矿物加工科技英语.doc

Technical English For Mineral Engineering 矿物加工科技英语 供理工科高校矿物加工工程专业第七学期使用 Zhang Weiqing 张维庆 主编 Northeastern University 东 北 大 学 Contents Unit 1 Introduction1 Lesson 1 Minerals and Ores1 Lesson 2 Scope of Mineral Processing4 Lesson 3 Liberation and Concentration7 Lesson 4 Particle Size and Shape9 Unit 2 Comminution13 Lesson 5 Principles of Comminution13 Lesson 6 Comminution Theory and Grindability16 Unit 3 Crushing19 Lesson 7 Introduction to Crushing19 Lesson 8 Crushers22 Unit 4 Grinding25 Lesson 9 Introduction to Grinding25 Lesson 10 Tumbling Mills27 Lesson 11 Control of the Grinding Circuit30 Lesson 12 Environmental Effects on Grinding33 Unit 5 Screening36 Lesson 13 Introduction to Screening36 Lesson 14 Factors Affecting Screening38 Lesson 15 Probability Screening40 Unit 6 Classification43 Lesson 16 Principles of Classification43 Lesson 17 Hydrocyclones46 Unit 7 Gravity Concentration49 Lesson 18 An Introduction to Gravity Concentration49 Lesson 19 Classification of Gravity Concentration Equipment51 Lesson 20 Gravity Concentration Equipment Selection 253 Lesson 21 Heavy Medium Separation56 Lesson 22 Jigging58 Lesson 23 Principles of Jigging Operation 260 Lesson 24 Principles of Jigging Operation 364 Lesson 25 Pinched Sluices, Cones and Spirals65 Lesson 26 The Shaking Table68 Lesson 27 Bartles-Mozley Tables and Bartles Cross-belt Separator71 Unit 8 Magnetic and High-tension Separation74 Lesson 28 Magnetic Separation74 Lesson 29 Principles and Mechansms of Magnetic Separation76 Lesson 30 The magnetic Force78 Lesson 31 Selection of Magnetic Separation Technique81 Lesson 32 Electrostatic Separation83 Unit 9 Froth Flotation85 Lesson 33 Principles of Flotation85 Lesson 34 Collectors87 Lesson 35 Anionic Collectors89 Lesson 36 Frothers92 Lesson 37 Regulators95 Lesson 38 Depressants97 Lesson 39 Laboratory Flotation Testing99 Lesson 40 Bulk of Laboratory Testwork101 Lesson 41 Pilot Plant Testword103 Lesson 42 Electroflotation and Agglomeration-Skin Flotation106 Lesson 43 Flotation of Lead-Zinc Ores108 Lesson 44 Flotation of Lead-Zinc-Copper Ores110 Unit 10 Ore Sorting113 Lesson 45 Introduction113 Lesson 46 Mechanics of Sorting115 Unit 11 Dewatering118 Lesson 47 Sedimentation118 Lesson 48 Filtration120 Unit 12 Tailing Disposal122 Lesson 49 Introduction122 Lesson 50 Tailings Ponds and Dams123 II 编 者 的 话 本书是在1989年东北工学院矿物工程系张维庆、韦大为、徐继润编写的An English Course For Mineral Processing基础上，进行修订的。修订中对原教材中不合适的章节和内容作了适当的改动，并按专业的完整性、系统性进行按单元排列，为了提高学生的阅读能力，每一课的后面都增加了练习部分。 本书为高等院校矿物加工工程专业学生第七学期使用的教材，其目的在于让学生掌握科技英语的特点，并掌握一定量的专业词汇，为今后阅读专业英文书刊及文献打下基础。书中的内容选自多种原版专业教材及论文， 书中的生词词性及中文注释是以在本书出现的词性和中文意思为主给出的，同时也在一定程度上兼顾了其它词性和词义。 全书共包括十二个单元五十课，授课时数50学时左右，使用时可根据具体情况选择合适的单元和课时。 参加本书修订的有东北大学张维庆、魏德洲，由张维庆担任主编，对全书作了统一整理和修改。由于编者的水平有限，书中难免会有缺点和错误，恳切希望读者批评指正。 PREFACE This book is split into twelve units and contains 50 lessons dealing with different facets of the subject. The objective of this book is to attempt to make students master the characteristics of technical English and learn some English words on mineral processing. The book is designed for use in the seventh semester, the first semester of the senior year. It is supposed to be completed in 50 hours, one hour allotted to each lesson. There is much left to be desired for the authors ability in English. Teachers, experts and all who use it are welcomed to make any comments about it. September, 1997 Authors Shenyang Unit 1 Introduction Lesson 1 Text Minerals and Ores The rocks that from the earth’s crust are classified as igneous, metamorphic, or sedimentary; But since the mantle is probably the starting point for all rocks, the average composition of the crust can be assumed to be similar to that of an average igneous rock. Such an estimate is shown in Table 1.1. A notable feature of these data is that the common metals are present in the crust in very small amounts. Also shown in the table are the prices of some elements, and it can be seen that there is little correlation between abundance and price. Despite the many factors that affect the selling price and the consumption, the general supply and demand situation means that production costs are still a significant factor in determining the selling price of a material. In turn, production costs depend on the costs of the three main processing stages mining, mineral processing, and extractive metallurgy. Table1.1 Average Composition of Igneous Rock Element Cost /kg Oxygen 46.6 Silicon 27.7 1.10 Aluminium 81 1.20 Iron 5.0 0.22 Calcium 3.6 4.40 Sodium 2.8 0.8 Potassium 2.6 6.6 Magnesium 21 2.22 Titanium 0.6 7.2 Manganese 0.1 1.28 Sulfur 0.06 0.05 Zirconium 0.03 37.74 Nickel 0.02 4.58 Vanadium 0.017 Copper 0.010 1.46 Zinc 0.004 0.68 Lead 0002 0.74 Cobalt 0001 24.4 Tin 0.001 13.87 Ce,Ga,Li,Nb,Th,Yt 10100ppm