Sulphuric acid pressure leaching of a limonitic

Key to Exercise Unit 1 Chemical Industries1. the Industrial Revolution2. organic chemicals3. the contact process4. the Haber process5. synthetic polymers6. intermediates7. artificial fertilizers 8. pesticides9. synthetic fibers10. pharmaceutical11. research and development12. petrochemical13. computers14. capital intensiveSome Chemicals Used In Our Daily LifeFood artificial fertilizers, pesticide, veterinary products Health antibiotics, β-blockersClothing synthetic fibers (e.g. polyesters, polyamides),synthetic dyesShelter synthetic polymers (e.g. urea-formaldehyde,polyurethanes),plasticsLeisure plastics and polymers (e.g. nylon)Transport additives (e.g. anti-oxidants, viscosity indeximpovements),polymers, plasticsUnit 2 Research and Development1. R&D2. ideas and knowledge3. process and products4. fundamental5. applied6. product development7. existing product8. pilot plant9. a emerging case10. environmental impact11. energy cost 12. technical support13. process improvement14. effluent treatment15. pharmaceutical16. sufficiently pure17. Reaction18. unreacted material19. by-products20. the product specification21. Product storageUnit 3 Typical Activities of Chemical Engineers1. Mechanical2. electrical3. civil4. scale-up5. commercial-size6. reactors7. distillation columns8. pumps9. control and instrumentation10. mathematics11. industry12. academia13. steam14. cooling water15. an economical 16. to improve17. P&I Drawings18. Equipment Specification Sheets19. Construction20. capacity and performance21. bottlenecks22. Technical Sales23. new or improved24. engineering methods25. configurationsUnit 4 Sources of Chemicals1. inorganic chemicals2. derive from3. petrochemical processes4. Metallic ores5. extraction process6. non-renewable resource7. renewable sources8. energy source9. fermentation process10. selective 11. raw material12. separation and purification13. food industry14. to be wetted15. Key to success16. Crushing and grinding17. Sieving18. Stirring and bubbling19. Surface active agents20. OverflowingUnit 5 Basic Chemicals1. Ethylene2. acetic acid3. Polymerization4. Polyvinyl acetate5. Emulsion paintHigh-volume sector Low-volume sectorProduction scale tens to hundreds of thousandstons per year tens to a few thousands tonsper yearProducts / a plant single product multi-products Operation manner continuous batchPrice or profit fairly cheap very profitable Usage intermediates end-productsChallengesreduced demand,environment pollutionProducts in the sectorsulphuric acid,phosphorus-containingcompounds,nitrogen-containingcompounds,chlor-alkali,petrochemicals,commodity polymersagrochemicals,dyestuffs,pharmaceuticals,speciality polymersUnit 6 Chlor-Alkali and Related Processes1. Ammonia2. ammonia absorber3. NaCl & NH4OH4. Carbon dioxide5. NH4Cl6. Rotary drier7. Light Na2CO38. WaterProduct Raw materialMajor steps orPrincipal reactionsUsesSoda-ashbrine,limestoneammoniating,carbonating,precipitating,filtering,drying,calciningraw material forglassmaking,sodium silicate;as an alkaliChlorine brine 2Na+ + 2Cl - +2H2O →NaOH +Cl2 +H2as water purification, bleaching of wood pulp;production of vinyl chloride, solvents,inorganic chlorine-containingproductsCaustic soda brine 2Na+ + 2Cl - +2H2O →NaOH +Cl2 +H2for paper-making, manufacture of inorganicchemicals, syntheses of organicchemicals, production of aluminaand soapSulfuric acid elemental sulphurS +O2 → SO2SO2 + O2 → SO3SO3 + H2O → H2SO4feedstock for fertilizers;production of ethanol,hydrofluoric acid,aluminum sulphatesUnit 7 Ammonia, Nitric Acid and Urea1. kinetically inert2. some iron compounds3. exothermic4. conversion5. a reasonable speed6. lower pressures7. higher temperatures8. capital9. energy10. steam reforming11. carbon monoxide12. secondary reformer13. the shift reaction 14. methane15. 3:11787 C. Berthollet discovers the composition of ammonia 1903 Fritz Haber synthesizes ammonia1909 Fritz Haber drives the optimum reaction conditions 1909-1914 C. Bosch, A. Mittasch scale-up the process 1913 in BASF build a pilot plant1919 Fritz Haber receives the Noble price1920s in Britain and AmericaIntroduce the Haber process1931 C. Bosch receives the Noble priceUnit 8 Petroleum Processing1. organic chemicals2. H:C ratios3. high temperature carbonization4. crude tar5. pyrolysis6. poor selectivity7. consumption of hydrogen8. the pilot stage9. surface and underground10. fluidized bed11. Biotechnology12. sulfur speciesUnit 9 PolymersAbbreviation Name of polymerLDPE Low density polyethylene 低密度聚乙烯低密度聚乙烯HDPE High density polyethylene 高密度聚乙烯高密度聚乙烯LLDPE Linear low density polyethylene 线性低密度聚乙烯线性低密度聚乙烯PET or PBT Poly ethylene terephthalate (PET)Polybutylene terephthalate (PBT)聚对苯二甲酸乙二醇酯聚对苯二甲酸乙二醇酯聚对苯二甲酸丁二醇酯聚对苯二甲酸丁二醇酯PVC Poly vinyl chloride 聚氯乙烯聚氯乙烯PS Polystyrene 聚苯乙烯聚苯乙烯POM Polyoxymethylene 聚甲醛聚甲醛 PP Polypropylene 聚丙烯聚丙烯PC Polycarbonate 聚碳酸酯聚碳酸酯PPO Polyphenylene oxide 聚苯醚聚苯醚PTFE polytetrafluoroethylene 聚四氟乙烯聚四氟乙烯PF phenol-formaldehyde resins 酚醛树脂酚醛树脂 PMMA poly (methyl methacrylate) 聚甲基丙烯酸甲酯聚甲基丙烯酸甲酯 UF urea-formaldehyde resins 脲醛树脂脲醛树脂Name of polymer Company or Inventor Year introduced Phenol-formaldehyde resin Baekland 1909Urea-formaldehyde resin 1929Alkyd resin late 1920sPoly(styrene-butadiene) GermanyPoly (acrylonitrile-butadiene) GermanyPoly (vinyl chloride) GermanyPolystyrene Germanypolyethylene ICI 1938Nylon Du pont 1941Polyacrylonitrile Du pont 1948Terylene ICI 1949Epoxy resins Du pont 1955polypropylene Montecatini 1956LLDPE late 1970sUnit 10 What Is Chemical EngineeringMicroscale (≤10-3m)● Atomic and molecular studies of catalysts● Chemical processing in the manufacture of integrated circuits● Studies of the dynamics of suspensions and microstructured fluidsMesoscale (10-3－102m)● Improving the rate and capacity of separations equipment● Design of injection molding equipment to produce car bumpers madefrom polymers● Designing feedback control systems for bioreactorsMacroscale (>10m)● Operability analysis and control system synthesis for an entire chemicalplant● Mathematical modeling of transport and chemical reactions ofcombustion-generated air pollutants● Manipulating a petroleum reservoir during enhanced oil recoverythrough remote sensing of process data, development and use of dynamicmodels of underground interactions, and selective injection of chemicalsto improve efficiency of recoveryCourse Course contentScience and Math. Chemistry, Physics, Biology, Material Science, Mathematics,Computer InstructionChemical EngineeringThermodynamics, Kinetics, Catalysis, Rector Design and Analysis, Unit Operations, Process Control, Chemical Engineering Laboratories, Design / EconomicsOther Engineering Electrical Engineering, Mechanics, Engineering DrawingHumanities and SocialScience Understand t he origins of one’s own culture as well as that ofothersUnit 12 What Do We Mean by Transport Phenomena?1. density2. viscosity3. tube diameter4. Reynolds5. Eddies6. laminar flow7. turbulent flow 8. velocity fluctuations9. solid surface10. ideal fluids11. viscosity12. Prandtl13. fluid dynamicsUnit 13 Unit Operations in Chemical Engineering1. physical2. unit operations3. identical4. A. D. Little5. fluid flow6. membrane separation7. crystallization 8. filtration9. material balance10. equilibrium stage model11. Hydrocyclones12. Filtration13. Gravity14. VaccumUnit 14 Distillation Operations1. relative volatilities2. contacting trays3. reboiler4. an overhead condenser5. reflux6. plates7. packing8. stripping section 9. rectifying section10. energy-input requirement11. overall thermodynamic efficiency12. tray efficiencies13. Batch operation14. composition15. a rectifying batchSieve plate Bubble-capplatesValve plates Cost 1 3 2Capacity 3 1 2 Operating range 3 1 2 Efficiency same same SamePressure drop 1 3 21 <2 < 3Unit 15 Solvent Extraction, Leaching and Adsorption1. a liquid solvent2. solubilities3. leaching4. distillation5. extract6. raffinate7. countercurrent8. a fluid9. adsorbed phase10. 400,00011. original condition12. total pressure13. equivalent numbers 14. H+or OH–15. regenerant16. process flow rates17. deterioration of performance18. closely similar19. stationary phase20. mobile phase21. distribution coefficients22. selective membranes23. synthetic24. ambient temperature25. ultrafiltration26. reverse osmosis (RO).Unit 16 Evaporation, Crystallization and Drying1. concentrate solutions2. solids3. circulation4. viscosity5. heat sensitivity6. heat transfer surfaces7. the long tube8. multiple-effect evaporators9. vacuum10. condensers11. supersaturation12. circulation pump13. heat exchanger14. swirl breaker 15. circulating pipe16. Product17. non-condensable gas18. barometric condenserDryer type General features ApplicationTray dryers Batch operation,Close control of drying conditionsand product inventoryDrying valuable productsConveyor dryersContinuous circulation,High drying rates,Good product-quality,High thermal efficiencies,High initial and maintenance costDrying materials that form abed with an open structureRotary dryerContinuous operation,High throughput,High thermal efficiency,Low capital cost and labor costsNon-uniform residence time,Dust generation,High noise levelsDrying free-flow granularmaterialsFluidized bed dryersContinuous or batch operation,Rapid and uniform heat transfer,Short drying times,Good control of the dryingconditions,Low floor area requirements;High power requirementsDrying granular andcrystalline materialsPneumatic dryersShort contact times,Low thermal efficiencyDrying fine and heatsensitive materialsSpray dryersShort contact times,Good control of the productparticle size, bulk density andform,High heat requirementsDrying liquid and diluteslurry feeds as well as heatsensitive materialsRotary drum dryers An alternative choice to spraydryersDrying liquid and diluteslurry feedsUnit 17 Chemical Reaction Engineering1. design2. optimization3. control4. unit operations (UO)5. many disciplines6. kinetics7. thermodynamics,8. fluid mechanics9. microscopic10. chemical reactions11. more valuable products12. harmless products13. serves the needs14. the chemical reactors15. flowchart 16. necessarily17. tail18. each reaction19. temperature and concentrations20. linearUnit 18 Chemical Engineering Modeling1. optimization2. mathematical equations3. time4. experiments5. greater understanding6. empirical approach7. experimental design8. differing process condition9. control systems 10. feeding strategies11. training and education12. definition of problem13. mathematical model14. numerical methods15. tabulated or graphical16. experimental data17. information1. the preliminary economics2. technological changes3. pilot-plant data4. process alternatives5. trade-offs6. Off-design7. Feedstocks8. optimize9. plant operations10. energy11. bottlenecking12. yield and throughput13. Revamping14. new catalystProblem Unexpected results Possible causeWater as impurity Kill a catalyst, or modify theperformances of catalystSteam leakDetermination ofexplosive limits Explosions Narrower limits in small-scaleequipmentStorage of unstablematerials Explosions and firesLower heat removal rate incommercial unitsUnit 19 Introduction to Process Design1. a flowsheet2. control scheme3. process manuals4. profit5. sustainable industrial activities6. waste7. health8. safety9. a reactor10. tradeoffs11. optimizations12. hierarchyUnit 20 Materials Science and Chemical Engineering1. the producing species2. nutrient medium3. fermentation step4. biomass5. biomass separation6. drying agent7. product8. water9. biological purificationMaterials areas Research activitiesPolymer Probe the microscale dynamics of macromolecules Develop improved processes,Create new materialsPolymer Composites Microstructural reinforcementAdvanced Ceramics Produce specific micro structures Application researchCeramic Composites Engineering the chemical reactions relatedComposite LiquidsUnit 21 Chemical Industry and Environment1. Atmospheric chemistry2. stratospheric ozone depletion3. acid rain4. environmentally friendly products5. biodegradable6. harmful by-product7. efficiently8. power plant emissions 9. different plastics10. recycled or disposed11. acidic waste solutions12. organic components13. membrane technology14. biotechnology15. microorganismsFrontier Research activities or problems facedIn-site processingField tests; Uncertainties of the process, Adverse environment impactsProcess solidsImprove solids fracture processes,Research on the mechanics of pneumatic and slurry transport, Understand the chemical reaction processes,Equipment design and scale-upSeparation processResearch on:membrane separations, chemical selective separation agents, shape-selective porous solids,traditional separation methodsMaterialsFind construction materials, Develop new process-related materials, Develop less energy intensive materialsDesign and scale-up Complexity, Lack of basic data,。

