外文翻译---波特兰水泥的分法及生产

水泥生产Fabrication ciment portlandLa fabrication de ciment se réduit schématiquement aux trois opérations suivantes: ∙préparation du cru∙cuisson∙broyage et conditionnementIl existe 4 méthodes de fabrication du ciment qui dépendent essentiellement du matériau: ∙Fabrication du ciment par voie humide (la plus ancienne).∙Fabrication du ciment par voie semi-humide (en partant de la voie humide).∙Fabrication du ciment par voie sèche (la plus utilisée).∙Fabrication du ciment par voie semi-sèche (en partant de la voie sèche).La composé de base des ciments actuels est un mélange de silicates et d’aluminates de calcium résultant de la combinaison de la chaux (CaO) avec la silice (SiO2), l’alumine(Al2O3), et l’oxyde de fer (Fe2O3). La chaux nécessaire est apportée par des roches calcaires, l’alumine, la silice et l’oxyde de fer par des argiles. Les matériaux se trouvent dans la nature sous forme de calcaire, argile ou marne et contiennent, en plus des oxydes déjà mentionnés, d’autres oxydes et en particulie r Fe2O3, l'oxyde ferrique.Le principe de la fabrication du ciment est le suivant: calcaires et argiles sont extraits des carrières, puis concassés, homogénéisés, portés à haute température (1450 °C) dans un four. Le produit obtenu après refroidissement rapide (la trempe) est le clinker.Un mélange d’argile et de calcaire est chauffé. Au début, on provoque le départ de l’eau de mouillage, puis au delà de 100 °C, le départ d’eau d’avantage liée. A partir de 400°C commence la composition en gaz carbonique (CO2) et en chaux (CaO), du calcaire qui est le carbonate de calcium (CaCO3).Le mélange est porté à 1450-1550 °C, température de fusion. Le liquide ainsi obtenu permet l’obtention des différentes réactions. On suppose que les composants du ciment sont formés de la façon suivante: un partie de CaO est retenu par Al2O3 et Fe2O3 en formant une masse liquide. SiO2 et CaO restant réagissent pour donner le silicate bicalcique dont une partie se transforme en silicate tricalcique dans la mesure où il reste encore du CaO non combiné.Fabrication par voie humideCette voie est utilisée depuis longtemps. C’est le procédé le plus ancien, le plus simple mais qui demande le plus d’énergie.Dans ce procédé, le calcaire et l’argile sont mélangés et broyés finement avec l’eau de façon, à constituer une pâte assez liquide (28 à 42% d’eau).On brasse énergiquement cette pâte dans de grands bassins de 8 à 10 m de diamètre, dans lesquels tourne un manège de herses.La pâte est ensuite stockée dans de grands bassins de plusieurs milliers de mètres cubes, oùelle est continuellement malaxée et donc homogénéisée. Ce mélange est appelé le cru. Des analyses chimiques permettent de contrôler la composition de cette pâte, et d’apporter les corrections nécessaires avant sa cuisson.La pâte est ensuite envoyée à l’entrée d’un four tournant, chauffé à son extrémité par une flamme intérieure. Un four rotatif légèrement incliné est constitué d’un cylindre d’acier dont la longueur peut atteindre 200 mètres. On distingue à l’intérieure du four plu sieurs zones, dont les 3 zones principales sont:∙Zone de séchage.∙Zone de décarbonatation.∙Zone de clinkerisation.Les parois de la partie supérieure du four (zone de séchage - environ 20% de la longueur du four) sont garnies de chaînes marines afin d’augm enter les échanges caloriques entre la pâte et les parties chaudes du four.Le clinker à la sortie du four, passe dans des refroidisseurs (trempe du clinker) dont il existe plusieurs types (refroidisseur à grille, à ballonnets). La vitesse de trempe a une influence sur les propriétés du clinker (phase vitreuse).De toutes façons, quelque soit la méthode de fabrication, à la sortie du four, on a unmême clinker qui est encore chaud de environ 600-1200 °C. Il faut broyer celui-ci très finement et très régulièrement avec environ 5% de gypse CaSO4 afin de «régulariser»la prise.Le broyage est une opération délicate et coûteuse, non seulement parce que le clinker est un matériau dur, mais aussi parce que même les meilleurs broyeurs ont des rendementsénergétiques déplorables.Les broyeurs à boulets sont de grands cylindres disposés presque horizontalement, remplis àmoitié de boulets d’acier et que l’on fait tourner rapidement autour de leur axe (20t/mn) et le ciment atteint une température élevée (160°C), ce qui nécessite l’arrosage extérieur des broyeurs. On introduit le clinker avec un certain pourcentage de gypse en partie haute et on récupère la poudre en partie basse.Dans le broyage à circuit ouvert, le clinker ne passe qu’une fois dans le broyage. D ans le broyage en circuit fermé, le clinker passe rapidement dans le broyeur puis à la sortie, est triédans un cyclone. Le broyage a pour but, d’une part de réduire les grains du clinker en poudre, d’autre part de procéder à l’ajout du gypse (environ 4%) pour réguler quelques propriétés du ciment portland (le temps de prise et de durcissement).A la sortie du broyeur, le ciment a une température environ de 160 °C et avant d'être transporter vers des silos de stockages, il doit passer au refroidisseur à force centrifuge pour que la température de ciment reste à environ 65 °C.Fabrication par voie sècheLes ciments usuels sont fabriqués à partir d’un mélange de calcaire (CaCO3) environ de 80% et d’argile (SiO2–Al2O3) environ de 20%. Selon l’origine des matières premières, cemélange peut être corrigé par apport de bauxite, oxyde de fer ou autres matériaux fournissant le complément d’alumine et de silice requis.Après avoir finement broyé, la poudre est transportée depuis le silo homogénéisateur jusqu’au four, soit par pompe, soit par aéroglisseur.Les fours sont constitués de deux parties:∙Un four vertical fixe, préchauffeur (cyclones échangeurs de chaleur).∙Un four rotatif.Les gaz réchauffent la poudre crue qui circule dans les cyclones en sens inverse, par gravité. La poudre s’échauffe ainsi jusqu’à 800 °C environ et perd donc son gaz carbonique (CO2) et son eau. La poudre pénètre ensuite dans un four rotatif analogue à celui utilisé dans la voie humide, mais beaucoup plus court.La méthode de fabrication pa r voie sèche pose aux fabricants d’importants problèmes techniques: ségrégation possible entre argile et calcaire dans les préchauffeurs. En effet, lesystème utilisé semble être néfaste et en fait, est utilisé ailleurs, pour trier desparticules. Dans le cas de la fabrication des ciments, il n’en est rien. La poudre restehomogène et ceci peut s'expliquer par le fait que l’argile et le calcaire ont lamême densité (2,70 g/cm3). De plus, le matériel a été conçu dans cet esprit et toutesles précautions ont été prises.2.Le problème des poussières. Ce problème est rendu d’autant plus aigu, que lespouvoirs publics, très sensibilisés par les problèmes de nuisance, imposent desconditions draconiennes. Ceci oblige les fabricants à installer des dépoussiéreurs, ce qui augmente considérablement les investissements de la cimenterie.Lesdépoussiéreurs sont constitués de grilles de fils métalliques portés à haute tension etsur lesquels viennent se fixer des grains de poussière ionisée. Ces grains de poussière s’agglomèrent et sous l’action de vibreurs qui agitent les fils retombent au fond dudépoussiéreur où ils sont récupérés et renvoyés dans le four. En dehors des pannes,ces appareils ont des rendements de l’ordre de 99%, mais absorbent une partimportante du c apital d’équipement de la cimenterie.3.Le problème de l’homogénéité du cru est délicat. Nous avons vu comment il pouvaitêtre résolu au moyen d’une préhomogénéisation puis d’une homogénéisation.。

