1、Specialty English for Iron & Steel Metallurgy ,Xu-ling Chen （陈许玲）E-mail：Mobile telephone：13808454610QQ number：413645166,Teaching Purpose,掌握钢铁冶金工程的基本专业英语词汇，能够阅读钢铁冶金及相关行业的英文文献，及时掌握国外相关领域的发展动态和新技术。提高翻译技巧和分析难句的能力，正确、通顺、快速地把冶金专业的英文资料译成中文，初步掌握把汉语专业文章译成英文的能力和英语听说能力。,Teaching Content,Theories and Technics o
2、f Agglomeration Theories and Technics of Ironmaking Theories and Technics of Steelmaking Introduction of Iron and Steel Industry in World,Section Agglomeration,1.1 Trends in Agglomeration1.1.1 The growth of sintering and pelletizing1.1.2 Location of sintering and pelletizing plants1.1.3 Future devel
3、opments1.2. Modern Agglomeration Practice1.2.1 Sintering1.2.2 Pelletizing,造块 Sintering Pelletizing Briquetting,Section Agglomeration,1.1.1 The growth of sintering and pelletizing,Sinter production grew slowly from its inception, in 1911, to the commencement of the Second World War, reaching six mill
4、ion tons in both the U.S.A. and the U.S.S.R. by 1940. Pelletizing commenced much later, in the early 1950s in the U.S.A. and not until the middle 1960s in the U.S.S.R. The growth of sinter and pellet production in these two countries, and of sinter production in the U.K., is shown in Figure 1.1.,Sec
5、tion Agglomeration,1.1.1 The growth of sintering and pelletizing,The following aims have resulted in the growth of sintering and pelletizing in these and other countries: (l) To improve the size grading and the reducibility of the furnace burden without wasting the ore fines. (2) To utilize certain
6、waste products containing iron, e.g. blast-furnace flue dust. (3) To minimize the quantity of volatile matter charged to the furnace. (4) To utilize fine concentrates produced from low-grade ores. (5) To enable ore fines and concentrates to be processed at or near the mine site and thus to enhance t
7、he value of exported ore.,粒度组成 size/grain distribution; size composition; dimension ratio,cause；lead to； bring about,Section Agglomeration,1.1.1 The growth of sintering and pelletizing,Both sintering and pelletizing enable item 1 to be accomplished. Pelletizing is superior in that the final product
8、size is more closely controlled but there is no evidence to suggest that the close size-grading of pellets enables either the output or the thermal efficiency of a blast furnace to be better than that which can be obtained using sinter. Sinter plants are better suited than pellet plants for utilizin
9、g waste materials, and in certain American works which use high proportions of pellets, the sinter plant has been reduced almost to the role of processor of waste materials and calciner of flux. However, a pelletizing plant has been built in Italy solely to process pyrites residues, a by-product fro
10、m the sulphur industry, and in Canada pellets are produced from the by-products of the non-ferrous industry.,煅烧；熔剂 硫铁矿烧渣 硫；有色,Section Agglomeration,1.1.1 The growth of sintering and pelletizing,Volatiles are contained in the flux and also, to a lesser extent, in certain ores. The addition of limesto
11、ne to the sinter mix to produce a fluxed sinter, (basicity l.0-1.4) has been practised for many years, and more recently super-fluxed inters with basicities as high as 3.0-4.0 have been made. The use of such sinters enables a mixture of ores, or pellets, and sinter to be used as blast-furnace burden
12、 with only a minimum of raw (uncalcined) flux.It has also been common practice for some years to sinter low-grade ores of high volatile content. This has greatly improved furnace operation in those regions of the United Kingdom and Western Europe where such ores are the basis of ironmaking.,calcium
13、carbonate burnt lime 生石灰； dolomite 白云石； olivine 橄榄石； serpentine 蛇纹石； magnesite 菱镁石,Section Agglomeration,1.1.1 The growth of sintering and pelletizing,Two pellet plants in North America have been built to process limonite ore at the mine and so ship a richer product, in a more desirable physical sta
14、te, to the steelworks.Fluxed pellets have been made and charged to the blast furnace, but only in relatively small quantities, and it is too early to assess their behaviour in the blast furnace. It is unlikely, however, that it would be economically justifiable to transport flux to the pelletizing p
15、lant and then ship it, as part of the fluxed pellet, for a considerable distance to the steelworks.,Limonite 褐铁矿 Hematite 赤铁矿； Magnetite 磁铁矿； Siderite 菱铁矿； Goethite 针铁矿,Section Agglomeration,1.1.1 The growth of sintering and pelletizing,Pelletizing was developed initially as a method of processing f
16、ine concentrates. Extensive tests were carried-out in the U.S.A. around 1950 to develop ways of agglomerating the fine concentrates obtained from taconites（铁燧石）. Both sintering and nodulizing were tried and abandoned as less suitable than pelletizing. The widespread development of low-grade ore bodi