Nickel electrolysis process at OutokumpuHarjavalta Metals Oy奥托昆普哈贾瓦尔塔金属公司镍电解工艺AbstractThis paper deals with the electrolysis of nickel from sulphate solution and its electrochemical principles. As an example, the nickel electrolysis process at Outokumpu Harjavalta Metals Oy is discussed in more detail. The leaching of nickel matte and the purification of the nickel sulphate solution prior to electrolysis is also discussed. In addition, a short review of other hydrometallurgical nickel matte treatment processes and nickel electrolysis technologies is given.摘要：本论文主要研究了硫酸镍溶液的电解过程及其电化学原理。

作为例子，本论文主要在细节方面讨论了奥托昆普哈贾瓦尔塔金属公司的镍电解过程。

同时也讨论了电解过程之前的镍浸出及净化过程。

除此之外，其它镍湿法冶金处理过程及电解技术也在文中涉及到。

Outokumpu has produced electrolytic nickel at Harjavaita works since 1960. Nickel is electrowon from a nickel sulphate solution using diaphragm cells where a diaphragm cloth is used to prevent the catholyte solution and the acidic anolyte frommixing. Nickel is deposited on thin nickel starter sheets and the anodes are of unalloyed lead. The current density is 200 A/m2 and the deposition time is seven days. The ready cathodes weigh about 65 kg and they are harvested, washed and cut into squares and strips and finally packed for delivery. Electrolytic nickel is supplied to the electroplating, melting and superalloying industry.早在1960年开始，奥托昆普便在哈贾瓦尔塔工厂开始生产电解镍。

小学上册英语自测题英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1._____ (花草) can brighten up any garden.2.She is a _____ (运动员) who plays soccer.3.What do we call the process of making something clean?A. OrganizingB. CleaningC. ArrangingD. TidyingB4. A __________ is known for its speed and grace.5.The chemical formula for sodium fluoride is ______.6.What is the process of a caterpillar turning into a butterfly called?A. MetamorphosisB. EvolutionC. TransformationD. DevelopmentA7.What is the currency used in the USA?A. EuroB. YenC. DollarD. PoundC Dollar8.The _____ (dog/cat) is barking.9. A ________ (河口) is where a river meets the ocean.10.The Earth's layers contain various ______ materials.11.The sunflowers turn toward the _______ during the day.12.What do fish live in?A. TreesB. OceansC. DesertsD. Mountains13.What is the name of the famous mountain in Nepal?A. K2B. KilimanjaroC. Mount EverestD. DenaliC14.tides) are influenced by the moon's gravity. The ____15.The ____ has a long beak and is very curious.16.What is the name of the longest river in the world?A. AmazonB. NileC. YangtzeD. MississippiB17.What is the name of the famous ancient city in Mexico?A. Machu PicchuB. TeotihuacanC. Chichen ItzaD. TulumC18.What do we call the process of converting food into energy?A. DigestionB. MetabolismC. AbsorptionD. Respiration19.The soup is _____ (hot/cold) today.20.The ____ has stripes and is known for its strength.21.What do we call the act of helping others?A. AssistanceB. SupportC. AidD. HelpingC22.Rust is formed when iron reacts with ______.23.My _____ (表姐) loves to draw pictures of animals. 我表姐喜欢画动物的图画。