混凝土工艺中英文对照外文翻译文献混凝土工艺中英文对照外文翻译文献混凝土工艺中英文对照外文翻译文献(文档含英文原文和中文翻译) Concrete technology and developmentPortland cement concrete has clearly emerged as the material of choice for the construction of a large number and variety of structures in the world today. This is attributed mainly to low cost of materials and construction for concrete structures as well as low cost of maintenance.Therefore, it is not surprising that many advancements in concrete technology have occurred as a result of two driving forces, namely the speed of construction and the durability of concrete.During the period 1940-1970, the availability of high early strength portland cements enabled the use of high water content in concrete mixtures that were easy to handle. This approach, however, led to serious problems with durability of structures, especially those subjected to severe environmental exposures.With us lightweight concrete is a development mainly of the last twenty years.Concrete technology is the making of plentiful good concrete cheaply. It includes the correct choice of the cement and the water, and the right treatment of the aggregates. Those which are dug near by and therefore cheap, must be sized, washed free of clay or silt, and recombined in the correct proportions so as to make a cheap concrete which is workable at a low water/cement ratio, thus easily comoacted to a high density and therefore strong.It hardens with age and the process of hardening continues for a long time after the concrete has attained sufficient strength.Abrams’law, perhaps the oldest law of concrete technology, states that the strength of a concrete varies inversely with its water cement ratio. This means that the sand content (particularly the fine sand which needs much water) must be reduced so far as possible. The fact that the sand “drinks” large quantities of water can easily be established by mixing several batches of x kg of cement with y kg of stone and the same amount of water but increasing amounts of sand. However if there is no sand the concrete will be so stiff that it will be unworkable thereforw porous and weak. The same will be true if the sand is too coarse. Therefore for each set of aggregates, the correct mix must not be changed without good reason. This applied particularly to the water content.Any drinkable and many undrinkable waters can be used for making concrete, including most clear waters from the sea or rivers. It is important that clay should be kept out of the concrete. The cement if fresh can usually be chosen on the basis of the maker’s certificates of tensile or crushing tests, but these are always made with fresh cement. Where strength is important , and the cement at the site is old, it should be tested.This stress , causing breakage,will be a tension since concretes are from 9 to 11times as strong in compression as in tension, This stress, the modulus of rupture, will be roughly double the direct tensile breaking stress obtained in a tensile testing machine,so a very rough guess at the conpressive strength can be made by multiplying the modulus of rupture by 4.5. The method can be used in combination with the strength results of machine-crushed cubes or cylinders or tensile test pieces but cannot otherwise be regarded as reliable. With these comparisons,however, it is suitable for comparing concretes on the same site made from the same aggregates and cement, with beams cast and tested in the same way.Extreme care is necessary for preparation,transport,plating and finish of concrete in construction works.It is important to note that only a bit of care and supervision make a great difference between good and bad concrete.The following factors may be kept in mind in concreting works.MixingThe mixing of ingredients shall be done in a mixer as specified in the contract.Handling and ConveyingThe handling&conveying of concrete from the mixer to the place of final deposit shall be done as rapidly as practicable and without any objectionable separation or loss of ingredients.Whenever the length of haul from the mixing plant to the place of deposit is such that the concrete unduly compacts or segregates,suitable agitators shall be installed in the conveying system.Where concrete is being conveyed on chutes or on belts,the free fall or drop shall be limited to 5ft.(or 150cm.) unless otherwise permitted.The concrete shall be placed in position within 30 minutes of its removal from the mixer.Placing ConcreteNo concrete shall be placed until the place of deposit has been thoroughly inspected and approved,all reinforcement,inserts and embedded metal properly security in position and checked,and forms thoroughly wetted(expect in freezing weather)or oiled.Placing shall be continued without avoidable interruption while the section is completed or satisfactory construction joint made.Within FormsConcrete shall be systematically deposited in shallow layers and at such rate as to maintain,until the completion of the unit,a plastic surface approximately horizontal throughout.Each layer shall be thoroughly compacted before placing the succeeding layer.CompactingMethod. Concrete shall be thoroughly compacted by means of suitable tools during and immediately after depositing.The concrete shall be worked around all reinforcement,embedded fixtures,and into the comers of the forms.Every precaution shall be taken to keep the reinforcement and embedded metal in proper position and to prevent distortion.Vibrating. Wherever practicable,concrete shall be internally vibrated within the forms,or in the mass,in order to increase the plasticity as to compact effectively to improve the surface texture and appearance,and to facilitate placing of the concrete.Vibration shall be continued the entire batch melts to a uniform appearance and the surface just starts to glisten.A minute film of cement paste shall be discernible between the concrete and the form and around the reinforcement.Over vibration causing segregation,unnecessary bleeding or formation of laitance shall be avoided.The effect spent on careful grading, mixing and compaction of concrete will be largely wasted if the concrete is badly cured. Curing means keeping the concretethoroughly damp for some time, usually a week, until it has reached the desired strength. So long as concrete is kept wet it will continue to gain strength, though more slowly as it grows older.Admixtures or additives to concrete are materials arematerials which are added to it or to the cement so as to improve one or more of the properties of the concrete. The main types are:1. Accelerators of set or hardening,2. Retarders of set or hardening,3. Air-entraining agents, including frothing or foaming agents,4. Gassing agents,5. Pozzolanas, blast-furnace slag cement, pulverized coal ash,6. Inhibitors of the chemical reaction between cement and aggregate, which might cause the aggregate to expand7. Agents for damp-proofing a concrete or reducing its permeability to water,8. Workability agents, often called plasticizers,9. Grouting agents and expanding cements.Wherever possible, admixtures should be avouded, particularly those that are added on site. Small variations in the quantity added may greatly affect the concrete properties in an undesiraale way. An accelerator can often be avoided by using a rapid-hardening cement or a richer mix with ordinary cement, or for very rapid gain of strength, high-alumina cement, though this is very much more expensive, in Britain about three times as costly as ordinary Portland cement. But in twenty-four hours its strength is equal to that reached with ordinary Portland cement in thirty days.A retarder may have to be used in warm weather when a large quantity of concrete has to be cast in one piece of formwork, and it is important that the concrete cast early in the day does not set before the last concrete. This occurs with bridges when they are cast in place, and the formwork necessarily bends underthe heavy load of the wet concrete. Some retarders permanently weaken the concrete and should not be used without good technical advice.A somewhat similar effect,milder than that of retarders, is obtained with low-heat cement. These may be sold by the cement maker or mixed by the civil engineering contractor. They give out less heat on setting and hardening, partly because they harden more slowly, and they are used in large casts such as gravity dams, where the concrete may take years to cool down to the temperature of the