17、es in the U.S.A., Canada and elsewhere, in the 1950s and 1960s, provided the stimulus for the growth of pelletizing capacity which is shown in Figure 1.2. More recently a number of pellet plants have been built to produce pellets from high-grade ore fines. This enhances the value of the product.,1.1
18、.2 Location of sintering and pelletizing plants,Sintering is always likely to be carried out at the steelworks. Sinter does not withstand handing very well, and the less the handling between the sinter plant and the blast furnace, the better. Added to this is the fact that certain of the raw materia
19、ls, e.g. flue dust and coke breeze, arise within the works. On the other hand, pelletizing is likely to be carried out at or near the mine site. There are some exceptions to this; at Chiba, the Kawasaki（川崎） Steel Company commenced making pellets in 1953. The fine ore used in the works was divided in
20、to two streams, that most suited to pelletizing, e.g. fine concentrates, and that most suited to sintering, e.g. the undersize from ore screening. It was claimed that in this way sintering practice was improved and the pre-treatment of the pelletizing mix was minimized. Pellet plants have been built
21、 at two other Japanese works and another has been built in Holland. However, the vast majority of new plants are being built at or near the mines. Pelletizing works most effectively if the raw material feed is consistent, and this can more easily be ensured if the pellet plant and the mine are close
22、ly linked. There is also an understandable desire on the part of the exporting country to provide a more valuable material. The data on page 12 gives an example of the difference in value between pellets and the ore fines from which they were produced.,Figure 1.2 World pellet capacity,It is dangerou
23、s to predict future developments from what has happened in the past. However, certain trends are fairly clear. Sintering will continue to be important. The increasing emphasis on a closely sized burden renders it inevitable that ore and pellet screenings will continue to be produced at the steelwork
24、s. It is most improbable that all the fines arising at the mines will be pelletized before dispatch. It is much more likely that a balance will always be maintained between fines sold relatively cheaply and the more expensive pellets. Add to this the necessity for utilizing waste materials arising i
25、n the steelworks, e.g. flue dust, and the desire to calcine the flux before charging it to the furnace, and the future of sintering appears to be assured. The only developments which could upset this would be the development of a new agglomeration process or a modification of the pelletizing process
26、 which enables it to accommodate a coarser feed. The only new process which has appeared over the horizon in recent years is hot briquetting, and this has not fulfilled its earlier hopes. Recent work has established that pellets can be made from certain ore mixes without having all the input finely
27、ground, but some grinding is still necessary and not all ore mixes are suitable for this type of pelletizing operation. This work has not been carried out on a large scale and the behaviour of such pellets in the blast furnace has not been investigated.,1.1.3.1 Status of sintering and pelletizing,Se
28、ction Agglomeration,Pelletizing also appears to have an assured future. Taking a long-term view, an increasing proportion of the blast-furnace burden is likely to come from low-grade deposits. These can be pelletized most conveniently at or near the mine and shipped in the processed form. It is also
29、 probable that the present trend of pelletizing part of the ore-rich fines before selling will continue.It is not possible to predict how the overall balance between sintering and pelletizing will change with time. In any case it is likely to vary greatly from country to country, and both processes
30、could eventually be rendered unnecessary by radical new developments in ironmaking.,1.1.3.1 Status of sintering and pelletizing,Section Agglomeration,1.1.3.2 Metallized agglomerates,The aim in recent years has been to minimize the metallurgical load on the blast furnace. This has resulted in limitin
31、g the chemical operations to be performed to the reduction of iron oxides, together with small quantities of other oxides, and slag formation. The volume of slag has been reduced to the necessary minimum so that the heat needed for melting has been minimized. The main thermal load is the energy requ
32、ired for reducing iron oxide, and the work to be done in the blast furnace would be reduced if part of the oxygen was removed before charging. Because of the operating conditions within the blast furnace, reducing the higher oxides to ferrous oxide does not lower the blast-furnace fuel consumption.