As,B,Ge,Hf,Mo,Sb,U,W 110ppm Bi,Cd,In 0.11ppm Ag,Pd,Se 0010.1ppm Au,Ir,Os,Pt 0.01ppm In broad terms the mineral processing employed depends on the mineral being processed, which in turn depends on whether that mineral is amenable to reduction to a metal. Three factors determine whether and how a metallic mineral can be reduced to a metal the chemical stability of the metal compound, the nature of the anions combined with the metal, and the ability to engineer a practical process. In general the more stable the compound the more difficult and expensive it will be to reduce it to a meal. Carbon as CO is the cheapest and most convenient reductant available, and so it is used wherever possible. Unfortunately, metals such as copper, lead, zinc, and nickel occur in suitable concentrations in the earth’s crust only as sulfides, and because the sulfur anion does not a stable compound with carbon, carbon cannot be used directly as a reducdant. To overcome this problem, sulfides first have to be converted to oxides by a process known as roasting Meal S O2→ metal O SO2 Engineering limitations can be illustrated by reference to the reduction of aluminum oxide. Although this comparatively stable oxide can be reduced by carbon, the high temperatures necessary impose severe engineering problems. Consequently, in practice, lower temperatures are used, employing electrical energy to bring about the reduction. In addition, because most of the impurities are reduced at the same time, they must be removed by a chemical refining process before reduction. The expense of this chemical refining means that ores with only one major impurity are acceptable, even though there are extensive deposits of less suitable minerals. In summary, whether a mineral area becomes an ore body depends on the technology and economics of the combined operations of mining, mineral processing, and extractive metallurgy. If the ore body is of a high grade, more expensive operations can be tolerated in one or more stages. However, as ore grade decreases, only highly efficient operations can be tolerated. The classic example is the gradual decrease in the minimum grade of copper ores since the turn of the century. This decline has been attained in face of virtually constant copper prices in real terms and has been achieved partly by improvements in technology, but largely by economics of scale. The most common nonferrous i.e., non-iron ores are the sulfides, and typically they are low grade. The term “oxide” or “oxidized ore” is applied to mineral containing oxygen, such as the oxides, hydrated oxides, sulfates, carbonates, and silicates. These vary from relatively high grade ores aluminium ores are given virtually no physical beneficiation, while a small proportion of iron ores are still used without concentration, down to very low grade materials containing less than 1 valuable, as in the case of some placer deposits of tin ores. Nonmetallic ores are those that are not used for the production of a metal they may however contain a metal. Examples are ores containing MgO or Al2O3 used to make refractories. Any ore can be considered to be made up of two components the valuable minerals, and the waste or gangue components. Complex ores are those that contain more than one valuable mineral Even so, one should appreciate that in many situations the valuable minerals are extracted one at a time, so that with respect to a given separator, any valuable that is removed later is considered to be tailings until it is recovered. It is essential at this stage to grasp the fact that each ore is unique, and as a consequence there are no standard mineral processing procedures, even though some may appear to be very similar. A thorough knowledge of the mineralogy of an ore is therefore essential not only for the design of a plant, but also for the research program that collects data to be used for plant design. Furthermore, once a mill is in operation, regular appraisal of the mineralogy is just as essential for fine tuning and for maintaining efficiency. This arises because ore bodies are not homogeneous; thus variations in feed mineralogy are normal and may occur to such an extent that major circuit modifications are required. Certain basic mineralogical knowledge is important The grade of the ore in terms of the valuable mineral. The grain size of the mineral. The combination of minerals present. The relative and association of minerals. The existence of trace elements in the lattice of the valuable mineral. The occurrence of minor amounts of potentially valuable minerals. New words rock n. 岩石；暗礁；大石块；v. 摇动 crust n. 硬壳；面包皮；the earth’s crust 地壳；v. 用外皮覆盖；结硬皮 igneous a. 火成的；似火的； rock 火成岩 metamorphic a. 变质的；rock 变质岩 sedimentary a. 沉积的；rock 沉积岩 mantle n. 