科技英语——冶金工程专业

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1、Unit OneBefore Reading1. Look up the following words and terms in your dictionary:extractive metallurgy, pyrometallurgy hydrometallurgy electrometallurgy electromotive series2. Main ideaExtractive metallurgy is concerned with the extraction of metals from ores or concentrates. It embraces the occurr

2、ence of metals, ore concentration, extraction and refining of metals, and ends with final casting of the metal ingot and by-products. In the extractive metallurgy, the method of treatment may be broadly classified in pyrometallurgy, hydrometallurgy and electrometallurgy. The metals obtained by the f

3、irst treatment of the ores generally contain impurities. In order to attain a higher order of purity, further refining is necessary on the crude metal.Text Extractive Metallurgy(1)Metals are derived from ore mined from deposits which are confined to certain areas of the earths crust. The geologists

4、discovery of ore and the raising of ore from the mine give the metallurgical industry its raw material, The function of extractive metallurgy is to process these ores, extract the metal and refine it. Between the mining of the ore and casting of the metal ingot for delivery to the fabricating indust

5、ries, a large number of specialized operations have to be performed.The first stage in metallurgical practice will, in most cases, be a process of ore concentration designed to separate, by mechanical means, as much as possible of the non-metallic gangue material from the mineral matter so that a co

6、ncentrate of rich material may be available to the subsequent processes of extraction.(2) The mechanical operations necessary to separate the mineral from the gangue are known as mineral dressing. Their use and the variety of method adopted have increased greatly in recent years and, in fact, the mo

7、dern output of metals would not be possible without the improved techniques devised to aid in concentrating both high-and low-grade raw materials. For example, the introduction of the flotation process permits the beneficiation of copper ore containing only 0.5 per cent copper, and formerly looked o

8、n as waste.Mineral dressing itself is only a preliminary stage in the isolation of the metal from the gangue material, and constitutes only a small part of the total effort expended in the recovery of metal. It concentrates the valuable mineral, and in no way effects any chemical change in its const

9、itution. The removal and elimination of the remaining gangue, decomposition of the mineral and collecting and refining of metal constitute the function of extractive metallurgy. Although the change to be brought about are essentially of a chemical nature, because of the differing nature of the compo

10、nents of the mineral and their varying properties, no one method of treatment is universally applicable; hence a diversity of methods is used(3).These may be broadly classified in three main types 1. Pyrometallurgy involves the extraction of metals by the application and action of heat.2. Hydrometal

11、lurgy, the metal being selectively dissolved from the ore by an appropriate liquid solvent, subsequently being recovered by a diversity of methods.3. Electrometallurgy covers the extraction and refining of metals by the application of electrical energy.The type of process applied to and particular m

12、ineral concentrate depends upon many factors, among which may be listed: nature and stability of ore or concentrate, particular properties of the metal concerned, required degree of purity of the metal, and facilities available in the locality where the extraction is to be operated.(4)Of these facto

13、rs, stability perhaps requires a few words of explanation. The stability of a compound relates to the free energy of formation (G); the greater the free energy loss involved in its formation, the greater the stability of the compound at any temperature, and hence, the less easily will the compound b

14、e reduced to its elements. Thus, mercury sulphide with a low free energy value is relatively unstable, reduction being possible below 400, whereas zinc oxide and manganese oxide are relatively stable, requiring temperatures in the vicinity of 950 and 1,500 respectively.(5) Stability or otherwise of

15、the metal concentrate has thus an important bearing on the temperature and, hence, the type of process required for the treatment.The facilities available in a particular locality may be the deciding factor in the choice of method. Thus, if cheap hydroelectric power is available then electrolysis ma

16、y be practised, if this is applicable, otherwise pyro-or hydro-metallurgical methods may have to be employed. The proper location of a reduction plant with regard to the geographic and economic factors involved in steady supplies of concentrates, power, fuel, water and transportation, and facilities

17、 for waste disposal, is of extreme importancefor a steady supply of materials, services and labour is necessary for the proper functioning of the processes of extractive metallurgy.(6)Any one of the above three types of treatment may not in itself suffice for the treatment of a particular material,

18、and in fact many ores require a combination of methods. Aluminium and magnesium are commonly produced by a combination of hydro-and electrometallurgical methods. Copper and nickel are first given by pyro-metallurgical treatments followed by electrometallurgical methods.It is largely by pyro-metallur

