DOCSLIB.ORG

Design and Prototype Development of a Mini-Electric Arc Furnace –12–

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Design and Prototype Development of a Mini-Electric Arc Furnace –12– Design and Prototype Development of a Mini-Electric Arc Furnace F.A. Oyawale, Ph.D.1 and D.O. Olawale, M.Sc.2 1 Department of Industrial and Prod. Engineering, University of Ibadan, Nigeria 2 Department of Mechanical Engineering, The Polytechnic, Ibadan, Nigeria 1E-mail: [email protected] ABSTRACT Although information relating to the design and Electric arc furnaces (EAF) have the capabilities fabrication of an electric arc furnace of such a required for furnaces used for metallurgical small size as that fabricated through this research. An electric arc furnace was designed research, was not readily available in literature, and constructed to melt approximately 5kg of the available information relating to the giant steel/cast iron scraps, using locally produced sized electric arc furnaces were used as a guide Soderberg electrodes. Tests carried out showed in the design of this prototype. that it required about 60 minutes to heat up the furnace to the melting temperature of cast iron (1150C – 1400C). It took about 95 minutes to DESIGN THEORY AND CALCULATIONS melt the first charge of 2kg resulting in a melting rate of 21.05g/minute. The average electrode An electric arc furnace should have a powerful consumption rate was 0.0467cm/minute. A transformer, high thermal and electrical transformer efficiency of about 83% was also efficiency, and a lining made of high-grade achieved. refractory [Edneral, 1979]. (Keywords: electric arc furnace, melting rate, Shape and dimensions of the bath electrode consumption rate, transformer efficiency) The bath is usually conical-spherical with the 0 INTRODUCTION banks inclined at an angle of 45 . This form ensures quick melting. One tonne of molten 3 In an EAF, electric arcs are used to provide heat steel occupies 0.145m . The mass ratio of slag for melting and for smelting. The few EAFs in for acid-lined furnaces may be taken equal to the study country (Nigeria) are located in the 0.03 – 0.04. [Edneral, 1979]. integrated steel plant, the Delta Steel Company, and other large industrial plants. They are so The diameter-to-depth ratio of the bath operating complicated in design and so expensive that by the basic process is usually taken as: even national universities cannot afford to buy prototypes for experimental purposes. D = 5H (1) EAFs have numerous advantages required in where D = bath diameter, and H = total depth of furnaces for metallurgical research. Such the bath. features include close temperature and heat In existing furnaces, the height (h1), of the control, accurate analysis of melt, definite metal 1 refining sequence, high thermal efficiency (as spherical portion is roughly /5 of the total bath high as 70%), and production of steel directly depth: from pig iron and steel scrap. h1 = 0.2H (2) The objective of this research work is to design and develop an electric arc furnace for melting and the depth of the conical portion: steel/cast iron scraps using locally available materials. h2 = 0.8H (3) The Pacific Journal of Science and Technology –12– http://www.akamaiuniversity.us/PJST.htm Volume 8. Number 1. May 2007 (Spring) The total volume of the bath, Vb, is the sum of D1= Drc + S (11) the volumes of the truncated cone and that of the spherical segment. By virtue of the The thickness of the lining is found by thermal relationships given above: analysis from the condition that the furnace shell 0 should not be heated above 200 C at the end of 3 3 Vb = 0.0968 D (m ) (4) the furnace campaign. With the refractory lining δ mm thick, the furnace will have the following inside diameter of the shell: Dimensions of the reaction chamber Di.sh = Drc + 2 δ (12) The banks of a furnace are usually made 100 to 200 mm above the door sill level or the bath The steel shell varies in thickness and may 1 surface, to ensure that the slag does not contact range from /4 inch (6mm) thick for small 1 the brickwork or reach the joint between the wall furnaces and up to 1 /4 in (32 mm) thick on 80 to blocks and banks. The diameter of the reaction 100 ton furnaces [Robiette, 1972]. chamber is: Transformer power and furnace productivity Drc = D + 200 (mm) (5) Table 1 contains some recommendations on It is recommended that the following relationship transformer power for furnaces of different size, be used in determining the height of the reaction which are based on experiences in many chamber (H1) [Edneral, 1979]: countries. H1= (0.04 - 0.6) Drc (6) By analogy with the existing furnaces (using Table 1), the