, location (face or corner), depth of hole, etc. With the introduction of high performance machines and particularly longwall mining, these prediction methods which require frequent measurements in hole depth of 2-3 m, was found to be unsuitable and fell into disrepute as they greatly impinged upon productivity and were at the same time unreliable.Based upon these studies and comparison with overseas data, threshold values for the safe mining of the Bulli seam were proposed in 1991 (Lama, 1991 & 1995). These threshold values took into consideration the differences in the initial desorption rate of methane and carbon dioxide as well as the effect of carbon dioxide on the strength of coal. These values were conservative and were proposed to take into account high rates of development of headings. Since 1991 these threshold values were further modified after more gas content data in the Bulli seam was collected and analysed.2.2 Threshold gas contentOn 4 May 1994, after reviewing the findings of the investigation relating to the fatal accident at West Cliff Colliery on 25 January 1994, the results of examination of operational outburst management, and other related event, the then New South Wales Chief Inspector of Mines applied a Section 63 notice of Coal Mines Regulation Act 1982 to the New South Wales coal industry, setting outburst threshold gas content limits for mining in the Bulli seam. The threshold value of gas content was based on studies of the outburst occurrences in the Bulli seam, comparison with overseas data, differences in the initial desorption rate of methane and carbon dioxide, effect of gas on the strength of coal, and a considerable safety margin. Part of the Notice is quoted as follows:(a) In situ total gas content and composition of the Bulli Seam coal, in accordance with AS3980 or an equivalent standard, shall be routinely conducted in the Bulli Seam as part of development roadway operations. The mine manager shall ensure that sufficient samples are taken at appropriate locations in advance of development roadways to determine seam gas content and composition of the coal to be mined at all time.(b) The mine manager shall take all reasonably practical steps to identify structures ahead of all development roadways in the Bulli Seam. If, in the opinion of the mine manager, a structure that has potential to generate an outburst, is identified or inferred from geological or other available information, or observed during the course of the mining, the mining in the vicinity of the structure shall be carried out under Outburst Mining Procedures.(c) Normal mining shall only be conducted where: 1. No structure has been identified as in (b), and 2. Total gas contents in (a) are less than 9 m3/tonne for CH4 or 5 m3/tonne for CO2, or for a mixture of these two gases, a gas content in the proportion of the percentages of each gas between these two limits.(d) Development roadways may be formed where the total gas content is higher than that set out above but only under full outburst procedures or fully remote mining.(e) Development roadways shall not be formed, except by fully remote operation methods, where the total gas contents in (a) are greater than 12 m3/tonne for CH4 or 8 m3/tonne for CO2 or for a mixture of these two gases, gas content in the proportion of percentages of each gas between these two limitsThe Section 63 notice declared that the occurrence of outbursts was not acceptable except under remote mining conditions and the threshold gas contents were based on the worst case scenario. Although the Section 63 notice was imposed on the coal mines in New South Wales, setting the Bulli seam threshold limits for mining, operators of gassy mines outside of the Bulli seam, including Queensland producers, have successfully applied the Bulli seam protocols with some modifications.Since the threshold gas contents were set and implemented in 1994, only nine small outbursts have been recorded in the Australian coal industry. None