HJ 中华人民共和国环境保护行业标准国家环境保护总局发布目次前 言 (II)1 适用范围 (1)2 术语和定义 (1)3 原理 (1)4 试剂 (1)5 仪器设备 (2)6 样品的保存和处理 (3)7 浸出步骤 (3)8 质量保证 (4)9 标准实施 (5)附录A（参考性附录） 零顶空提取器（ZHE）示意图 (6)前言为贯彻《中华人民共和国环境保护法》和《中华人民共和国固体废物污染环境防治法》，加强危险废物的污染防治，保护环境，保障人体健康，制定本标准。

本标准规定了固体废物的浸出毒性浸出程序及其质量保证措施。

本标准为指导性标准。

本标准由国家环境保护总局科技标准司提出。

本标准起草单位：中国环境科学研究院固体废物污染控制技术研究所。

本标准国家环境保护总局2007年04月13日批准。

本标准自2007年5月1日起实施。

本标准由国家环境保护总局解释。

II固体废物浸出毒性浸出方法硫酸硝酸法1 适用范围本标准规定了固体废物浸出毒性的浸出程序及其质量保证措施。

本标准适用于固体废物及其再利用产物、以及土壤样品中有机物和无机物的浸出毒性鉴别。

含有非水溶性液体的样品，不适用于本标准。

2 术语和定义下列术语和定义适用于本标准。

2.1 浸出 leaching可溶性的组分溶解后，从固相进入液相的过程。

2.2 浸出毒性leaching toxicity固体废物遇水浸沥，浸出的有害物质迁移转化，污染环境，这种危害特性称为浸出毒性。

2.3 初始液相 initial liquid phase明显存在液固两相的样品，在浸出步骤之前进行过滤所得到的液体。

3 原理本方法以硝酸/硫酸混合溶液为浸提剂，模拟废物在不规范填埋处置、堆存、或经无害化处理后废物的土地利用时，其中的有害组分在酸性降水的影响下，从废物中浸出而进入环境的过程。

4 试剂4.1 试剂水：使用符合待测物分析方法标准中所要求的纯水。

4.2 浓硫酸：优级纯。

4.3 浓硝酸：优级纯。

红土镍矿湿法处理现状及研究龙艳【摘要】文章总结了红土镍矿湿法处理现状,即还原焙烧-氨浸法和加压酸浸法.介绍了几种新的红土镍矿湿法处理工艺,包括常压硫酸浸出法、盐酸浸出法、生物浸出法、碱融脱硅法等.碱融脱硅法有利于资源综合利用,硫酸堆浸技术将会有更大的发展空间.【期刊名称】《湖南有色金属》【年(卷),期】2009(025)006【总页数】5页(P24-27,64)【关键词】红土镍矿;湿法处理;现状;研究【作者】龙艳【作者单位】中南大学冶金科学与工程学院,湖南,长沙,410083【正文语种】中文【中图分类】TF803.2镍具有熔点高、耐腐蚀、强磁性等特点，是军事、航天航空、钢铁行业重要的功能材料。

目前，镍主要用于生产不锈钢、高镍合金以及电镀和铸造。

世界陆基镍矿床主要分为两类：一类是硫化镍矿，约占世界镍资源总量的28%；另一类是红土镍矿，约占世界镍储量的72%。

由于镍在红土镍矿中以固溶体存在，难以通过普通的选矿工艺得到显著富集，与处理硫化矿相比存在工艺复杂、物料处理量大、成本较高的问题，因此目前仅 40%的镍产量来自于红土镍矿。

随着硫化镍矿的逐渐消耗以及镍需求的不断增长，开发利用红土镍矿资源显得日益必要［1～3］。

截至 2007年底，我国镍矿资源储量为 839万 t。

其中，红土镍矿约占总量的 10%［4］。

红土镍矿是由含铁镁硅酸盐矿物（如橄榄石、辉石、角闪石）的超镁铁质岩经长期风化变质形成的。

在长期风化过程中，通过抬升和侵蚀作用，风化层的成分发生变化。

上层是褐铁矿类型，主要由铁的氧化物组成，中间为过渡层，下层是硅镁镍矿层［5］。

三种红土镍矿的成分及适宜采用的处理工艺列于表1。

1.1 还原焙烧－氨浸（RRAL）［6，7］还原焙烧－氨浸法的实质是先将矿石干燥脱除一部分自由水，再经回转窑或竖炉进行还原焙烧，最后进行多段常压氨浸。

古巴的尼加罗厂于 1943年首次将还原焙烧－氨浸法用于工业生产。

其主要工艺流程如图 1所示。

A s p e n_P l u s推荐使用的物性计算方法-CAL-FENGHAI.-(YICAI)-Company One1做模拟的时候物性方法的选择是十分关键的，选择的十分正确关系着运行后的结果。

是一个难点，高难点，而此内容与化工热力学关系十分紧密。

首先要明白什么是物性方法比如我们做一个很简单的化工过程计算，一股100C,1atm的水-乙醇(1:1的摩尔比，1kmol/h）的物料经过一个换热器后冷却到了80C,,问如分别下值是多少1.入口物料的密度，汽相分率。

2.换热器的负荷。

3.出口物料的汽相分率，汽相密度，液相密，还可以问物料的粘度，逸度，活度，熵等等。

以上的值怎么计算出来好，我们来假设进出口的物料全是理想气体，完全符合理想气体的行为，则其密度可以使用PV=nRT计算出来。

并且汽相分率全为1，即该物料是完全气体。

由于理想气体的焓与压力无关，则换热器的负荷可以根据水和乙醇的定压热熔计算出来。

在此例当中，描述理想气体行为的若干方程，比如涉及至少如下2个方程：=nRT，=CpdT. 这就是一种物性方法（aspen plus中称为ideal property method)。

