煤矿科技英语——1. INTRODUCTION Coal, a combustible organic rock [1] composed primarily of carbon, hydrogen, and oxygen [2]. Coal is burned to produce energy and is used to manufacture steel. It is also an important source of chemicals used to make medicine, fertilizers, pesticides [3], and other products. Coal comes from ancient plants buried over millions of years in Earth’s crust [4], its outermost layer [5]. Coal, petroleum, natural gas, and oil shale [6] are all known as fossil fuels [7] because they come from the remains of ancient life buried deep in the crust.Coal is rich in hydrocarbons [8](compounds made up of the elements hydrogen and carbon). All life forms contain hydrocarbons, and in general, material that contains hydrocarbons is called organic material. Coal originally formed from ancient plants that died, decomposed, and were buried under layers of sediment [9] during the Carboniferous Period [10], about 360 million to 290 million years ago. As more and more layers of sediment formed over this decomposed plant material, the overburden [11] exerted increasing heat and weight on the organic matter. Over millions of years, these physical conditions caused coal to form from the carbon, hydrogen, oxygen, nitrogen, sulfur, and inorganic mineral [12] compounds in the plant matter. The coal formed in layers known as seams.Plant matter changes into coal in stages. In each successive stage, higher pressure and heat from the accumulating overburden increase the carbon content of the plant matter and drive out more of its moisture content [13]. Scientists classify coal according to its fixed carbon content [14], or the amount of carbon the coal produceswhen heated under controlled conditions. Higher grades of coal have a higher fixed carbon content.NOTES TO THE TEXT[1] organic rock：有机岩[2] carbon, hydrogen, and oxygen：碳，氢和氧[3] pesticides：农药[4] Earth’s crust：地壳[5] outermost layer：最外层地层[6] oil shale：油页岩[7] fossil fuels：化石燃料[8] hydrocarbons：碳氢化合物[9] layers of sediment ：沉积层[10] Carboniferous Period：石炭纪[11] overburden：覆盖岩层[12] inorganic mineral：无机材料[13] moisture content：含水量[14] fixed carbon content：固定碳含量煤矿科技英语——2. MODERN USES OF COAL Eighty-six percent of the coal used in the United States is burned by electric power plants [1] to produce electricity. When burned, coal generates energy in theform of heat. In a power plant that uses coal as fuel, this heat converts water into steam, which is pressurized to spin the shaft of a turbine. This spinning shaft [2] drives a generator that converts the mechanical energy of the rotation into electric power.Coal is also used in the steel industry. The steel industry uses coal by first heating it and converting it into coke [3], a hard substance consisting of nearly pure carbon. The coke is combined with iron ore [4] and limestone [5]. Then the mixture is heated to produce iron. Other industries use different coal gases given off during thecoke-forming process [6] to make fertilizers, solvents [7], medicine, pesticides, and other products.Fuel companies convert coal into easily transportable gas [8] or liquid fuels [9]. Coal-based vapor fuels [10] are produced through the process of gasification [11]. Gasification may be accomplished either at the site of the coalmine [12] or in processing plants [13]. In processing plants, the coal is heated in the presence of steam and oxygen to produce synthesis gas [14], a mixture of carbon monoxide [15], hydrogen, and methane [16] used directly as fuel or refined into cleaner-burning gas [17].On-site gasification [18] is accomplished by controlled, incomplete burning of an underground coal bed while adding air and steam. To do this, workers ignite the coal bed, pump air and steam underground into the burning coal, and then pump the resulting gases from the ground. Once the gases are withdrawn, they may be burned to produce heat or generate electricity. Or they may be used in synthetic gases to produce chemicals or to help create liquid fuels .Liquefaction [19] processes convert coal into a liquid fuel that has a composition similar to that of crude petroleum [20] Liquefaction. Coal can be liquefied either by direct or indirect processes. However, because coal is a hydrogen-deficient hydrocarbon [21], any process used to convert coal to liquid or other alternative fuels[22] must add hydrogen. Four general methods are used for liquefaction: (1) pyrolysis[23] and hydrocarbonization [24], in which coal is heated in the absence of air or in a stream of hydrogen; (2) solvent extraction [25], in which coal hydrocarbons are selectively dissolved and hydrogen is