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英文原文Environmental issues from coal mining and their solutionsBIAN Zhengfu1，INYANG Hilary I2 ，DANIELS John L3 ，OTTO Frank4， STRUTHERS Sue51. Institute of Land Resources, China University of Mining & Technology, Xuzhou 221008, China 2. Global Institute for Energy and Environmental Systems, University of North Carolina, Charlotte NC 28223, USA 3. Natural Science Foundation of the USA, Arlington VA 22230, USA 4.Department of Geoengineering and Mining, University of Applied Science, Bochum 44801, Germany 5. Skapa Mining Services, Orkney KW17 2SX, UKAbstract: The environmental challenges from coal mining include coal mine accidents, land subsidence, damage to the water environment, mining waste disposal and air pollution. These are either environmental pollution or landscape change. A conceptual Frame work for solving mine environmental issues is proposed. Clean processes, or remediation measures, are designed to address environmental pollution. Restoration measures are proposed to handle landscape change. The total methane drainage from 56 Chinese high methane concentration coal mines is about 101.94 million cubic meters. Of this methane, 19.32 million, 35.58 million and 6.97 million cubic meters are utilized for electricity generation, civil fuel supplies and other industrial purposes, respectively. About 39% of the methane is emitted into the atmosphere. The production of coal mining wastes can be decreased 10% by reuse of mining wastes as underground fills, or by using the waste as fuel for power plants or for raw material to make bricks or other infra-structure materials. The proper use of mined land must be decided in terms of local physical and socio-economical conditions. In European countries more than 50% of previously mined lands are reclaimed as forest or grass lands. However, in China more than 70% of the mined lands are reclaimed for agricultural purposes because the large population and a shortage of farmlands make this necessary. Reconstruction of rural communities or native residential improvement is one environmental problem arising from mining. We suggest two ways to reconstruct a farmers house in China. Keywords: mine environment; management of mining wastes; reuse of mine gas; mined land reclamation; clean coal mining1 IntroductionWhile coal makes an important contribution to worldwide energy generation, its environmental impact has been a challenge. In essence, the coal energy production system consists of coal mining, preparation or processing and energy generation. Fig. 1 shows the complete process of the coal energy system. Environmental issues arise at every stage of the process. This paper will discuss environmental issues due to coal mining. In fact, environmental problems from coal mining have been studied since coal mining became industrialized. Nevertheless, environmental issues from coal mining have become important concerns only since the 1970s. The majority of the available literature related to mining and the environment date from the end of the 1970s to the end of the 1980s. However, coal production has changed significantly since the beginning of the 1990s and as a result, the way and the extent that mining operation impact the environment are also different now. Fig. 2 shows the change in worldwide coal production over time, which illustrates that coal production increased strikingly after 2000. Six countries, the USA, Russia, India, China, Australia and South Africa, produced 81.9% of the total coal extracted throughout the world in 2006. These same countries have about 90% of the Worlds coal reserves. Coal production in China accounted for 38.4% of the worldwide total and has increased about 66% over the past five years from 1.38 billion tons in 2001 to 2.3 billion tons in 2006. During the same time period the number of coal mines was reduced by 50%. The annual production of the Daliuta Coal Mine, one of the underground mines operated by the Shendong Coal Mining Company, reached 20 million tons from only two longwall work faces in 2007. In the U.S，the situation is similar to China. There were 2475 coal mines with a total production of 945424 thousand short tons in 1993 but 1438 coal