transformer power may be taken as the lower value relating to large-capacity Pap (MVA). Noting the inevitable switching off of furnaces. the furnace during melting required to push the scrap from the banks, partial operation of the The camber of the roof (h3 ) is: furnace at a reduced voltage when the arcs are open and radiation of much heat onto the walls h3 = 0.15Dr (7) and roof, the average power consumed during the melting period can be found by using a factor where Dr is roughly taken 1000 mm wider than of 0.8 – 0.9: Drc. Pav = 0.8 Pap (KVA) (13) Dr= Drc + 1000 h3= 0.15 (Drc + 1000 ) (8) Useful power consumed during the melting period (power consumed for the melting proper) The total height of the roof above the bath level is represented as: is given as: Pu = Pav cos φηel (KW) (14) H2 = H1 + h3 (9) Voltage taps The recommended slope (S) for the inclination of the wall is roughly 10% of the height from the The upper voltage tap of the secondary voltage line of banks to roof skewbacks: for small furnaces can be selected by using the following empirical formulae [Edneral, 1979]: H −100 For basic furnaces S = 1 (10) 10 3 = 15 PV AP (15) The diameter of the reaction chamber at the level of the roof skewbacks (i.e. at the level of For acid furnaces: the upper edge of the furnace shell) is: 3 V += 1570 PAP (16) The Pacific Journal of Science and Technology –13– http://www.akamaiuniversity.us/PJST.htm Volume 8. Number 1. May 2007 (Spring) Table 1: Recommended Transformer Power for Furnaces of Different Sizes. Furnace Capacity (t) Transformer Power (MVA) for 25 50 75 100 150 200 250 400 Making Various Steels (i) Alloy steels 5-18 20-25 - 30-35 - 55-70 - - (ii) Carbon steels 18-22 28-32 30-45 40-50 45-60 60-80 90 120 Transformer power of super - 40 - 60 - 125 - 200 powerful furnaces of the future (Source: Electrometallurgy and Ferro-alloys, 1979) Electrode diameter where, m = mass to be melted (kg), The diameter of electrodes can be found by the c = specific heat capacity of metal to be melted formula: (KJ/Kg0C), 0 406.0 I 2δ θ2 = melting point of the metal ( C), 3 (cm) (17) d = 0 K θ1 = room temperature ( C), and Where I = linear current, (A) L = latent heat of fusion of the metal 3 Pap10 I = , MATERIAL AND METHODS V 3 max The electric arc furnace comprises two Soderbeg self baking electrodes (Afolabi, 2004); δ = electrode resistivity at 5000C (for graphitized an electrode support and sliding mechanism; a electrodes δ = 10 ohm. Mm2/m), and tiltable crucible lined with refractory silica brick in which melting takes place; the roof also lined K = coefficient (for graphitized electrodes K = 2.1 with silica brick, which is removable for charging W/cm2). and for pouring; and the support frame which carries the other parts. The crucible and roof The diameter of electrodes can also be found by were constructed using 4mm thick mild steel the allowable current density (A/cm2). sheet. The furnace is shown schematically in Figure 1 and pictorially in Figure 2. Electrode spacing The recommended ratio of the electrode spacing The furnace is supplied at 50Hz using a tapped diameter to the bath diameter is 0.45 for small power transformer with a high current furnaces, 0.35 for medium sized and large secondary, the connections between the furnaces, and still lower for super powerful transformer and the electrodes is a length of furnaces (Edneral, 1979). flexible cable which allows the electrodes to be moved vertically and also for the complete roof Energy distribution assembly to be lifted and moved horizontally. The energy required for melting of metal scrap is Melting is achieved by the heat generated by the electric arc drawn between the electrodes tips and the scrap metals. The transformer is oil Q = mc(θ2- θ1) + mL (18) cooled. The Pacific Journal of Science and Technology –14– http://www.akamaiuniversity.us/PJST.htm Volume 8. Number 1. May 2007 (Spring) Table 2: Test Data. (cm) (kg) Test Electrode Electrode Time of Consumption Consumption Mass of charge Mass of charge Operation (min) 1 2 1 2 102 1.0 3.0 2 2 89 1.0 3.0 3 2 94 1.0 3.0 4 3 128 2.0 4.0 5 3 130 2.0 4.0 6 3 123 2.0 4.0 Figure 1: Schematic of the Electric Arc Furnace. Vp= 220V, Vo= 62V, Ip= 30.5A, Io= 90A Soderberg Table 2: Average Melting Rate and Electrode electrodes Consumption. Melting Chamber η rate, (cm/min.) consumption (cm) Mass of charge (Kg) Average total electrode Melting temperature (C) Transformer efficiency, Average melting rate (g/min) Electrode Consumption ratio Average time of melting (min.) Oil-Cooled Average electrode consumption Transformer 1150- 2 95 4.0 1:3 21.05 0.042 83 1400 1150- 3 127 6.0 1;2 23.62 0.047 83 Figure 1: Prototype Electric Arc Furnace.