added to produce the desired liquids; (3) catalytic liquefaction [26], in which hydrogenation [27] takes place in the presence of a catalyst; and (4) indirect liquefaction, in which carbon monoxide and hydrogen are combined in the presence of a catalyst.NOTES TO THE TEXT[1] electric power plants：发电厂[2] spinning shaft：旋转轴[3] coke：焦炭[4] iron ore：铁矿石[5] limestone：石灰岩[6] coke-forming process：焦炭形成过程[7] solvents：溶剂[8] easily transportable gas：易输送的气体l[9] liquid fuels：液体燃料[10] coal-based vapor fuels：以媒为基础的气态燃料[11] gasification：气化[12] coalmine：煤矿[13] processing plants：加工厂[14] synthesis gas：合成煤气[15] carbon monoxide：一氧化碳[16] methane：沼气，甲烷[17] cleaner-burning gas：洁净煤气[18] on-site gasification：地下气化[19] liquefaction：液化[20] crude petroleum：原油[21] hydrogen-deficient hydrocarbon：缺氢碳氢化合物[22] alternative fuels：替代燃料[23] pyrolysis：高温分解[24] hydrocarbonization：碳氢化作用[25] solvent extraction：溶剂提取[26] catalytic liquefaction：催化液化作用[27] hydrogenation：氢化作用煤矿科技英语——3. FORMATION AND COMPONENTS OF COAL2006年8月1日12:40:0Coal is a sedimentary rock [1] formed from plants that flourished millions of years ago when tropical swamps [2] covered large areas of the world. Lush vegetation [3], such as early club mosses [4], horsetails [5], and enormous ferns, thrived in these swamps. Generations of this vegetation died and settled to the swamp bottom, and over time the organic material lost oxygen and hydrogen, leaving the material with a high percentage of carbon. Layers of mud and sand [6] accumulated over the decomposed plant matter, compressing and hardening the organic material as the sediments deepened. Over millions of years, deepening sediment layers, known as overburden, exerted tremendous heat and pressure on the underlying plant matter, which eventually became coal.Before decayed plant material [7] forms coal, the plant material forms a dark brown, compact organic material known as peat [8]. Although peat will burn when dried, it has a low carbon and high moisture content relative to coal. Most of coal’s heating value comes from carbon, whereas inorganic materials, such as moisture and minerals [9], detract from its heating value. For this reason, peat is a less efficient fuel source than coal. Over time, as layers of sediment accumulate over the peat, this organic material forms lignite [10], the lowest grade of coal. As the thickening geologic overburden gradually drives moisture from the coal and increases its fixed carbon content, coal evolves from lignite into successively higher-graded coals: subbituminous coal [11], bituminous coal [12], and anthracite [13]. Anthracite, the highest rank of coal, has nearly twice the heating value of lignite.Coal formation began during the Carboniferous Period (known as the first coalage), which spanned 360 million to 290 million years ago. Coal formation continued throughout the Permian [14], Triassic [15], Jurassic [16], Cretaceous [17], and Tertiary [18] Periods, which spanned 290 million to 1.6 million years ago. Coals formed during the first coal age are older, so they are generally located deeper in Earth’s crust. The greater heat and pressures at these depths produce higher-grade coals such as anthracite and bituminous coals. Conversely, coals formed during the second coal age under less intense heat and pressure are generally located at shallower depths. Consequently, these coals tend to be lower-grade subbituminous and lignite coals.Coal contains organic (carbon-containing) compounds transformed from ancient plant material. The original plant material was composed of cellulose [19], the reinforcing material [20] in plant cell walls [21]; lignin [22], the substance that cements plant cells together; tannins [23], a class of compounds in leaves and stems; and other organic compounds, such as fats and waxes. In addition to carbon, these organic compounds contain hydrogen, oxygen, nitrogen, and sulfur. After a plant dies and begins to decay on a swamp bottom, hydrogen and oxygen (and smaller amounts of other elements) gradually dissociate from the plant matter, increasing its relative carbon content.Coal also contains inorganic components, known as ash. Ash includes minerals such as pyrite [24] and marcasite [25] formed from metals that accumulated in the living tissues of the ancient plants. Quartz [26], clay, and other minerals are also added to coal deposits by wind and groundwater [27]. Ash [28] lowers the fixed carbon content of coal, decreasing its heating value.NOTES TO THE TEXT[1] sedimentary rock：沉积岩[2] tropical swamps：热带沼泽[3] Lush vegetation：茂盛的植物[4] club mosses：石松[5] horsetails：马尾（木贼属的一种植物）[6] layers