surrounding air. In countries like Britain or France, where pulverized coal is burnt in the power stations, the ash, which is very fine, has been mixed with cement to reduce its production of heat and its cost without reducing its long-term strength. Up to about 20 per cent ash by weight of the cement has been successfully used, with considerable savings in cement costs.In countries where air-entraining cement cement can be bought from the cement maker, no air-entraining agent needs to be mixed in .When air-entraining agents draw into the wet cement and concrete some 3-8 percent of air in the form of very small bubbles, they plasticize the concrete, making it more easily workable and therefore enable the water |cement ratio to be reduced. They reduce the strength of the concrete slightly but so little that in the United States their use is now standard practice in road-building where heavy frost occur. They greatly improve the frost resistance of the concrete.Pozzolane is a volcanic ash found near the Italian town of Puzzuoli, which is a natural cement. The name has been given to all natural mineral cements, as well as to the ash from coal or the slag from blast furnaces, both of which may become cementswhen ground and mixed with water. Pozzolanas of either the industrial or the mineral type are important to civil engineers because they have been added to oridinary Portland cement in proportions up to about 20 percent without loss of strength in the cement and with great savings in cement cost. Their main interest is in large dams, where they may reduce the heat given out by the cement during hardening. Some pozzolanas have been known to prevent the action between cement and certain aggregates which causes the aggregate to expand, and weaken or burst the concrete.The best way of waterproof a concrete is to reduce its permeability by careful mix design and manufacture of the concrete, with correct placing and tighr compaction in strong formwork ar a low water|cement ratio. Even an air-entraining agent can be used because the minute pores are discontinuous. Slow, careful curing of the concrete improves the hydration of the cement, which helps to block the capillary passages through the concrete mass. An asphalt or other waterproofing means the waterproofing of concrete by any method concerned with the quality of the concrete but not by a waterproof skin.Workability agents, water-reducing agents and plasticizers are three names for the same thing, mentioned under air-entraining agents. Their use can sometimes be avoided by adding more cement or fine sand, or even water, but of course only with great care.The rapid growth from 1945 onwards in the prestressing of concrete shows that there was a real need for this high-quality structural material. The quality must be high because the worst conditions of loading normally occur at the beginning of the life of the member, at the transfer of stress from the steel to theconcrete. Failure is therefore more likely then than later, when the concrete has become stronger and the stress in the steel has decreased because of creep in the steel and concrete, and shrinkage of the concrete. Faulty members are therefore observed and thrown out early, before they enter the structure, or at least before it The main advantages of prestressed concrete in comparison with reinforced concrete are :①The whole concrete cross-section resists load. In reinforced concrete about half the section, the cracked area below the neutral axis, does no useful work. Working deflections are smaller.②High working stresses are possible. In reinforced concrete they are not usually possible because they result in severe cracking which is always ugly and may be dangerous if it causes rusting of the steel.③Cracking is almost completely avoided in prestressed concrete.The main disadvantage of prestressed concrete is that much more care is needed to make it than reinforced concrete and it is therefore more expensive, but because it is of higher quality less of it needs to be needs to be used. It can therefore happen that a solution of a structural problem may be cheaper in prestressed concrete than in reinforced concrete, and it does often happen that a solution is possible with prestressing but impossible without it.Prestressing of the concrete means that it is placed under compression before it carries any working load. This means that the section can be designed so that it takes no tension or very little under the full design load. It therefore has theoretically no cracks and in practice very few. The prestress is usually applied by tensioning the steel before the concrete in which it isembedded has hardened. After the concrete has hardened enough to take the stress from the steel to the concrete. In a bridge with abutments able to resist thrust, the prestress can be applied without steel in the concrete. It is applied by jacks forcing the bridge inwards from the abutments. This methods has the advantage that the jacking force, or prestress, can be varied during the life of the structure as required.In the ten years from 1950 to 1960 prestressed concrete ceased to be an experinmental material and engineers won confidence in its use. With this confidence came an increase in the use of precast prestressed concrete particularly for long-span floors or the decks of motorways. Whereever the quantity to be made was large enough, for example in a motorway bridge 500 m kong , provided that most of the spans could be made the same and not much longer than 18m, it became economical to usefactory-precast prestressed beams, at least in industrial areas near a precasting factory prestressed beams, at least in industrial areas near a precasting factory. Most of these beams are heat-cured so as to free the forms quickly for re-use.In this period also, in the United States, precast prestressed roof beams and floor beams were used in many school buildings, occasionally 32 m long or more. Such long beams over a single span could not possibly be successful in reinforced concrete unless they were cast on site because they would have to be much deeper and much heavier than prestressed concrete beams. They would certainlly be less pleasing to the eye and often more expensive than the prestressed concrete beams. These school buildings have a strong, simple architectural appeal and will be a pleasure to look at for many years.The most important parts of a precast prestressed concrete beam are the tendons and the concrete. The tendons, as the name implies, are the cables, rods or wires of steel which are under tension in the concrete.Before the concrete has hardened (before transfer of stress), the tendons are either unstressed (post-tensioned prestressing) or are stressed and held by abutments outside the concrete ( pre-tensioned prestressing). While the concrete is hardening it grips each tendon more and more tightly by bond along its full length. End anchorages consisting of plates or blocks are placed on the ends of the tendons of post-tensioned prestressed units, and such tendons are stressed up at the time of transfer, when the concrete has hardened sufficiently. In the other type of pretressing, with pre-tensioned tendons, the tendons are released from external abutments at the moment of transfer, and act on the concrete through bond or archorage or both, shortening it by compression, and themselves also shortening and losing some tension.Further shortening of the concrete (and therefore of the steel) takes place with time. The concrete is said to creep. This means that it shortens permanently under load and spreads the stresses more uniformly and thus more safely across its section. Steel also creeps, but rather less. The result of these two effects ( and of the concrete shrinking when it dries ) is that prestressed concrete beams are never more highly stressed than at the moment of transfer.The factory precasting of long prestressed concrete beams is likely to become more and more popular in the future, but one difficulty will be road transport. As the length of the beam increases, the lorry becomes less and less manoeuvrable untileventually the only suitable time for it to travel is in the middle of the night when traffic in the district and the route, whether the roads are straight or curved. Precasting at the site avoids these difficulties; it may be expensive, but it has often been used for large bridge beams.混凝土工艺及发展波特兰水泥混凝土在当今世界已成为建造数量繁多、种类复杂结构的首选材料。