简单的说，物性方法就是计算物流物理性质的一套方程，一种物性方法包含了若干的物理化学计算公式。

当然这例子选这种物性方法显然运行结果是错误的，举这个例子主要是让大家对物性方法有个概念。

对于水-乙醇体系在此两种温度压力下，如果当作理想气体来处理，其误差是比较大的，尤其对于液相。

按照理想气体处理的话，冷却后仍然为气体，不应当有液相出现。

那么应该如何计算呢想要准确的计算这一过程需要很多复杂的方程，而这些方程如果需要我们用户去一个个选择出来，则是一件相当麻烦的工作，并且很容易出错。

好在模拟软件已经帮我做了这一步，这就是物性方法。

对于本例，我们对汽相用了状态方程，srk,液相用了活度系数方程(nrtl,wilson,等等），在aspen plus中将此种方法叫做活度系数法。

含稀土磷精矿湿法制磷酸过程稀土的浸出规律梅吟;张泽强;张文胜;吴启海;吴健;池汝安【摘要】为查明二水法制磷酸过程稀土的走向规律,以贵州织金含稀土磷精矿为研究对象,在实验室模拟二水物湿法磷酸生产过程,研究了不同工艺条件下稀土的浸出规律.研究结果表明,在温度75 ℃,酸过量系数1.25,液固比41,反应时间4 h的条件下,稀土的浸出率最高为53.45%.当浸出率综合考虑磷和稀土的浸出率时,最佳的工艺条件为:温度75 ℃,酸过量系数1.25,液固比31,反应时间4 h的条件下,含稀土磷精矿中P2O5的浸出率为96.85%,稀土的浸出率为52.26%.%The production of (NH4)2SO4 from phosphogypsum and (NH4)2CO3 has been investigated.The factors affecting the conversion of phosphogypsum to (NH4)2SO4, such as (NH4)2CO3 to phosphogypsum ratio, reaction temperature, reaction time, stripping speed and liquid to solid ratio were studied. The optimum reaction conditions obtained at (NH4)2CO3 to phosphogypsum ratio 1.15,50℃, reaction time 120 min, stripping speed 150 r/min and liquid to solid ration 5: 1. The maximum conversion of phosphogypsum to (NH4)2SO4 obtained under these conditions was 98. 68％. A new crystallization method of (NH4)2SO4 was proposed, and the main factors affecting crystallization rate such as crystallization temperature and concentration of sulfate ion have been investigated. Results indicated that temperature and concentration of sulfate ion have obvious effects on crystallization rate of (NH4)2SO4. Suitable temperature was 25 ℃, and the higher the concentration of sulfate ion, the higher the crystallization rate of (NH4)2 SO4.【期刊名称】《武汉工程大学学报》【年(卷),期】2011(033)003【总页数】4页(P9-11,15)【关键词】含稀土磷精矿;稀土的浸出规律;浸出率【作者】梅吟;张泽强;张文胜;吴启海;吴健;池汝安【作者单位】武汉工程大学环境与城市建设学院,湖北,武汉,430074;武汉工程大学环境与城市建设学院,湖北,武汉,430074;贵州锦麟化工有限责任公司,贵州,贵阳,550005;贵州锦麟化工有限责任公司,贵州,贵阳,550005;贵州锦麟化工有限责任公司,贵州,贵阳,550005;武汉工程大学环境与城市建设学院,湖北,武汉,430074【正文语种】中文【中图分类】TD983;TD9540 引言自然界中部分磷矿床,尤其是氟磷灰石矿床伴生大量稀土[1-2].由于稀土离子与钙离子性质很相近,稀土主要以类质同象方式赋存于磷酸盐矿物中,因此分选富集磷矿时,稀土也富集到磷精矿中,具有很大的回收价值[3-4].磷矿主要用于制磷酸,从中提取伴生稀土,也在制酸过程中进行.其工艺方法可分为热法和湿法两类.因为热法存在成本高和能耗大等问题,有实用意义的还是在湿法磷酸生产过程中提取稀土[5].其中用硫酸分解磷矿的二水法工艺由于技术成熟、工艺简单、操作稳定,在湿法磷酸工艺中居主导地位,因此研究二水法制磷酸过程稀土的走向规律,对从中有效回收稀土具有一定的指导意义.1 试验磷精矿物质组成本实验研究对象为贵州织金含稀土磷精矿,表1为该磷精矿多元素化学分析结果,其中稀土钇、铈、镧和镨在稀土总量中的含量较高,分别占稀土总量的29.25%、23.77%、16.17%、12.19%;其次是钕、钆、钐和镝,含量分别占稀土总量的8.58%、2.36%、2.11%和1.32%;其它稀土元素的含量相对较低,分配率在1%以下.2 实验部分2.1 试验方法取磷精矿试验样品30 g,在不同条件下用硫酸分解磷精矿浸出磷和稀土,然后过滤固液分离,分析得到的浸出液及浸出渣中稀土及磷的走向,考查不同分解条件对磷精矿中磷和稀土浸出率的影响.表1 磷精矿多元素化学分析结果Table 1 Multielement chemical analysis of phosphate concentrates成分P2O5REOCaOSiO2MgOw/%33.560.1651.164.700.82成分Al2O3Fe2O3F酸不溶物烧失w/%0.881.144.065.754.822.2 分析方法P2O5的分析方法:磷钼酸铵容量法.方法原理:在硝酸溶液中,磷酸根与钼酸铵和柠檬酸反应生成磷钼酸铵黄色沉淀,过滤后,将沉淀溶解于碱标准溶液中,然后用盐酸标准溶液返滴过量的碱,即可求出P2O5含量.操作方法:称取P2O5 0.1 g,加80 mL沉淀剂加热搅拌至沸腾,然后冷却,将沉淀剂转移到漏斗中,用硝酸钾和蒸馏水轮流洗剂数次使滤液呈中性为止;将沉淀和脱脂棉移入原烧杯中,从滴定管中加入NaOH的浓度为0.25 mol/dm3的标准溶液,边加边搅拌,使沉淀完全溶解变成原来白色为止,然后加入酚酞呈紫色,再用浓度为0.1mol/dm3盐酸标准溶液滴至沉淀从紫色变为白色为终点.稀土的分析方法:稀土矿石化学分析方法.操作方法:称0.20 g左右样品于刚玉坩埚中,加入一定量的Na2O2,搅匀,再覆盖一层,置于已升温的高温炉中,熔融片刻,取下稍冷,置于加有100 mL水的烧杯中,在电炉上加热至微沸取下,用稀盐酸洗出坩埚,加水稀至200 mL,搅匀,澄清后过滤,用1% NaOH洗烧杯和沉淀7～8次,水洗1～2次,滤液弃去,用盐酸分次溶解沉淀于容量瓶中,定容到刻度.上机测量.测试仪器:全镨直读等离子体发射光谱仪,型号:Optima 4300DV;美国PerKinElmer 公司;主要技术指标:波长范围:165～782 nm;分辨率:<0.006 nm;重复性:优于1%;工作气体:冷却气(15 L/min)、雾化气(0.8 L/min).美国PerkinElmer公司的Optima 4300DV全谱直读型ICP-AES(双向观察).3 实验结果与分析3.1 硫酸用量对磷和稀土浸出率的影响硫酸分解磷精矿实际上是沉淀磷精矿中所有钙的反应过程.硫酸的理论用量可以根据磷精矿中的CaO的含量计算.计算出每1 kg磷精矿所需硫酸的理论用量QS为:以此理论硫酸用量做为参考,进行不同用量硫酸分解磷精矿的试验,得到浸出磷及浸出稀土总量的试验结果列于图1.试验过程固定条件为:液固比3∶1,浸出温度75 ℃,浸出时间4 h,洗涤水用量180 mL.