mines producing 1162750 thousand short tons in 2006.Fig. 2 Worldwide coal productionChina consumes more coal than Europe, Japan and the United States combined; 40% of the worlds total. Chinas coal use continues to grow every year and it is estimated that 90% of the rise in world coal consumption is from increased activity in China. As a result, mining intensity in some coalfields is ten times greater than it was in the past. Therefore, the impact of mining on the environment today is significantly different from that in the 1980s. Thus, this paper focuses on environmental issues due to coal mining in the context of current mining operations. 2 Importance of coal mining to energy systems worldwide and challenges to the environmentThe main use of coal in the United States is to generate electricity. Coal generates half of the electricity used in the United States. Today, 91.9% of all the coal in the United States is used for electricity production. In contrast, less than 50% of all the coal mined in China was used for electricity generation in 2005 when 82% of the electricity used in China came from coal fired plants. Coal accounts for approximately 74% of Chinas primary energy consumption. Coal is recognized as a dirty source of energy and has been rendered obsolete in many European countries. For example, France closed all coal mines in 2004 and, in early 2007, the German government announced that subsidies for coal production would be completely phased out by 2018. Whether this will mark the end of deep mining in Germany remains to be seen.Some experts and institutions forecast that coal will continue to underpin the economic and social development of the worlds biggest economies in both the developed and developing world. The World Bank Group estimated that coal is one of the Worlds most plentiful energy resources and that its use is likely to quadruple by 2020. Global recover-able coal deposits exceed 1 trillion tons with enough deposits to last for the next 270 years at current consumption rates. Hence, it is reasonable to conclude that coal will continue to be an important energy source and that coal mining is not a sunset industry. This will be especially true in those countries with abundant coal reserves and increased energy demands for their development. Using coal as an energy source requires addressing environmental challenges from mining. This includes coal mine accidents, land subsidence, water pollution, air pollution, spoil heaps, acid mine drainage, disturbance of hydro-geology and so on. The impact of coal mining on the environment varies in severity depending on whether the mine is active or abandoned, the mining methods used and the geological conditions.2.1 Coal mine accidents Every year nearly 80% of the Worlds total deaths due to coal mine accidents occur in China. The main causes of coal mine accidents are gas leaks, roof cave-ins, fires, blasts and floods/water bursting. Table 1 shows accident statistics for Chinese coal mines for the years 2006 and 2007. This data was compiled by the corresponding author from the State Administration for Coal Mine Safety safety bulletins. It is easy to see that coal dust and methane blasts are in the absolute majority. In addition, 117 of the 374 deaths in 2006, and 92 of the 399 deaths in 2007, occurred in coal mines with a production of less than 200 thousand tons. It was reported that coal mines with small scale production account for one third of total production, two third of the total coal mine accidents and 75% of the deaths. Table 1 Chinese coal mine accident statisticsAccidentsCoal dust andmethane blastWater burstingCO poisoningRoof cave-inFires2006Times15821Death322311472007Times213211Death31741125242.2 Land subsidence Approximately 60% of the worlds coal production comes from underground mines. Since 95% of the coal production in China is from underground mines and, in 2007, Chinese production was 2523 million tons, which accounts for more than one-third of the worlds production, China accounts for much of the underground operation, see Table 2. Table2 Percentage of coal production by mining method in the main coal producing countries (2006)CountryUnderground mining(%)Surface