波特兰水泥的标准规范本标准在C150基础上修订发布, 后面指定的数字表示年份。

这个标准已经被批准由美国国防部机构使用。

1.范围1.1 本规范包括8种硅酸盐水泥，如下（见注2）1.1.1第一类Ⅰ---使用时特殊属性指定的任何其他类型并不是必需的。

1.1.2 第一类ⅠA---引气水泥同样作为I型，其预期环境中含有空气带。

1.1.3 第二类Ⅱ---标准用于一般的使用，特别是在理想的温和抗硫酸盐侵蚀或中度水化热环境。

1.1.4 第二类ⅡA---有理想空气夹带的引气水泥的使用和第二类一样。

1.1.5 第三类---早期强度高是理想的使用情况。

1.1.6 第三类ⅢA---有理想空气夹带的引气水泥的使用和第三类一样。

1.1.7 第四类Ⅳ---低水化热是理想的使用情况。

1.1.8 第五类Ⅴ---高抗硫酸盐是理想的使用情况。

注1：有些水泥与指定类型分类,如I型/ II,表明了水泥符合要求的显示类型和被提供适合用在这两种,是理想的1.2 当S1和英寸磅单位同时出现时以SI为理想单位，英寸磅单位为近似列出的。

1.3 本标准的引用注释和脚注，提供文字说明材料。

这些笔记和注释（不包括表和数字的），不被视为标准的要求。

2．引用的文献2.1 ASTM标准：C33混凝土骨料规范C 109/C 109M 液压水泥砂浆试验方法（抗压强度2英寸或[50毫米]立方体试样）C114 液压水泥的化学分析试验方法C115 用浊度仪测试硅酸盐水泥细度的方法C151 蒸压扩展液压水泥的测试方法C183 液压水泥砂浆空气含量的测试方法C186液压水泥水化热测试方法C191 维卡仪测定液压水泥凝结时间的测试方法C204 透气仪测定液压水泥细度的测试方法C219 液压水泥术语C226 引气剂在液压水泥生产使用当中的使用规范C266吉尔莫尔针测定液压水泥凝结时间的测试方法C451 液压水泥早期强度的试验方法(粘贴法)C452 波特兰水泥砂浆硫酸盐侵蚀的潜在扩张测试方法C465 液压水泥在生产、使用、加工当中的规范C563 最佳SO3测定24H抗压强度的测试方法C1038存放在水中的水硬性水泥灰浆棒膨胀的标准试验方法E29 使用试验数据中重要数字以确定对规范的适应性3．术语1.3 定义，参见术语C219.4．订购信息4.1 本规格订单的材料,应包括下列4.1.1 本规范编号和日期4.1.2允许的类型或种类。

中英文对照资料外文翻译原文：History of cementEarly usesThe earliest construction cements are as old as construction, and were non-hydraulic. Wherever primitive mud bricks were used, they were bedded together with a thin layer of clay slurry. Mud-based materials were also used for rendering on the walls of timber or wattle and daub structures. Lime was probably used for the first time as an additive in these renders, and for stabilizing mud floors.A “daub” consisting of mud, cow dung and lime produces s tou gh coating, due to coagulation by the lime, of proteins in the cow dung. This simple system was common in Europe until quite recent times.With the advent of fired bricks, and their use in larger structures, various cultures started to experiment with higher-strength mortars based on bitumen (in Mesopotamia), gypsum (in Egypt) and lime (in many parts of the world).It is uncertain where it was first discovered that a combination of hydrated non-hydraulic lime and a pozzolan produces a hydraulic mixture, but concrete made from such mixtures was first used on a large scale by the Romans. They used both natural pozzolans ( trass or pumice) and artificial pozzolans (ground brick or pottery) in these concretes. Many excellent examples of structures made from these concretes are still standing, notably the huge monolithic dome of the Pantheon in Rome. The use of structural concrete disappeared in medieval Europe, although weak pozzolanic concretes continued to be used as a core fill in stone walls and columns.Modern cementModern hydraulic cements began to be developed from the start of the Industrial Revolution (around 1800), driven by three main needs:Hydraulic renders for finishing brick buildings in wet climates.˙Hydraulic mortars for masonry construction of harbor works etc, in contact with sea water.˙Development of strong concretes.In Britain particularly, good quality building stone became ever more expensive during a period of rapid growth, and it became a common practice to construct prestige buildings from the new industrial bricks, and to finish them with a stucco to imitate stone. Hydraulic limes were favored for this, but the need for a fast set time encouraged the development of new cements. Most famous among these was Parker’s “Roman cement.” This was development by James Parker in the 1780s, and finally patented in 1796. It was, in fact, nothing like any material used by the Romans, but was a “Natural cement” made by burning septaria-nodules that are found in certain clay deposits, and that contain both clay minerals and calcium carbonate. The burnt nodules were ground to a fine powder. This product, made into a mortar with sand, set in 5—15 minutes. The success of “Roman cement” led other manufacturers to develop rival products by burning artificial mixtures of clay and chalk.John Smeaton made an important contribution to the development of cements when he was planning the construction of the third Eddystone Lighthouse (1755-9) in the English Channel. He needed a hydraulic mortar that would set and develop some strength in the twelve hour period between successive high tides. He performed an exhaustive market research on the available hydraulic limes, visiting their production sites, and noted that the “hydraulicity” of the lime was directly related to the clay content of the limestone from which it was made. Smeaton was a civil engineer by profession, and took the idea no further. Apparently unaware of Smeaton’s work, the same principle was identified by Louis Vicat in the first decade of the nineteenth century. Vicat went on to devise a method of combining chalk and clay into an intimate mixture, and, burning this, produced an “artificial cement” in 1817. James Frost, working in Britain, produced what he called “British cement” in a similar manner around the same time, but did not obtain a patent until 1822. In 1824, Joseph Aspdin patented a similar material, which he called Portland cement, because the render made from it was in color similar to the prestigious Portland stone.All the above products could not compete with lime/pozzolan concretes because of fast-setting (giving insufficient time for placement) and low early strengths(requiring a delay of many weeks before formwork could be removed). Hydraulic limes “natural” cements and “artificial” c ements all rely upon their belite content for strength development. Belite develops strength solely. Because they were burned at temperatures below 1259℃, they contained no alite, which is responsible for early strength in modern cements. The first cement to consistently contain alite was that made by Joseph Aspdin’s son William in the early 1840s. This was what we call today “modern” Portland cement. Because of the air of mystery with which William Aspdin surrounded his product, others (e.g.Vicat and I C Johnson) have claimed precedence in this invention, but recent analysis of both his concrete and raw cement have shown that William Aspdin’s products made at Northfleet, Keen was a true alite-based cement. However, Aspdin’s methods were “rule-of-thumb”:Vica t is responsible for establishing the mix in the kiln.William Aspdin’s innovation was counter-intuitive for manufacturers of “artificial cement”, because they required morelime in the mix ( a problem for his father ), because they required a much higher kiln temperature ( and therefore more fuel ) and because the resulting clinker was very hard and rapidly wore down the millstones which were the only available grinding technology of the time. Manufacturing costs were therefore considerably higher, but the product set reasonably slowly and developed strength quickly, thus opening up a market for use in concrete. The use of concrete in construction grew rapidly from 1850 onwards, and was soon the dominant use for cements. Thus Portland cement began its predominant role.译文：水泥的历史早期应用最早的建筑水泥是和建筑一起起步的，但是这种水泥在水中不会硬化。