图1 硫酸用量对稀土及磷浸出率影响试验结果Fig.1 The test results of dosage of sulfuric acid impact on sulphuric acid leaching rates of Re2O3 and P2O5 从图1可以看出,硫酸用量在1.25 kg/kg矿时,稀土的浸出率是最好的,浸出率为52.26%,而同时硫酸用量在1.46 kg/kg矿时,磷的浸出率最好为97.53%.由于硫酸用量在1.25 kg/kg矿时,磷的浸出率仍有96.85%.硫酸用量过小,磷和稀土的浸出率都较低;硫酸用量过大,矿浆粘度增大,对磷和稀土的浸出也不利,而且会造成硫酸的浪费.因此,浸出率综合考虑磷和稀土的浸出率,每1 kg磷精矿所需硫酸用量以1.25 kg为佳.3.2 液固比对磷和稀土浸出率的影响在确定硫酸用量的基础上,考查了液固比对磷和稀土浸出率的影响,得到浸出磷及稀土的试验结果列于图2.试验过程固定条件为:硫酸用量1.25 kg,浸出温度75 ℃,浸出时间4 h,洗涤水用量180 mL.图2 液固比对稀土及磷浸出率影响试验结果Fig.2 The test results of liquid-to-solid ratio impact on sulphuric acid leaching rates of Re2O3 and P2O5从图2可以看出,当液固比为4∶1时,稀土的浸出率最好,可达到53.45%,而磷的浸出率只有94.79%.而当液固比为3∶1时,稀土的浸出率为52.26%,相比53.45%下降不明显,而磷的浸出率可达到96.85%.当液固比过大或过小时,磷的浸出率都比3∶1效果要差,而稀土的浸出率相当,因此该试验应选用液固比3∶1的反应条件.3.3 浸出温度对磷和稀土浸出率的影响在确定硫酸用量的基础上,考查了浸出温度对磷和稀土浸出率的影响,所得试验结果见图3,试验过程固定条件为:硫酸用量1.25 kg,液固比3∶1,浸出时间4 h,洗涤水用量180 mL.图3 浸出温度对稀土及磷浸出率影响试验结果Fig.3 The test results of leaching temperature impact on sulphuric acid leaching rates of Re2O3 and P2O5 从图3可以看出,在反应温度为75 ℃时,稀土的浸出率最好,可达52.26%,磷的浸出率也可达96.85%,而在反应温度为90 ℃时磷的浸出率为97.58%,稍稍高于96.85%,但相差不明显,而稀土的浸出率仅45.51%.因此,在反应温度为75 ℃时,磷和稀土的浸出率相对来说是最高的,固反应温度应选择在75 ℃.3.4 浸出时间对磷和稀土浸出率的影响控制硫酸用量1.25 kg,液固比3∶1,浸出温度75 ℃,洗涤水用量180 mL,考查了浸出时间对磷和稀土浸出率的影响,试验结果见图4.图4 浸出时间对稀土及磷浸出率影响试验结果Fig.4 The test results of leaching time impact on sulphuric acid leaching rates of Re2O3 and P2O5由图4可以看出,当浸出时间为4 h时,磷和稀土的浸出率相对来说是最高的,分别为96.85%和52.26%,因此选择浸出反应时间应为4 h.综上所述,在二水物法萃取磷酸的最优浸出工艺条件即温度75 ℃,酸过量系数1.25,液固比4∶1,反应时间4 h的条件下,稀土的浸出率最好,但最优浸出率仅为53.45%,这说明大部分稀土元素损失在石膏中,对于该难题还需进一步研究.4 结语a. 采用贵州织金含稀土的磷精矿,在实验室研究了硫酸用量、液固比和浸出温度等不同工艺条件下稀土的浸出规律,由不同工艺条件下稀土浸出进入磷酸溶液和留磷石膏的规律可知:在温度75 ℃,酸过量系数1.25,液固比4∶1,反应时间4 h的条件下,稀土的浸出率最好,可达到53.45%.b. 当浸出率综合考虑磷和稀土的浸出率时,最佳的工艺条件为:温度75 ℃,酸过量系数1.25,液固比3∶1,反应时间4 h的条件下,含稀土磷精矿中P2O5的浸出率为96.85%,稀土的浸出率为52.26%.即可看出稀土的浸出规律与磷的浸出规律基本一致.参考文献:[1]Jorjani E, Bagherieh A H, Mesroghli Sh, et al. Prediction ofyttrium,lanthanum,cerium,and neodymium leaching recovery from apatite concentrate using artificial neural networks[J].Journal of University of Science and Technology Beijing,2008,15(4):367-374.[2]Preston J S, Cole P M, Craig W M, et al. The recovery of rare earth oxidesfrom a phosphoric acid by-product. Part 1 Leaching of rare earth values and recovery of a mixed rare earth oxide by solventextraction[J].Hydrometallurgy,1996,41:1-19.[3]Awadallah R M,Soltan M E,El Taher,et al.Concentration of lanthanide and actinides present in Sibaiya phosphate ores[J].Modelling, Measurement & Control,C: Energetics,Chemistry & ChemicalEngineering,Earth,Resources,Environment,BiomedicalProblems,2002,63(1):1-20.[4]施春华,胡瑞忠,王国芝.贵州织金磷矿岩稀土元素地球化学特征研究[J].矿物岩石,2004,24(4):71-75.[5]龙志奇,王良士,黄小卫,等.磷矿中微量稀土提取技术研究进展[J].稀有金属,2009,33(3):434-441.Abstract: In order to ascertain the distribution of rare earths in production of phosphate by dihydrate process, the main participants of this study is Zhijin phosphate concentrates bearing rare earths in Guizhou Province. The production process of dihydrate wet-process phosphoric acid in the laboratory is stimulated and the leaching rules of rare earth are investigated under different conditions. The test results show that when the leachin g temperature is 75 ℃, the excess coefficient of sulfuric acidis 1.25, liquid to solid ratio 3∶1, time consumption is 4 hours, the highest leaching rates of Re2O3 is 53.45%. Under the optimum conditions the leaching temperature is 75 ℃, the excess coeffici ent of sulfuric acid 1.25, liquid-to-solid ratio 3∶1 and time consumption 4 hours. The leaching rates of P2O5 and Re2O3 are 96.85% and 52.26%, respectively.Key words: phosphate concentrates bearing rare earths; leaching rule of rare earth; leaching rates。

