External arc heating permits better thermal control than does the basic oxygen process, in which heating is accomplished by the. Overview eaf automation packages energy supply and power control for a safe and stable plant operation furnace switchgear switchyard and compensation systems for meltshop and mill, nucor. There were 109 participants at the 22nd annual electric steelmaking conference. Electric arc furnace steelmaking is the manufacture of steel from scrap or direct reduced iron melted by electric arcs. Future green steelmaking technologies sara hornby anderson, gary e. Foamy slag fundamentals and their practical application to electric furnace steelmaking eugene b. In an eaf scrap andor manufactured iron units such as dri, pig iron, iron carbide is melted and converted into high quality steel by using highpower electric arcs.
Pdf feasibility study of bangladeshi electric arc furnace. This includes eafs of all sizes and types, twinshell furnaces, and shaft furnaces in addition to all related processes, automation, and environmental systems. The stirring intensity of a supersonic oxygen jet supplied to a molten bath is an important factor in electric arc furnace eaf steelmaking 3,4. Development of the technology of electric arc furnace. Pig iron and refined iron ore pellets briquetted iron can also be used, and because his t method is economic at lower volumes these operations are called mini mills. Development of the technology of electric arc furnace steelmaking. The electric arc furnace is the most important scrap recycling process. Electric based steelmaking enjoys a much comfortable position than integrated classical blast furnace oxygen steelmaking facilities, regarding greenhouse emissions. Quite rightly the initial focus is on securing the existing asset base on a stable footing. The lower part of the submerged electric arc furnace is composed of a cylindrical steel shell with a flat bottom or hearth.
Electric arc furnace industrial efficiency technology. About onequarter of the worlds steel is produced by the electricarc method, which uses highcurrent electric arcs to melt steel scrap and convert it into liquid steel of a specified chemical composition and temperature. Steel cost modelling notes the steel costing model the economic model shown above is prepared only to shown how liquid steel cost can be calculated through a simple cost benchmarking type approach. Development of an electric arc furnace simulator based on. Electric steelmaking a full array of advanced and energysaving solutions finetuning eaf technology to achieve an optimum balance of charge materials, process control, cycle times, logistics, and productivity requires both indepth experience and a precise analysis of steelmaking requirements. Inclined jetting and splashing in electric arc furnace. The harmonics created by powerful nonlinear loads and abrupt changes of such loads eaf can considerably.
Pdf this chapter deals with electric furnace steelmaking, a tool for the massive production of steels, which is responsible for 30% of the current. Most steelmaking operations require a slag fluidizer to promote the required reactions, to increase productivity, to improve tapping operations, and to conserve energy. The electric furnace steelmaking process uses an arctype electric furnace and comprises steps of. Electric arc furnace eaf steel making technology is more than hundred years old. In electric furnace steelmaking, some carbon will be contained in the scrap feed, in dri, hbi or other alternative iron furnace feeds. Looking into an electric arc furnace with the power on. What youre seeing here is the arc between the tip of an electrode and liquid steel, which is hidden under nearly a foot of slag the bubbling liquid you see here. Introduction to electric arc furnace steelmaking tc1077. The same idea is used in a larger scale in an electric arc furnace.
In considering the prospects for continuous steelmaking, elliott indicated that electricarc heating would probably play a major role as a heat source in a continuous process. Plants that use electric arc furnaces can be sited closer to the market. The splashed metal droplets cause wear of furnace wall and loss of production. Looking into an electric arc furnace with the power on youtube. To ease this transition, this project will explore an alternative ironmaking technology that can process available raw. Since 1960, construction and techno logical improvements have enabled shorter taptotap times in electric arc furnace operation. Next generation metallic iron nodule technology in.
All components are dedicated to cutting the cost of electric steel production. Electric arc furnace eaf is one of the most common methods of steel making which is used in. Most current electric arc furnace eaf steelmaking makes use of level2 automation systems nil00, hei97. Download free sample and get upto 48% off on mrprental.