of mud and sand：泥砂层[7] decayed plant material：腐烂的植物材料[8] peat：泥炭[9] minerals：矿物[10] lignite：褐煤[11] subbituminous coal：次烟煤[12] bituminous coal：烟煤[13] anthracite：无烟煤[14] Permian：二叠纪[15] Triassic：三叠纪[16] Jurassic：侏罗纪[17] Cretaceous：白垩纪[18] Tertiary：第三纪[19] cellulose：纤维素[20] reinforcing material：加固的材料[21] cell walls：细胞壁[22] lignin：木质[23] tannins：丹宁，鞣酸[24] pyrite：黄铁矿[25] marcasite ：白铁矿[26] quartz：石英[27] groundwater：地下水[28] ash：灰分煤矿科技英语——4. COAL DEPOSITS ANDRESERVESAlthough coal deposits exist in nearly every region of the world, commercially significant coal resources occur only in Europe, Asia, Australia, and North America. Commercially significant coal deposits occur in sedimentary rock basins [3], typicallysandwiched as layers called beds or seams [4] between layers of sandstone [5] and shale [6]. When experts develop estimates of the world’s coal supply, they distinguish between coal reserves and resources. Reserves are coal deposits that can be mined profitably with existing technology—that is, with current equipment and methods. Resources are an estimate of the worl d’s total coal deposits, regardless of whether the deposits are commercially accessible. Exploration [7] geologists [8] have found and mapped the world’s most extensive coal beds. At the beginning of 2001, global coal reserves were estimated at 984.2 billion metric tons, in which 1 metric ton [9] equals 1,016 kg (2,240 lb). These reserves occurred in the following regions by order of importance: the Asia Pacific, including Australia, 29.7 percent; North America, 26.1 percent; Russia and the countries of the former Union of Soviet Socialist Republics (USSR), 23.4 percent; Europe, excluding the former USSR, 12.4 percent; Africa and the Middle East, 6.2 percent; and South and Central America, 2.2 percent.Coal deposits in the United Kingdom, which led the world in coal production until the 20th century, extend throughout parts of England, Wales, and southern Scotland. Coalfields in western Europe underlie the Saar and Ruhr valleys in Germany, the Alsace region of France, and areas of Belgium. Coalfields [10] in central Europe extend throughout parts of Poland, the Czech Republic, and Hungary. The most extensive and valuable coalfield in eastern Europe is the Donets Basin, between the Dnieper and Donrivers (in parts of Russia and Ukraine). Large coal deposits in Russia are being mined in the Kuznetsk Basin in southern Siberia. Coalfields underlying northwestern China are among the largest in the world. Mining of these fields began inthe 20th century.United States coal reserves are located in six major regions, three of which produce the majority of domestically [11] mined coal. The most productive region [12] in the United States is the Appalachian Basin, covering parts of Pennsylvania, West Virginia, Kentucky, Tennessee, Ohio, and Alabama. Large quantities of coal have also been produced by both the Illinois Basin—extending through Illinois, Indiana, and Kentucky—and the Western Interior Region—extending through Missouri, Kansas, and Oklahoma. Other commercially important U.S. coal regions include the Powder River Basin, underlying parts of Montana and Wyoming; the Green River Basin in Wyoming; the Uinta Basin, covering areas of Utah and Colorado; and the San Juan Basin, underlying parts of Utah, New Mexico and Colorado.In 2001 estimates of total U.S. coal reserves were approximately 246 billion metric tons. At the beginning of the 21st century production amounted to about 980 million metric tons each year.NOTES TO THE TEXT[1] coal deposit：煤矿床[2] reserves：储量[3] sedimentary rock basins：沉积岩盆地[4] seams：媒层[5] sandstone：砂岩[6] shale：页岩[7] exploration：勘探[8] geologist：地质学家[9] metric ton：公吨[10] coalfields：媒田[11] domestically：国内（产）地，民用地，家用地[12] productive region：生产区煤矿科技英语——5. BRIEF INTRODUCTION TO COALMININGCoal mining [1] is the removal of coal from the ground. The mining method employed to extract the coal depends on the following criteria: a. seam thickness [2], b. the overburden thickness, c. the ease of removal of the overburden, d. the ease withwhich a shaft [3] can be sunk to reach the coal seam, e. the amount of coal extracted relative to the amount that cannot be removed, and f. the market demand for the coal.The two types of mining methods are surface mining [4] and underground mining [5]. In surface mining, the layers of rock or soil overlying a coal seam are first removed after which the coal is extracted from the exposed seam. In underground mining, a shaft is dug to reach the coal seam. Currently, underground mining accounts for approximately 60 percent of