Load more

Recommended publications
  • Wear Behavior of Austempered and Quenched and Tempered Gray Cast Irons Under Similar Hardness
    metals Article Wear Behavior of Austempered and Quenched and Tempered Gray Cast Irons under Similar Hardness 1,2 2 2 2, , Bingxu Wang , Xue Han , Gary C. Barber and Yuming Pan * y 1 Faculty of Mechanical Engineering and Automation, Zhejiang Sci-Tech University, Hangzhou 310018, China; [email protected] 2 Automotive Tribology Center, Department of Mechanical Engineering, School of Engineering and Computer Science, Oakland University, Rochester, MI 48309, USA; [email protected] (X.H.); [email protected] (G.C.B.) * Correspondence: [email protected] Current address: 201 N. Squirrel Rd Apt 1204, Auburn Hills, MI 48326, USA. y Received: 14 November 2019; Accepted: 4 December 2019; Published: 8 December 2019 Abstract: In this research, an austempering heat treatment was applied on gray cast iron using various austempering temperatures ranging from 232 ◦C to 371 ◦C and holding times ranging from 1 min to 120 min. The microstructure and hardness were examined using optical microscopy and a Rockwell hardness tester. Rotational ball-on-disk sliding wear tests were carried out to investigate the wear behavior of austempered gray cast iron samples and to compare with conventional quenched and tempered gray cast iron samples under equivalent hardness. For the austempered samples, it was found that acicular ferrite and carbon saturated austenite were formed in the matrix. The ferritic platelets became coarse when increasing the austempering temperature or extending the holding time. Hardness decreased due to a decreasing amount of martensite in the matrix. In wear tests, austempered gray cast iron samples showed slightly higher wear resistance than quenched and tempered samples under similar hardness while using the austempering temperatures of 232 ◦C, 260 ◦C, 288 ◦C, and 316 ◦C and distinctly better wear resistance while using the austempering temperatures of 343 ◦C and 371 ◦C.
    [Show full text]
  • Society, Materials, and the Environment: the Case of Steel
    metals Review Society, Materials, and the Environment: The Case of Steel Jean-Pierre Birat IF Steelman, Moselle, 57280 Semécourt, France; [email protected]; Tel.: +333-8751-1117 Received: 1 February 2020; Accepted: 25 February 2020; Published: 2 March 2020 Abstract: This paper reviews the relationship between the production of steel and the environment as it stands today. It deals with raw material issues (availability, scarcity), energy resources, and generation of by-products, i.e., the circular economy, the anthropogenic iron mine, and the energy transition. The paper also deals with emissions to air (dust, Particulate Matter, heavy metals, Persistant Organics Pollutants), water, and soil, i.e., with toxicity, ecotoxicity, epidemiology, and health issues, but also greenhouse gas emissions, i.e., climate change. The loss of biodiversity is also mentioned. All these topics are analyzed with historical hindsight and the present understanding of their physics and chemistry is discussed, stressing areas where knowledge is still lacking. In the face of all these issues, technological solutions were sought to alleviate their effects: many areas are presently satisfactorily handled (the circular economy—a historical’ practice in the case of steel, energy conservation, air/water/soil emissions) and in line with present environmental regulations; on the other hand, there are important hanging issues, such as the generation of mine tailings (and tailings dam failures), the emissions of greenhouse gases (the steel industry plans to become carbon-neutral by 2050, at least in the EU), and the emission of fine PM, which WHO correlates with premature deaths. Moreover, present regulatory levels of emissions will necessarily become much stricter.