Smelting processes2.1. Outokumpu flash smeltingIn most cases, smelting furnaces accommodate both roasting and smelting operations in one unit although some traditional units such as reverberatory furnaces require prior roasting of the concentrate feed by means of fluid bed roasters or multiple hearth Herreshoff roasters. The two basic and widely applied smelting processes include flash smelting and bath smelting. Flash smelting employs oxygenated air to promote autogenous conditions while bath smelting is dependent upon the roasting and smelting steps occurring within amolten pool containing both matte and slag phases. The smelting furnace produces a high grade matte with Cu/Fe sulphides for further treatment plus a high iron slag formed with silica addition. Waste slags can be cleaned in electric furnaces to recover entrained metal values before being discarded. It is noteworthy that Outokumpu Oyj sold its first flash-smelting licence to the Furukawa Co. Ltd. at Ashio, Japan in 1956 after installing two units at its Harjavalta smelter in Finland during 1949 for the copper and nickel smelting circuits. The technology is employed at its Kokkola sulphur plant for smelting of pyrites. A progress review during the past 50 years was provided by Koho et al. (2000).Outokumpu conquered the smelting furnace market on several continents and thereby demonstrated the benefits of its proprietary technology for sustainable development in areas of economics and ecology. The well known process utilizes dry concentrates which are introduced by means of a burner into the top of a vertical reaction shaft in conjunction with appropriate fluxes and heated air. The heavy molten particles fall into the molten bath at the furnace bottom while the hot gases rise. The matte phase separates from the slag within the molten pool and is then transferred to a converter. There sulting high matte grade allows less blowing time in the downstream converters. The molten slag is treated by means of one of several proven decopperising techniques as adopted in each facility. Although the Outokumpu process is essentially autogenous, supplement aryheating is required in the settler. The well established process features advantages such as a high throughput rate and energy efficiency. Low energy requirements provide benefits of deceased fuel consumption in context with utilization of tonnage oxygen. An Outokumpu system requires about two thirds of the energy for smelting green batches as compared to traditional reverberatory furnaces and generates up to 30%SO2 in furnace exhaust gases which are suitable for acidmanufacture. The overall energy consumption of primary production processes such as Outokumpu, Inco, and Mitsubishi ranges from 23 to 25 GJ/tonne of copper for the process consisting of concentrate drying, smelting and converting, fire refining, electrolytic refining and capture of SO2 as sulphuric acid (Rentz et al., 1999).A review of the patents indicates that Outokumpu has installed 40 furnace systems. Outokumpu’s applications at Kennecott Utah, WMC’s Olympic Dam and the DON Process (Direct Outokumpu Nickel) were outlined by Hanniala et al. (1999) in conjunction with future scenarios. Kennecott is the only company that has purchased two Outokumpu flash furnace units for copper smelting and converting (Hanniala et al., 1998;George et al., 1995; George, 1994). Gas flow and wasteheat boilers design were addressed for the Outokumpu flash smelting process (Yang et al., 1998, 1999). Boliden’sR€onnsk€ar smelter in Sweden, expanded its capacity from 130 to 230k tpa of copper cathodes. The $245Mfacilities were commissioned in September1999. TheR€onnsk€ar smelter in Skelleftehamn included an Outokumpu flash furnace for its Cu/Pb operations (Phelps,2001; Isaksson and Lehner, 2000). MMC Norilsk Nickel employs Outokumpu flash furnaces at its Nadezhdasmelter in Siberia, the Russian Federation. The People’sRepublic of China (PRC) has flash furnace units inservice which are not of Finnish design. The only two Outokumpu flash furnaces located in China (Zeping,1998), were installed by the Jiangxi Copper Corporationand Jinlong Copper Co. Ltd. during 1985 and 1997 respectively(Kang and Park, 1997). Umicore acquired theState owned MDK copper smelter, which has a 1987vintage Outokumpu flash furnace, in Pirdop, Bulgaria, in September 1997. The Bulgarian plant was ramped up to 210,000 tpa of anode copper by mid 2002 while address ingenvironmental concerns. The Głog_ow II plantin Poland (KGHM Polska Mied_z S.A.) installed an Outokumpu flash furnace during 1978 for direct conversion to blister but does not include matte granulationor a two stage smelting system as at Kennecott. Outokumpu is involved in the expansion of the Sarcheshmehsmelter in Iran. The project involves aKhatoon-Abad flash smelting plant to increase out put from 120 to 280k tpa within two years. Today, it is perceived that Outokumpu installations account for 35–50% of installed smelting capacity world wide. The Olympic Dam copper deposit in South Australiawas discovered by WesternMining Corporation in 1975.The metallurgical plant produces refined copper, uranium,gold and silver. Olympic Dam (WMC Ltd.) inAustralia installed an Outokumpu flash furnace called#1 Smelter during 1988 for direct production of blisterbut also initially employed an Ausmelt system for thispurpose (E&Mj, 1999). The Ausmelt furnace consistedof a 1 tph pilot unit which was first used to evaluateslags produced from treating copper concentrates tofacilitate leaching of the contained uranium. The unitwas used to produce copper matte and convert withinthe same furnace in early development preceding installationof the Outokumpu unit. The Ausmelt unit wasdecommissioned (Matusewicz, 2003). The Olympic Damoperations located at Roxby Downs mothballed theoriginal furnace. On January 20, 1999 it commissionedanother Outokumpu flash furnace (#2 Smelter) whichconsists of adirect-to-blister system (97–98% Cu) withoutany matte production to smelt 380,000 tpa of concentratecontaining about 50% copper. The directto-blister process incorporates a flash smelting furnace,an electric smelting furnace and two anode furnaces. Adescription of the first 10 years of flash furnace operationand initial impressions of the replacement unit wereoutlined by Hunt et al. (1999). WMC’s copper productioncommenced in 1988 and amounted to 200,523tonnes in 2001 mainly comprised of electrorefined copperbased on MIM technology and electrowon copperwhich represents about 10% of the production. Thecompany produced 113,412 oz. gold, 912,859 oz. silver,and about 4500 metric tonnes of uranium during thesame period. Although the optimization project to increasecapacity was completed in 2002, copper productionwas affected by the rebuild of the solvent extractionplant. Copper output in 2003 is estimated to be 185,000tonnes due to a major furnace rebuild during the latterhalf of the year. Production is targeted to reach WMC’sfull capacity of 235,000 tpa of copper cathode in 2004.WMC’s 2002 annual report indicated that its Kwinananickel refinery produceda record 65,065 tonnes of nickel(WMC, 2003).2.2. Noranda reactor systemThe Noranda bath smelting process is energy efficientand employs a refractory-linedcylindrical vessel to smelta broad range of copper-bearing materials such as sulphideconcentrates, inerts, scrap, and recycled substances.The flexible smelting process is suited toprocessing a wide range of recycled materials, complexconcentrates, and secondary feed such as industrialwaste, electronic scrap, and metal-bearing residues.Suitable fluxes, fossil fuel, and feedstock are injectedinto one end of the reactor via a high-speed belt (slinger)while oxygen-enriched air is forced into the liquid meltby means of submerged tuyeres (NORSMELT, 2003).Additional process heat may be provided by supplementaryfuel consisting of oil, natural gas, coal, or coke.Wet coal may be added with the solid charge without thenecessity of pulverising or sizing the carbonaceous material.Despite variations in feed composition and supply,the controlled conditions enable collection of a highSO2 concentration in furnace off-gases which are suitablefor the manufacture of metallurgical grade sulphuricacid. Advantages of the Noranda process are (i) ano frills feed system without expensive blending and/ordrying equipment (ii) usage of common siliceous fluxes(iii) elimination of expensivewater-cooling which lowersrunning and capital costs (iv) improved campaignlengths between relines thereby permitting lower refractoryconsumption than some competing smeltingmethods. The process features a higher recovery ofcopper and associated precious metals than competitivesystems which is enhanced by the stirred slag and capability of maintaining a low silica slag and avoidance898 R.R. Moskalyk, A.M. Alfantazi / Minerals Engineering 16 (2003) 893–919of magnetite build-up. The similarity in shape andconstruction to a Peirce–Smith (P –S) converter results inimproved fabrication and repair techniques. The productiveunits range in capacity from 1000 to 3500 tonnesper day of concentrate. A comparison was made betweenthe Noranda reactor (NR) and Teniente Converter(CT) (Harris, 1999). Although the NR and CT arecompeting technologies, it appears that the Norandasystem has a slight edge over the Chilean approach. It isrecognized that the CT continues to evolve as improvementsare added over the long-term. Similarly, theNR augments its performance upon introduction oftechniques with each successive installation. Figs. 1 and2 depict an isometric view of a NORSMELT system anda cross section of the cylindrical vessel respectively. TheAltonorte copper smelter in Chile was retrofitted with aNoranda reactor system during the year 2001. Thesmelter, rated at 130,000 tpa and