19、gical methods that the major non-ferrous metals (copper, lead, tin, zinc and nickel) are recovered. The final stages of refining of the crude metal may, however, involve electrolytic deposition. The two lightweight metals aluminium and magnesium are extracted by a combination of the processing.a pre

20、liminary hydrometallurgy process being followed by electrolytic isolation of the metal. In some circumstances copper and zinc are also recovered from their ores by electrolytic reduction.Gold and silver, although often by-products resulting from the refining of copper and lead, are also recovered by

21、 treating their ores with suitable solvents.Other metals may require a highly specialized sequence of operations for their extraction.In general, the metals obtained by the first or immediate treatment of ore or concentrate contain impurities derived from the ore and those taken up from the reducing

22、 agent, flux, etc., during the extraction treatment. In order to attain a higher order of purity, further treatments have to be performed on the crude metal, and these subsequent treatments, following the first production of metal, constitute refining. The methods used vary with the difficulties inv

23、olves in the removal of the impurities and may be classified under the following four headings1. Fire refining.2. Electrolytic refining.3.Distillation.4. Chemical.The removal of impurities by fire refining, which is the most widely employed of the refining treatments, depends on the oxidation of the

24、 impurities by means of air or oxidation agents followed by removal as slag of the resulting oxidized products.Metals such as gold and silver, which stand high in the electromotive series and so are resistant to oxidation, are usually refined by readily electrolysis or chemical methods. Volatile met

25、als such as zinc, mercuryand cadmium may be readily purified by the method of distillation. On the other hand, to prepare some of the high melting point metals in a state which could be regarded as pure is a task of some difficulty. Elements such as titanium, zirconium, chromium, niobium and molybde

26、num are so chemically active in the molten state that there are no practical refractory crucible materials to contain them. Not only that, but they are extremely sensitive to contamination by oxygen and nitrogen of the air. Ten parts per million of nitrogen, for example, render chromium metal brittl

27、e, and two parts per million of oxygen does the same to molybdenum. Hence, for the refining of such metals, special operational techniques have had to be developed.pyrometallurgy 火法冶金hydrometallurgy 湿法冶金electrometallurgy 电冶金non-ferrous metals 有色金属reducing agent 还原剂slag 渣electromotive series 电化序benef

28、iciation 矿物处理；选矿suffice 足够，满足需要Words and Expressionsextractive 提取的metallurgy 冶金学，冶金术deposit 沉积，矿床ingot 铸锭fabrication 加工，制作gangue 脉石mineral dressing 选矿flotation 浮选concentrate 精选，富集；精矿Notes to the Text（1）本文摘自“Extractive Metallurgy”, W.H.Dennis, LONDON SIR ISAAG PITMAN & SONS LTD.（2）为主从复合句。So that 引导结果

29、状语从句；by mechanical means 为插入成份，进一步说明to separate, be available to 可译为“可采用的”。（3） 为主从复合句。Although 引导让步状语从句; because为原因状语从句; hence为结果状语从句。（虽然所产的变化主要是化学变化，但由于矿物的组成不同及各组份性质的不同，没有那一种方法能用于处理各种矿物，因此需使用各种不同的处理方法。）（4）applied to 为过去分词短语，作process的定语；among which引导定语从句，修饰factors; where引导定语从句，修饰locality。（对任一种特定的精矿，

30、所采用的处理方法取决于许多因素，其中有矿石或精矿的稳定性、所含金属的特性、产品金属的纯度以及冶炼厂所在地区的条件。）（5） 本段第二个句子为“the+比较级。the +比较级”结构。hence 为第二分句的结果状语从句，句子部分倒装，也可不倒装。本段说“化合物的稳定性和其生成自由焓(G)有关，在一定的温度下，化合物的生成自由焓值越负，化合物就越稳定，因此就越不容易被还原为元素状态。”文中又提到硫化汞有低的自由能值，应理解为绝对值较低。因硫化汞，氧化锌及氧化镁的生成自由能分别为82.4、363.6及609.3千焦。（6）The proper location is of extreme impo

31、rtancefor a steady supply for 为连接词,它后面的句子对前面的句子进一步加以说明。With regard to 可译为“就而论”。“involved in ”为过去分词短语，做factors的定语。（就地理和经济因素而论，合适的冶炼厂的地址涉及到精矿、能量、燃料、水的稳定供给，运输条件及废水处理的方便。原料、各种服务和劳动力的稳定供给对于正确地完成提取冶金过程是必需的。）ExercisesI. Answer the following questions:1. What is the function of extractive metallurgy?2. What