of these outbursts resulted in a fatality. Furthermore, outbursts have not occurred during the period in Australia when mining has been conducted in coal which was drained to below the threshold values.2.3 Outburst ManagementOutburst management relates to managing the outburst risk. This risk management approach utilizes outburst prediction and prevention techniques and protection measures. The inter-relationship of outburst prediction, prevention and protection is explained diagrammatically in Figure 2. It involves procedures and processes aimed at eliminating the occurrence of outbursts.Figure 2. Diagrammatic representation of outburst management (after Harvey, 2002)It should be noted that there is no one specific technology or mining technique, which could be used to guarantee safety in outburst prone mines. The effective management of the outburst risk involves a number of techniques and technologies. These technologies including measurement of seam gas content and composition, identification of geological structures, use of gas drainage techniques, identifying in situ and mining-induced stress regimes should be integrated in outburst management plans. It is through the application of outburst management plans that outburst risk is controlled.While it is of primary importance that any OMP is developed for each specific site with due regard for geological and mining conditions, for the plan to be considered to be acceptable it must have a number of key elements. These elements are contained within guidance documentation as provided by the Department of Mineral Resources (MDG 1004, 1995). An OMP comprises general requirements, plan elements and processes. While the general requirements provide a basis for the development and implementation of OMPs and the plan elements provide the broad management framework, the processes are those activities and equipment than form the day to day operation of an OMP and which are to be performed under controlled conditions. The human and organisational aspects of an OMP are considered as equal in importance to the technologies utilized.3 Issues and Research RoadmapThe current approach of outburst management, the OMP in combination with threshold gas content limits, has greatly reduced the number of outburst incidents in Australia since its implementation in 1995. However, there are a number of aspects of the current system of managing outburst risk that are perceived as either inadequate or inappropriate or impractical in some seam conditions. These issues include mainly: The one-parameter approach of gas content is simplistic in ignoring other factors which might increase or decrease outburst propensity; it may be inadequate; The methodology for determining safe threshold gas contents was based on a limited local dataset; the proposed threshold values were conservative at the time; and their application to other seams and locations might be inappropriate; and The implementation of the current approach in areas of poor drainability and drillability is impractical.To address the issues mentioned above and to ensure safe and reliable mining using timely and cost effective outburst controls (strategic goals), an Outburst Research Task Group (AORT) comprising representatives from coal producers, researchers, consultants and other stakeholders was formed in 2005 to steer further outburst R&D.The strategic goals are achieved through the development of a technology roadmap. The roadmap has three key elements: defining goals, current status and pathways. Four outburst research goals were developed by AORT in 2006. They are:1. Review and identification of the outburst mechanism and the roles of the various parameters, and the parameters must be practically measurable;2. Understanding of the (structural) conditions which cause zones of poor drainability or drillability and therefore, increase outburst proneness, and to confidently locate these zones with adequate response time;3. Development and