水泥的历史中英文对照资料外文翻译文献外文翻译History of cementEarly usesThe earliest construction cements are as old as construction, and were non-hydraulic. Wherever primitive mud bricks were used, they were bedded together with a thin layer of clay slurry. Mud-based materials were also used for rendering on the walls of timber or wattle and daub structures. Lime was probably used for the first time as an additive in these renders, and for stabilizing mud floors. A “daub” consisting of mud, cow dung and lime produces s tough coating, due to coagulation by the lime, of proteins in the cow dung. This simple system was common in Europe until quite recent times. With the advent of fired bricks, and their use in larger structures, various cultures started to experiment with higher-strength mortars based on bitumen (in Mesopotamia), gypsum (in Egypt) and lime (in many parts of the world). It is uncertain where it was first discovered that a combination of hydrated non-hydraulic lime and a pozzolan produces a hydraulic mixture, but concrete made from such mixtures was first used on a large scale by the Romans. They used both natural pozzolans ( trass or pumice) and artificialpozzolans (ground brick or pottery) in these concretes. Many excellent examples of structures made from these concretes are still standing, notably the huge monolithic dome of the Pantheon in Rome. The use of structural concrete disappeared in medieval Europe, although weak pozzolanic concretes continued to be used as a core fill in stone walls and columns.Modern cementModern hydraulic cements began to be developed from the start of the Industrial Revolution (around 1800), driven by three main needs:Hydraulic renders for finishing brick buildings in wet climates.˙Hydraulic mortars for masonry construction of harbor works etc, in contact with sea water.˙Development of strong concretes.In Britain particularly, good quality building stone became ever more expensive during a period of rapid growth, and it became a common practice to construct prestige buildings from the new industrial bricks, and to finish them with a stucco to imitate stone. Hydraulic limes were favored for this, but the need for a fast set time encouraged the development of new cements. Most famous among these was Parker’s “Roman cement.” This was development by James Parker in the 1780s, and finally patented in 1796. It was, in fact, nothing like any material used by the Romans, but was a “Natural cement” made by burning septaria-nodules that are found in certain clay deposits, and that contain both clay minerals and calcium carbonate. The burnt nodules were ground to a fine powder. This product, made into a mortar with sand, set in 5—15 minutes. The success of “Roman cement” led other manufacturers to develop rival products by burning artificial mixtures of clay and chalk.John Smeaton made an important contribution to the development of cements when he was planning the construction of the third Eddystone Lighthouse (1755-9) in the English Channel. He needed a hydraulic mortar that would set and develop some strength in the twelve hour period between successive high tides. He performed an exhaustive market research on theavailable hydraulic limes, visiting their production sites, and noted that the “hydraulicity” of the lime was directl y related to the clay content of the limestone from which it was made. Smeaton was a civil engineer by profession, and took the idea no further. Apparently unaware of Smeaton’s work, the same principle was identified by Louis Vicat in the first decade of the nineteenth century. Vicat went on to devise a method of combining chalk and clay into an intimate mixture, and, burning this, produced an “artificial cement” in 1817. James Frost, working in Britain, produced what he called “British cement” in a similar manner around the same time, but did not obtain a patent until 1822. In 1824, Joseph Aspdin patented a similar material, which he called Portland cement, because the render made from it was in color similar to the prestigious Portland stone.All the above products could not compete with lime/pozzolan concretes because of fast-setting (giving insufficient time for placement) and low early strengths(requiring a delay of many weeks before formwork could be removed). Hydraulic limes “natural” cements and “artificial” cements all rely upon their belite content for strength development. Belite develops strength solely. Because they were burned at temperatures below 1259℃, they contained no alite, which is responsible for early strength in modern cements. The first cement to consistently contain alite was that made by Joseph Aspdin’s son William in the early 1840s. This was what we call today “modern” Portland cement. Because of the air of mystery with which William Aspdin surrounded his product, others (e.g.Vicat and I C Johnson) have claimed precedence in this invention, but recent analysis of both his concrete and raw cement have shown that William Aspdin’s products made at Northfleet, Keen was a true alite-based cement. However, Aspdin’s methods were “rule-of-th umb”:Vicat is responsible for establishing the mix in the kiln. William Aspdin’s innovation was counter-intuitive for manufacturers of “artificial cement”, because they required more lime in the mix ( a problem for his father ), because they required a much higher kiln temperature ( andtherefore more fuel ) and because the resulting clinker was very hard and rapidly wore down the millstones which were the only available grinding technology of the time. Manufacturing costs were therefore considerably higher, but the product set reasonably slowly and developed strength quickly, thus opening up a market for use in concrete. The use of concrete in construction grew rapidly from 1850 onwards, and was soon the dominant use for cements. Thus Portland cement began its predominant role.水泥的历史早期应用最早的建筑水泥是和建筑一起起步的，但是这种水泥在水中不会硬化。

（一）粉磨设备风扫式煤炭磨:Air swept coal plant风扫磨：Air swept mill锥形球磨机：Conical mill轮碾磨: Edge-runnerPan grinder水泥磨（细粉磨磨机终粉磨机）：Finish mill 立磨：Vertical mill辊磨：Roller mill辊压机：Roller press原料磨:Finish raw mill球磨机:ball mill中心驱动球磨机central—shaft-driven ball mill自磨机: Autogenously mill管磨机：Tube mill（二）筛粉设备(classifier，separator) 粗粉分离器：Air-flow classifie/rAir-flow separator选粉机：Air classifier/ Air separator调速选粉机:Speed controlled separator涡流式选粉机：Turbo air separator离心式选粉机:whizzer /centrifugal classifier高效选粉机:Dynamic classifier脱水机：Water separator(三) 其它固定鄂板：Fixed jaw锤头：Beater打击板：Impeller bar（反击）打击板：Blow bar鄂破进料口（宽）：Jaw opening挡风板(选粉机）:Impact ring磨机进料口：Intake of mill磨机衬板：Armor plate 研磨体：Crusher ball（辊磨）磨盘：Bowl（磨机)搭接式衬板：Shiplap （shell) liner 滚筒筛:trommel（四）。

库仓及设施水泥仓库棚：Cement shed配料仓synchronous belt料斗：Batch bin原形预均化堆场：Circular preblend stockpile空气搅拌库:Aerated blending silo集料配料仓：Aggregate bather bin锥底库：Hopper-bottomed bin水平料仓：Horizontal bunker矫正仓：Calibration bin中间仓：Intermediate bin溢流仓：Overflow bin原料混合料仓：Composition bin原石库：Raw stone store储仓:Storage bunker储库、堆场：Storage hall圆筒仓、料仓：Silo计量仓(重量喂料）：Weigh bin槽形卸料口料仓：Slot bunker露天堆场：Yard料仓、料斗：Bunker长方形堆场：Longitudinal bed圆屋顶预混合堆场：Preblend dome自卸仓、重力仓：Gravity bin石膏仓：Gypsum bin分料溜子:Diversion chute / distribution chute伸缩槽：Telescopic chute检修门：Access door/Service door可调闸门：Adjustable deflector可调刮板：Adjustable plough料仓卸料设备：Bin discharge device底卸式料仓：Bottom dump bucket闸门：Gate装料料斗：Charging funnel卸料装置：Emptying device防雨盖：Cover of weather-proof给料口、装料口:Receiving opening筒仓料斗：Silo bunker清灰门：Soot door卸料溜子：Tip chute隔仓板：partition plate生料均化库:Raw meal homogenizing silo 气动均化库：Pneumatic Homogenizing silo 气动存储库：Pneumatic storage silo弃料中间仓：Reject intermediate bin砂岩、页岩、铁粉储库：Silica 、shale、pyrite storage生料仓：Raw meal bin原煤喂料仓:Raw coal feed bin废料仓：Scrap bin（五）输送装置输送机空气输送斜槽：1。