32、 is the action of mineral dressing in extractive metallurgy?3. Which methods of treatment are used in extractive metallurgy?4. Why may any one of the three types of treatment not in itself suffice for the treatment of a particular material in extractive metallurgy?5. Which factors does the type of p

33、rocess applied to any particular mineral concentrate depend on?6. What is meant by stability of a compound?7. Why can the mercury sulphide be reduced below 400, whereas zinc oxide requires temperature in the vicinity of 950?8. Why is the proper location of a reduction plant extremely important for t

34、he proper functioning of the processes of extractive metallurgy?9. Which methods are used in the refining of the Crude metals?10. How are the volatile metals purified?II. Translate the following into English:1. 提取冶金是一门从矿石或精矿中提取金属的科学。2. 在历史文明中，提取冶金一直发挥着重要的作用。3. 因为大多数金属在自然界都是以化合状态存在，因此初始的冶金学家不得不寻求从矿石中

35、提取金属的方法。4. 提取冶金的方法一般有火法冶金、湿法冶金和电冶金三种类型。5. 选矿是通过机械的方法使矿物同脉石分离，以便得到富金属精矿。6. 根据过程进行的温度，提取冶金过程可分为火法冶金和湿法冶金。7. 矿石或精矿的性质和稳定性对选择处理方法非常重要。8. 厂址所在地区的条件也是选择冶炼方法的决定因素，因为稳定地提供各种原料和服务对冶金过程是必需的。9. 一般来说，当金属初次从矿石中提取出来时是不纯的。10. 因此，必须精炼粗金属，以制备纯金属。III. Translate the following into Chinese:The effective use of metals h

36、as been central to the development of civilizations for over two millennia. Nevertheless, metals are now coming under increasing competition from alternative materials, which increases the need for the development of a better understanding of their characteristics and how to use them effectively. Th

37、e properties which make metals attractive must be appreciated as well as those which make them unattractive in particular circumstances. Likewise, the means by which their desirable properties can be obtained and their undesirable properties avoided must be understood. The production of usable metal

38、 from an ore mined from the earth involves a large number of distinct steps, and the term “metallurgy” is used to describe the broad technological discipline which covers all of these steps. However, the various groupings of these steps are backed by rather different branches of science, and so it i

39、s necessary to subdivide the discipline into primary metallurgy, which covers the steps necessary to produce molten refined metal from the ore, and secondary metallurgy, which encompasses the steps required to process this melt into usable material. As a further subdivision, physical metallurgy, wit

40、h which we shall mostly be concerned, is taken to be a branch of secondary metallurgy, which deals with the science and technology of the effects of composition, processing, and environment on the properties of metals and alloys. In this sense, a physical metallurgist can be described as a metals en

41、gineer who is part of the manufacturing engineering team.Reading Material Non-ferrous MetalsNon-ferrous metals play a key role in industrial production and our world of technology, both present and future, would be inconceivable without them. Nevertheless, these are not new materials. Some of them h

42、ave been known to mankind since historic times, others were discovered centuries ago. Non-ferrous metals only became indispensable raw materials, however, at the beginning of the industrial era, when their special properties revolutionized production process. Use of these metals enabled industry to

43、solve technical problems of ever-increasing complexity in a growing number of fields and progress in technology continually opened up new applications for these metals in various forms. The demand for non-ferrous metals, both in quantity and quality, rapidly rose to unprecedented levels. To meet the

44、 escalating demand, intensive efforts were needed to explore and open up new deposits where economic extraction would be feasible and also to transform the mining and working of these raw materials. Traditional methods had to give way at all stages of production to more advanced techniques-a process

45、 which is still continuing. At the same time it was necessary to gear the market structures to the changing demand arising in consequence of expanding industrialization. A broad field of activity was thus opened up for a free enterprise sector whose salient features were a bold and courageous approa

46、ch, resourceful planning and willingness to take risks.The natural basis for the metal industry consists of the metals present in the earths crust. Like all materials these may occur in four states, as plasma, gas, liquids and solids; in the narrower sense, however, the term metals is applied to tho

47、se elements which have the distinctive characteristics of metallic compounds. The characteristic properties of metals are:(a) opacity in the solid state;(b) high reflectivity and lustre(or glance);(c) high electrical and thermal conductivity;(d) ductility, i.e., the capacity for plastic deformation

48、by hammering, forging, extrusion, pressing or drawing;(e) strength, hardness, toughness-properties which can be influenced by alloying or heat treatment.Metals rarely occur in nature in the native or almost pure state; among the non-ferrous metals, virtually the only pure copper deposits of importan