mining(%)Total(MT)China9552380.0USA30.969.11053.6India1981447.0Australia2278405.1Russia309.2South Africa256.9Germany197.2Indonesia195.0Poland156.1Total world60406195.1Land subsidence over underground mines is one important adverse impact of mining on the environment. About 1 million hectares of subsided land exists today. Mining ten thousand tons of raw coal will result in 0.2 hectares of subsiding land in China. Land subsidence not only reduces crop production but also causes other environmental problems, such as utility failures, plant death, surface fracture and soil loss, drainage system failure, building damage and so on. Subsidence falls into two forms of deformation: continuous and discontinuous. Continuous, or trough, subsidence involves the formation of a smooth surface profile free of steps. Discontinuous subsidence is characterized by large surface displacements over a limited surface area and by the formation of steps or discontinuities in the surface profile. Mining subsidence will affect land use or the environment differently depending upon the context of the terrain, groundwater level and the original type of land use. For example, in eastern China, which has plain land-form, shallow groundwater levels and was prime farmland before mining, mining subsidence has resulted in large area flooding. After this the land use was changed as buildings, roads and croplands were seriously damaged by major incidents of land subsidence. Mining subsidence in mountain areas will induce slope failure causing the loss of water and soil from the formation of surface cracks and overburden fracture from mining.2.3 Water environment Coal mining affects the water environment mainly by inducing a drop in the ground water table, causing water loss or water pollution and by altering water-courses. Mining drainage and mine subsidence have an immediate effect on the water environment due to the connection of underground water bodies to the mined space through fractured overburden. When water is redirected as a result of fracturing or cracking it interacts with the various subsurface strata with which it comes in contact. In these strata there are many compounds and sediments that may be dissolved by the flowing water to eventually leach into the drainage lines. Many of these newly exposed minerals can react with gaseous or liquid components in their new environment to yield contaminants. These have an impact on water chemistry and aesthetics and can increase the level of suspended solids in the water. This results in a significant reduction in the quality of the water and the aquatic habitat. Mine drainage can pollute surface water and the disposal of mining wastes will also affect water quality when contaminants leach into the surrounding surface or ground water. Acidic Mine Discharge (AMD) is formed when pyrite reacts with air and water to form sulfuric acid and dissolved iron. This acid run-off dissolves heavy metals such as copper, lead and mercury that may end up in ground and surface waters. In the United States AMD is still of great concern as it is estimated that there are over 1.1 million surface acres of abandoned coal mines, over 9000 miles of streams polluted by acid mine drainage and many miles of dangerous embankments, highwalls and surface impoundments. Surface watercourses have to be changed, obviously, to strip overburden and apply surface mining to coal resources. If coal resources are mined underground subsidence would change the slope of the relief, broaden the surface-water pathways and consequently change the surface water regime. 2.4 Mining wastes disposal Waste products from underground coal mining comprise coarse discard (mine stone or coal reject) and fines that are produced by the washing process. The former comes to the surface, mostly with run of mine coal, as a result of the cutting of roadways and drives or other underground development work and the high degree of automation applied to variable geology. Surface coal mining involves material that must be removed to gain access to the coal resource including topsoil, overburden and waste rock. While the coalfield operator does not seek to produce waste unnecessarily geology and mining methods combine to increase the waste quantities