Technology change and environmental management for cement manufacturing and Industrial pollution control in PeruAbstract:This article mainly introduced some research results made by USA In the cement industry pollution control, and in Peru, for example, analyzed the important influence that cement industrial pollution for a government.key words :pollution control cement industry industry pollutionenvironmental managementHistorically, the cement industry has been challenged with the requirement of improving its manufacturing process while reducing its footprint on the environment. At the same time, global competition poses more challenges to improving the bottom line of the business. Research and development of pollution abatement technology for cement manufacturing is key for effectively operating in this new environment. These new technological advancements compete against established technologies when cement manufacturers evaluate different pollution prevention strategies.;This research developed a quantitative tool to benchmark various technologies available to produce Portland cement in the United States. The model "Technology Change Evaluation for the Cement Industry" (TCECI) was developed to achieve this goal considering a full cost approach. Several production scenarios were designed and evaluated to represent the current and potential future conditions of the cement industry in the United States. The decision making process to select the Best Available Technology (BAT) for cement manufacturing in the United States considered the minimization of the private and the total cost (i.e., including private and social costs) under different multi-pollutant approaches. One of these approaches considered the minimization of carbon dioxide emissions from the calcination of raw materials and the combustion of the fuel from cement manufacturing. These emissions were estimated for each production scenario considering an emission tax scheme and an emission allowance trading program.;The most relevant result obtained from this research is the integration of environmental and social aspects of cement making into the currentdecision making process for technology change. This integration led to production alternatives with improved environmental, social and economic performance. Additionally, the results of this research indicate that the current technology mix for cement manufacturing in the United States limits the feasibility of new cement plants when considering the full cost approach. However, the results of the analysis indicate that the implementation of BAT in existing plants (under the conditions and characteristics assumed by the TCECI model) improves their overall economic and environmental performance. The reduction estimated for the full cost ranged from 19% to 22% while comparing the baseline scenario for the year 2004 with a multipollutant approach (i.e., in 2004 dollars per ton of clinker, $50 -production scenario No. 8- and $48 -production scenario No. 7- versus $61 from the baseline scenario).;Finally, the results also indicate that within the limited sample of production scenarios considered there is large variability in the estimated uncertainty of the costs associated with the production of cement, the air emissions reported from the production process and the performance data from available technologies for pollution control and process optimization. The differences of the social costs estimated for each production scenario were found statistically more significant when considering the effect of the use of alternative fuels (i.e., tire fuel instead of coal) than the effect of a more stringent regulatory environment.;Since performance data for control technologies and air emissions are becoming more important to private and public policy decision making, it is recommended that the Environmental Protection Agency and the cement industry treat uncertainty explicitly, by means of adopting standardized measurement and reporting methodologies for air emissions among other relevant measures.The absence of reliable and comprehensive systems of monitoring industrial pollution has been an obstacle for better environmental management in developing countries. Peru is not an exception. While there is some progress in environmental protection, industrial pollution control is lagging behind. This research assesses priorities in industrial pollution control in Peru, identifies sectors deserving most attention by the policy-maker to better allocate scarce resources, and proposes cost-effective industrial pollution policies.;Priority sectors are identified based on their contribution to total industrial pollution. This is achieved by applying the World Bank's Industrial Pollution Projection System (IPPS) with original firm-level data from the Peruvian Ministry of Industry. Among the priority sectors, which are essentially the same for Lima and Callao and the Provinces, two are selected: cementand chemicals.;To estimate an industrial pollution baseline in Peru is virtually impossible due to the absence of monitoring. This research uses unpublished results from the only scientific survey of effluents and emissions for Peruvian industries (1997) to estimate a baseline for the cement and chemicals sectors. The difference between the targets and the observed levels of pollution is significant, but concentrated on key pollutants. Three policies are proposed for priority sectors and key pollutants: (1) current standards for the cement sector; (2) modified standards for the cement sector and new standards for the chemicals sector; and (3) a combination of standards and pollution charges. These policies were evaluated using a cost-savings framework, estimating potential savings of applying market-based instruments vs. command and control mechanisms. Sectoral abatement costs are calculated using World Bank estimates and Peruvian plant-level data from the Ministry of Industry. The policy that includes a market-based instrument is considered the least-cost option for both sectors.;Empirically, this research provides projected industrial pollution intensities and sectoral pollution data for Peru, which will aid future research. In addition to providing unique data on industrial abatement costs, it calculates cost-savings for market-based instruments vs. command and control mechanisms. This dissertation also identifies opportunities for future industrial pollution control in Peru.美国水泥工业生产中技术的改变和环境管理以及秘鲁水泥生产中污染的控制摘要：本文主要介绍了美国在水泥工业污染控制方面所取得的一些研究成果，并以秘鲁为例，分析了水泥工业污染对一个政府的重要影响。

ASTM C150波特兰水泥标准规范介绍1.标准主要内容（1）简介和范围·本规范覆盖了Portland水泥的物理和化学性质以及其制备的要求。

·本规范不包括白色Portland水泥。

注：白色Portland水泥，英文名White Portland cement或white ordinary Portland cement (WOPC)是一种特殊类型的水泥，它的生产过程与普通Portland水泥基本相同，但采用的原材料中不含或仅含很少量的氧化铁和其他着色元素，以达到白色的效果。