49、ce were those, now largely exhausted, at Lake Superior in the United States. As a rule metals are compounded with nonmetallic elements to form ores, usually in mineral combinations with silicic acid, lime, alumina or magnesia. The minerals are denoted as acid ores or basic ores depending on the natu

50、re of the surrounding (barren) rock, the gangue. From the metallurgical point of view, a distinction is made between oxide ores, in which the metal is compounded with oxygen-as is the case with the carbonates, silicates and sulphates-or sulphide ores, in which the metal is combined with sulphur.Acco

51、rding to the criterion of use as industrial materials, the technically most important non-ferrous metals, excluding the precious metals, may be classified as follows:(a) heavy metals: lead, copper, zinc and tin;(b) light metals: aluminium, magnesium and titanium;(c)steel improving agents (as alloyin

52、g metals) or special metals (as base metals): chromium, cobalt, manganese, molybdenum, nickel, vanadium and tungsten;(d) other alloying or special metals: antimony, cerium, hafnium, cadmium, lanthanum, lithium, niobium, mercury, rhenium,silicon, tantalum, bismuth, yttrium and zirconium.Comprehension

53、:1. Non-ferrous metals play a key role in industrial production and our world of technology, this is because A. they are indispensable raw materials for industry B. they have been known to mankind since historic times C. use of metals enabled industry to solve technical problems of ever-increasing c

54、omplexity D. metals have special properties2. In production of non-ferrous metals, traditional methods by more advanced techniques. A. have been replaced B. had been replaced C. are being gradually replaced D. were replaced3. In nature, non-ferrous metals generally occur . A. in the native state B.

55、in the mineral state C. in the element state D. in the compounds state4. The distinction of oxide ores from sulphide ores is that . A. the former contain oxygen B. the former contain sulphur and oxygen C. the former are carbonates D. the later are sulphates5. According to the criterion use as indust

56、rial materials, which metals can not be classified non-ferrous metals? A. lead, copper B. aluminium, magnesium C. iron D. molybdenum, tantalumUnit TwoBefore reading1. Look up the following words and terms in your dictionary nonferrous metals, rare earths, sulphur dioxide2. Hydrometallurgy is one of

57、the established and highly recognized branches of extractive metallurgy today. It is the extraction and recovery of metals from their ores by processes in which aqueous solution plays a predominant role. Hydrometallurgical processes normally operate in the temperature range of 25250 and at pressures

58、 of only a few kilopascals (vacuum) to as high as 5000KPa. The advantages of hydrometallurgy are applicability to low-grade ores and to separation of high similar materials. However, hydrometallurgical processes can not compete commercially with the pyrometallurgical processes for some metal product

59、ion.TextHydrometallurgy(1)The extraction of metals from ores and /or concentrates is carried out either by pyrometallurgy or by hydrometallurgy. Pyrometallurgy encompasses the traditional high-temperature processes of roasting, smelting, converting, and refining. Hydrometallurgy is a relatively rece

60、nt development compared with pyrometallurgy, the ancient art of metal production. Thousands of years ago, as history records, people learned to construct furnaces and use fire to melt rocks and extract metals. Much later came the use of water and aqueous solutions in place of dry, high-temperature m

61、ethods for processing ores. Modern hydrometallurgy, in fact, can be traced back only to the end of the 19th century. Hydrometallurgy is essentially concerned with methods whereby metals, metal salts, or other metal compounds are produced by means of chemical reactions involving aqueous and organic s

62、olutions(2). Hydrometallurgical processes normally operate in the temperature range of 25 to 250. The processes can operate at pressures of only a few kilopascals(vacuum) to as high as 5000kPa.The late 1960s and early 1970s witnessed a great spurt in research and development of hydrometallurgical al

63、ternatives to conventional pyrometallurgical processes used to produce the bulk of nonferrous metals in the world (3). The strong points of hydrometallurgical processing lie in the wide and varied techniques and combinations of techniques that can be used to separate metals once they have been extra

64、cted into aqueous solutions. In principle, all the techniques of classic inorganic analytical chemistry are available to the hydrometallurgists and can be adapted to use in industrial processes. It is, indeed, true that it is the hydro-metallurgists of recent times who are the main users of the vast amount of chemical knowledge built up by the classic inorganic chemists of the late 19th and early 20th centuries(4). Hydrometallurgists may aptly call themselves modern alchemists.There is a general awareness of