the world recovery of coal.5-1 Surface MiningSurface mining is used to reach coal reserves that are too shallow to be reached by other mining methods. Types of surface mining include open-pit mining [6], drift mining [7], slope mining [8], contour mining [9], and auger mining [10].A. Open-pit MiningIn open-pit mining, or strip mining, earth-moving equipment is used to remove the rocky overburden and then huge mechanical shovels [11] scoop [12] coal up from the underlying deposit. The modern coal industry has developed some of the largest industrial equipment ever made, including shovels capable of holding 290 metric tons of coal.To reach the coal, bulldozers [13] clear the vegetation and soil. Depending on the hardness and depth of the exposed sedimentary rocks, these rocky layers may be shattered with explosives. To do this, workers drill blast holes [14] into the overlying sedimentary rock, fill these holes with explosives [15], and then blast the overburden to fracture the rock. Once the broken rock is removed, coal is shoveled from theunderlying deposit into giant earth-moving trucks [16] for transport [17].B. Drift MiningDrift mining is used when a horizontal seam [18] of coal emerges at the surface on the side of a hill or mountain, and the opening [19] into the mine can be made directly into the coal seam. This type of mining is generally the easiest and most economical type because excavation through rock is not necessary. If coal is available in this manner, it is likely to be mined.C. Slope MiningSlope mining occurs when an inclined opening is used to tap the coal seam (or seams). A slope mine may follow the coal seam if the seam is inclined and exposed to the surface, or the slope may be driven through rock strata overlying the coal to reach a seam. Coal transportation from a slope mine can be accomplished by conveyor [20] or by track haulage [21] (using a trolley locomotive [22] if the grade is not severe) or by pulling mine cars [23] up the slope using an electric hoist [24] and steel rope [25] if the grade is steep. The most common practice is to use a belt conveyor.D. Contour MiningContour mining occurs on hilly or mountainous terrain, where workers use excavation equipment to cut into the hillside along its contour to remove the overlying rock and then mine the coal. The depth to which workers must cut into the hillside depends on factors such as hill slope and coal bed thickness.E. Auger MiningAuger mining is frequently employed in open-pit mines where the thickness ofthe overburden is too great for open-pit mining to be cost-effective [26]. Open-pit mining would require the lengthy and costly removal of the overburden, whereas auger mining is more efficient because it cuts through the overburden and removes the coal as it drills. In this technique, the miners drill a series of horizontal holes into the coal bed with a large auger (drill) powered by a diesel or gasoline engine [27]. These augers are typically about 60 m (200 ft) long and 0.6 to 2.1 m (2 to 7 ft) in diameter. As these enormous drills bore into the coal seam, they discharge coal like a wood drill producing wood shavings. Additional auger lengths are added as the cutting head of the auger penetrates farther into the coal. Penetration continues until the cutting head drifts into the top or bottom of the coal seam, into a previous hole, or until the maximum torque [28] (energy required to twist an object) of the auger is reached.F. Satellite Aids [29] to Surface MiningIn the late 1990s some coal mining enterprises used technologies such as the global positioning system (GPS) [30] to help guide the positioning of mining equipment. Satellites operated by the United States Air Force Space Command and leased to companies for commercial use track the position of mining equipment against a map of a mine’s topography [31]. This map uses colors to distinguish soil that should be excavated, soil that should remain in place, and areas that should be filled in. The equipment driver observes this visual information [32] on a monitor [33] while operating the equipment. Some coal mining enterprises have used GPS to increase mining efficiency up to 30 percent.5－2 Underground MiningUnderground, or deep, mining occurs when coal is extracted from a seam without removal of the overlying strata. Miners build a shaft mine that enters the earth through a vertical opening and descends from the surface to the coal seam. In the mine, the coal is extracted from the seam by various methods, including conventional mining[34], continuous mining [35], longwall mining [36], and