这种水泥通常用于特殊的建筑和装饰项目，如白色砖、瓦和石材的生产，以及浅色混凝土、灰浆和砂浆的制备。

与普通Portland水泥相比，白色Portland水泥的颜色更为均匀和明亮，但成本较高。

在一些国家，白色Portland水泥的质量标准和测试方法可能与普通Portland水泥不同，需要进行特殊的测试和验证。

（2）规范参考文件·列出了其他与本规范相关的ASTM标准。

（3）术语和定义·定义了与本规范相关的术语。

（4）分类·Portland水泥按其化学成分、早期强度和晚期强度分为十种类型。

（5）物理要求·列出了Portland水泥的各种物理性质的最小要求。

·这些要求包括比表面积、凝结时间、强度和振实密度等。

（6）化学要求·列出了Portland水泥的各种化学性质的最大要求。

·这些要求包括硫酸盐含量、氯离子含量和烧损等。

（7）制备要求·列出了Portland水泥的制备过程中的要求。

·这些要求包括原材料的选择、熟料的制备、熟料磨粉和水泥的包装等。

（8）标志和质量保证·规定了水泥包装上应标注的信息。

·列出了关于水泥质量保证的要求。

（9）样品采集、检验和测试·列出了采样、检验和测试的方法和程序。

（10）报告·要求将所有检验结果记录并汇总成报告。

Portland cementPortland cement(often referred to as OPC, from Ordinary Portland Cement) is the most common type of cement in general use around the world because it is a basic ingredient of concrete, mortar, stucco and most non-specialty grout. It is a fine powder produced by grinding Portland cement clinker (more than 90%), a limited amount of calcium sulfate (which controls the set time) and up to 5% minor constituents as allowed by various standards such as the European Standard EN197.1ASTM C 150 defines portland cement as "hydraulic cement (cement that not only hardens by reacting with water but also forms a water-resistant product) produced by pulverizing clinkers consisting essentially of hydraulic calcium silicates, usually containing one or more of the forms of calcium sulfate as an inter ground addition." Clinkers are nodules (diameters：0.2-1.0 inch [5–25 mm]) of a sintered material that is produced when a raw mixture of predetermined composition is heated to high temperature. The low cost and widespread availability of the limestone, shales, and other naturally occurring materials make portland cement one of the lowest-cost materials widely used over the last century throughout the world. Concrete becomes one of the most versatile construction materials available in the world.Portland cement clinker is made by heating, in a kiln, a homogeneous mixture of raw materials to a sintering temperature, which is about 1450 °C for modern cements. The aluminium oxide and iron oxide are present as a flux and contribute little to the strength. For special cements, such as Low Heat (LH) and Sulfate Resistant (SR) types, it is necessary to limit the amount of tricalcium aluminate (3CaO.Al2O3) formed. The major raw material for the clinker-making is usually limestone (CaCO3) mixed with a second material containing clay as source of alumino-silicate. Normally, an impure limestone which contains clay or SiO2 is used. The CaCO3 content of these limestones can be as low as 80%. Second raw materials (materials in the rawmix other than limestone) depend on the purity of the limestone. Some of the second raw materials used are: clay, shale, sand, iron ore, bauxite, fly ash and slag. When a cement kiln is fired by coal, the ash of the coal acts as a secondary raw material HistoryPortland cement was developed from natural cements made in Britain in the early part of the nineteenth century, and its name is derived from its similarity to Portland stone, a type of building stone that was quarried on the Isle of Portland in Dorset, England.The Portland cement is considered to originate from Joseph Aspdin, a British bricklayer from Leeds. It was one of his employees (Isaac Johnson), however, who developed the production technique, which resulted in a more fast-hardening cement with a higher compressive strength. This process was patented in 1824. His cement was an artificial cement similar in properties to the material known as "Roman cement" (patented in 1796 by James Parker) and his process was similar to that patented in 1822 and used since 1811 by James Frost who called his cement "British Cement". The name "Portland cement" is also recorded in a directory published in 1823 being associated with a William Lockwood, Dave Stewart, and possibly others.Aspdin's son William, in 1843, made an improved version of this cement and he initially called it "Patent Portland cement" although he had no patent. In 1848 William Aspdin further improved his cement and in 1853 he moved to Germany where he was involved in cement making. Many people have claimed to have made the first Portland cement in the modern sense, but it is generally accepted that it was first manufactured by William Aspdin at Northfleet, England in about 1842. The German Government issued a standard on Portland cement in 1878.ProductionThere are three fundamental stages in the production of Portland cement:1.Preparation of the raw mixture2.Production of the clinker3.Preparation of the cementTo simplify the complex chemical formulae which describe the compounds present in cement, a cement chemist notation was invented. This notation reflects the fact that most of the elements are present in their highest oxidation state, and chemical analyses of cement are expressed as mass percent of these notional oxidesRawmix preparationThe raw materials for Portland cement production are a mixture of minerals containing calcium oxide, silicon oxide, aluminium oxide, ferric oxide, and magnesium oxide, as fine powder in the 'Dry process' or in the form of a slurry in the 'Wet process'. The raw materials are usually quarried from local rock, which in some places is already practically the desired composition and in other places requires the addition of clay and limestone, as well as iron ore, bauxite or recycled materials. The individual raw materials are first crushed, typically to below 50 mm.Formation of clinkerThe raw mixture is heated in a cement kiln, a slowly rotating and sloped cylinder, with temperatures increasing over the length of the cylinder up to a peak temperature of 1400-1450 °C. A complex succession of chemical reactions takes place (see cement kiln) as the temperature rises. The peak temperature is regulated so that the product contains sintered but not fused lumps. Sintering consists of the melting of25-30% of the mass of the material. The resulting liquid draws the remaining solid particles together by surface tension and acts as a solvent for the final chemical reaction in which alite is formed. Too low a temperature causes insufficient sintering and incomplete reaction, but too high a temperature results in a molten mass or glass, destruction of the kiln lining, and waste of fuel. When all goes according to plan, the resulting material is clinker. On cooling, it is conveyed to storage. Some effort is usually made to blend the clinker because, although the chemistry of the rawmix may have been tightly controlled, the kiln process potentially introduces new sources of chemical variability. The clinker can be stored for a number of years before use. Prolonged exposure to water decreases the reactivity of cement produced from weathered clinker.The enthalpy of formation of clinker from calcium carbonate and clay minerals is about 1500 to 1700 kJ/kg. However, because of heat loss during production, actual values can be much higher. The high energy requirements and the release of significant amounts of carbon dioxide makes cement production a concern for global warming.Cement grindingIn order to achieve the desired setting qualities in the finished product, a quantity(2-8%, but typically 5%) of calcium sulfate (usually gypsum or anhydrite) is added to the clinker and the mixture is finely ground to form the finished cement powder. This is achieved in a cement mill. The grinding process is controlled to obtain a powder with a broad particle size range, in which typically 15% by mass consists of particles below 5 μm diameter, and 5% of particles above 45 μm. The measure of fineness usually used is the "specific surface area", which is the total particle surface area of a unit mass of cement. The rate of initial reaction (up to 24 hours) of the cement on addition of water is directly proportional to the specific surface area. Typical values are 320–380 m2·kg−1 for general purpose cements, and 450–650 m2·kg−1 for "rapid hardening" cements. The cement is conveyed by belt or powder pump to a silo for storage. Cement plants normally have sufficient silo space for 1–20 weeks production, depending upon local demand cycles. The cement is delivered to end-users either in bags or as bulk powder blown from a pressure vehicle into the customer's silo. In industrial countries, 80% or more of cement is delivered in bulkUseThe most common use for Portland cement is in the production of concrete. Concrete is a composite material consisting of aggregate (gravel and sand), cement, and water. As a construction material, concrete can be cast in almost any shape desired, and once hardened, can become a structural (load bearing) element. Users may be involved in the factory production of pre-cast units, such as panels, beams, road furniture, or may make cast-in-situ concrete such as building superstructures, roads, dams. These may be supplied with concrete mixed on site, or may be provided with "ready-mixed" concrete made at permanent mixing sites. Portland cement is also used in mortars (with sand and water only) for plasters and screeds, and in grouts (cement/water mixes squeezed into gaps to consolidate foundations, road-beds, etc.).When water is mixed with Portland Cement, the product sets in a few hours and hardens over a period of weeks. These processes can vary widely depending upon the mix used and the conditions of curing of the product, but a typical concrete sets in about 6 hours and develops a compressive strength of 8 MPa in 24 hours. The strength rises to 15 MPa at 3 days, 23 MPa at 1 week, 35 MPa at 4 weeks and 41 MPa at3 months. In principle, the strength continues to rise slowly as long as water is available for continued hydration, but concrete is usually allowed to dry out after a few weeks and this causes strength growth to stop.Cement plants used for waste disposal or processingDue to the high temperatures inside cement kilns, combined with the oxidizing (oxygen-rich) atmosphere and long residence times, cement kilns are used as a processing option for various types of waste streams: indeed, they efficiently destroy many hazardous organic compounds. The waste streams also often contain combustible materials which allow the substitution of part of the fossil fuel norma lly used in the process.Waste materials used in cement kilns as a fuel supplement∙Paint sludge from automobile industries∙Waste solvents and lubricants∙Meat and bone meal - slaughterhouse waste due to bovine spongiform encephalopathy contamination concerns∙Waste plastics∙Sewage sludge∙Rice hulls∙Sugarcane waste∙Used wooden railroad ties (railway sleepers)Portland cement manufacture also has the potential to remove industrialby-products from the waste-stream, effectively sequestering some environmentally damaging wastes∙Slag∙Fly ash (from power plants)∙Silica fume (from steel mills)∙Synthetic gypsum波特兰水泥硅酸盐水泥(OPC),通常是指从普通硅酸盐水泥)是最常见的一种水泥在世界各地的一般用途,因为它是一种基本成分的混凝土、砂浆、粉刷、最非专业浆液。