application of tools (methods) to rapidly, efficiently, and preferably economically reduce gas content/pressure as a routine and as a last resort, plus awareness; 4. Facilitation of continuous improvement in outburst management through information transfer, development of more efficient procedures and upgrading of management plans.Current status of outburst controls has been extensively reviewed and compiled by Hanes (2004). Based on the recommendations of Hanes work and on subsequent deliberations by AORT, an outburst research roadmap has been developed by AORT in 2006. The roadmap has been structured under the generic hazard management headings of prediction, prevention and protection. Key elements are outlined under each heading and current status of each element is described with “next step” research recommendations proposed in relation to current status assessment. The key elements in prediction of outburst conditions include characterisation of outburst parameters, locating structures, modelling outbursts, and monitoring for outburst conditions; the key elements in prevention of outbursts include reducing gas content and pressure and enhancing permeability; the key elements in protection against harms from outbursts include education and training, protocols and standards, sustainable use of explosives and remote mining.Five research themes have been developed by AORT in 2007 to move the roadmap research projects towards a plan. Each theme addresses a number of research elements included in the outburst research roadmap. The themes are: 1. Collect and interpret key outburst parameters efficiently;2. Refine methods to locate and characterise structural features that increase outburst proneness; 3. Improve efficiency and effectiveness of drainage systems;4. Education, training and communication of outburst management; and 5. Challenge and improve current outburst protocols. At present there are a dozen active outburst research projects in Australia. The projects are related to improving drilling technology, gas drainage, outburst risk assessment, and understanding of outburst mechanism.4 ConclusionsOutburst risk controls in Australia utilize management plans and threshold gas content values. An outburst management plan is based on the assessment of the outburst risk to be managed at the particular mine and threshold gas content values are based upon the values set for Bulli seam with some modifications.Current approach of outburst controls has been successful in preventing outbursts in Australia. However, there are a number of aspects of the current gas content based control technologies of managing outburst risk that are perceived as either inadequate or impractical in some seam conditions. Technology roadmaps have been developed to address the issues and a cluster of research themes relating to the key elements of the roadmap have been developed. References1Hanes, J, 2004, Outburst scoping study, Australian Coal Association Research Program Report C10012, Australia.2Hargraves, AJ, 1963, Instantaneous outbursts of coal and gas, thesis submitted to the University of Sydney for the degree of PhD, Australia.3Hargraves, AJ, Hindmarsh, J and McCoy, A, 1964, The control of instantaneous outbursts at Metropolitan Colliery, NSW, In: Proceedings of Australasian Institute of Mining and Metallurgy, no. 209, pp. 38-66.4Hargraves, AJ, 1985, Instantaneous outbursts of coal and gas, In: Proceedings of Australasian Institute of Mining and Metallurgy, vol. 186, no. 6, pp. 21-72.5Harvey, C, 2002, History of outbursts in Australia and current management controls, In: Proceedings of 2002 Coal Operators Conference, 6-8 February 2002, Wollongong, Australia, pp. 36-42.6Lama, RD, 1982, Outbursts and gas drainage investigations, End of Grant Report, NERDDP Project No. 578, Department of Primary Industries, Canberra, Australia.7Lama, RD, 1991, Control of outbursts in the Bulli seam, Kembla Coal & Coke Internal Report, December, 1991.8Lama, RD, 1995, Saf gas