located near the port city of Antofagasta, is 100% wholly owned by NorandaInc. The giant vessel shell weighing about 500 tonneswas 27.4 m long by 5.5 m in diameter was unloaded inone piece at the harbour. Noranda permanently closedits 40 year old Gasp_e copper smelter at Murdochville,Quebec (JOM, 2002). It is the labour union’s contentionthat Noranda is considering permanent closure of itsstrike-affected Horne smelter since within three years themajority of mines in the area will become depleted.Workers have been without a contract since February2002. Possible synergy of the copper assets betweenNoranda and Falconbridge within Ontario and Quebecis regarded as a factor (Bloomsbury Minerals Economics,2003). It is worth noting that Noranda Inc. owns58.4% of the common shares of Falconbridge Limitedwhich is a worldwide producer of copper, nickel, cobalt,and precious metals. Falconbridge’s refined copperoutput increased by 22% to 263,140 tonnes in 2002partly due to diversion of raw material from the Hornesmelter affected by a long strike.Noranda Inc. invested over $16-million on environmentalimprovements completedin late 2002 to reducesulphur dioxide (SO2) by 90% from the current level of80% and particulate emissions at its Horne coppersmelter in RouynNoranda, Quebec. Initial NR operationwas described by Pr_evost et al. (1999). The Hornesmelter was the site of the original Noranda reactorcommissioned during March 1973 which was upgradedduring the late 1990s. The original furnace design capacityof 1200 tonnes per day has increased significantlyto an average of 2800 tpd. at the present day. Availabilityof tonnage oxygen for enrichment has facilitateda peak daily throughput of 3600 tonnes of concentratewhich represents a factor of three times the initial designcriteria. During June 1999 a Noranda reactor systemwas commissioned at Southern Copper Ltd. (formerlyER&S), NSW, Australia, to process 413,000 tpa of wetconcentrate at the former Port Kembla Copper facility.The SCL system was designed to treat concentrates,scrap, residues, and reverts. The custom design involvedfitting the rotary vessel within an existing plant andscaling down capacity to about half the normal capacity.Consequently, some novel solutions were required torefurbish an existing smelter. The furnace unit interfacedwith an electric furnace for slag cleaning and an acidplant for sulphur dioxide fixation (Innis et al., 1992).The oxygenated air injected through 27 tuyeres maintainsturbulent bath conditions. Slag is skimmed at the opposite end to feed entry while molten matte is tappedin the reactor’s side. After smelting, the 70% copper matte phase and low-silica slag separate by gravity in thequiesent zone of the continuous reactor. A water-cooledhood directs furnace off-gases to an evaporative coolingtower followed by an electrostatic precipitator (ESP).Collected dust is recycled to the reactor while thecleaned off-gases are treated in a contact acid plant.H.G. Engineering (HGE), based in Canada, providedthe technical design input to faciliate implementation.Southern Copper (parent company CRA Ltd.) wasprovided with the reactor design, training, and technicalassistance by means of the engineering and licensingagreements. Furukawa Co. Ltd (Japan) is planning to boost the capacity of its 52.5% owned Southern CopperLtd. smelter to increase copper cathode production to140,000 tpa by 2003 or 2004.Although the identification of leading edge technologiesfor copper continuous smelting and converting isa difficult choice, the leading universal contender appearsto be the Noranda reactor system (Mackey et al., 1995).The expansion plans of Chinese copper smelters seriouslyconsidered the Noranda reactor system which alreadyhas penetrated the Asian technological market formodernization of some plants in situ (Levac et al., 1995).A Noranda reactor system was commissioned in October1997 at the Daye Non-Ferrous Metals Co. smelterlocated in the province of Hubei near the Yangtze Riverin China. The 1500 tpd unit was described in a paper byYe Weidan which was presented at a conference in China. Additional company details are available inseveral publications which address the copper communityin China and the entire mineral industry within thePRC (Pui-Kwan, 2003; CCDC, 2003). The Daye smeltercommenced operations in 1960. The Noranda processreplaced a traditional reverberatory furnace and improvedenvironmental conditions in the surrounding countryside to meet government regulations. The modificationsdoubled annual copper production and tripled the amount of sulphuric acid recovered by fixation of waste gases. In the past only converter gas was treatedand large amounts of SO2 escaped to atmosphere andcontributed to crop damage. The 4.7 m by 18 m reactorwas designed by HGE in Canada. The plant uses its fourexisting P–S converters. The gas treatment systemadopted for theChinese smelter differs from the Horne,PQ, smelter in areas such as inclusion of a gas sealinghood, a waste heat boiler, and high efficiency ESP unit.It was rumoured that the 140,000 tpa Daye operationmay close indefinitely until it can secure adequate feed(CRU, 2003). Although the Southern Per_u CopperCompany (SPCC) initially considered a Kennecott systemfor its Ilo smelter, industry obervers indicate that astrong likelihood exists that SPCC will adopt Norandatechnology. At present, the Peruvian copper operationsrun their existing Teniente converter in a Norandamode. It is worth noting that Grupo Mexico owns54.2% of SPCC through its Asarco subsidiary. It wasreported that ZCCM in Zambia will switch their Tenientevessel in the state-owned Nkana smelter to aNoranda mode later in 2003 (Harris, 2003). ZambiaConsolidated Copper Mines Ltd. (ZCCM) also operatesa copper smelter at Mulfulira.2.3. Mitsubishi continuous smelting and convertingThe Mitsubishi system is deemed a bath smeltingprocess which combines roasting, smelting and convertingin a continuous operation enabled by three furnaceunits interconnected via heated and coveredlaunders. The first commercial facility was commissionedin 1974 at Naoshima, Japan, with an annualcapacity of 70,000 tonnes (Iida et al., 1997). The Mitsubishiprocess includes a smelting furnace (S-furnace)consisting of: (i) the charging of dried concentrates andfluxes (ii) air and oxygen lances plus and (iii) burners.This is followed by the slag cleaning furnace (CL-furnace)which features a slag overflow and matte syphon900 directing the molten impure copper to the convertingfurnace (C-furnace). The concentrates mixed with fluxesand other raw materials are rapidly melted as they areinjected through the top blowing lances with oxygenenriched air into the S-furnace. The 65% Cu matte gradeis next treated in the C-furnace to produce blister copperwhile the slag fraction is directed to the CL-furnace. Anelectric furnace is normally employed for slag cleaningby the addition of coke and pyrite to decopperize thewaste slag. The continuous converting furnace producesblister copper by oxidising the matte and uses limestoneto create a slag phase which is recycled for cleaning. The off-gases contain about 15–20% SO2 which is used forthe production of sulphuric acid (Newmand et al.,1992). Falconbridge Ltd. installed a Mitsubishi systemat its Kidd Creek facility, Canada, in 1981 to increaseplant capacity. Although the energy consumption issimilar to Outokumpu’s process, the initial capital investmentand manpower costs are apparently lower. Adescription of control methodology was provided byGoto et al. (1998). An interesting situation exists at LGMetals Corporation’s (LGMC) copper operations. TheOnsan smelter was brought online in 1979 with an Outokumpuflash smelting furnace and three P–S converters(Lee et al., 1999). Capital expansion at the Onsanworks reached full production in November 1998 afterimplementation of a Mitsubishi continuous process (Japan) coupled with construction of a new refinerybased on the KIDD Process (Canada). LGMC’s capacitywas increased from 200,0000–360,000 tonnes peryear expressed as full plate cathode.The world’s most modern copper smelter employs theMitsubishi Continuous Process (60.5% owned by MitsubishiMaterials). P.T. Smelting’s plant at Gresik, Indonesia,which was built on a greenfield site begancommercial production in May 1999 (Phelps, 2000). Thesmall and compact facility employs a Hazelett twin beltcontinuous slab caster to produce copper anodes. The45 mm anode thickness is achieved by continuouslycasting a copper strip with integral lug at 100 tph. Ahydraulic shear cutsthe strip into individual anodeswhich are then water cooled and stacked into 15 batch lots for the refinery. The continuously cast anodes aresuperior to static cast anodes (e.g., wheel systems) due totheir flatness and uniformity of weight and dimensions. The refinery has a design capacity of 200,000 metrictonnes of LME Grade ‘‘A’’ cathodes per year via theISA Process (i.e. permanent stainless steel cathodeblanks) at a current density of 280 A/m2. The continuousoperation enabled state-of-the-art environmental control, worker health and safety, plus high energy andmetallurgical efficiency. The plant feedstock consists ofcopper concentrates from the Grasberg mine while afertilizer plant is situated adjacent to the smelter to consume the sulphuric acid by-product. A description ofthe smelter and refinery operations was provided by Ajima et al. (1999). At Gresik, the circular and refractorylined S-furnace is about 10 m inside diameter. Thecircular C-furnace is 9 m in diameter and fitted with 10lances which direct a limestone coolant via oxygenatedair into the molten bath. Blister copper is continuouslysiphoned out of the converting furnace and directed toeither of two circular anode furnaces to facilitate refiningand casting operations. The off-gases