外文资料译文Portland cement of its Types and Manufacture of Portland cement Portland cement is made by heating a mixture of limestone and clay, or other materials of similar bulk composition and sufficient reactivity, ultimately to a temperature of about 1450°C. Partial fusion occurs, and nodules of clinker are produced. The clinker is mixed with a few percent of gypsum and finely ground to make the cement. The gypsum controls the rate of set and may be partly replaced by other forms of calcium sulfate. Some specifications allow the addition of other materials at the grinding stage. The clinker typically has a composition in the region of 67% CaO, 22% SiO2, 5% Al2O3, 3%Fe2O3, and 3% of other components,and normally contains four major phases,called alite , belite , aluminate phase and ferrite phase . Several other phases, such as alkali sulfates and calcium oxide, are normally present in minor amounts.Alite is the most important constituent of all normal Portland cement clinkers,of which it constitutes 50%--70%.It is tricalcium silicate (Ca3SiO5)modified in composition and crystal structure by incorporation of foreign ions, especially Mg2+, Al3+ and Fe3+. It reacts relatively quickly with water, and in normal Portland cement is the most important of the constituent phases for strength development at ages up to 28 days, it is by far the most important.Belite constitutes 15%---30% of normal Portland cement clinker. It is declaim silicate (Ca2SiO4) modified by incorporation of foreign ions and normally present wholly or largely as theβ polymorph. it reacts slowly with water , thus contributing little to the strength during the first 28 days ,but substantially to the further increase in strength that occurs at later ages .By one year, the strength obtainable form pure alit and pure belite are about the same under comparable conditions.The aluminates phase constitutes 5%--10% of most normal Portland cement clinkers. it is Tricalcium aluminates (Ca3Al2O6), substantially modified in composition and sometimes also in structure by incorporation of foreign ions , especially Si4+, Fe3+, Na+and K+. It reacts rapidly with water and can cause undesirably rapid setting unless a set-controlling agent, usually gypsum, is added.The ferrite phase makes up 5%-15% of normal Portland cement clinkers. It is tetra calcium aluminoferrite (Ca4AlFeO7) substantially modified in composition by variation in Al/Fe ratio and incorporation of foreign ions. The rate at which it reacts with water appears to be somewhat variable, perhaps due to differences in composition or other characteristics, but in general is high initially and intermediate between those of Alite and Belite at later ages.The great majority of Portland cements made throughout the world are designed for general constructional use. The specifications with which such cements must comply are similar, but not identical, in all countries and various names are used to define the material, such as OPC (Ordinary Portland Cement) in the UK, or Type IPortland Cement in the USA.Specifications are, in general based partly on chemical composition or physical properties such as specific surface area, and partly on performance tests, such as setting time or compressive strength developed under standard conditions. The content of MgO is usually limited to either 4 or 5%, because quantities of this component in excess of about 2% are liable to occur as periclase (magnesium oxide), which through slow reaction with water can cause destructive expansion of hardened concrete. Free lime (calcium oxide) can behave similarly, and its potential formation sets a practical upper limit to the Alite content of a clinker. Excessive contents of SO3 can also lead to delayed expansion, and upper limits of 2.5%-4% are usually imposed. Alkalis (K2O and Na2O) can undergo expansive reactions with certain aggregates, and some national specifications limit the content, e.g. to 0.6% equivalent Na2O (Na2O+0.66K2O) .other upper limit of composition widely used in specifications relate to matter insoluble in dilute acid, and loss on ignition. Many other minor components are limited in content by their effects on the manufacturing process, or the properties, or both, and in some cases the limits are defined in specifications.Rapid-hardening Portland cement have been produced in various ways , such as varying the composition to increase the alite content , finer grinding of the clinker , and improvements in the manufacturing process , e.g. finer grinding or better mixing of the raw materials . The alite contents of Portland cements have increases steadily over the one and a half centuries during which the latter have been produced, and many presentday cements that would be considered normal today would have been described as rapid hardening only a few decades ago. In USA specifications, rapid-hardening Portland cements are called high early strength or Type III cements.Destructive expansion from reaction with sulfates can occur not only if the latter are present in excessive proportion in the cement, but also form attack on concrete by sulfate solutions. The reaction involves the Al2O3 containing phases in the hardened cement, and in sulfate-resisting Portland cements, its effects are reduced by decreasing the proportion of the aluminates phase, sometimes to zero. This is achieved by decreasing the ratio of Al2O3to Fe2O3in the materials. In the USA, sulfate-resisting Portland cements are called Type V cements.White Portland cements are made by increasing the ratio of Al2O3 to Fe2O3, and thus represent the opposite extreme in composition to sulfate-resisting Portland cements. The normal, dark color .of Portland cement is due to the ferrite phase, formation of which in white cement must thus be avoided. It is impracticable to employ raw materials that are completely free from Fe2O3 and other components, such as Mn2O3, that contribute to the color. The effects of these components are therefore usually minimized by producing the clinker under slightly reducing conditions and by rapid quenching. In addition to alite, belite and aluminates phase, some glass may be formed.Portland cement is made from some of the earth's most abundant materials .about two-thirds of it is derived from calcium oxide, whose source is usually some form of lime-stone(calcium carbonate),marls, chalk, or shells(for example, oyster).the other ingredients-silica,SiO2,about20％;alumina ,Al2O3,about5％; and iron oxide,Fe2O3,about 3％are derived from sand shale, clays, coal ash, and iron ore metal slag. Because the individual ingredients must be fused and sintered to produce new compounds they must de ground to pass a 200 mesh screen in order to react within a reasonable time in the kiln .in addition, the composition of the raw materials must be held within narrow limits of the above oxides to produce a useful product. Other elemental oxides which can be detrimental to the cement must be limited: these include magnesium MgO; potassium oxide, K2O; sodium oxide, and phosphorus oxide, P2O5.after blending to the proper composition, the raw materials are interground in ball mills, rod mills, or roller millers. Depending on the raw materials characteristics, they are ground either dry (dry process) or in water (wet process). The resultant raw feed is introduced into the kiln system, usually a rotary kiln, where the material is heated to about 2700°F. The material progressively loses first the water, then the carbon dioxide CO2, at about 1750°F, and at about 2300°F, a small amount at liquid phase forms. This liquid is the medium through which the higher-melting phases are formed. The resultant product, called clinker because the whole never truly melts, is cooled and again ground, in ball mills to such a fineness that about 90％will pass a screen having 325 openings per linear inch. The final product has a texture much like face powder. During grinding, about 5％of calcium sulfate(gypsum or anhydride) is added to control setting time, strength development, and other properties.The major trend in manufacture of Portland cement has shifted to a greater emphasis on the reduction of the energy consumed for its production and increasing use of coal to replace gas and oil, which were the major fuels for burning the clinker. Energy consumption is generally greater for the wet process; therefore most new plants use the dry process. The characteristics of the final product are not any different for either process. The world's largest kiln (as of 1957) produced about 7500 tons (6750 metric tons) per day of clinker. An average kiln produces about 1800 tons (1620 metric tons) per day. The latest kilns utilize some form of preheating system, which fully utilizes the hot exit gases to warm the incoming raw materials; In addition, decarbonation of the limestone can be done on the raw feed prior to its entrance to the rotary kilns by use of auxiliary burners. These techniques enable much shorter rotary kilns for equal production and save much energy. Because of these developments, the world's longest kiln (760 ft or 228 m long, 25 ft or 7.5 m in diameter) will probably remain the longest. Another trend is toward a newer type of grinding mill, called a roller mill. This mill can use waste heat for drying, lends itself readily to automatic control, and uses less energy. These mills can grind up to 400 tons (360 metric tons) per hour. Several employees in a control room can operate a whole plant except for the quarry. Control is exercised by means of television monitors, sensors, computers, and automatic continuous chemical analysis.Other types of kilns which have been used or are in the process of being developed are vertical or shaft kilns, fluid-bed furnaces, and swirl calciners.波特兰水泥的分法及生产波特兰水泥是通过加热石灰岩和粘土的混合物，或者其他具有相似组成并具有活性的块状物来生产的，加热的最高温度可以达到大约1450摄氏度。