    [Show full text]
  • Higher-Quality Electric-Arc Furnace Steel
    ACADEMIC PULSE Higher-Quality Electric-Arc Furnace Steel teelmakers have traditionally viewed Research Continues to Improve the electric arc furnaces (EAFs) as unsuitable Quality of Steel for producing steel with the highest- Even with continued improvements to the Squality surface finish because the process design of steelmaking processes, the steelmaking uses recycled steel instead of fresh iron. With over research community has focused their attention 100 years of processing improvements, however, on the fundamental materials used in steelmaking EAFs have become an efficient and reliable in order to improve the quality of steel. In my lab steelmaking alternative to integrated steelmaking. In at Carnegie Mellon University, we have several fact, steel produced in a modern-day EAF is often research projects that deal with controlling the DR. P. BILLCHRIS MAYER PISTORIUS indistinguishable from what is produced with the impurity concentration and chemical quality of POSCOManaging Professor Editorof Materials integrated blast-furnace/oxygen-steelmaking route. steel produced in EAFs. Science412-306-4350 and Engineering [email protected] Mellon University Improvements in design, coupled with research For example, we recently used mathematical developments in metallurgy, mean high-quality steel modeling to explore ways to control produced quickly and energy-efficiently. phosphorus. Careful regulation of temperature, slag and stirring are needed to produce low- Not Your (Great-) Grandparent’s EAF phosphorus steel. We analyzed data from Especially since the mid-1990s, there have been operating furnaces and found that, in many significant improvements in the design of EAFs, cases, the phosphorus removal reaction could which allow for better-functioning burners and a proceed further.
    [Show full text]
  • ITP Metal Casting: Advanced Melting Technologies
    Advanced Melting Technologies: Energy Saving Concepts and Opportunities for the Metal Casting Industry November 2005 BCS, Incorporated 5550 Sterrett Place, Suite 306 Columbia, MD 21044 www.bcs-hq.com Advanced Melting Technologies: Energy Saving Concepts and Opportunities for the Metal Casting Industry Prepared for ITP Metal Casting by BCS, Incorporated November 2005 Acknowledgments This study was a collaborative effort by a team of researchers from University of Missouri–Rolla, Case Western Reserve University, and Carnegie Mellon University with BCS, Incorporated as the project coordinator and lead. The research findings for the nonferrous casting industry were contributed by Dr. Jack Wallace and Dr. David Schwam, while the ferrous melting technologies were addressed by Dr. Kent Peaslee and Dr. Richard Fruehan. BCS, Incorporated researched independently to provide an overview of the melting process and the U.S. metal casting industry. The final report was prepared by Robert D. Naranjo, Ji-Yea Kwon, Rajita Majumdar, and William T. Choate of BCS, Incorporated. We also gratefully acknowledge the support of the U.S. Department of Energy and Cast Metal Coalition (CMC) in conducting this study. Disclaimer This report was prepared as an account of work sponsored by an Agency of the United States Government. Neither the United States Government nor any Agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any Agency thereof.
    [Show full text]
  • Utilising Forest Biomass in Iron and Steel Production
    LICENTIATE T H E SIS Department of Engineering Sciences and Mathematics Division of Energy Science Nwachukwu Chinedu Maureen ISSN 1402-1757 Utilising forest biomass in iron ISBN 978-91-7790-761-9 (print) ISBN 978-91-7790-762-6 (pdf) and steel production Luleå University of Technology 2021 Investigating supply chain and competition aspects Utilising forest biomass in iron and steel production biomass in iron Utilising forest Chinedu Maureen Nwachukwu Energy Engineering 135067 LTU_Nwachukwu.indd Alla sidor 2021-03-12 08:10 Utilising forest biomass in iron and steel production Investigating supply chain and competition aspects Chinedu Maureen Nwachukwu Licentiate Thesis Division of Energy Science Department of Engineering Sciences and Mathematics Lulea University of Technology April 2021 Copyright © 2021 Chinedu Maureen Nwachukwu. Printed by Luleå University of Technology, Graphic Production 2021 ISSN 1402-1757 ISBN 978-91-7790-761-9 (print) ISBN 978-91-7790-762-6 (pdf) Luleå 2021 www.ltu.se ii For my family past, present, and future iii iv Preface The research work presented in this thesis was carried out at the Division of Energy Science, Luleå University of Technology, Sweden, during the period 2017 - 2020. The studies were carried out under the BioMetInd project, partly financed by the Swedish Energy Agency and Bio4Energy, a strategic research environment appointed by the Swedish government. The thesis provides an overview of forest biomass utilisation in the Swedish iron and steel industry from a supply chain perspective. Results also highlight the biomass competition between the iron and steel industry and the forest industry and stationary energy sectors. Findings from the studies are detailed in the three appended papers.