33、To achieve this it is necessary to reduce at least a proportion of the iron to the metallic state.,Section Agglomeration,1.1.3.2 Metallized agglomerates,It is not possible to make highly reduced sinter by increasing the coke content of the mix. The higher bed temperatures obtained, and the reducing
34、atmosphere, lead to the production of a high proportion of partly reduced ferruginous slag. On the other hand, highly reduced (metallized) pellets can be produced by modifications of the normal hardening procedure. Metallized pellets can be made from fired oxidized pellets, but it is also possible t
35、o harden the green pellets under reducing conditions to produce the metallized pellets in one operation. Two methods are being used commercially, a horizontal rotary kiln and a vertical-shaft kiln.,Section Agglomeration,1.1.3.2 Metallized agglomerates,The SL/RN process uses a horizontal rotary kiln.
36、 Green or fired pellets and a solid fuel - fine coal or coke - and fine flux are fed into the rotary drum. The solids travel through the drum counter-current to the combustion gases from a gas- or oil-fired burner located in the exit from the drum. The reduced pellets are cooled in a second drum, an
37、d separated from the spent flux and excess solid fuel. Figure 1.3 shows the layout of an SL/RN plant. Commercial plants have been built in New Zealand, South Korea and Canada.,Figure 1.3. The SL/RN process,Section Agglomeration,Sponge iron,Section Agglomeration,1.1.3.2 Metallized agglomerates,A numb
38、er of shaft-furnace processes have been developed. In the Wiberg process, fired oxidized pellets are reduced in a shaft by gases produced in an electrically heated gas carburizer. In the Midland Ross shaft process (Midrex process), fired oxidized pellets are reduced in a shaft by gases produced by r
39、eforming methane(甲烷). The same method of producing reducing gases is used in the Purofer process, but here the intention is to use unfired green pellets and to reduce and harden in the same operation. Commercial shaft-furnace plants are in operation or under construction in Sweden, Japan, the U.S.A.
40、, and Germany. Metallized agglomerates can also be produced by reducing fine iron ore, for example in fluidized beds, and briquetting the product. A commercial plant using this method has been built in Venezuela.,Section Agglomeration,1.1.3.2 Metallized agglomerates,Metallized pellets have only been
41、 used as a blast furnace burden for short trial periods. The results were encouraging in that outputs rose and coke rates fell, but the economic advantages are very doubtful. Whilst metallized agglomerates may be used to a limited extent as a blast-furnace feed, it seems likely that, in the main, th
42、ey will be melted and refined directly to steel, thus by-passing the blast furnace altogether. In this case, the manufacture of metallized pellets becomes an alternative ironmaking process like those described in Chapter 3. This is borne out practically, since most of the processes for making metall
43、ized pellets can also operate using sized ore which, when reduced, is melted and refined to steel.,Section Agglomeration,1.1.3.3 Technical bases of sinter and pellet-plant design and operation,Before 1945 little was known of the basic principles underlying the sintering process, and the design, cons
44、truction and operation of sinter plants was largely based on experience. In the next fifteen years or so great efforts were made to rectify this position. Laboratory studies were carried out aimed at elucidating the basic theory, both chemical and physical, and pilot-plant studies and investigations
45、 on commercial plants were made to provide a basis for plant design and operation. During this period, work was carried out in many countries in universities, research associations, steelworks and by plant manufacturers. Interchange of information was good and the results were rapidly incorporated i
46、nto the design and operation of sinter plants. Three international meetings were held during this periodin London in 1953, in Paris in 1957, and in Philadelphia in 1961which provided useful opportunities for the exchange of information.,Section Agglomeration,1.1.3.3 Technical bases of sinter and pel
47、let-plant design and operation,At about the same time, the basic research and development which led to the establishment of the pelletizing industry was being carried out. Much of the basic work was carried out in the University of Minnesota and later by Jernkontoret in Sweden. As soon as it had bee
48、n proved that pelletizing was of potential commercial importance, i.e. by the early 1940s, the American (and later the European) plant manufacturers carried out on the mechanism of balling and on the problems connected with heat for the commercial exploitation of the idea. During this period, basic
49、studies were carried out on the mechanism of balling and on the problems connected with heat flow during pellet firing.,Section Agglomeration,1.1.3.3 Technical bases of sinter and pellet-plant design and operation,At the present time, the design and operation of both sinter and pellet plants are firmly based on an understanding of basic factors which control the processes. The basic theory is discussed in the early chapters of each section, and the application of this theory to construction and operation of commercial plants is considered in later chapters.,