地幔；罩，盖，外层；v. 罩上，盖上，扩展 abundance n. 数量；丰富 mining n. 采矿；矿业； a. 矿业的，采矿的 mineral processing n. 选矿；矿物加工 extractive a. 提取的；萃取的；n. 萃取物 amenable a. 适合于的；有义务的 reduction n. 还原；减小；压缩 reductant n. 还原剂 sulfide n. sulphide 硫化物 oxide n. 氧化物 roast n. v. 焙烧，烘烤 impurity n. 杂质 refining n. 精炼，提纯 mineral area n. 矿物区 ore body n. 矿体 sulfate n. sulphate 硫酸盐 carbonate n. 碳酸盐 silicate n. 硅酸盐 placer deposits n. 沉积矿床 refractory n. 耐火材料；a. 耐火的；难控制的 gangue n. 脉石；尾矿 tailing n. 尾矿；残渣 mineralogy n. 矿物学 mill n. 选矿厂；磨坊；磨机； v. 选矿；磨碎 appraisal n. 评价，估价 homogeneous a. 均匀的 circuit n. 流程；电路；巡回 grade n. 品位 lattice n. 晶格 trace n. 微量；痕迹；v. 描绘；追溯；追踪 rcise Answer the following questions 1. What are the three factors which determine whether and how a metallic mineral can be reduced to metal 2. What are nometallic ores 3. What are complex ores 4. What is the basic mineralogical knowledge Lesson 2 Text Scope of Mineral Processing “As-mined” or “run-of-mine” ore consists of valuable metallic minerals and waste gangue. Mineral processing, sometimes called ore dressing, mineral dressing, or milling, follows mining and prepares the ore for extraction of the valuable metal in the case of metallic ores, but produces a commercial end product of non-metallic minerals and coal. Apart from regulating the size of the ore, it is a process of physically separating the grains of valuable minerals from the gangue minerals, to produce an enriched portion, or concentrate, containing most of the valuable minerals, and a discard, or tailing, containing predominantly the gangue minerals. This concentration, or enrichment process, considerably reduces the volume of material which must be handled by the extractive metallurgist, so reducing to economic quantities the amounts of energy and reagents required to produce the pure metal. There are two fundamental operations in mineral processing, namely the release, or liberation, of the valuable minerals from their waste gangue minerals, and separation of these values from the gangue, this latter process being known as concentration. Liberation of the valuable minerals from the gangue is accomplished by comminution, which involves crushing, and, if necessary, grinding, to such a particle size that the product is a mixture of relatively clean particles of mineral and gangue. The correct degree of liberation is the key to success in mineral processing. The valuable mineral should be freed from the gangue, but only just freed. A process which overgrinds the ore is wasteful, since it needlessly consumes grinding power and makes efficient recovery more difficult to attain. So important is it to avoid overgrinding, that, as will be seen later, some ores are comminuted to a size coarser than their liberating size before initial concentration. After the minerals have been liberated from the gangue, the ore is subjected to some process of concentration, which separates the minerals into two or more products. Separation is usually achieved by utilizing some specific difference in physical or chemical properties between the valuable mineral and gangue minerals in the ore. Mineral processing is concerned mainly with the physical s of separation, which may be 1. Separation dependent on optical and radioactive properties, etc. This is often called sorting, which commonly included hand selection of high-grade ores until relatively recently. 2. Separation dependent on specific gravity differences. This utilizes the differential movement of minerals due to mass effects, usually in hydraulic currents. Although the declined in importance with the development of the froth flotation process, it is now being increasingly used due to improved techniques and its relative simplicity compared with other s. It also has advantage of producing less environmental pollution. 3. Separation utilizing the different surface properties of the minerals. Froth flotation, which is undoubtedly the most important of concentration, is affected by the degree of affinity of the minerals for rising air-bubbles within the agitated pulp. By adjusting the “climate” of the pulp by various reagents, it is possible to make the valuable minerals air-avid aerophilic and the gangue mineral water-avid aerophobic. This results in separation by transfer of the valuable minerals to the air-bubbles which the froth floating on the surface of the pulp. 4. Separation dependent on magnetic properties. Low intensity magnetic separators can be used to concentrate ferromagnetic minerals such as magnetite Fe3O4, while high-intensity separators are used to separate paramagnetic minerals from their gangue. Magnetic separation is an important process in the beneficiation of iron ores, but also finds application in the treatment of paramagnetic non-ferrous mineral