involved. Theoretically, mining methods could be made more sustainable by minimizing waste production. The need to accommodate both dry mine stone and wet fines imposes the main engineering constraints on tip design and that controls the pace of progressive restoration. Although waste reduction and reuse have recently become the most preferable methods of waste management (for example, mine stone has been accepted in many places as alternative aggregate for use in embankment, road, pavement, foundation or building construction) most of the coal mining waste still must be transported to dumps or used to fill gullies or tipped as a hill. Mining wastes have significant impacts on the environment in the following ways: slope failure and erosion; occupation of lands; potential leaching of contaminants into groundwater; dust pollution driven by wind; air pollution and explosion by spontaneous combustion; visual and landscape impact; and land use constraints. Oxidation of pyrite within spoil-heap waste will pollute the air as well as ground water. This oxidation is governed by access to oxygen, which in turn depends upon the particle size distribution, the amount of water saturation and the degree of compaction 。The impact of mining waste can have lasting environmental and socio-economic consequences and be extremely difficult and costly to address through remedial measures. Coal mining wastes have, therefore, to be properly managed to ensure the long-term stability of disposal facilities and to prevent or minimize any water and soil pollution arising from acid or alkaline drainage and leaching of heavy metals.2.5 Air pollution Air pollution from coal mines is mainly due to the fugitive emission of particulate matter and gases including methane, sulfur dioxide and oxides of nitrogen. Surface mining operations like drilling, blasting, movement of heavy earth moving machinery on haul roads, collection, transportation and handling of coal and the screening, sizing and segregation units are the major sources of such emissions. Underground mining also emits dust from uncovered coal piles and wastes dumps. The emission of CO, CO2, NOx, SOx happens because of spontaneous coal combustion and methane leaking from the coal strata and coal seams. Methane is a “greenhouse gas” that is 21 times more potent in its greenhouse effect than carbon dioxide. Methane emission from coal mining depends on the mining method, the depth of coal mining, the coal quality and the entrapped gas content within the coal seam. As mining proceeds methane is released into the mine air to be eventually discharged into the atmosphere. Methane emissions from coal mining are listed in Table 3 by country in terms of the rank as of 2000. Methane is highly explosive and has to be drained during mining operations to keep working conditions safe. At active underground mines in China, large-scale ventilation systems move massive quantities of air thereby releasing methane into the atmosphere at very low concentrations.Table 3 Methane emissions from coal mining (million tons CO2 equivalent)Rank as of 2000CountryMethane emissionMost recent year availableYearMethane emissions1China117.620041932Us56.2200354.03Russia29.0200220.64Ukraine28.3200127.05Australia19.6200521.86India15.8200519.57Poland11.920036.78Germany10.220055.42.6 Landscape change Coal mining changes the local landscape dramatically by introducing things such as mining waste dumps, high shaft towers, large scale surface scarring from surface mining or land subsidence from underground mining. All of these are typical within the mine landscape. In addition, land use can change, native residents may migrate away from the coal mining or the course of rivers may change. All these things will affect the structure and function of the ecosystem. For example, in the Yulin coal mining area, which is located in western China, fallow land decreased by 125148 hm2 between 1985 and 2000 while at the same time grassland and woodland increased by 107975 and 17157 hm2 , respectively 9. The major factors responsible for these changes are a change in the government policy on preserving the environment, continued growth in mining and urbanization. Efforts to restore the deteriorated