Corresponding to these processes, a differentiation is made between oxygen steel and electric steel. Introduction the steelmaking process requires continuous stirring to promote the oxidation of elements in molten steel, such as carbon, silicon, phosphorus, and manganese 1,2. Electric steelmaking attendees who wish to gain a fundamental understanding of the electrical, thermomechanical and technical aspects of modern electric furnace steelmaking. In the electric arc furnace eaf sector, some of these technologies involve the increased use of chemical.
This course covers safety, the basics of electrical and mechanical features of electric arc furnaces, refractories, and the role of raw materials. In an electric arc furnace, a batch of steel heat may be started by loading scrap or direct reduced iron into the furnace, sometimes with a hot heel molten steel from a previous heat. Electric steelmaking a full array of advanced and energysaving solutions finetuning eaf technology to achieve an optimum balance of charge materials, process control, cycle times, logistics, and productivity requires both indepth experience and. An electric arc furnace used for steelmaking consists of a refractorylined vessel, usually. Also, for proper evaluation between induction furnace and electric arc furnace, minimill steelmaking concept has to be considered in order to avoid talking. Steelmaking in electric arc furnace has emerged as an important steelmaking process in recent years. Lecture 15 electric furnace steelmaking contents nptel.
In the developed world, 100% steel scrap is the most common charge. It is only slightly more than a century when the first furnace was commissioned to melt steel by utilizing electric power. Optimization of the operating condition lance angle, lance height and. The program will explore the fundamentals of electric furnace steelmaking technology, the use of energy.
Electric arc furnace design operation and working principle. Nearly 194,000 st of fluorspar was consumed in steelmaking in 1983. Foamy slag fundamentals and their practical application to. A typical submerged electric arc furnace design is depicted in figure 1. Electricbased steelmaking enjoys a much comfortable position than integrated classical blast. Pr908046 1960 electric furnace proceedings future developments in electric furnace steelmaking.
Emerging new technology started in the beginning of the twentieth century when wideranging generation of relatively cheap. Using oxygen reaction as electricity saving in electric arc furnace. Highimpedance furnace today, highimpedance furnaces are state of the art. The ore part of a charge consists of iron ores and concentrates, manganese ores and various types of scrap containing iron. These improvements to the processing of scrap steel comprised of larger more efficient and higher capacity furnaces.
The second world war saw a steep increase in the use of these furnaces leading to the modern electric arc furnace design operation and working principles. Carlisle, year1999 using a massbalance approach and isothermal saturation diagrams, steelmakers not only can monitor. This study was conducted to explore the possibility of utilization of electric arc furnace eaf slag produced in bangladesh as fine aggregate in concrete blocks. Electric based steelmaking enjoys a much comfortable position than integrated classical blast. May 05, 2016 the same idea is used in a larger scale in an electric arc furnace.
Feb 18, 2012 what youre seeing here is the arc between the tip of an electrode and liquid steel, which is hidden under nearly a foot of slag the bubbling liquid you see here. In the past when oxygen consumption of less than 300 cubic feet per ton of steel were common, lancing. The basic principle of electric steelmaking today is that the furnace is a melting machine that produces liquid steel with required chemistry, temperature, and mass in time to feed steel to successive ladle treatments and continuous caster, which finally determines the production rhythm. In germany, ld steelmaking accounts for around 75 % of production, while the electric arc furnace is used for 25 %. An electric arc furnace eaf is a furnace that heats charged material by means of an electric arc.
Electric arc furnaces eafs are a central part of the production route that is an alternative to the dominant bfbof route. The history of electric arc furnace eaf steelmaking is not very old. Modern electric furnace steelmaking a practical training seminar. Bill rider, meltshop manager, gerdau long steel north america jacksonville mill, was the keynote speaker. The flexibility and easy adoptability of eaf steelmaking to. Higherquality electricarc furnace steel carnegie mellon university.
The major cost for steel making with eaf is electricity about one. Eafs are used to produce carbon steels and alloy steels primarily by recycling ferrous scrap. In electric arc furnace eaf steelmaking, liquid metal splashes on the furnace wall due to the impingement of high speed oxygen jet on molten metal surface. The predicted total costing shown is not meant to represent an actual cost for any real steel company.