room-and-pillar mining [37].A. Conventional MiningConventional mining, also called cyclic mining, involves a sequence of operations that proceed in the following order: a. supporting the roof [38], b. ventilation [39], c. cutting [40], d. drilling [41], e. blasting [42], f. coal removal [43], and g. loading [44]. First, miners make the roof above the seam safe and stable by timbering [45] or by roof bolting [46], processes intended to prevent the roof from collapsing [47]. At the same time, they create ventilation openings so that dangerous gases [48] can escape and fresh air can reach the miners. Then one or more slots [49]—a few centimeters wide and extending for several meters into the coal—are cut along the face of the coal seam, also known as the wall face, by a large, mobile cutting machine [50]. The cut, or slot, provides easy access to the face and facilitates the breaking up of the coal, which is usually blasted from the seam by explosives known as permissible explosives. This type of explosive produces an almost flame-free explosion [51] and markedly reduces the amount of noxious fumes [52] in comparison with conventional explosives. The coal may then be transported by rubber-tired electric vehicles (shuttle cars) [53] or by chain (or belt) conveyor systems [54].B. Continuous MiningContinuous mining involves the use of a single machine known as a continuous miner that breaks the coal mechanically and loads it for transport. This mobile machine [55] has a series of metal-studded rotating drums [56] that gouge coal from the face of the coal seam. One continuous miner can mechanically break apart about 1.8 metric tons of coal per hour. Roof support is then installed, ventilation is advanced, and the coalface [57] is ready for the next cycle. The method used to transport the coal requires the installation of mobile belt conveyors.C. Longwall MiningThe longwall mining system uses a remote-controlled [58] self-advancing support [59] in which large blocks of coal are completely extracted in a continuous operation. Hydraulic or self-advancing jacks [60], known as chocks [61], support the roof at the immediate face as the coal is removed. As the face advances [62], the roof is allowed to collapse behind the remote-controlled, roof-building machinery [63]. Miners then remove the fallen coal. Coal recovery [64] is comparable to that attainable with the conventional or continuous mining systems.D. Room-and-Pillar MiningRoom-and-pillar mining is a means of developing a coalface and, at the same time, retaining supports for the roof. With this technique, rooms are developed from large, parallel tunnels driven into the solid coal [65], and the intervening pillars [66] of coal are used to support the roof. The percentage of coal recovered from a seam depends on the number and size of protective pillars of coal thought necessary to support the roof safely. Workers may remove some coal pillars just before closing themine.NOTES TO THE TEXT[1] coal mining：采煤[2] seam thickness：煤层厚度[3] shaft：立井[4] surface mining：地面开采[5] underground mining：地下开采[6] open-pit mining：露天矿开采[7] drift mining：平峒开采[8] slope mining：斜井开采[9] contour mining：台阶开采[10] auger mining：螺旋钻开采[11] mechanical shovels：机械铲[12] scoop：铲斗[13] bulldozer：推土机[14] blast holes：炮眼[15] explosives：炸药[16] earth-moving trucks：地面移动卡车[17] transport：运输，输送[18] horizontal seam：水平煤层[19] opening：坑道[20] conveyor：输送机[21] track haulage：轨道运输[22] trolley locomotive：架线式电机车[23] mine cars：矿车[24] electric hoist：电动提升机[25] steel rope：钢丝绳[26] cost-effective：成本效果[27] gasoline engine：汽油发动机[28] maximum torque：最大扭矩[29] satellite aids：卫星辅助[30] global positioning system (GPS)：地球定位系统[31] topography：地形[32] visual information：可视信息[33] monitor：监控器，监视器[34] conventional mining：传统式开采法[35] continuous mining：连续（采煤机）式开采法[36] longwall mining：长壁式开采法[37] room-and-pillar mining：房柱式开采法[38] supporting the roof：支护顶板[39] ventilation：通风[40] cutting：截割，掏槽[41] drilling：钻眼[42] blasting：爆破，放炮[43] coal removal：出媒[44] loading：装载[45] timbering：木支架[46] roof bolting：顶板锚杆支护[47] collapsing：垮落，崩落[48] dangerous gases：危险气体[49] slot：槽，沟[50] mobile cutting machine：移动式截媒机[51] flame-free explosion：无焰爆破[52] noxious fumes：有毒烟雾[53] rubber-tired electric vehicles (shuttle cars)：电动胶轮车（梭车）[54] chain (or belt) conveyor system：刮板（胶带）输送机系统[55] mobile machine：移动式机器[56] metal-studded rotating drums：金属双头螺栓式旋转滚筒[57] coalface：采煤工作面[58] remote-controlled：遥控的[59] self-advancing support：自移式支架[60] hydraulic or self-advancing jacks：液压或自移式千斤顶[61] chocks：垛式（液压）支架[62] face advances：工作面推进[63] roof-building machinery：筑顶机械[64] coal recovery：媒炭回收率[65] solid coal：实体煤[66] intervening