ecosystem have reaped certain benefits in reducing the spatial extent of sandy land through replacement by non-irrigated farmland, woodland and grassland. On the other hand, continued expansion of the mining industry and of urbanization has exerted adverse impacts on the landscape. Coal mining has caused the destruction of land resources and the fragmentation of the landscape accompanied by land desertification; the situation is even serious in some localities. In the Xuzhou coal mining area, which is located in eastern China, farm land decreased by 13.04% from 1987 to 2001, construction areas increased by 37.62% and flooded land resulting from mining subsidence increased by 137.62%. This subsidence accounts for 30% of the total subsided land. 3 A conceptual framework and potential solutions to the mine environment 3.1 A conceptual framework for solving mine environmental issues The key words green mining, ecological mines, recycling economy, industrial ecology, site characterization for remediation of abandoned mine lands and life cycle assessment were proposed by environmentalists, economists and scholars working in the field of mining science. The core ways to solve mine environmental problems may fall into two types. One is the taking of measures to lessen the impact of mining on the environment during mining. The other is the taking of measures to clean or remediate or restore or reclaim the environment post mining as illustrated in Fig. 4. Fig. 4 A conceptual framework for solving mine environmental issuesGreen mining as posed by Professor Qian, a Chinese Engineering Academician, is one of many ideas proposed to solve the environmental issues. The foundation of these ideas is the distribution behavior of joints, fractures and bed separations and the seeflow of methane and water through broken rock strata caused by mining 11. Green mining techniques under development include water-preserved-mining, coal mining under infrastructures, grouting into the space between separated rock layers to reduce surface subsidence, partial extraction and backfill mining, simultaneous extraction of coal and coal-bed methane, underground roadway support, underground discharge of partial mining wastes and underground coal gasification. The principles of industrial ecology and mining science also should promote the rational utilization of natural resources by reducing waste, reusing waste and recycling waste. A reduction in the mining waste produced by excavating roadways along coal seams and other innovative mining methods are one approach to this. Using coal mining waste as fuel for thermal electric plants is a good example of reusing mining wastes. Recycling of mining waste is a more environmental friendly technique. For example, after mining waste is burned in an electric plant the fly ash can be used as raw material for cement production. Or rather than just converting fly ash into cement some useful elements of the fly ash , such as refractories, can first be extracted. 3.2 Use of mine gas Venting mine gas imposes a considerable burden on the environment and also wastes valuable energy. Because mine gas is explosive in certain concentrations it is traditionally removed by intricate ventilation systems during active operations of the mine. Recent statistics show that the number of Chinese coal mines with high methane concentrations is 49.8% of all the mines and coal production from these mines accounts for 42% of the total production. Furthermore, coal mine accidents from mine gas explosion account for 94.97% of the total accidents and deaths in these accidents account for 96.25% of all deaths. Reducing mine accidents and making full use of methane as a new energy source is an important goal. The Ministry of Environmental Protection and the General Administration of Quality Supervision, Inspection and Quarantine of China have jointly issued the Emission Standard of Coal bed Methane Coal Mine Gas (on trial). The Standard requires that measures to drain and utilize the mine gas must be taken before mining. Coal mining operations may only be implemented after the methane content in the coal seam is reduced to less than eight cubic meters per ton of coal. If the concentration of