content threshold value for safety against outbursts in the mining of the Bulli seam, In: Proceedings of International Symposium-cum-Workshop on Management and Control of High Gas Emissions and Outbursts in Underground Coal Mines, Wollongong, 20-24 March, pp. 175-189.9Lama, RD and Bodziony, J, 1996, Outbursts of Gas, Coal and Rock in Underground Coal Mines, R D Lama and Associates, Wollongong, Australia.10Lunarzewski, L, 1995, Immediate assessment of in-situ gas content using underground manometric desorbometer readings, In: Proceedings of International Symposium-cum-Workshop on Management and Control of High Gas Emissions and Outbursts in Underground Coal Mines, Wollongong, 20-24 March, pp. 569-571.11MDG1004, 1995, Outburst mining guidelines, Department of Mineral Resources, New South Wales, Australia.中文译文瓦斯的突出控制技术在澳大利亚的应用Sheng XueCSIRO Exploration & Mining, PO Box 883, Kenmore, Queensland 4069 Australia摘要：爆炸和难以预料的自然现象增加了煤矿工人开采过程中的危险。大量的技术被用来预测和防止发生爆炸，并保护矿工预防从突发事件。本文主要介绍了瓦斯的突出控制技术,这是众多成功的突出控制技术的一个,广泛应用于澳大利亚煤矿。目前这种技术在某些方面,被视为既不充足,不恰当或不切实际,本文中的研究策略就是来解决这些问题的。关键词:煤矿；突出；突出预测和控制；瓦斯含量1、简介煤与瓦斯突出是从煤岩壁内突然释放的大量的气体并向工作面或者工作地点喷发大量煤炭和岩石。突出是通过力学效应的粒子弹射和通过爆炸产生的气体使人窒息而产生危险。突出会导致相互交互的许多因素如岩石的压力、煤炭中的气体和煤的物理力学特性。瓦斯含量是瓦斯突出的一个重要的因素。除非瓦斯含量达到一定的标准，突出的煤与瓦斯将不会出现。作为煤层的一个基本参数，瓦斯含量已经在澳大利亚被用于开发多个和天然气有关指数对突出预测，但是这还没有用于其他地方。这可能是由于在澳大利亚不同煤层条件下，还缺乏一种快速的方法来测量瓦斯的含量。瓦斯含量高的澳大利亚是一个瓦斯突出频繁的地方。直到1994年工业采用突出阈值后，瓦斯突出造成的死亡率才被西崖煤矿控制住。从那时起，只有少数的瓦斯爆炸发生,并且没有人员伤亡。澳大利亚煤炭行业已经通过密集的气体pre-drainage实践的运用以及照片的射击或者远程煤矿技术来取得这些结果，这些结果很难流失。在澳大利亚，标准的瓦斯含量已成功地防止瓦斯爆炸。然而，就目前来说，天然气含量的控制爆炸技术的风险管理在很多方面被视为不充足、不恰当，在不同煤层条件者也是不切实际或者昂贵的。技术路线图正致力于解决这方面的问题。2、突出控制协议2.1在澳大利亚的发展历史煤与瓦斯突出发生在澳大利亚两个主要的生产煤炭的盆地，分别为悉尼的南部盆地(Illawarra煤田)和中部和北部的博文盆地。纯甲烷和纯二氧化碳爆炸发生在澳大利亚煤矿。在过去的100年里，澳大利亚煤矿发生了700多次的爆炸。第一次爆炸发生于1895年在大都会煤矿Bulli煤田。自那以后，Bulli煤田发生465次爆炸。澳大利亚最近的一次大爆炸死亡事故发生在1994年。因此，致力于解决Bulli煤田爆炸危险的瓦斯爆炸控制技术在澳大利亚发展起来并不奇怪。在1980年代早期，Bulli煤田的瓦斯爆炸现象被用来做了大量的研究(Hargraves, 1985; Lama, 1982)。研究表明，Bulli煤田的爆炸有以下几点： （1）开采的深度是350 - 600米,煤层倾角为2-5o，瓦斯含量变化与煤层的深度有关（从海拔350米的深度的3 - 6立方米/ t到海拔600米的深度的15 - 20立方米/ t），煤层气体成分包括纯甲烷和二氧化碳，煤的强度范围为8 - 21 MPa，两个水平应力的比例从1.6到2.4不等，中间主应力是1 - 1.6倍的垂直应力； （2）爆炸通常发生在掘进头； （3）只要到一些地质构造（断层，褶曲）的最小距离(约2.5米)得到保持,就不会发生的爆炸；当煤壁与构造停采线的距离小于2.5m时，爆炸就被控制住了； （4）没有任何迹象表明爆炸发生在应力增高区，而且多数的爆炸发生在地质构造区。基于这些研究，Bulli 煤田爆炸的一种机制被假定出来。图2-1显示了一般化的概念，这一发生在Bulli突出煤层的现象被放在第三象限（高表示瓦斯，低表示压力和强度比值）。如同面对方法，结构和最小距离(厚度的屏障）被打破，气体压力越高，高流量提供了能量,就能导致发生一次大爆炸。图2-1 压力与气体对开采稳定性的影响Bulli 煤田的煤层强度，被放置在世界各地的煤炭强度中的某个地方。煤层中的水平压力是有介质的，由于没有迹象表明压力的作用。可以概括来说，减小煤层的压力在有爆炸危险性的Bulli 煤田中起不了重要作用。Bulli 煤田爆炸过程中所释放出来的煤炭是收瓦斯控制的。因此可以总结为，Bulli 煤田中几乎所有的爆炸都是有瓦斯引起的，也跟地质构造比如说断层褶曲有关系。在澳大利亚的Bulli 煤田，某些基于测量气体排放速度的指数被开发来预测突出条件(Hargraves, 1963; Hargraves et al, 1964; Lunarzewski, 1995)。然而一些关于测定指标的问题出现了。这些包括水份效应,煤厚度可变性、位置(工作面或角落)、钻孔的深度等等。通过引入高性能机器和特别长壁采煤法，这些预测方法,需要频繁的测量孔深度的2 - 3米，被发现不适和，同时大大影响生产力并且不可靠。基于这些研究和比较与海外数据，阈值安全开采的特点，在1991年(Lama, 1991 & 1995)被提出了。这些阈值的差异考虑了初始解吸率的甲烷和二氧化碳以及二氧化碳对煤炭强度的影响。这些值是保守的，而且提出了考虑开发高水平发展的标题。自1991年以来，在对Bulli 煤田的瓦斯含量的数据进行收集和分析后，这些阈值被进一步修改。2.2 瓦斯含量的阈值1994年5月4日，在对1994年1月25日煤矿西崖致命事故进行重新调查之后，检查了爆炸后的操作管理和其他相关事项，新南威尔士州矿山总监列出了1982年新南威尔士的煤矿工业的煤矿监管法案中的63个条款，设定瓦斯含量的阈值用于限制Bulli 煤田的瓦斯爆炸。瓦斯含量的阈值基于Bulli 煤田突出煤层的研究，与海外数据比较，在初始解吸率的甲烷和二氧化碳气体对煤炭强度的影响上存在差异。有关事项的一部分引述如下：（a）Bulli 煤层煤炭原位总瓦斯的含量和成分的分析，按照AS3980或同等标准，作为操作的发展道路应当定期进行。矿长应当保证在适当的位置有足够的样品，并按着之前的开拓方案来确定煤层瓦斯含量的成分及煤炭开采。（b）矿长应当采取一切合理实用的步骤确定开采巷道前面的地质构造。如果，在矿长指导下，一个可能要发生突出的构造，必须要标识或显示其他可用的信息，或者在采矿过程中要注意观察，采矿过程中的地质构造才会被发现，并防止瓦斯爆炸。（c）正常的采矿活动要在以下条件允许时才可以进行：1、没有地质构造被发现，2、总的瓦斯含量低不高于9立方米/吨甲烷或5立方米/吨二氧化碳，或这两种气体的混合物，瓦斯含量的比例应当这两中气体的范围之内。（d）采矿方案可能形成于总瓦斯含量高的方面,但只有在瓦斯含量过高时完全爆发过程时采用完全远程采矿。（e）当全部气体含量大于12立方米/吨甲烷或8立方米/吨二氧化碳或这两种气体的混合物，瓦斯含量的比例应当这两中气体的范围之内时，采矿方案不得形成，除了完全远程操作方法。这63个条款宣布了爆炸的发生是不可接受的，除了在远程开采条件和瓦斯含量阈值是基于最糟糕的情况下。尽管63个条款是强加在新南威尔士州的煤矿上的，设置了Bulli 煤田采矿过程中的阈值，运营矿山以外的瓦斯，包括昆士兰州生产商，已经成功地应用了Bulli 煤田协议并进行了一些修改。1994年，自从瓦斯含量阈值设定和实现以来，澳大利亚的煤炭行业只有9个小爆炸的记录。所有这些爆炸都没有导致人员死亡。而且，当采煤过程中，瓦斯含量阈值低的时候，澳大利亚还没有发生过瓦斯爆炸事故。2.3突出管理 突出管理指的是管理突出风险，这种风险管理方法利用突出预测和预防技术保护措施。突出预测、预防和保护之间的关系可以用图2-2中来解释。它所涉及的流程和过程旨在消除爆炸的发生。图2-2 突出管理的图表形式应该指出的是,没有一个特定的技术或采矿技术，可以用来保证矿山爆炸的安全。有效的管理爆炸