pillars：煤房间的煤柱煤矿科技英语——6. LONGWALL MINING SYSTEMS Longwall mining has a long history of successful applications, even in thin and inclined coal seams [2]. This type of mining is more mechanized than any other method, and necessitates careful attention to the selection of the expensive equipment required. Longwall mining is a unique method with one principal variation. According to the direction of coal extraction, there are longwall advance mining [3] and longwall retreat mining [4].6-1 Longwall Advance MiningLongwall advance mining has been primarily used in the deeper underground mines where strata pressures [5] do not permit maintaining roadway [6] for long period of time.The majority of coalfields in Europe use longwall advance system of mining. The coal seam is divided into panels [7], generally 100 to 230m wide by up to 1800m long. Production may commence following a minimal capital outlay [8] for pre-production development. Yet the geological conditions [9] ahead of the advancing coalface may be uncertain, thus introducing an element of risk. Any sudden worsening of geological conditions may cause the production face to halt and an equipment capital outlay can be temporarily at a stand still. Shallow mining depths are not favored longwall advance mining; however, weak strata may require its use even though it may not suit NorthAmerican requirements for high productivity.A. Advance system with single entry [10]: The single entry is driven only a short distance ahead of the advancing face to avoid excessive frontal abutment pressures [11], The advance of roadways has been greatly improved through the use of longwall shearer [12] for roadway excavation.The main problem of the longwall advance system with single entry is maintaining the roadway behind face in the gob [13] for the life of the panel. Roadway support is provided by arches set [14]. The packs [15] are built along the gob edge for maintaining the roadway. The application of the Pump Pack [16] for pack building has reduced the difficulties relating to roadway maintenance [17].B. Advance system with double entries [18]: These have rib pillars [19] with a least width equal to or greater than one tenth of the panel depth separating panels. The ribs provide roadway protection against strata pressure deformation [20] effect. The driving of double entries in advance is integrated with the transport of coal from the longwall face. The main advantage of this system is that there is no need for roadway maintenance because one collapse is with the gob and the other in the rib is not affected by gob closure [21].The mining system requires more development work, but this is more than offset [22] by the savings in roadway maintenance.6-2. Longwall Retreat MiningLongwall retreat mining is basically the same as longwall advancing extraction, except that the coal seam is block-out [23] and then retreated in panels betweendevelopment roadways. Its advantages over advance mining are low risk and consistently high output. However, there are factors, which limit the application of retreat mining. The most important of which is the development of high stress [24] levels due to the influence of nearby workings, which affect the stability [25] of development roadways in soft strata. The life of the coalface depends upon the life of the roadway gate support. Reinforcement [26] techniques are available to assist in stabilizing the mine roadways.A. A retreat system with a single entry: this system is similar to the advance system with one entry, except that the panel is fully developed before extraction starts. There is a problem of roadway maintenance near the gob.This method has the advantages of economical use roadways and the efficient recovery of coal reserves. The mining direction is either down-dip [27] or along strike [28]. The disadvantages of the system are that the developed roadways in solid coal are liable to interaction from neighboring workings in the same seam: and the panel in extraction must be mined-out before the next one can start to avoid short circuiting ventilation.B. Integrated advance and retreat system [29]: this system is used mostly in deeper and gaseous coalmines. Single entry is used resulting in limited development and easier face-end [30] operations. Alternate faces advance in opposite directions. This method, as in other single entry longwall mining methods, re-uses the roadway of the mined-out panel for extraction of the adjacent panel. In some countries, integrated single entry system has been used to control surface subsidence strains.。