methane is higher than 30% atmospheric release is prohibited. There are currently two ways to drain mine gas in China. One is by drilling wells through the coal seam at the coalfield before mining operations begin. The concentration of methane obtained this way is higher than 90% the other method is to drill boreholes through the goaf after coal has been mined. Methane concentrations obtained in this way are higher than 30%. The total magnitude of methane drainage from 56 Chinese coal mines high in methane was about 101.94 million cubic meters. Of this gas 19.32 million cubic meters, 35.58 million cubic meters and 6.97 million cubic meters were used for electricity generation, civil fuel and other industrial purposes, respectively. About 39% of the methane was not utilized and was emitted into the atmosphere. Methane continues to escape from the old workings of abandoned coal mines where it reaches the surface through cracks and crevices caused by mining activity. In Herne, Germany, more than a million cubic meters of mine gas were discharged into the atmosphere annually up to the end of 1997 from the closed No.3 pit of the Mont-Cenis colliery, which ceased operation 38 years ago. In 2000 extraction units pumped gas with a methane content of up to 80% from the old mine and delivered it to a cogeneration plant where it was converted into power and heat. A local utility company, Stadwerke Herne AG, installed the pilot plant in 1997 and feeds the electricity generated, around 300 million kilowatt-hours per year, into its network. The roughly 4.5 million kilowatt-hours of energy produced each year are used to heat a college of continuing education, a hospital and around 250 homes.4 ConclusionsCoal is one of the Worlds most plentiful energy resources. It is today and will be in the future the most important global source of electricity. This is likely to be true for the next 50 years in light of available natural resources and technological advances. Coal mining and utilization will inevitably cause negative environmental effects including coal mine accidents, land subsidence, pollution of water environments, disposal of mine waste and air pollution. Current Chinese coal production and its environmental impacts were analyzed under the context of worldwide coal mining. Coal production in China accounts for 38.4% of all worldwide production. Coal production in China has increased by 102%, from 1.38 billion tons in 2001 to 2.79 billion tons in 2008, but the number of coal mines has been reduced by 50%. This implies that coal mining activity is becoming more intensive and the environmental effects are becoming more prominent problems. Recent studies show that some environmental issues from coal mining could be eliminated by taking proper measures during the mining process but that some issues should be remediated after mining is finished. Using mine gas, conservation and restoration of the mine-water environment and the management of mining wastes are actions taken when using green mining technology. Reclamation of mined lands and reconstruction of rural communities affected by coal mining should be done after mining. Rural community reconstruction or native residential improvement is very important for sustainable development of the mining industry because the conflict between the mining company and local farmers has exists once mining operation begins. This paper proposes a framework for solving environmental problems from coal mining and introduces two ways to reconstruct a farmers house in China. Because the mining industry plays a different role in different countries, and because developed countries have experienced and suffered those problems that the developing countries are just facing, the authors believe it is necessary to strengthen cooperation between various parties to solve environmental problems from coal mining. On the one hand, we must to seek clean substitute energy. On the other hand, we must consider that coal will still be a dominant source of energy in some countries and that we must, therefore, develop clean mining technologies.Acknowledgements The investigations are supported by the 111 Project (No.B07028) and the Project for New Century Talents of Ministry of Education of China (No.NCET-04-0487). The investigations are also supported by the Natural Science Foundation of Jiangsu Province of China (No.50574095). References 1 Nlida JDGC .Towards a Sustainable Energy Production: a Study and Comparison of the Coal and Biomass Energy Production Systems Master dissertation. Lund: Lund University, 2005. 