    [Show full text]
  • Effect of Melting Process and Aluminium Content on the Microstructure and Mechanical Properties of Fe–Al Alloys
    ISIJ International, Vol. 50 (2010), No. 10, pp. 1483–1487 Effect of Melting Process and Aluminium Content on the Microstructure and Mechanical Properties of Fe–Al Alloys Shivkumar KHAPLE, R. G. BALIGIDAD, M. SANKAR and V. V. Satya PRASAD Defence Metallurgical Research Laboratory, Kanchanbagh, Hyderabad, 500058 India. E-mail: [email protected] (Received on January 4, 2010; accepted on July 1, 2010) This paper presents the effect of air induction melting with flux cover (AIMFC) versus vacuum induction melting (VIM) on the recovery of alloying element, reduction of impurities, workability and mechanical prop- erties of Fe–(7–16mass%)Al alloys. Three Fe–Al alloy ingots containing 7, 9 and 16 mass% Al were prepared by both AIMFC and VIM. All these ingots were hot-forged and hot-rolled at 1 373 K and were further charac- terized with respect to chemical composition, microstructure and mechanical properties. The recovery of aluminium as well as reduction of oxygen during both AIMFC and VIM is excellent. AIMFC ingots exhibit low level of sulphur and high concentration of hydrogen as compared to VIM ingots. VIM ingots of all the three alloys were successfully hot worked. However, AIMFC ingots of only those Fe–Al alloys containing lower concentration of aluminium could be hot worked. The tensile properties of hot-rolled Fe–7mass%Al alloy produced by AIMFC and VIM are comparable. The present study clearly demonstrates that it is feasible to produce sound ingots of low carbon Fe–7mass%Al alloy by AIMFC process with properties comparable to the alloy produced by VIM. KEY WORDS: air inducting melting with flux cover; vacuum induction melting; Fe–Al alloy; microstructure; mechanical properties.
    [Show full text]
  • BAT Guide for Electric Arc Furnace Iron & Steel Installations
    Eşleştirme Projesi TR 08 IB EN 03 IPPC – Entegre Kirlilik Önleme ve Kontrol T.C. Çevre ve Şehircilik Bakanlığı BAT Guide for electric arc furnace iron & steel installations Project TR-2008-IB-EN-03 Mission no: 2.1.4.c.3 Prepared by: Jesús Ángel Ocio Hipólito Bilbao José Luis Gayo Nikolás García Cesar Seoánez Iron & Steel Producers Association Serhat Karadayı (Asil Çelik Sanayi ve Ticaret A.Ş.) Muzaffer Demir Mehmet Yayla Yavuz Yücekutlu Dinçer Karadavut Betül Keskin Çatal Zerrin Leblebici Ece Tok Şaziye Savaş Özlem Gülay Önder Gürpınar October 2012 1 Eşleştirme Projesi TR 08 IB EN 03 IPPC – Entegre Kirlilik Önleme ve Kontrol T.C. Çevre ve Şehircilik Bakanlığı Contents 0 FOREWORD ............................................................................................................................ 12 1 INTRODUCTION. ..................................................................................................................... 14 1.1 IMPLEMENTATION OF THE DIRECTIVE ON INDUSTRIAL EMISSIONS IN THE SECTOR OF STEEL PRODUCTION IN ELECTRIC ARC FURNACE ................................................................................. 14 1.2 OVERVIEW OF THE SITUATION OF THE SECTOR IN TURKEY ...................................................... 14 1.2.1 Current Situation ............................................................................................................ 14 1.2.2 Iron and Steel Production Processes............................................................................... 17 1.2.3 The Role Of Steel Sector in