from thesmelting and converting stages are passed through awaste heat boiler for initial cooling to about 700 _C inthe radiation section then cooled to 350 _C in a convectionsection. Process steam is produced in the wasteheat boilers. The cooled gas is next directed to electrostaticprecipitators for removal of entrained dust thenducted to an acid recovery plant of 592,000 tpa capacity.As a point of information the world’s most modern zincsmelter and refinery (2001) is the Asturiana de Zincoperation located at San Juan de Nieva in Spain with anameplate capacity of 460k metric tpa of zinc. The facilitiesat the Xstrata AG subsidiary include roasting,sulphuric acid leaching, a tankhouse, melting and castingunits.2.4. El Teniente converterThe Caletones or El Teniente (CT) modified converter,which primarily is used for autogenous bathsmelting, is longer than the P–S converter and includestwo separated mouths for charging and off-gas evacuation,lateral tap holes for molten slag and white metal(Torres, 1998; Alvarado et al., 1995, 1998). The continuoussmelting and converting process involves pneumaticinjection of the concentrate through tuyeres intothe reactor’s molten bath (Gonz_alez and Vargas, 1995).Copper concentrate is dried to a 0.2% moisture levelprior to tuyere injection into the molten bath of theTeniente reactor. The exothermic reaction caused byoxygenated air with iron sulphides in the green charge allows smelting without external heat application.Availability of technical oxygen has enhanced CT operations.An important feature of the Teniente unit is itsability to process both wet and dried concentrates.Concentrates with residual H2O content require the coadditionof seed matte as produced in a standard reverbfurnace (Rentz et al., 1999). The resultant high-gradematte typically contains 74–76% Cu, plus a slag containing 4–6% Cu and 16–18% magnetite (Fe3O4). Thewhite metal is converted to blister in a traditional P–Sconverter. CT off-gases contain an average of 25–35%SO2 at the reactor mouth while air inleakage createsdilution in the flue exhaust system. The dirty slags containing 6–8% copper require additional treatment ina batch slag cleaning furnace to recover metal valuesbefore discarding the material to a dump site. Finaldiscard slags contain less than 0.85% copper. On aglobal basis, slag is either discarded in its moltenstate at dumps or water granulated then pumped to an impoundment area. The CT exhaust gases are cooled,treated in conventional dust cleaning equipment then directed to an acid plant. Advantages of CT units arelow capital investment, low operating costs, and lowenergy consumption (Morales and Mac-Kay, 1999).Apart from South American applications, the Tenienteunit is employed at the Rayong smelter in Thailand.The units are mainly employed within the Chileancopper smelters (Campos et al., 1998). It is noteworthythat Chile’s 11 smelters include seven major coppersmelters (three owned by Codelco, one by Disputada,two by Enami, one by Noranda) and each smelter employsa different strategy for slag cleaning (Demetrioet al., 2000). The current operating capacity of theCaletones smelter owned by Codelo-Chile approaches1,250,000 tonnes per year of copper concentrate (mainly chalcopyrite) which translates into a daily throughput of3650 tpd. The Caletones smelter consists of one reverb,two CT units, three slag cleaning furnaces, two anodefurnaces and three refining furnaces. The smelter upgradingin 2002 facilitated a CT processing rate of 2400tpd (Alvarado and Godoy, 1999). Disputada (Compa~niaDisputada de las Condes) owns two mines and theChagres copper smelter 95 km north of Santiago, Chile.The US-based oil producer Exxon Mobil Corporation isconsidering the sale of its wholly owned Chilean subsidiaryDisputada. One variation of the Caletones typeis the Inspiration converter which also has two mouths,the larger opening for off-gas venting and the smallermouth for charging purposes. This design, that is employedin Arizona, features excellent hooding in alloperating positions. Oxygen is employed in the Tenienteconverters in Chile (Schwarze et al., 1995). A Teniente unit was commissioned in 1994 at ZCCM’s Nkana 1931vintage smelter in Zambia to supplement oxy–fuel reverboperation (Beene et al., 1999). The present annualsmelting rate of 740,000 tonnes of concentrate generates240,000 tpa anode copper. The CT unit reduced operatingand energy costs whilst providing a steady streamof concentrated SO2 suitable for acid manufacture. Althoughthe CT units were first developed in the 1970s, animprovement in their performance has been an ongoingactivity. A paper by Morales and Mac-Kay (1999)provided an insight into present practice and proposalsfor future upgrading. In October 2000, Outokumpu andCodelco agreed to collaborate in implementing Outokumputechnology for the direct production of blister copper from a mixture of concentrate and white metal(high-grade copper matte) in its El Teniente converters. The existing Outokumpu flash furnace at Chuquicamata will be modified to produce blister copper thereby replacingthe present P–S converters. Start-up is scheduledfor 2004 at an annual rate of 750k metric tpa coppermetal which will be the largest production worldwidefrom a single vessel (E&Mj, 2002).2.5. Inco’s bulk concentrate flash furnace Two flash furnace units of Inco in-house design wereimplemented in 1993 as part of the $625-million (Cdn.)smelter modernization program. The mandate of theSO2 Abatement Program (acronym of SOAP) was toreduce sulphur dioxide stack emissions from 685 to 265 kilotonnes per annum at the Copper Cliff smelter complexin Ontario, Canada. Inco was the first company inthe non-ferrous industry to utilize technical oxygen in itsearlier flash furnace unit which treated copper and highnickel pyrrhotite concentrates as feed material. Sinceinception in 1952, Inco has acquired 40 years of experiencein the operation of flash furnaces. Apart from theOntario application and a few in North America (e.g.,Hayden, AZ and Chino, NM) this design apparently hasnot found any application inEurope. Salient designfeatures include a symmetrical furnace with a pair ofconcentrate burners at each end plus a central uptake.One large advantage of the Inco design is an off-gascomposition containing 75–80% SO2 by volume. TheInco design for handlingoff-gases includes a waterquench and cleaning stage. Treated rich SO2 furnacegases are directed to an acid plant with a daily capacityof 2900 tons of sulphuric acid, oleum, and liquid sulphurdioxide products. The significant tonnage of by-productsfrom SO2 fixation are handled by the Marsulexorganization. Inco’s flash furnace employs extensive usage of water cooling. The earlier experience with watercooled jackets was employed to maximize water coolingthereby extending refractory life and hence the campaign period between major repairs and furnace relines.A water cooled transition piece (1 m) was installed betweenthe furnace uptake and the quench chamber. Thefurnace uses water cooled copper plates, copper fingersand ports. The copper plate coolers were installed in thesidewall end panels to reduce potential damage from thenatural gas burners. Copper finger cooler tips were installedin the sidewalls by means of interlocking a novel tongue and grove arrangement with the basic refractory.Additional details regarding water cooling and otherrelevant design features are found in papers by Carret al. (1997) and Queneau and Marcuson (1996). Thedata included in the Inco installation was provided as anexample in order for the reader to place details in context.Although the Vanyukov process (Russian equities,mining, and metals report, 1997) is similar to Inco indesign the differences are described below (Bystrov andKomkov, 1995; Strishkov, 1984).2.6. Vanyukov smelting systemThe Vanyukov bath smelting furnaces for annuallyprocessing over two million tonnes of copper, Cu/Ni,Cu/Zn, and antimony sulphide have been in use formany years in a large number of enterprises within the Russian Federation and Kazakhstan. The process was commercialized in 1977 and used at five locations withinthe CIS in the 1990s (Rentz et al., 1999). The uniquesystem is used at facilities such as Norilsk Nickel’splants located at the JSC Norilsk Kombinat in northernSiberia and AO ‘‘GMK Pechenganikel’’ in the Kolapeninsula near Finland. The Nadezhda Cu/Ni smelter inSiberia employs a Vanyukov unit in its operations.Tarasov will present a paper at the Copper 2003–Cobre2003 conference which outlines the characteristics ofcopper losses in slag with a Vanyukov unit at the NorilskNickel Combine operations. The furnace consists ofa two step process involving two furnace baths to accommodatethe smelting. Several papers regarding theVanyukov process are published in Russian by TsvetnyeMetally (Non-ferrous Metals Journal) and Academia(e.g., Izvestia Vuzov). Feed material is injected by meansof tuyeres into the molten upper slag layer which isabout 1.5 m thick. The difference in this operation is thatthe gaseous oxidising medium is injected directly intothe foaming upper slag layer rather than into the mattelayer as employed within other systems. The turbulentagitation caused by the continuous addition of feedstockmixed with oxygen and carbonaceous fuel creates rapidinteraction and exothermic conditions. The heaviermatte phase settles into the lower molten layer. Bothmolten matte and slag are continuously removed fromthe furnace (Bystrov, 2003). To date, technology transferto western countries has been very sparse. It waspredicted that the Vanyukov’s attributes of high productivitycoupled with efficiency and flexibility eventuallymay compete with the Outokumpu system in thenext decade to process in excess of 5000 tonnes daily(Demetrio et al., 1999). The Gintsvetmet。