2 Energy Watch Group. Coal: Resources and Future Production. EWG: The German Member of Parliament Hans-Josef Fell, 2007. 3 The NEED Project. Intermediate Energy Info Book . Manassas: West Virginia University, 2007. 4 World Coal Institute. Coal and sustainable development . 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Krakow: University of Agriculture in Krakow, 1993: 873- 880.中文翻译煤炭开采的环境影响及解决办法卞正富1 伊尼扬希拉里2 丹尼尔斯约翰逊3 奥托弗兰克4 史特瑟斯苏51.中国矿业大学土地资源学院-中国（徐州）邮编：2210082.北卡罗纳大学全球能源与环境系统学院-美国夏洛特 邮编:：282233.美国国家科学基金会-美国阿灵顿 邮编：222304.应用科学大学地球工程与采矿学院-德国波鸿 邮编：448015.讯佳普采掘服务-英国奥尼克KW17 2SX摘要：煤炭开采所造成的环境影响包括：煤矿事故，地表沉降，水资源破坏，矿山废弃物的排放及空气污染。这些影响或者造成了环境的污染，或者造成了风景的破坏。因此，一个解决采矿污染问题方法的概念框架就应运而生。边开采边清洁，或者是采后清洁的方式，都旨在解决环境和污染问题。采后恢复的方式来解决地表沉降与变化。56所中国高瓦斯矿总计排放甲烷量101940000立方米，这些甲烷中，1932万用于发电，3558万用作民用燃料供应以及6970000立方米用于其他工业用途。大约39%的甲烷被排放到大气中。煤矿废弃物的产生通过废弃物地下填充再利用，或作为燃料的电厂或原料，使得砖或其它基础结构材料的使用量被减少10。开采过的煤矿占地正确的使用方式必须就当地的物理和经济条件而决定。在欧洲国家，有超过50%的采过土地被开垦为森林或者草地。然而，在中国超过70%的采过土地被回收用于农业生产，这么做也是基于中国人口众多，耕地资源短缺的原因。农村社区的重建或本地居住条件的改善也是开采后所要解决的环境问题中的一种。我们建议两种方式来重建一个中国农民的房子。关键词：矿山环境;采矿废弃物管理;矿井瓦斯再利用;矿山土地复垦;煤的清洁开采1 引言虽然煤炭对世界能源发电做出了十分重要的贡献，但是其对环境的影响已经成为了人类面临的一个巨大挑战。本质上来讲，煤炭能源生产系统包括采煤，加工和能源发电。图表一中展示了煤炭能源系统的完整过程。这个过程中的每一环节都会引发环境问题。本文就要探讨一下由煤炭引起的环境问题。事实上，自煤炭采掘工业化以来，人们就一直在研究由于采煤引起的环境问题。然而，自从二十世纪七十年代开始，由于采煤引起的环境问题才引起越来越多的关注。大部分与采煤和环境问题相关的可利用的文献都是二十世纪七十年代末期到二十世纪八十年代末期编著的了。然而，从二十世纪九十年代初开始，煤炭生产发生了巨大的改变，与此相对应的，煤炭生产对环境影响的方式和内容也发生了变化。图表二中显示了过去一段时间内世界范围内煤炭生产产量的变化，可以看出，2000年以后，煤炭产量大幅度增加。2006年，美国，俄罗斯，印度，中国，澳大利亚和南非六个国家采出了全世界煤炭总量的81.9%的煤。这六个国家拥有占世界大约90%的煤炭储量。中国的煤炭产量占世界总产量的38.4%，在过去的五年，煤炭产量增长了大约66%，从2001年的13.8亿吨增长到了2006年的23亿吨。五年间煤矿的数量减少了50%。神东煤炭集团下属的一个地采煤矿大柳屯煤矿，其2007年产量达到了20000000吨，并且只开采了两个采用了长壁开采的工作面。美国与中国的情况类似，1993年美国有2475个煤矿，总产量为945424000短吨，但是在2006年，1438个煤矿就生产了1162750000短吨煤炭。图2 世界煤炭生产中国消费的煤炭占世界总量的40%，比欧洲日本和美国消费的煤炭总量还要多。中国的煤炭消费量每年都在增长，据估计，世界90%的煤炭消耗增长都来自中国。这导致了在一些采区的采煤工作量是过去的的十倍。因此，如今煤炭采掘对环境的影响与20世纪80年代有很大的不同。那么，本文将根据现在的煤炭生产来集中探讨由于采煤引起的环境问题。2 煤炭开采对于世界能源系统的重要性以及环境面临的挑战美国主要用煤炭来发电。煤炭发电供给美国一边的电能。如今的美国煤炭产量的91.9%都用来发电。与之对比，2005年，中国用不到50%的煤炭用来发电，中国82%的电能都来自于火力发电厂。煤炭大约占据中国首要能源消费的74%。在许多欧洲国家，煤炭被认为是不清洁能源并且已经被禁止使用。例如，法国在2004年关闭了所有的煤矿，在2007年初，德国宣布到2018年，煤炭生产津贴将逐步取消。这是否标志着德国的深部开采的结束还有待见证。一些专家和研究机构预测，无论是发达国家还是发展中国家，煤炭仍然是经济和社会发展的基本能源。世界银行组织预测，煤炭是世界上储量最丰富的能源，到2020年，煤炭的消耗量会是现在的四倍。全球可采煤炭储量超过1万亿吨，按照现在的消费水平，这些煤炭足够维持270年。因此，我们可以得到结论：煤炭仍然会是重要的能源，采煤行业还不是一个夕阳行业。特别是那些煤炭储量丰富并且为了发展需要更多能源的国家，情况更是如此。那么，把煤炭作为主要能源的国家，就需要专注于由于采煤引起的环境问题了。这些问题包括：采煤事故，地表沉陷，水污染，空气污染，矸石山，酸性矿水排放，水文地质扰动等等。采煤对环境的破坏程度不同条件下不一样。煤矿是否废弃，是否应用了先进技术，地形条件如何，都会产生影响。2.1 采煤事故每年由于煤炭开采引起的死亡事故80%都发生在中国。发生采煤事故的主要原因有瓦斯泄漏，顶板塌陷，火灾，爆炸还有透水事故。表格一记录了2006年和2007年发生在中国的采煤事故数据。这项数据是由来自国家煤矿安全监察局的作者编辑完成。可以清晰的看出煤尘和瓦斯爆炸是引起事故的主要原因。另外可以看出，2006年死亡374人中的117人，2007年死亡399人中的92人，都死在那些煤炭年产量小于200000吨的矿井。据报道，小规模产量矿井的产量占据了全部产量的三分之一，然而三分之二的事故以及75%的死亡人数发生在这些矿井。表1 中国煤炭开采事故统计事故煤与瓦斯爆炸突水一氧化碳中毒顶板塌陷火灾2006次数15821死亡人数322311472007次数213211死亡人数31741125242.2 地表沉降全世界大约60%的煤炭产量来自于地下开采。2007年，中国煤炭产量为2523000000吨，占了世界煤炭产量的三分之一，其中95%来自于地下开采。从表格二中可以看出中国煤炭产量在世界上所占的比例。表2 主要采煤国的煤炭产量百分比（2006年）国家井工开采 (%)露天开采(%)总计(百万吨)中国9552380.0美国30.969.11053.6印度1981447.0澳大利亚2278405.1俄罗斯309.2南非256.9德国197.2印尼195.0波兰156.1总计60406195.1由于地下开采引起的地表沉降是煤炭开采对环境不利的影响之一。中国现在大约有100万公顷沉陷土地。在中国，开采10000吨原煤会导致0.2公顷土地沉陷。地表沉陷不仅减少了粮食的产量，也会引起其它的环境问题，例如土地利用率低，植物死亡，地表破裂，土壤松散，排水系统失效，破坏建筑物等问题。地表以两种方式沉降：连续沉降和非连续沉降。连续沉降会逐渐形成光滑的表面轮廓以及台阶。非连续沉降表现为由于表面轮廓的不连续形成的台阶引起的在有限的地表平面上发生的大块地表位移。由于采煤引起的地表沉陷会影响土地利用或者影响环境，由于地形，地下水水平，土里利用的原始类型等原因，影响程度会不用。例如，在中国东部存在的大片的平原，地下水埋藏很浅，在进行煤炭开采以前被用作农田，现在由于地表沉降导致了大面积的洪灾。这之后，由于地表沉陷，土地利用情况发生了改变，建筑物，道路，农田都被严重破坏。在山区，采煤引起的地表沉陷会导致边坡的不稳定从而引起水土流失，形成地表破裂和上覆岩层破坏。2.3 水环境污染问题采煤引起的环境问题主要表现为地下水位的下降，引起水资源流失或者水污染还有改变水循环过程。由于地下水体通过上覆岩层与开采空间相连接，使得矿井水排放和矿井地表沉陷对水环境有剧烈的影响。第三部分将阐述河南省焦作煤矿采区的开采时间内的地下水位下降情况。由于承载水流动的各种地下岩层纷纷破碎，水就需要被重新定向导流。在这些岩层，有许多化合物和沉积物可能会被流动水溶解并最终流向矿井排水线路。在新的环境下，这些新暴露出来的矿物会和气体或者液体发生反应，最终成为新的污染物。这些污染物会影响水的化学性质，使水不再洁净，并且会增加水中悬浮颗粒的浓度。这会使得水的质量大幅度的下降并会影响水生生物的栖息地。矿井排水会污染地表水同时矿井垃圾的处理也会影响水质，因为污染物会进入附近的地表或者地下水从而造成污染。煤矿酸性水排放（AMD）的产生原因是：黄铁矿与空气和水反应生