    [Show full text]
  • Primary Mill Fabrication
    Metals Fabrication—Understanding the Basics Copyright © 2013 ASM International® F.C. Campbell, editor All rights reserved www.asminternational.org CHAPTER 1 Primary Mill Fabrication A GENERAL DIAGRAM for the production of steel from raw materials to finished mill products is shown in Fig. 1. Steel production starts with the reduction of ore in a blast furnace into pig iron. Because pig iron is rather impure and contains carbon in the range of 3 to 4.5 wt%, it must be further refined in either a basic oxygen or an electric arc furnace to produce steel that usually has a carbon content of less than 1 wt%. After the pig iron has been reduced to steel, it is cast into ingots or continuously cast into slabs. Cast steels are then hot worked to improve homogeneity, refine the as-cast microstructure, and fabricate desired product shapes. After initial hot rolling operations, semifinished products are worked by hot rolling, cold rolling, forging, extruding, or drawing. Some steels are used in the hot rolled condition, while others are heat treated to obtain specific properties. However, the great majority of plain carbon steel prod- ucts are low-carbon (<0.30 wt% C) steels that are used in the annealed condition. Medium-carbon (0.30 to 0.60 wt% C) and high-carbon (0.60 to 1.00 wt% C) steels are often quenched and tempered to provide higher strengths and hardness. Ironmaking The first step in making steel from iron ore is to make iron by chemically reducing the ore (iron oxide) with carbon, in the form of coke, according to the general equation: Fe2O3 + 3CO Æ 2Fe + 3CO2 (Eq 1) The ironmaking reaction takes place in a blast furnace, shown schemati- cally in Fig.
    [Show full text]
  • AISI | Electric Arc Furnace Steelmaking
    http://www.steel.org/AM/Template.cfm?Section=Articles3&TEMPLATE=/CM/HTMLDisplay.cfm&CONTENTID=12308 Home Steelworks Home Electric Arc Furnace Steelmaking By Jeremy A. T. Jones, Nupro Corporation SIGN UP to receive AISI's FREE e-news! Read the latest. Email: Name: Join Courtesy of Mannesmann Demag Corp. FURNACE OPERATIONS The electric arc furnace operates as a batch melting process producing batches of molten steel known "heats". The electric arc furnace operating cycle is called the tap-to-tap cycle and is made up of the following operations: Furnace charging Melting Refining De-slagging Tapping Furnace turn-around Modern operations aim for a tap-to-tap time of less than 60 minutes. Some twin shell furnace operations are achieving tap-to-tap times of 35 to 40 minutes. 10/3/2008 9:36 AM http://www.steel.org/AM/Template.cfm?Section=Articles3&TEMPLATE=/CM/HTMLDisplay.cfm&CONTENTID=12308 Furnace Charging The first step in the production of any heat is to select the grade of steel to be made. Usually a schedule is developed prior to each production shift. Thus the melter will know in advance the schedule for his shift. The scrap yard operator will prepare buckets of scrap according to the needs of the melter. Preparation of the charge bucket is an important operation, not only to ensure proper melt-in chemistry but also to ensure good melting conditions. The scrap must be layered in the bucket according to size and density to promote the rapid formation of a liquid pool of steel in the hearth while providing protection for the sidewalls and roof from electric arc radiation.