As electric arc furnaces use large amounts of electricity, the improvement of energyefficiency has been a major issue in the past. The electric steel process is characterized by its flexibility and, in the case of smaller steelmaking units socalled minimills with 300 to 1,200kta its cost effectiveness. Harmonics mitigation using the dc power supply case. Comprehensive electric arc furnace electric energy consumption. An opentopped cylindrical container made of heavy steel plates and lined with refractory, the ladle is used for holding and transporting liquid steel. Air pollution control equipment for the shop was installed to meet or exceed the legal requirements of applicable air pollution ordinances and regulations. Using oxygen reaction as electricity saving in electric. Short history of electric steelmaking until today the electric arc furnace applied in steelmaking was invented in 1889 by paul he. Based on decades of experience in designing electric arc furnaces, primetals offers steel producers a broad range of powerful options for highperformance electric steelmaking.
An electric arc furnace eaf is a furnace that heats charged material by means of an electric arc industrial arc furnaces range in size from small units of approximately one ton capacity used in foundries for producing cast iron products up to about 400 ton units used for secondary steelmaking. The eaf is a field for dynamic development of technology, adapting to changing and challenging scenarios. An electric arc furnace eaf is a furnace that heats charged material by means of an electric. Jones, nupro corporation continued furnace charging melting refining deslagging tapping furnace turnaround top refining refining operations in the electric arc furnace have traditionally involved the removal of phosphorus, sulfur, aluminum, silicon, manganese and carbon from the steel. Direct reduction scrap ladle refining electric arc furnace steelmaking iron ore pellets electric arc furnace steelmaking continuous casting design by cover photo. Electric arc furnace steelmaking costs 2020 conversion costs for electric arc steelmaking. Salzgitter the process shown above is illustrative only and is not designed to show the steelmaking process in detail. Comparative assessment of ld converter and electric arc. Using oxygen reaction as electricity saving in electric arc furnace steel making. Theory and practice by ghosh, ahindra, chatterjee, amit pdf online. Pdf foamy slag fundamentals and their practical application.
Introduction to electric steelmaking the history of electric steelmaking is quite shortonly little over 100 years from the first trials to melt steel by utilizing electric power. Electricbased steelmaking enjoys a much comfortable position than integrated classical blast furnaceoxygen steelmaking facilities, regarding greenhouse emissions. Harmonics mitigation using the dc power supply case electric arc furnace y. An electric arc furnace is a steel making plant that melts iron sources such as scrap and directreduced iron dri using electric energy. Air pollution control of an electric furnace steelmaking shop.
Provided is a steelmaking process that drastically improves the disadvantages of conventional electric furnaces. The interior of the shell is lined with two or more layers of carbon blocks. Arc furnace slag was collected from a steel plant in chittagong. The number of charge buckets of scrap required to produce a heat of steel is dependent primarily on the volume of the furnace and the scrap. Labar abstract electric arc electric eafs highly reduce power quality of the network by generating disturbances such as flicker and harmonics. Todays ac furnaces are ultra highpowered furnaces with specific transformer ratings up to and more than 1 mvat. Industrial arc furnaces range in size from small units of approximately one ton capacity used in foundries for producing cast iron products up to about 400 ton units used for secondary steelmaking. Eaf furnace operators, maintenance personnel, upstreamdownstream personnel, metallurgists and suppliers would benefit from this comprehensive seminar. The situation is not the same in the emerging countries, where scrap is not always available in the required amount. Over the years, the ac furnace has been improved in design and further developed. A blast furnace charge consists of ore, fluxes and fuel.
Here all secondary metallurgical work takes place, including deslagging and reslagging, electrical heating, chemical heating or cooling with scrap, powder injection or wire feeding, and stirring with gas. Electric arc furnace an overview sciencedirect topics. Modern electric furnace steelmaking a practical training. The electric arc furnace eaf process is the main process for recycling of ferrous scrap 1 and the second most important steelmaking process. Technology in electric furnace a current trend in the steel industry is a gradual decline in blast furnace coke oven steel production and an increase in electric furnace steel production. Carlisle baker refractories york, pa abstract this paper will define the slag compositions required to obtain and control optimum foamy slag conditions in the electric furnace.