    [Show full text]
  • Understanding the Benefits of Electric Arc Furnace Technology
    Industry Focus #mullite #alumina #silica #refractories #furnaces Understanding the Benefits of Electric Arc Furnace Technology Minerals processed via electric arc furnace technology provide optimal purity, porosity and crystal size to meet the increasingly stringent needs of a range of industries. hether a finishing process uses sandpaper or a grinding wheel, pres- sure blasting or thermal spraying, abrasive and ceramic grains and powders play an integral role in the appearance and performance of thousands of products that are used every day all over the world. WThese minerals, which are also used to produce ceramic parts and kiln furniture, through various size reduction and among other refractory products, undergo a meticulous production process in order powder processing steps to achieve the to meet the increasingly stringent requirements of various end-use applications. A material’s desired finished properties. vital aspect of that process is the electric arc furnace, which helps ensure the miner- Virtually any oxide material can be als’ optimal purity, porosity, and crystal size. processed in an electric arc furnace. Because the materials are melted and The Fusion Process actually reach the liquid state, the end Simply put, an electric arc furnace is a vessel that uses electricity to melt miner- result is a near-perfect fusion. Let’s take als or other materials. The process begins when the dry minerals are weighed and a look at mullite as an example. To pro- mixed together, then evenly distributed throughout the furnace via feed chutes. duce mullite, alumina and silica are put Power is supplied to the furnace by a transformer and graphite electrodes.
    [Show full text]
  • Historic Lighthouse Preservation: IRON WPTC Photo Figure 1
    Historic Lighthouse Preservation: IRON WPTC photo Figure 1. Cast-iron-and-steel skeletal 191-foot-tall tower at Cape Charles, Virginia Second to masonry, iron was the most Iron was also used for the production of common lighthouse construction material. architectural trim features such as gallery For lighthouse construction, iron was used deck brackets, entryway pilasters and in a variety of its commercially pediments, doors, and prefabricated lantern manufactured alloys: wrought iron, cast components. These iron features were used iron, steel, galvanized iron and steel, and on masonry and wood as well as iron stainless steel. In historic lighthouses the lighthouses. Other iron alloys such as steel, most widely used alloy was cast iron. The galvanized iron and steel, and stainless steel use of cast iron in lighthouse construction are mostly found in modern additions such ranged from simple prefabricated lanterns as handrails, equipment brackets, security to caisson-style foundations to 190-foot-tall doors, etc. first-order coastal towers. For more on the This section will discuss the preservation of variety of iron lighthouse construction types iron alloys used in lighthouse tower refer to Part II., History of the Lighthouse construction and decoration. Because of Service and Lighthouse Construction their similar properties, the various iron Types. alloys will be discussed together; special treatments concerning a specific alloy will Historic Lighthouse Preservation Handbook Part IV. B, Page 1 WPTC photo Figure 2. Example of a keeper's quarters fitted with a prefabricated cast-iron-and-steel lantern. WPTC photo Figure 4. Double-wall, cast-iron, first-order 163-foot-tall WPTC photo coastal tower at Cape Henry, Virginia.
    [Show full text]
  • Process of Cokeless Without Waste Treatment of Direct Vanadium
    PROCESS OF COKELESS WITHOUT WASTE TREATMENT OF DIRECT VANADIUM ... PROCESS OF COKELESS WITHOUT WASTE TREATMENT OF DIRECT VANADIUM ALLOWING STEEL MELTING Lisienko, V.G., Droujinina, O.G., Morozova, V.A.., Ladigina, N.V., Yusfin Yu.S. and Parenkev A.E. Urals State Technical University, Mira str., 19, Ekaterinburg, Russia Moscow Stell and Alloys Institute, Leninskii av.,4, Moscow, Russia \y/ Abstract: The development of new methods of steel production are now conducted with the purpose of energy consumption and harmful emissions reduction. The choice of technology and equipment in this case plays a cricinal role. It is well known that vanadium alloying steel has increased service properties. The known classical scheme of vanadium steel melting is very power-intensive, as includes such power- intensive processes as blast furnace process and chemical processing of vanadium slag therewith sintering and by-product coke processes are accompanied by significant harmful emissions. In so doing the vanadium losses may run to 60%. In view of requests of environment protection and economical efficiency the new process of cokless without wastes processing of vanadium-bearing raw material with direct vanadium allowing of steel - LP-process is developed. Its purpose is the melting on the basis of vanadium-bearing titanomagnetite of vanadium allowing steel with increase of vanadium concentration in steel and diminution of vanadium losses without application coke and natural gas with use of any coals and carbon-bearing wastes. LP-process consists of three aggregates and corresponding processes: process of liquid-phase reduction, process of vanadium-bearing pellets metallization in the shaft furnace, and process of alloying steel melting in the arc electric furnace.
    [Show full text]